METHOD OF TREATING SOFT TISSUE SARCOMAS OF EXTREMITIES Russian patent published in 2024 - IPC A61N5/10 

FIELD: medicine; oncology; radiotherapy.

SUBSTANCE: invention can be used for treating soft tissue sarcomas of extremities. Topometric spiral X-ray computed tomography of the affected extremity is performed using a laser navigation system, individual fixing devices and a Singo Via virtual simulation station. Radiation fields are delineated with removal of critical areas from the radiation zone using radiotherapeutic software with subsequent calculation and formation of a treatment plan: 3D planning using the VMAT technique for linear electron accelerators. Determination of the target geometry is carried out according to the diagnostic, topometric images as follows: the total length of the irradiation target and its geometric center are determined; volume of macroscopic volume of tumor—GTV 1, which is 50% of total length of target, is located in geometric center; target peripheral volumes located symmetrically on both sides relative to GTV 1 are divided into four equal parts—GTV 2–5. Dose prescription is carried out for each volume of GTV with coefficient α/β=4.0 taking into account dose summation per one fraction: GTV 1–10 Gy, BED=35 Gy; GTV 2–9 Gy, BED=29.25 Gy; GTV 3–7.5 Gy, BED=21.56 Gy; GTV 4–6 Gy, BED=15 Gy; GTV 5–4 Gy, BED=8 Gy. Then, within next 24 hours, an organ-preserving surgical intervention is performed in the amount of fascial excision of the tumor. In 3–4 weeks after the surgical treatment, the postoperative bed tissues are restored by the postoperative radiation therapy with matching and summation of dose distribution by volumes of irradiation in inversion, inverse gradient, taking into account biologically effective dose of preoperative irradiation and status of resection edge, bringing the total focal dose on the tumor bed to 66–76 Gy.

EFFECT: use of the method enables to significantly reduce the number of radiation complications and injuries of soft tissues of extremities, preventing the development or considerably prolonging the recurrence-free period due to the declared determination of the target geometry and the declared doses.

1 cl, 6 dwg, 1 ex