Medical applicator

Abstract

A kit for a modular applicator 100 suitable for delivering brachytherapy treatment. The kit comprises a tubular central body 110 comprising a seed passage channel to enable passage of a radioactive s

Description

This disclosure relates to a medical applicator for cancer treatment, and in particular to applicators suitable for enabling treatment of cancers which affect the female reproductive system via brachytherapy. Background Brachytherapy is a form of radiation therapy used to treat various types of cancer. It involves the placement of radioactive sources, known as "seeds" or "implants," in or near the tumor site to deliver a targeted dose of radiation. During brachytherapy, the radiation sources are typically placed directly inside the body, either temporarily or permanently, depending on the treatment plan. The radioactive sources emit high-energy radiation, such as gamma rays or X-rays, which damage the DNA of cancer cells, inhibiting their ability to grow and divide. The goal is to deliver a high dose of radiation directly to the tumor while minimizing the exposure to surrounding healthy tissues. There are two primary types of brachytherapy: interstitial (IS) and intracavitary (IC). In interstitial brachytherapy, the radiation sources are inserted directly into the tissue surrounding the tumor. This may involve the use of thin needles or catheters to deliver the seeds, ensuring they are properly positioned. This method is commonly used for prostate, breast, head and neck, and gynecological cancers. In intracavitary brachytherapy, the radiation sources are placed within a body cavity close to the tumor site. This is often used for cancers located in hollow organs, such as the uterus, cervix, vagina, esophagus, or bronchial tree. The specific application of brachytherapy depends on the type, size, and location of the tumor(s), as well as the overall health of the patient. Brachytherapy applicators are specialized devices used to position and hold the radioactive sources in place. Current systems utilize applicators that consist of tubes which serve as guides for directing the radiation sources to the desired treatment sites. Applicator shape, size, and functionality differ greatly according to the type of cancer the applicator is intended to treat. To provide an example: endometrial and vaginal cancers are examples of cancers which can affect the female reproductive system. Currently, a brachytherapy applicator particularly suited for treating endometrial cancer is very different to an applicator suitable for treating primary vaginal cancer. Even within the same general category of cancer, each patient and each tumour is different. To account for differences in tumour position, shape and placement; patient anatomy; cancer type; and other treatment needs, a hospital must own a large number of brachytherapy applicator types in order to provide its clinicians with the range of options they need to provide effective treatment to a range of patients. Even with a large number of options, it still may not be possible to position the radiation source(s) in optimal positions as required by the particular patient's tumour placement and shape, and their anatomy. The present invention seeks to address these and other disadvantages encountered in the prior art by providing an improved medical applicator for radiotherapy. Summary One or more inventions are set out in the claims. Figures Specific embodiments are now described, by way of example only, with reference to the drawings, in which: Figure 1 depicts a modular applicator according to the present disclosure; Figures 2a-d depicts options for central tubes and components which may make up modular applicators in accordance with the present disclosure; Figures 3a-f depict modular applicators according to the present disclosure; Figure 4 depicts dose profile and possible needle placements using modular applicators according to the present disclosure; Figures 5a-l depict mechanisms via which modular applicators can be assembled and held together in accordance with the present disclosure; Figure 6 depicts example central tubes according to the present disclosure, in particular those which are suitable for treating endometrial cancer; Figure 7 depicts a modular applicator according to the present disclosure; Figures 8a-d depict modular applicators according to the present disclosure; Figures 9a-g depict possible needle placements using applicators according to the present disclosure. Figures lOa-e depict shapes for cuff segments according to the present disclosure; Figure 11 depicts a modular applicator according to the present disclosure; Figures 12a, 12b depict a needle locking mechanism according to the present disclosure; Figure 13 depicts example recommended applicators for particular treatment needs; Figure 14 depicts a computer-implemented method according to the present disclosure; Figure 15 depicts a system according to the present disclosure; Figure 16 depicts an example computer readable media according to the present disclosure. Detailed Description In overview, and without limitation, the application discloses a medical applicator suitable for brachytherapy. The applicator is 'modular' and can be assembled from any of a plurality of different components, each with different lengths, sizes, shapes, and features in order to optimise the assembled applicator for a large number of potential treatment needs. Figure 1 depicts an example configuration of an applicator apparatus in accordance with the present disclosure. The apparatus comprises a plurality of components, and the apparatus can be disassembled into its component parts and re-assembled, with the same, similar or different component parts, as will be described later herein according to the needs of the treatment and / or the patient. The apparatus comprises a central body. The central body is tube-shaped and may be described herein as a central tube. The central tube comprises a central cavity through which, in use, a radioactive source may be moved. The depicted central tube comprises an intrauterine tube, which extends at an angle from the main body of the central tube. In general, the central tube acts as a central foundation on which a particular applicator configuration can be built. The depicted applicator apparatus further comprises a cuff segment, a paravaginal segment, and a vaginal segment. While these components are referred to as segments, they may similarly be referred to as "components", "elements", "pieces" or "portions" herein. Each of these components is configured to be inserted inside a patient during use. The apparatus further comprises a perineal template, which in turn comprises a perineal template base and a perineal template extension. The perineal template base is removably coupled to the perineal template extension. The apparatus further comprises a fixation element configured to fix the perineal template and / or the other components which make up the applicator in place during use. Each of these components comprises an opening through which, in an assembled state as depicted in figure 1, the central tube can pass. In use, the applicator central tube is connected, at an opposite end to the intrauterine tube, to a transfer tube (not shown). The transfer tube enables a radioactive source to pass from an afterloader and into the cavity of the central tube. The radioactive source can be advanced along the central body, including into the intrauterine tube, to the extent required by the treatment plan. In addition, the applicator apparatus can be configured to hold and help position one or more interstitial needles (not shown). Each of the cuff segment, paravaginal segment, vaginal segment components comprise a plurality of channels 105 to secure and guide interstitial needles. The channels are substantially parallel with the central channel of each component. The perineal template also includes a plurality of channels, otherwise named apertures or holes, to guide interstitial needles. These apertures may be provided in a grid pattern. These channels are configured to receive and route interstitial needles in which the radiation source can move to treatment sites. This gives clinicians a range of options, and enables them to provide either intracavity and / or interstitial delivery of radiation according to the treatment needs. Figures 2a-e depict an example range of options of modular components which may be used to assemble a configuration of an applicator apparatus in accordance with the present disclosure. Figure 2a depicts a plurality of different central body options. The different options comprise different lengths to accommodate different components, and in addition comprise different options when it comes to intrauterine tubes. The topmost central tube depicted in figure 2a does not comprise any intrauterine tube. This design may be suitable, for example, when treating endometrial cancers post-hysterectomy. The options depicted in figure 2a comprise options with intrauterine tubes of different lengths. The clinician can thereby select the central body which comprise the intrauterine tube most suitable for treating a patient. The central tube may also comprise a plurality of intrauterine tubes, in a manner which will be disclosed in greater detail below. Such central bodies may be particularly suited for treating certain kinds of cancer, for example endometrial cancer. Figure 2b depicts a plurality of different options for the cuff segment. Again, the clinician or other user can select the cuff segment which is most suited for the treatment needs of the patient at hand. The top row of options shows different diameter options, without interstitial needle guidance channels. Each cuff segment in the top row top row is short and rounded in shape. The second row of options shows the same diameter and general shape options as the first row, but with a plurality of interstitial needle guidance channels both comprised within the body of the component, and also around an outer perimeter which are partially enclosed by the component. The third row of options are substantially frustoconical in shape and do not comprise channels for interstitial needles, whereas the fourth row shows the same diameter options as the third row, but with interstitial needle channels. The fifth and sixth row show options which have a 'double dog ear' shape. The diameter of these cuff segments is not constant, and instead increases and flares outward as the cuff segment extends from a first to a second circular face of the segment. The fifth row options do not comprise channel for interstitial needles, but the sixth row options do. The seventh row of options are shaped and configured much like the second row, but with fewer interstitial needle channels. The eight row of options comprise a first and a second circular face which are at an angle to one another, such that the final face is slanted. Finally, the ninth row of options is similar in shape and function to the first row, but these cuff segments are longer. Figure 2c depicts different options for the paravaginal segment. As can be appreciated, just as with the cuff segment options, a variety of diameters can be provided, along with a variety of options for interstitial needle channels. Each row depicts different options for interstitial needle channels, and each column is a different diameter. Figure 2d depicts different options for the vaginal segment. Figure 2e depicts different options for the perineal template base (first row), each of which have different interstitial channel / aperture patterns and options, and an example of a perineal template extension or extender (second row). As can be appreciated, each perineal template base component comprises an outer perimeter shape that aligns with an inner perimeter shape of the perineal template extension component, allowing the components to fit together easily during assembly. Each component depicted herein may comprise an individual unique tag or marker that enables that component to be uniquely identified in medical images. In an example, the tag or marker may be radio-opaque and / or MR visible. To assemble the applicator apparatus, for example into the configuration depicted in figure 1, a clinician or other user first starts with the appropriate central tube. In particular, the central tube that comprises the intrauterine tube depicted in figure 1. The user would then, according to the needs of the treatment and patient at hand, would additionally decide whether a cuff segment, a paravaginal segment, a vaginal segment, a perineal template base and / or an extension are needed. If the user decides that an applicator comprising each of these components is required, then they connect the perineal template base with the perineal template extension by fitting the extender over the base component and aligning the surface geometries of these components to fit them together. Then, the user inserts the central tube into the central aperture in each of the selected cuff segment, paravaginal segment, vaginal segment, and perineal template base component. The user then similarly slides on the fixation element and locks the fixation element in place, thereby affixing the applicator together into a custom configuration optimised and tailored for a particular patient's treatment. In use, the user would position the applicator for treatment, and connect one or more transfer tubes to the central channel of the applicator and / or to any interstitial needles positioned in the applicator. An afterloader is used to advance radiation sources / seeds into the central channel and / or interstitial needles in a known way, which need not be discussed in detail herein. The modular applicator design disclosed herein is advantageous for several reasons. By tailoring the applicator shape, size, and design for a particular patient, it is possible to achieve an improved anatomical fit, and improve patient comfort. It is also possible to reduce air gaps between the radiation source and the patient tissue, thereby aligning expected and planned dose delivery with realised dose delivery. In addition, there are an extremely large number of options for positioning the radiation source, which in turn means that the treatment plan can be personalised and made more accurate and tailored for the patient's cancer and anatomy. Finally, hospital staff can be confident they have the 'right' applicator to match the patient's cancer, and that additional applicator products are not required. Figures 3a-f depict particular configurations for an applicator assembly in accordance with the present disclosure. The depicted applicators can be assembled by selection of the appropriate options depicted in figures 2a-e. Figures 3a-c depicts applicator assemblies configured to be particularly suitable for treating endometrial cancer in post-hysterectomy. Figure 3a depicts an applicator with no interstitial needle channels, whereas figure 3b depicts an applicator comprising multiple guide channels suitable for IC treatment. Figure 3c depicts an applicator comprising guide channels for IC treatment, in addition to multiple channels for IS treatment. Figure 3d depicts an applicator assembly particularly suited for treating primary vaginal &cervical cancers, where the target is positioned in a lower part of the vagina. The applicator comprises a single-channel intrauterine tube, multi-channel components which enable the positioning of IS needles, and a perineal template to enable further IS needle placement. Figure 3e depicts an applicator arrangement / configuration suitable for treating inoperable endometrial cancer. The arrangement comprises a multi-channel intrauterine tube, along with multichannel components including the double dog-eared shaped cuff and paravaginal segment to enable both IC and IS needle placement. Figure 3f depicts an applicator arrangement / configuration suitable for treating vulval cancer. For this applicator an intrauterine tube is not needed. The applicator comprises a rounded cuff, and cylindrical segments without channels or guides for IC / IS needles. The applicator comprises an IS perineal template, as well as flexible implant tubes. Figure 4 depicts different possible needle placements which can be achieved using modular applicator assemblies of the present disclosure. The figures depict both IC and IS needles. IC needles are those which will provide dose from within the cavity, and IS needles are those which will be inserted into patient tissue to provide dosage from the tissue directly surrounding the tumour. The different colours represent different diameter needles. It will be appreciated that a large number of options is made available to the healthcare provider when determining optimal dose profile and needle placement. Cuff segments according to the present disclosure may comprise 'parallel' channels which are parallel with the central axis of the applicator, and / or parallel with the central channel of the applicator. These channels enable catheters / needles to extend out from the cuff segment and be positioned substantially along the axis of the applicator, and these are suitable for treating a back wall of a uterus (or a vagina for patients post-hysterectomy). Cuff segments according to the present disclosure may also comprise 'oblique' channels, which extend substantially parallel to the applicator central channel before being configured to divert a needle / flexible catheter out from the cuff segment at an oblique angle. Similarly, paravaginal segments according to the present disclosure may comprise 'parallel' channels which are parallel with the central axis of the applicator, and / or parallel with the central channel of the applicator. These channels align with one or more corresponding channels in the cuff segment, and allow a clinician to insert a needle / catheter through the paravaginal segment, through the cuff segment, and potentially out form the end of the cuff segment into the patient's tissue. Paravaginal segments according to the present disclosure may also comprise 'oblique' channels, which extend substantially parallel to the applicator central channel before being configured to divert a needle / flexible catheter out from the paravaginal segment at an oblique angle. As can be appreciated from the figure, paravaginal components according to the present disclosure enable the placement of oblique needles which extend from the applicator at an angle. These needles can be IS needles positioned, for example, in the vaginal walls of the patient. The combination of the appropriate cuff segment 404 with the appropriate paravaginal segment 406 gives clinicians a large range of options for needle placement, both for IS and IC treatment. Providing a plurality of options enables clinicians to plan treatment to reduce the effects of either so-called "hot" or "cold" spots. The modular components which make up an assembled applicator can be fitted together and held in the correct orientation and alignment in a number of ways. Generally speaking, in one implementation, the components can be assembled and fitted together in any of several ways. In an example, the components (e.g. selections from figures 2b-2e) are fitted onto a central tube (e.g. selections from figure 2a). The user positions and orients the components for their intended purpose, and then locks the components into place using a fixation element. The components stay in their position and orientation by virtue of friction between each component. In some implementations, each component, as appropriate, may comprise a small annular lip, extension, or ridge at its proximal end (i.e. the end which, in use, will be closest to the clinician as they insert and position an applicator). This annular extension has a smaller radius than the component generally. Each component may also comprise, as appropriate, a corresponding annular recess which is sized, shaped, positioned, and otherwise configured to accept an annular ridge of another component. By virtue of providing each component with an annular extension on its proximal side and a corresponding annular recess on its distal side, a user is guided to position the components along the central tube, and the friction between each component is increased significantly. This ensures that the components cannot move from the user-selected position and orientation. Figures 5a-5e depict one or more mechanisms by which components, for example cuff segments and paravaginal segments, of the present disclosure may be positioned, and / or fixed in place, with respect to a central tube 510. Figures 5a and 5b depict an end section of a central tube 510. The central tube 510 comprises a central channel 513 to accommodate a radioactive source, and / or needles and catheters. The central tube 510 also comprises a recess 511 along its length. The recess 511 is positioned on an underside of the central tube 510 (with respect to its orientation in use). The recess 511 is shaped, positioned and otherwise configured to receive a corresponding ridge positioned on other components which may be fitted onto the central tube. In an example, paravaginal segments according to the present disclosure, for example the segment 530 depicted in figure 5e, may comprise elongated ridges / protrusions 531 placed on their inner annular surface. This inner annular surface, when the segment is positioned on a central tube, will contact an outer surface of a central tube. The ridge is elongated in the direction of a central axis of the central tube. The ridges are positioned, shaped, and otherwise configured to interact with the elongated recess 511 of a central tube such that, in use, the user is guided to position the paravaginal segment 530 on the central tube 510 in the correct orientation. By providing similar and corresponding ridges and protrusions on each component, the user is guided to position each component on the central tube in a manner which is appropriate for the assembled applicator and in a manner which will ensure the various channels of the components (for example the paravaginal segment and cuff segment) will align with one another. Cuff segments, such as the cuff segment 520 depicted in figure 5c, comprise an elongated ridge 521, much like other components, that fits into the elongated recess 511 of the central tube 510. However, this ridge 521 does not extend along an entire length of the cuff segment 520. The cuff segment also comprises a recess 522. The recess 522 is shaped, positioned, and configured to interact with the end stopper 512 of the central tube. The ridge 521 and recess 522 are positioned along a length of the cuff segment, on an inward facing annular surface of the cuff segment 520. To assemble an applicator, a user slides the cuff segment 520 onto the central tube 510, making sure that the ridge 521 is aligned and fits within the guiding recess 511. As the cuff segment 520 nears the end portion of the central tube 510, the ridge 521 meets the end stopper 512. This defines the maximum degree to which the cuff segment 520 can be slid along the central tube 510. Figure 5d depicts a cross-section of the cuff segment 520 located at an end point of the central tube 510. The ridge 521 is in contact with the end stopper 512, preventing movement of the cuff segment 520. In use, another component such as a paravaginal segment will be positioned behind and alongside the cuff segment 510 on the central tube 510, and thereby the cuff segment 510 can be locked in place in its correct orientation at the end of the central tube 510. While the mechanism has been described with recesses on the central tube and ridges on the components, the skilled person will appreciate that these features can be 'swapped' and interchanged, for example so that the components comprise grooves or recesses, and the central tube comprises an elongated ridge. Figures 5f-i depict a fixation element 570, and the manner in which it may fix components in place with respect to the central tube 510. As shown in figure 5g, the central tube 510 may comprise a series of notches 580 located at fixed intervals along a length of the central tube 510. These notches 580 are shaped, positioned and otherwise configured to receive a corresponding notch 575 on an inner surface of the annular fixation element 570. the notch 575 takes the form of a ramp or wedge with a flat back face. The wedges 580 mirror this shape. The fixation element 570 is broadly annular and substantially U-shaped. In other words, element 570 has a cut-out such that it can be described as comprising an incomplete ring. The shape can be thought of as comprising two curved arms which curve toward each other, but which do not come into contact while the fixation element is in a rest position. The shape of the fixation element 570, and the resilience of the material it is comprised of, means that its diameter can be adjusted by user pressure, and / or the curved arms can be forced apart. The wedge 575 is positioned on one of these curved arms of the U-shaped fixation element 570. In an example, a user places their chosen components on the central tube 510. The components have the correct orientation, as guided by the ridge and groove / recess mechanisms described above. When the user has positioned the desired components on the central tube 510, the user positions the fixation element 570 on the central tube 510. Due to the wedge shape of the protrusion 575 and the recesses 580, the user can easily slide the fixation element 570 along the central tube in a direction toward the distal end of the applicator. When the fixation element 570 is positioned behind the other components, the user can rotate and position the fixation element 570 such that the wedge 575 is positioned in a recess 580. This prevents the fixation element 570 from moving backwards, i.e. in a direction of a proximal end of the applicator, and thereby locks the components in place on the central tube 510. When a user wishes to release the fixation element 570, they simply need to twist, i.e. rotate the fixation element 570. The twisting action forces the curved arms of the element 570 apart slightly, and the wedge 575 can be easily removed from the recess 580. Figure 6 depicts a plurality of options for a central tube, in addition to those depicted in figure 2a. These central tubes are particularly suited for forming an applicator optimised for treating endometrial cancer. All the central tubes depicted in figure 6 are comprised of MR-safe materials. They applicator components may be comprised of one of more thermoplastics which will enable flexibility, but are also glass-fibre reinforced to prevent breakage. The first central tube, 600, comprises a multi-channel main body 606, and a multi-channel intrauterine section 604. The central tube 600 comprises a plurality of channels which extend through a main body 606. Each of the channels 601, 602, 603 is configured to receive a radioactive source or 'seed', which can be passed along the main body of the central tube toward the intrauterine section in use. The plurality of channels comprise a first channel 601, a second channel 602, and a third channel 603 which are each biased out and away from a central axis of the first central tube 600. The first central tube 600 further comprises a slideable sheath 605. The slideable sheath 605 is configured to slide along and over the main body 606 of the first central tube 600. Both the slideable sheath 605 and main body 606 are annular in cross-section. The slideable sheath 605 is configured to slide along an axis parallel with, or coincident with, a central axis of the main body. The first central tube 600 comprises a disc-shaped 'stop' 607 which defines the extent to which the slideable sheath 605 can be retracted back and away from the intrauterine portion 604. The slideable sheath 605 is configured to slide over the main body 606 of the central tube 600 toward the intrauterine portion 604. As the slideable sheath reaches the first intrauterine channel 601 and the second intrauterine channel 602, it passes over them and pushes them together. As the slideable sheath 605 continues to move along the main body 606, each of the channels 601, 602 and 603 are brought together to fit under the slideable sheath 605. As the slideable sheath 605 is retracted, i.e. moved in the opposite direction away from the intrauterine portion 604, the channels 601, 602 and 603 again open out and splay apart to form the configuration depicted in figure 6. In use, a clinician may insert an applicator apparatus comprising the first central tube 600 while the slideable sheath 605 is in an extended position; i.e. while the intrauterine channels 601-603 are held together via the slideable sheath 605. After the intrauterine portion has been inserted into the patient, the clinician can retract the slideable sheath 605, causing the intrauterine channels 601, 602, 603 to extend and splay apart. By this action, the channels 601-603 extend toward patient tissue and can be positioned according to the requirements of the treatment plan. When the clinician comes to withdraw the applicator, they can once again move the slideable sheath 605 into the extended position, thereby bringing the channels 601-603 together again to facilitate withdrawal. In this way, the first central tube 600 provides a multi-channel intra-uterine portion, thereby providing clinicians with multiple options for source placement, while also enabling simple placement and withdrawal of the applicator in a way that maximises patient comfort. While the depicted implementation comprises three channels in the intrauterine portion 604, it should be understood that any number of biased / outwardly splaying channels can be used. The second central tube 610 comprises an intrauterine portion 614 and a main body 616. These components both comprise multiple channels in the manner described above. The intrauterine portion 614 comprises a plurality of flexible tubes. In the depicted implementation, these flexible tubes are flexible catheters. These flexible catheters have some degree of rigidity and extend from the main body 616 in a rest state, but are also configured to bend and deform slightly as they encounter resistance. The flexible catheters extend through the main body 616 such that, in use, a radioactive source can be passed through any of the catheters. This configuration is advantageous as the flexible catheters may be simply removed from the main body 616 to enable sterilisation, and then re-inserted. The third central tube 620 also comprises an intrauterine portion 624 and a main body 626. The intrauterine portion 624 comprises a plurality of hollow tubes which are flexible but semi-rigid. The hollow tubes splay apart as they extend from the main body 626. Each hollow tube is of a sufficient diameter to allow a flexible catheter 629 to pass along it. Each hollow tube is open-ended. As can be appreciated from the figure, the central body 626 comprises a plurality of channels, each of which becomes a hollow tube at the intrauterine portion. In use, a flexible catheter 629 can be passed along a channel in the main body 626, toward the intrauterine portion 624. The flexible catheter passes into one of the hollow tubes of the intrauterine portion 624. Because the hollow tubes are each open-ended, the catheter can continue to be passed through the central tube 620 and out the distal end of the hollow tube(s) in the intrauterine section. This functionality is useful for clinicians since it effectively enables a degree of extension of the intrauterine channels, and this 'extension' can be performed while the applicator is positioned inside the patient. By virtue of pushing the catheters further down the channels of the central tube 630, the clinician can plan for the radioactive source to be positioned as close as possible to a tumour, and the adjustable length of the intrauterine tube enables a clinician to further reduce the air gap between the radioactive source and the tumour. The fourth central tube 630 is similar in form to the second central tube 620, though the intrauterine tubes are not open-ended and thus the length of the intrauterine tubes cannot be adjusted. The tubes are reasonably rigid, providing certainty to clinicians that the tubes won't bend or otherwise change position during treatment. The fifth central tube 640 comprises a spiral-shaped intrauterine portion 644. The spiral shaped intrauterine comprises at least one helical channel. The portion 644 may be single or multi-channel. The spiral-shaped intrauterine portion 644 is particularly optimised for positioning radiation seeds close to the internal walls of the uterus, and provides clinicians with a large number of options when it comes to dwell position for the radiation seed. The radius of the spiral swept out by the helical channel increases as it extends away from the central body 646, so as to match the internal shape of the uterus. The spiral-shaped intrauterine portion 644 is comprised of resiliently collapsible material which can be compressed on insertion of the applicator, and which springs outward after insertion. This means that the applicator head (the intrauterine portion) expands to fill the available space after insertion, and the helical channel is thereby positioned very close and / or in contact with the patient tissue around its entire circumference. The central body 640 may also comprise a retractable sleeve (not shown). The retractable sleeve, or sheath, covers and compresses the spiral-shaped intrauterine portion in a 'closed' or 'extended' configuration, and does not cover and compress the intrauterine portion in an 'open' or 'retracted' configuration. This removal sheath facilitates insertion and withdrawal of an applicator comprising the central tube 640 in much the same way as the slideable sheath 605 does for the first central tube 600. Each loop of the spiral shape may comprise a unique CT-visible, i.e. radio-opaque, marker. These markers enable each loop to be distinguished in medical images, and thus treatment planning and treatment delivery is facilitated. The sixth central tube 650 also comprises a main body 656 and an intrauterine portion 654. The sixth central tube 650 comprises a plurality of flexible channels, which may take the form of flexible catheters, or otherwise be made of flexible, resilient material. The intrauterine portion, 654, comprises a balloon comprised of resilient material. The main body 656 comprises an inflation channel that passes along the main body 656 and is positioned and configured to pass fluid into the balloon. The fluid can be liquid or gas. The balloon is resilient such that, upon pressurised fluid entering the balloon, it expands. The plurality of flexible channels are configured for receiving a radioactive source as with the channels described above in connection with the other tubes 600-640. The main body 656 comprises a rigid material which retains its shape. The flexible channels pass along the main body 656 and are then attached to either an inner, or an outer, surface of the balloon. The flexible channels have sufficient rigidity that, in a rest position, they extend away from the main body 656 in the manner depicted in figure 6, but are flexible such that expansion of the balloon causes expansion of the flexible channels. In use, a clinician would insert an applicator comprising the sixth central tube 650 into the patient, and would inflate the balloon using the inflation channel and a suitable source of fluid. The balloon, along with the flexible channels, expands inside the patient, bringing the flexible channels close to the interior wall of the patient's uterus. The applicator can be rotated and positioned, and the degree of inflation of the balloon can be adjusted, giving the clinician a range of options for positioning the flexible channels with respect to the patient's anatomy. In particular, such an applicator is particularly beneficial for positioning the channels close to an interior wall of the uterus, while allowing easy and comfortable insertion and withdrawal of the applicator. While particular implementations have been described and are shown in the figures, it should be understood that features of each Figure 7 depicts an assembled applicator 700 according to the present disclosure. The assembled applicator 700 is comprised of several different components / modules in the manner generally described herein. The assembled applicator 700 is particularly suited for treating inoperable endometrial cancer. The applicator 700 comprises a central tube of the same type and function as the 'first' central tube 600 described above in relation to figure 6. The central tube comprises a multi-channel main body 718, leading to a multi-channel intrauterine portion 702. The depicted applicator 700 has been fitted with a cuff segment 704, with a shape to optimise contact with internal tissue; a paravaginal segment 706 to enable the placement of oblique (angled) needles via the vaginal wall, a vaginal segment 708, and a perineal template base 710 complete with an extension 712. The fixation element (which is not fully visible in the figure) affixes and locks all the components together in the depicted arrangement such that they move with the slideable sheath 716. The applicator 700 is depicted with the slideable sheath in its retracted configuration. As described above, when the applicator is to be inserted into a patient, the slideable sheath 716 is moved forward, such that the arms (i.e. resilient flexible channels) are enclosed within the sheath 716. After insertion, the clinician can retract the sheath while pushing forward with the stopping element 720, thereby keeping the perineal template in position against the patient's perineum while the intrauterine section 702 is moved forward into the patient's uterus. As described above, the arms of the intrauterine portion expand as the sheath is retracted in this way. When the time has come to withdraw the applicator 700, then the clinical holds the applicator in place while pulling the stopper 720 backward. Thereby, a simple and comfortable insertion and withdrawal of the applicator is facilitated. Figures 8a-d depict a selection of the central bodies depicted in figure 6 from different angles and / or in different configurations. Figures 8a and 8b depict the first central tube 600. Figure 8a depicts the first central applicator tube in a 'closed' configuration in which the slidable sheath 605 is pushed forward to enclose the arms of the intrauterine portion. Figure 8b depicts the same central tube 600 with the main body 606 pushed forward, within the slidable sheath 605. The slidable sheath 605 and main body 606 are slidably coupled to one another. The action of pushing the main body 606 forward within the slidable sheath, and relative to the slidable sheath, causes the plurality of flexible arms to splay outward bi virtue of their natural biasing away from a central axis of the central tube 600. Figures 9a-g depict different possible source channel and needle placement options, when appropriate selections are made from the different available cuff segment options depicted in figure 2b, and different available paravaginal segment options depicted in figure 2c. the arrangements get more complex as they progress form a to g. Figure 9a depicts an applicator in which a central channel for the radioactive source is provided. Depending on the choice of central tube (e.g. from figures 2a and 6), the applicator assembly may, or may not, comprise an intrauterine tube which extends from the cuff segment. Figure 9b depicts a multi-channel central tube. Each channel is parallel with each other and with the central axis of the central tube. There may be a central, large diameter channel, surrounded by smaller diameter channels. Each of which allow the placement of a radioactive source. Figure 9c depicts a similar cuff and paravaginal segment to that depicted in figure 9b, but with the addition of a tendon, or catheter, in the central channel which can extend into the patient. Such an approach is suitable for patients who have undergone partial hysterectomies. Figure 9d depicts an arrangement in which needles are passed through the channels surrounding the central channels. Figure 9e depicts an arrangement with oblique, i.e. angled needle placement, in addition to a straight needle placement. Figure 9f depicts an arrangement comprising additional oblique needles, suitable for insertion through the vaginal wall. These additional needles may increase insertion accuracy. Finally, figure 9g depicts an applicator with needles positioned via a perineal template. Figures lOa-lOe depict cuff segment shapes according to the present disclosure. One issue that can face clinicians in the brachytherapy space as they try to reach an optimal placement and position of the applicator is that the vagina, and other internal tissue associated with the female reproductive system, is not always round, and does not always display rotational symmetry. In an example, if a patent has had their uterus removed, clinicians typically place stitches in order to create a new back wall in the patient's vagina. In this case, the vagina can collapse slightly, or can be opened up slightly to form an atypical shape. Despite this, prior art applicator heads are typically broadly cylindrical in shape, with a regular circular cross-section. This type of known applicator cross-sectional shape is depicted in figure 10a, and this shape is depicted in dashed lines in each of figures lOb-lOe to assist the skilled person in comparing the novel shapes depicted in figures lOb-e with this generally known shape. Speaking generally for each of the cuff segments depicted in figures lOb-e, the goal is to reach a better anatomical fit that matches the internal walls of a patient's vagina, particularly after the vagina has been stitched to create a new back vaginal wall post-hysterectomy. Providing different cuff segment options enables clinicians to make choices which ultimately lead to a better anatomical fit, and thereby to improved dose delivery. In addition to depicting cross-sectional shapes of cuff segments, figures 10b, 10c, and lOd additionally depict needle patterns that are possible by using the relevant cuff segment. Each cuff segment has a plurality of needle / catheter channels which enable to the needle placements depicted in the figures. For cases where the patient's vagina has collapsed slightly, or otherwise where the patient has an atypically shaped vagina, an applicator shaped in accordance with the shape presented in figure 10b may be an optimal shape for brachytherapy treatment. It is possible to imagine a vagina that has the same cross-sectional shape as the cuff segment depicted in figure 10b; in this case, a cuff segment which is shaped in accordance with the shape depicted in figure 10a is non-optimal, since it cannot reach the back wall of the vagina while still providing a good anatomical fit with the surrounding vaginal walls. This is a problem as, often, it is the back wall of the vagina which the clinician wants to irradiate via brachytherapy treatment. Using a sub-optimally shaped applicator as depicted in figure 10a would lead to air gaps between the radiation source and the tumour, since it is not possible to bring the applicator head close enough to the tumour. By instead using a cuff segment (and accordingly applicator head) shaped as depicted in figure 10b, a better anatomical fit can be achieved, leading to improved dose delivery. In addition, with a better anatomical fit, it can be easier for a clinician to insert needles via the applicator. The cuff segments depicted in figure 2b, in particular the 3rd and 4th row, may comprise the cross-sectional shape depicted in figure 10b. The cuff segment comprises a first substantially circular face which, in use, is likely positioned against a paravaginal segment or vaginal segment. This first circular face interfaces with the other components of the applicator and is proximal to a clinician when inserting and positioning the applicator. The second substantially circular face is positioned at an opposite end of the cuff segment and, in use, this second face would be positioned against, or close to, a back wall of the patient's vagina or uterus. This second face is distal to the clinician when inserting and positioning the applicator. The second substantially circular face has a smaller diameter than the first substantially circular face, and the cuff segment smoothly transitions between these two diameters to form a rounded cone shape. Optionally, the cone may be 'offset, in that the centre of the second circular face may not align with the centre of the first circular face along a central axis of the applicator main body. Such an offset, smoothed, frustoconical shape is depicted in figure 10b, and can be appreciated by inspection of the sagittal view of the cuff segment. Figure 10c depicts a cuff segment comprising what can informally be called "double dog ear" shape. Cuff segments comprising this kind of cross-sectional shape are depicted in the 5th and 6th row of figure 2b. Again, cuff segments taking this cross sectional shape may be particularly suited for particular patient's anatomies. In an example, post-hysterectomy, after stitching has taken place then a patient's back vaginal wall may take the cross-sectional shape depicted by the applicator / cuff segment of figure 10c. While reference is made to patients that have undergone a hysterectomy, cuff segments with this kind of cross-sectional shape may also be suited to a patient's anatomy who have not undergone this procedure. In cross-section through a coronal plane, the cuff segment depicted in figure 10c flares radially outward at its distal face. Approaching the distal face, the diameter of the cuff segment increases to create a bulge on either side of the cuff segment. After reaching a point of maximal diameter, the diameter reduces again toward the distal face. A U-shaped recess is formed in the very end of the cuff-segment. In cross-section through a sagittal plane, the cuff segment comprises a smoothed, broadly cylindrical shape. The result is two curved extensions which take the rough shape of "dog ears", and which extend out from opposing sides of the cuff segment and at a far, distal end of the cuff segment. Figure lOd depicts a similar shape to that depicted in figure 10c, but with only a single "dog ear" shape displayed. Figure lOe depicts a cuff link with an alternative shape. Figure 11 depicts an assembled brachytherapy applicator 1100, in accordance with the present disclosure. The assembled applicator 1100 comprises a cuff segment 1101 that takes the general form and shape as that shown in figure 10c. As described above, the cuff segment comprises channels which enable needles to be positioned at a variety of angles and positions, for example radially inner channels 1120a which are primarily parallel to a central axis of the applicator body which enable needles to be placed at an angle substantially parallel to the central axis, and also radially outer, angled channels 1120b which angle out and away from the central axis and which enable the placement of oblique, angled needles, for example into patient tissue. The assembled applicator 1100 further comprises an extending segment 1190. Extending segments 1190 can be used in any applicator arrangement of the present disclosure. The purpose of the extending segment 1190 is to extend the length of the applicator 1100 according to the treatment requirements, for example to ensure the cuff segment 1101 can be placed proximal to a back wall of the patient's uterus or vagina. The extending segment 1190 can be positioned between any components described herein to provide extra length or extension to the applicator, and thereby to provide the clinician and treatment planning team with additional options for source and needle placement. The assembled applicator 1100 comprises a perineal template base 1110 and two template extenders 1112a,b, positioned either side of the template base 1110. As can be appreciated from the figure, the template base 1110 and the base extenders 1112a,b, have complementary outer perimeter shapes, such that the extenders 1112a,b, can fit against the base template 1110. The template base 1110 also comprises a protrusion or ridge, 1111, which extends from a main body of the template base 1110 and is shaped, positioned and otherwise configured to fit into a corresponding recess in the template extenders 1112a,b. This ensures proper placement and fitting of the extenders 1112a,b. The template base 1110 further comprises one or more extensions 1113 which are configured to extend from a main body of the base template 1110 and provide a backing for an extender to be placed against. The protrusion9s) 111 may be positioned at least partially on the extensions 1113. The extensions 1113 provide support for the template. The base plate 1110 and extenders 1112a,b, may also comprise additional attachment means (not shown) to enable the extenders 1112a,b, to be fixed in place, for example channels to enable a screw fitting to lock an extender 112 against an extension 1113. Figures 12a, 12b depict a needle locking mechanism in accordance with the present disclosure. When using needles, a clinician wants to place needles right below the surface of the applicator (before inserting the applicator in the patient). Once the applicator is inserted, the clinician wants to insert the needle to a certain (pre-defined) depth. For this, they need a reference length, which is the length of the front of the Guiding Tube to the applicator surface, the length of the Guiding Tube and the length of the needle. By providing the depicted needle locking mechanism in the cuff segment for each channel, the reference lengths can be kept the same for all the different channels, clinicians can insert the needles to the preferred depth independent to which channel they want to use or independent to the design / curve of the channel. It should be understood that the features described above and generally herein in relation to specific component or central tube implementations can be combined together, and that features of a particular component may be used with features of a different component. Applicator configuration selection, and accompanying software The presently disclosed modular applicator provides clinicians with a range of options for treating different types of cancer, different patient anatomies, and generally providing optimised and personalised brachytherapy treatment. The present application also relates to methods of selecting a particular applicator configuration which is optimised for particular treatment needs. This method may be fully or semi-automated, and may be based on information provided by a clinician, or retrieved from a database, about the treatment needs. Figure 13 depicts five examples of different treatment needs, and appropriate modular applicator configurations which can be assembled rom available components in the manner disclosed herein in order to optimally treat the patient. The skilled person will appreciate that the figure exists to provide an example of software functionality, and the recommended applicator configurations depicted in the figure may, or may not, in reality be optimised for the particular treatment needs depicted. In a first example, a user intends to treat a post hysterectomy patient that has endometrial tumours. A schematic depiction of a medical image showing the patient's anatomy and tumour position(s) is shown in the figure in the first row. The user inputs information into a user interface about the treatment needs, for example information regarding the type of cancer, the tumour shape, location and orientation, the location, orientation and shape of any organs at risk (OARs), as well as any already prescribed dosages including minimum dose to be delivered to the tumour and maximum doses that can safely be delivered to any OARs. Providing this information may comprise providing one or more medical images depicting the patient anatomy. The images may be segmented to depict particular tissues, or the software can run auto-segmentation software in order to extract information about the patient anatomy. In the first example, the user uploads one or more medical images of the patient anatomy, and provides information that the patient is post-hysterectomy and that the cancer is endometrial in nature. This information is processed, and the user receives an output that the appropriate configuration of medical applicator comprises an intravaginal tube, with no intrauterine tube. The software is also able to recommend appropriate options for a cuff segment (e.g. IC single channel), a paravaginal segment (IC and IS multi-channel). The appropriate applicator configuration is depicted in the far right column of the first row. The present disclosure therefore relates to a computer implemented method, and system, for recommending an appropriate configuration for a modular applicator. In a second example, based on the inputted treatment and / or patient information, the software recommends two appropriate options for applicator configuration, which enables user-choice. The third row of figure 13 depicts three types of cancer which may all be treated by the same applicator configuration (see far right column). In an example, a processor receives information about the patient anatomy. This may take the form of one or more medical images, for example of one of the cancer types shown in figure 13, for example primary vaginal cancer. The one or more images may be CT, MRI, or other imaging modalities, and may be a plurality of 2D slices depicting the 3D treatment volume and / or may be a 3D image. The processor segments the images using known auto-segmentation techniques (alternatively, the image(s) may be already segmented by the user). The processor derives, from the one or more images, information regarding the location of tumours in the patient anatomy. Based on the location of tumour(s) in the patient anatomy, the processor outputs an appropriate applicator configuration. In the depicted example in the third row, the processor determines that an applicator comprising a central tube comprising a single-channel intrauterine tube is optimal, and that the applicator should be further assembled to comprise IS multi-channel cylinder segments (e.g. paravaginal segments), along with a perineal template base (with no extension) to enable IS needle placement. The processor is further configured to output suggested needle positions and placements, and which channels of the components will be optimal to use when placing these needles. While the overall applicator configuration is the same for each of the depicted three cancer types, these needle suggestions will be different for each type of cancer and depending on the tumour location and patient anatomy. In a fourth example, in which a patient has been diagnosed with inoperable endometrial cancer, the user does not provide medical images but instead manually inputs information regarding the type of cancer (e.g. inoperable endometrial) and about the tumour location (e.g. large, multi-site, back wall of uterus). Based on this information, a processor processes the information and outputs an optimal applicator configuration as depicted in the fourth row of figure 13. In a fifth example, a processor retrieves one or medical images of a patient. The medical images show patient anatomy, where the patient has vulval cancer with tumours positioned at the vulva. The processor also accesses medical records associated with the patient, which indicate that the patient has been diagnosed with vulval cancer. Based on this information, and the medical images, the processor outputs an optimal applicator configuration as depicted in the figure, in which a perineal template base and extension should be used. A recommended position for each of a plurality of needles and flexible implant tubes is also recommended to the user. In addition, based on the retrieved information, a full treatment plan is generated using the recommended applicator configuration. Figure 14 depicts a high-level computer implemented method 1400. At 1410, the processor receives information regarding the treatment needs, or treatment requirements. This information may comprise any of: information regarding the location, orientation, and shape of one or more tumours; information regarding the location, orientation, and shape of one or more OARs; information regarding the type of cancer and / or the cancer diagnosis; one or more medical images depicting the patient anatomy; medical information associated with the patient; dose information as prescribed by a clinician or in accordance with any existing treatment plan. At 1420, the received information is processed. The processing stage may comprise consulting one or more look-up tables, flowcharts and / or decision trees. For example, if a patient has vulval cancer, it is typical to make use of a perineal template and this information can be stored in a look-up table, such that if the information receives at block 1410 indicates that the patient has vulval cancer then the software will recommend the use of a perineal template. Alternatively, or additionally, the processing stage at block 1420 may comprise entering the received information into one or more Al or ML-based models. For example, one or more medical images can first be input into a trained ML model such as a neural network or convolutional neural network. This ML model may segment the medical image(s) and identify the location and shape of tumours present in the patient anatomy. The same model, or a different model, may similarly take this information, and / or the segmented images directly, and process them to output a recommended applicator configuration. In an example, an ML model can be trained using a dataset comprising a plurality of medical images depicting different cancer types and tumour positions in the female reproductive system, such as vaginal and endometrial cancers. Each image has been reviewed by a clinician, who has recommended a particular applicator type for the tumour(s) depicted in the image. This forms the basis of a labelled data set suitable for training an ML model, such as a NN or CNN, to process new images and output recommended applicator configurations. Alternatively, a simulation technique such as a Monte Carlo simulation technique may be used. For example, every possible applicator configuration, and / or a subset of possible applicator configurations produced according to the type of cancer to be treated, may form part of a simulation on the patient's anatomy to depict which needle and source positions provide the most accurate dose to the patient's tumour(s) according to the dose prescribed by the clinician. At block 1430, an optimal applicator configuration is outputted, or generated, based on the processing. This can comprise outputting the recommended applicator components to the user for example via a GUI or other display device. In an implementation, the recommended optimal applicator configuration may comprise one or more bespoke, 3d-printable component recommendations. In an example, based on one or more medical images of a patient, it is determined that a non-standard needle placement will enable optimal treatment to be delivered. In this case, the processor may determine a needle / source placement which would provide an optimal dose distribution, and then, by virtue of determining the number of needles and / or flexible catheters that are required, and / or the angle at which these needles and catheters must be placed, can extrapolate these angles back to (for example) a perineal template base component which comprises channels which enable the optimal needle and / or catheter positioning. In other words, a bespoke, personalised component can be designed which will enable optimal needle and / or catheter placement for the patient's particular treatment needs. In turn, instructions for a 3d printing device are generated in a known way, and are passed to the user to enable them to produce the device. This kind of analysis can be performed for any of the components described herein, and needn't only be based on needle angle and placement but also the patient's anatomy, for example the size and shape of the patient's vagina and uterus. In an example, a 3d-printed perineal template can take practically any shape, to align with the patient's anatomy. Similarly, a cuff segment of any size and shape can be generated, thereby enabling a more accurate anatomical fit to be established during treatment. At block 1440, optionally, a treatment plan is generated and output based on the received information, and which uses the optimal applicator configuration. The treatment plan may specify particular needle, catheter and channel usages, along with usual brachytherapy treatment plan information such as type and number of radiation source, the location of the radiation source (i.e. how far they should be extended along each channel), dwell times at each location, etc. 3D printable components As described above, methods of the present disclosure may comprise generating data which can be relayed to an additive manufacturing device to enable the additive manufacturing device to fabricate a bespoke component for fitting to a central tube, ultimately for the purpose of providing hyper-tailored treatment to a patient via brachytherapy. The 3D printing process and system itself may be standard. As is known to the skilled person, the 3D printing process typically begins with the use of CAD software. This software allows the user to create a digital model of the object to be printed. The CAD software facilitates the precise manipulation of the object's dimensions, geometry, and overall design, ensuring accurate representation during the fabrication process. According to the present disclosure, this model can be automatically generated based on the treatment needs in question. The generated digital model of the component may be saved in a standardized file format, such as STL (Stereolithography) or OBJ (Object). These file formats capture the geometrical data of the component and serve as input for the subsequent stages of the 3D printing process. The digital file may be processed using slicing software, which converts the 3D model into a series of two-dimensional cross-sectional layers or slices. Each slice represents a specific layer of the component and includes instructions for the printer on how to deposit material for that particular layer. The printer hardware may comprise several components, including: a. Build Platform: The build platform provides a stable surface upon which the component may be printed layer by layer. b. Extruder / Nozzle: The extruder or nozzle is responsible for depositing the printing material, such as thermoplastics or resins, layer by layer based on the instructions provided by the slicing software. c. Control System: The printer is controlled by a central control system, which interprets the instructions from the slicing software and coordinates the movements of various components during the printing process. d. Heating System: Many 3D printers incorporate a heating system to maintain optimal temperature conditions for the printing material, ensuring proper adhesion and solidification. The printing material used in 3D printing can vary depending on the desired properties of the object being printed. Common materials include thermoplastics, photopolymers, metals, ceramics, and composites. Example system Figure 15 illustrates a block diagram of one implementation of a system 1500 which may be used to implement methods according to the present disclosure, in particular the methods discussed above with respect to figures 13 and 14. The system 1500 comprises a computing system 1510 within which a set of instructions, for causing the computing system 1510 to perform any one or more of the methods discussed herein, may be executed. The computing system 1510 shall be taken to include any number or collection of machines, e.g. computing device(s), that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methods discussed herein. That is, hardware and / or software may be provided in a single computing device, or distributed across a plurality of computing devices in the computing system. In some implementations, one or more elements of the computing system may be connected (e.g., networked) to other machines, for example in a Local Area Network (LAN), an intranet, an extranet, or the Internet. One or more elements of the computing system may operate in the capacity of a server or a client machine in a client-server network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. One or more elements of the computing system may be a personal computer (PC), a tablet computer, a set-top box (STB), a Personal Digital Assistant (PDA), a cellular telephone, a web appliance, a server, a network router, switch or bridge, or any machine capable of executing a set of instructions (sequential or otherwise) that specify actions to be taken by that machine. The computing system 1510 includes controller circuitry 1511 and a memory 1513 (e.g., read-only memory (ROM), flash memory, dynamic random access memory (DRAM) such as synchronous DRAM (SDRAM) or Rambus DRAM (RDRAM), etc.). The memory 1513 may comprise a static memory (e.g., flash memory, static random access memory (SRAM), etc.), and / or a secondary memory (e.g., a data storage device), which communicate with each other via a bus (not shown). Controller circuitry 1511 represents one or more general-purpose processors such as a microprocessor, central processing unit, accelerated processing units, or the like. More particularly, the controller circuitry 1511 may comprise a complex instruction set computing (CISC) microprocessor, reduced instruction set computing (RISC) microprocessor, very long instruction word (VLIW) microprocessor, processor implementing other instruction sets, or processors implementing a combination of instruction sets. Controller circuitry 1511 may also include one or more special-purpose processing devices such as an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a digital signal processor (DSP), network processor, or the like. One or more processors of the controller circuitry may have a multicore design. Controller circuitry 1511 is configured to execute the processing logic for performing the operations and steps discussed herein. The computing system 1510 may further include a network interface circuitry 1518. The computing system 1510 may be communicatively coupled to an input device 1520 and / or an output device 1530, via input / output circuitry 1517. In some implementations, the input device 1520 and / or the output device 1530 may be elements of the computing system 1510. The input device 1520 may include an alphanumeric input device (e.g., a keyboard or touchscreen), a cursor control device (e.g., a mouse or touchscreen), an audio device such as a microphone, and / or a haptic input device. The output device 1530 may include an audio device such as a speaker, a video display unit (e.g., a liquid crystal display (LCD) or a cathode ray tube (CRT)), and / or a haptic output device. In some implementations, the input device 1520 and the output device 1530 may be provided as a single device, or as separate devices. In some implementations, computing system 1510 includes training circuitry 1518. The training circuitry 1518 is configured to train a method of producing, or generating, an optimal applicator configuration, for example. For example, training circuitry 1518 may train a model for performing a method of optimal applicator configuration generation. The model may comprise a deep neural network (DNN), such as a convolutional neural network (CNN) and / or recurrent neural network (RNN). Training circuitry 1518 may be configured to execute instructions to train a model that can be used to generate the optimal applicator assembly. Training circuitry 1518 may be configured to access training data and / or testing data from memory 1513 or from a remote data source, for example via network interface circuitry 1515. In some examples, training data and / or testing data may be obtained from an external component, such as image acquisition device 1540 and / or treatment device 1550. In some implementations, the computing system 1510 may comprise image processing circuitry 1519. Image processing circuitry 1519 may be configured to process image data 1580 (e.g. images, or imaging data), such as medical images obtained from one or more imaging data sources, a treatment device 1550 and / or an image acquisition device 1540. Image processing circuitry 1519 may be configured to process, or pre-process, image data. For example, image processing circuitry 1519 may convert received image data into a particular format, size, resolution or the like. In some implementations, image processing circuitry 1519 may be combined with controller circuitry 1511. In some implementations, the system 1500 may further comprise an image acquisition device 1540 and / or a treatment device 1550, such as those disclosed herein. The image acquisition device 1540 may be a CT or MRI scanner, for example. Image acquisition device 1540 may be configured to output image data 1580, which may be accessed by computing system 1510. Treatment device 1550 may be configured to output treatment data 1560, which may be accessed by computing system 1510. Computing system 1510 may be configured to access or obtain treatment data 1560, planning data 1570 and / or image data 1580. Treatment data 1560 may be obtained from an internal data source (e.g. from memory 1513) or from an external data source, such as treatment device 1550 or an external database. Planning data 1570 may be obtained from memory 1513 and / or from an external source, such as a planning database. Planning data 1570 may comprise information obtained from one or more of the image acquisition device 1540 and the treatment device 1550. The various methods described above may be implemented by a computer program. The computer program may include computer code (e.g. instructions) 1610 arranged to instruct a computer to perform the functions of one or more of the various methods described above. The steps of the methods described above may be performed in any suitable order. The computer program and / or the code 1610 for performing such methods may be provided to an apparatus, such as a computer, on one or more computer readable media or, more generally, a computer program product 1600), depicted in Figure 16. The computer readable media may be transitory or non-transitory. The one or more computer readable media 1600 could be, for example, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, or a propagation medium for data transmission, for example for downloading the code over the Internet. Alternatively, the one or more computer readable media could take the form of one or more physical computer readable media such as semiconductor or solid state memory, magnetic tape, a removable computer diskette, a random access memory (RAM), a read-only memory (ROM), a rigid magnetic disc, and an optical disk, such as a CD-ROM, CD-R / W or DVD. The instructions 1610 may also reside, completely or at least partially, within the memory 1513 and / or within the controller circuitry 1511 during execution thereof by the computing system 1510, the memory 1513 and the controller circuitry 1511 also constituting computer-readable storage media. In an implementation, the modules, components and other features described herein can be implemented as discrete components or integrated in the functionality of hardware components such as ASICS, FPGAs, DSPs or similar devices. A "hardware component" is a tangible (e.g., non-transitory) physical component (e.g., a set of one or more processors) capable of performing certain operations and may be configured or arranged in a certain physical manner. A hardware component may include dedicated circuitry or logic that is permanently configured to perform certain operations. A hardware component may comprise a special-purpose processor, such as an FPGA or an ASIC. A hardware component may also include programmable logic or circuitry that is temporarily configured by software to perform certain operations. In addition, the modules and components can be implemented as firmware or functional circuitry within hardware devices. Further, the modules and components can be implemented in any combination of hardware devices and software components, or only in software (e.g., code stored or otherwise embodied in a machine-readable medium or in a transmission medium). Unless specifically stated otherwise, as apparent from the following discussion, it is appreciated that throughout the description, discussions utilizing terms such as "receiving", "determining", "comparing ", "enabling", "maintaining," "identifying," or the like, refer to the actions and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices. It is to be understood that the above description is intended to be illustrative, and not restrictive. Many other implementations will be apparent to those of skill in the art upon reading and understanding the above description. Although the present disclosure has been described with reference to specific example implementations, it will be recognized that the disclosure is not 5 limited to the implementations described, but can be practiced with modification and alteration within the spirit and scope of the appended claims. Accordingly, the specification and drawings are to be regarded in an illustrative sense rather than a restrictive sense. The scope of the disclosure should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. 10

Claims

1. A kit for a modular applicator, the applicator being suitable for delivering brachytherapy treatment, the kit comprising:a tubular central body comprising a seed passage channel to enable passage of a radioactive seed therethrough;at least one component comprising an opening through which the tubular central body can pass; andmeans for detachably attaching the at least one component to the tubular central body.

2. The kit of any preceding claim, wherein the at least one component comprises a plurality of needle channels, each needle channel configured to guide an interstitial needle.

3. The kit of claim 2, wherein at least one of the plurality of needle channels is configured to guide a needle to form an angle offset from, and oblique to, the seed passage channel.

4. The kit of claim 2 or claim 3, wherein at least one of the plurality of needle channels is configured to guide a needle parallel to the seed passage channel.

5. The kit of any preceding claim, wherein the at least one component is a 3d printed component, wherein the 3d printed component is shaped to fit a specific patient's anatomy.

6. The kit of any preceding claim, wherein the at least one component is a cuff segment configured to be positioned at a distal end of the tubular central body.

7. The kit of claim 6, wherein the cuff segment comprises an offset frustoconical shape.

8. The kit of claim 6, wherein the cuff segment flares outward toward its outer rim.

9. The kit of any preceding claim, wherein the at least one component comprises a plurality of components, each comprising a respective opening through which the tubular central body can pass.

10. The kit of any claim 9, wherein one of the plurality of components is a cuff segment configured to be positioned at a distal end of the modular applicator, wherein another one of the plurality of components is a paravaginal component configured to be positioned alongside the cuff segment in use;wherein both the cuff segment and paravaginal component comprise a plurality of needle channels positioned such that, in use, one or more needles can pass through both the paravaginal component and the cuff segment.

11. The kit of claim 10, wherein both the cuff segment and the paravaginal component comprise needle channels configured to guide a needle to form an angle offset from, and oblique to, the seed passage channel.

12. The kit of any preceding claim, wherein the tubular central body comprises a recess on its outer surface and along at least a majority of its length, and the at least one component comprises a corresponding ridge positioned on an inner surface of the opening, such that, by interaction of the recess and ridge, the at least one component is guided onto the tubular central body in a particular orientation.

13. The kit of any preceding claim, wherein the tubular central body comprises an intrauterine portion configured, in use, to enter the patient's uterus, wherein the intrauterine portion comprises a plurality of tubes, each configured to receive a radioactive seed via the seed passage channel.

14. The kit of claim 13, wherein each tube of the plurality of tubes is biased away from a central axis defined by the seed passage channel; andwherein the tubular central body further comprises a slidable sheath configured to slide over the intrauterine portion and thereby bring the plurality of tubes together.

15. The kit of claim 14, wherein the at least one component is configured to removably attach to the slidable sheath.

16. The kit of any of claims 13 to 15, wherein one or more tubes of the plurality of tubes are opened ended such that a flexible catheter may pass through the seed passage channel, through the tube, and extend out from the open end of the one or more tubes.

17. A modular applicator comprising:a tubular central body comprising a seed passage channel to enable passage of a radioactive seed therethrough;at least one component comprising an opening through which the tubular central body is passed pass; andmeans for detachably attaching the at least one component to the tubular central body.

18. The modular applicator of claim 17, wherein the modular applicator is assembled from the kit of any of claims 1 to 16.

19. A computer-implemented method of generating an optimal applicator configuration, the applicator being suitable for treating a patient via brachytherapy; the method comprising: receiving information regarding treatment needs of the patient; and outputting, based on the received information, an optimal applicator configuration for the patient's brachytherapy treatment;wherein the optimal applicator configuration comprises a recommended tubular central body selected from a plurality of tubular central body options, and at least one recommended component for attaching to the central tubular body selected from a plurality of component options.

20. The method of claim 19, wherein the information regarding the treatment needs of the patient may comprise one or more of: information regarding the location, orientation, and shape of one or more tumours; information regarding the location, orientation, and shape of one or more organs at risk (OARs); information regarding the type of cancer and / or the cancer diagnosis; one or more medical images depicting the patient anatomy; medical information associated with the patient; and / or dose information as prescribed by a clinician or in accordance with an existing treatment plan.

21. The method of claim 19 or claim 20, wherein outputting, based on the received information, the optimal applicator configuration comprises using a trained machine learning model.

22. The method of any of claims 19 -21, further comprising generating a brachytherapy5 treatment plan based on the received information, wherein the treatment plan comprisesusing the optimal applicator.

23. A system configured to perform the method of any of claims 19 to 22.1034

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