Robotic Endocavitary Alignment for Repeatable Radiotherapy Positioning

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Solution Overview

Problem

Existing radiotherapy systems struggle to accurately position internal tissues relative to an ionizing radiation beam due to their movement, leading to increased treatment margins and higher side effects, as they do not account for the displacement of internal organs like the cervix, bladder, and rectum, which can vary significantly during treatment sessions.

Innovation Solution

A radiotherapy treatment system utilizing a robotic arm and a positioning tool with a steering guide and inflatable shafts to reproducibly align bodily canals, such as the vagina or rectum, with respect to the radiation beam, enabling precise positioning through real-time adjustments and empirical data integration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional radiotherapy positioning methods using laser beams and external marks are used, then the subject can be accurately positioned on the treatment table, but the internal organs (cervix, bladder, rectum) cannot be accurately positioned relative to the radiation beam due to their movement

Engineering Contradiction:
Improvepositioning accuracy of internal organsVSAvoidconsistency of internal organ position
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent introduces an endocavitary positioning tool as an intermediary device that inserts into the cervix to directly position and stabilize the internal organ relative to the radiation beam. This mediator overcomes the limitation of external positioning methods by providing internal support and alignment, ensuring the cervix remains in the correct position despite movements of surrounding tissues.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The positioning tool is inserted and adjusted before radiation delivery begins, establishing the correct position of the cervix in advance. This preliminary positioning ensures that subsequent radiation beams are delivered accurately to the target while avoiding damage to surrounding healthy tissues.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If larger treatment margins are used to account for organ movement, then all internal organs are covered, but the treated volume increases leading to higher rates of acute and late side effects

Engineering Contradiction:
Improvecoverage of target volumeVSAvoidside effects on healthy tissue
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The endocavitary positioning tool serves as a stable reference framework within the cervix, allowing radiation oncologists to precisely define the target volume boundaries. This internal reference enables smaller, more accurate treatment margins compared to external positioning methods, reducing the volume of healthy tissue exposed to radiation while ensuring complete coverage of the target.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Stability of the object's composition

If patients are instructed to empty rectum and fill bladder before each session, then some uterus displacement is reduced, but the positioning remains non-reproducible due to variable patient compliance and physiological changes

Engineering Contradiction:
Improveposition stability of internal organsVSAvoidreproducibility of positioning
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The positioning tool inserted into the cervix provides a direct mechanical reference for organ position, eliminating dependence on patient preparation instructions. This internal mediator ensures reproducible positioning across multiple treatment sessions regardless of variations in bladder filling or rectal emptying, as the tool is directly anchored to the target organ.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system incorporates imaging capabilities that provide real-time feedback on the position of the positioning tool and surrounding organs. This feedback loop allows for verification and adjustment of positioning, ensuring reproducible alignment of the cervix with the radiation beam across multiple treatment sessions.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4251267B1System for repeatable alignment of bodily tissue for programme of external radiotherapy treatment
Publication Date: 2026.02.18 PELVIRAY IP LTD
  • EP4251267B1 patent drawingFigure 1~2
  • EP4251267B1 patent drawingFigure 3~4F
  • EP4251267B1 patent drawingFigure 5~6

AI summary

Provided herein is radiotherapy treatment system (100) for assisting treatment of a subject in an external radiotherapy programme comprising one or more external radiotherapy treatment sessions, the system (100) comprising a robotic arm, RA, (400, 400a) having a base end (422, 422a) and an effector end and a steering guide (300) having a proximal (40) and distal (20) end comprising a rigid effector shaft (310) at the distal end (20) configured for insertion into the canal (602) of the subject (50), or for attachment to an inserter (204) configured for insertion into the canal (602) of the subject (50), wherein the positioning tool (200) is configured to move and/or fix the canal (602) for the external radiotherapy treatment session responsive to movements of the robotic arm.