Long-term outcomes of hypofractionated radiation therapy in patients with high risk prostate cancer

Background. Hypofractionated radiation therapy is a standard radical approach for treatment of patients with localized prostate cancer of low and intermediate risk. Clinical practice of applying this approach in patients with high and very high risk of progression has not been established. Aim: improving the effectiveness of hormonal/radiation therapy in patients with high and very high risk prostate cancer using an original radiotherapy technique. Materials and methods. In 2012, a new technique of hypofractionated radiation therapy based on simultaneous integrated boost aimed at the prostate, seminal vesicles, and regional lymph nodes was developed at the Radiotherapy Department of the N.N. Blokhin National Medical Research Center of Oncology. The phase II single-center prospective cohort trial included 40 patients with high and very high risk prostate cancer who received combination hormonal/ radiation therapy between 2012 and 2018. Median follow-up was 96 (61-124) months. Results. None of the patients had grade III-IV adverse events (according to the RTOG/EORTC scale) in the distal parts of the gastrointestinal tract and urogenital system. Five-year biochemical and local controls were 80 % and 100 %, respectively. Conclusion. The results of this study show that the developed hypofractionated radiation therapy technique is safe with 5-year biochemical control outcomes matching reported in the literature. However, to determine true clinical significance of the technique, initiation of a randomized phase III trial is required.