Brachytherapy of localized prostate cancer by domestic sources I-125: own experience of the National Medical Research Center of Radiology

Introduction. One of the effective and minimally invasive methods prostate cancer treatment is interstitial radiation therapy, the essence of which is the implantation of radioactive microsources into the tumor tissue. Brachytherapy of prostate cancer is performed in more than 20 clinics in the Russian Federation using mainly foreign microsources, but their high cost does not allow increasing the number of operations and opening new brachytherapy departments in the Russian Federation. Based on the model of foreign microsources such as seed No. 6711 (Nicomed Amersham), a technology for the manufacture of microsources with iodine-125 (IPPE SEED) has been developed at the State Research Center of the Russian Federation - IPPE, as well as a pilot production facility with a capacity of up to 50 thousand items per year. Materials and methods. In order to assess the safety of microsources for medical personnel during brachytherapy, local dosimetric control was carried out. As part of a clinical study in 2015, 36 patients with stage T1 – T2 prostate cancer underwent low-power brachytherapy using domestic microsources. Results. The obtained values of absorbed doses do not differ within the limits of measurement errors from the values of doses determined during the operation with foreign microsources under similar conditions. It follows from the data obtained that even the maximum values of the measured local absorbed doses do not pose a radiation hazard when using IPPE SEED microsources for brachytherapy. Among the treated patients, adverse reactions were in the expected manifestations of grade 1 dysuria according to the RTOG / EORTC classification. No gastrointestinal toxicity has been reported. Patient monitoring was continued in order to obtain long-term results of treatment. PSA disease-free survival at 5-year follow-up was 94.4%. Discussion. Clinical trials of Russian medical devices have demonstrated their safety for patients and medical personnel, which was proved by conducting dosimetry control during the procedure itself, as well as during examination of patients after brachytherapy. The effectiveness of Russian microsources I-125 during low-power brachytherapy is demonstrated by a decrease in PSA level from baseline by 87% at a follow-up period of 6 months. The disease-free survival rate for 5 years was 94.4%. The absence of significant radiation reactions both in the early and in the late postoperative period is important. The low cost of microsources produced by JSC «SSC RF – IPPE» relative to foreign analogs makes it possible to increase the number of operations performed annually, and also gives prospects for opening new divisions performing interstitial radiation therapy operations. Conclusions. Russian microsources «IPPE SEED» have successfully passed clinical trials, during which their effectiveness and safety were proved. The study also demonstrated high rates of relapse-free survival and a low level of adverse reactions in treated patients.