A method for conducting radiation therapy in the complex treatment of patients with locally advanced cervical cancer with contraindications to intracavitary radiation therapy

Claims

A method for conducting radiation therapy in the complex treatment of patients with locally advanced cervical cancer with contraindications to intracavitary radiation therapy, including at the first stage a course of conformal radiation therapy to the pelvic area in a fractionation mode - a single dose of 2 Gy, 5 times a week up to a total dose of 44-50 Gy with drug radiomodification with a platinum preparation at a calculated dose of 40 mg per m 2, with the implementation of dose escalation to the affected lymph nodes to 55.2 or 57.5 Gy, expanding the irradiation fields to the level of L3 or renal vessels, and at the second stage - radiation therapy to the cervix, characterized in that at the second stage of treatment, a course of stereotactic external beam radiation therapy is carried out, before the start of which repeated computer topometry and specialized pre-radiation preparation are performed on the pelvic area with a slice thickness of 3 mm, fixing devices are used to immobilize the patient's body: a headrest and a kneerest, when planning photon irradiation, immobilization of risk organs is carried out - a tampon is inserted into the vagina to the level of the cervix, at the stage of topometric preparation, and at the stage of treatment, each session, 100-200 ml of physiological sodium chloride solution is introduced into the bladder through a Foley urethral catheter No. 16, 18, bowel preparation is carried out, including adherence to a diet with restriction of products,leading to gas formation, a cleansing enema the day before pre-radiation preparation and each treatment session and taking simethicone 1 capsule 3 times a day, organs at risk are identified in accordance with the ASTRO 2019 concept: bladder, rectum, sigmoid colon, femoral heads, intestinal loops, the irradiation target includes the cervix or the entire uterus with initial invasion of the myometrium, the indentation on the PTV is 2-5 mm, the target and organs at risk are identified at the stages of linear accelerator contouring, before the target contouring procedure, they are combined using the fusion function with MR images, dosimetric planning is performed in the Eclipse environment, version 15.6, Varian Medical Systems, Palo Alto, CA, Monaco, version 5.51.10, the technique for delivering the absorbed dose to the tumor is radiation therapy Volume-modulated arc therapy (VMAT) uses photon energy of 6-10 MeV,Treatment regimen: fractionation scheme 2-3 times a week, 4-7 fractions, the isoeffective dose from the second stage of treatment is calculated according to EQD2, α / β for squamous cell carcinoma of the cervix is ​​10 Gy, the total dose to the tumor for the entire treatment period is not less than 85 isogy, evaluation of the effectiveness of radiation therapy for both SBRT and intracavitary radiation therapy - MRI of the cervix with contrast immediately after treatment, and then during observation by a gynecological oncologist.