Stereotactic body radiotherapy for early localized prostate cancer in a regional oncology care: A single-institution experience

Introduction: Radiation therapy (RT) is the standard of care for radical treatment of early prostate cancer (PCa). The use of stereotactic radiotherapy (SBRT) in the treatment of localized PCa is currently being studied. Most researchers believe that SBRT is a highly effective RT method, comparable in oncologic outcomes to conventional radiation techniques. The efficacy and safety of SBRT without the use of additional imaging techniques (gold fiducials) and anatomical protectors (biodegradable perirectal spacers) remain controversial. Therefore, the development and testing of SBRT for PCa using a modern “standard” linear accelerator is relevant and has significant scientific and practical significance.The aim of the study: improving the results of radical radiation treatment for patients with localized prostate cancer by developing a method of SBRT without using of gold fiducials and biodegradable perirectal spacers on a linear accelerator in a regional oncology center.Materials and methods: A single-center, prospective, non-randomized study of the use of SBRT in patients with localized PCa was conducted. The study group included 80 patients with histologically confirmed low or intermediate risk PCa who underwent SBRT (36.25 Gy / 5 fractions, 3 times per week) at the Vladimir Regional Clinical Oncology Dispensary from December 2021 to March 2023.Results: The two-year biochemical relapse-free survival was 97.5 %. No grade 3 acute genitourinary or rectal toxicity was recorded. Grade 2 acute genitourinary toxicity according to CTCAE v5.0 was 6.2 %. Late genitourinary toxicity of grade ≥ 2 at 2 years was 15 %. Grade 2 acute rectal toxicity was 1.2 %. Late rectal toxicity grade ≥ 2 at 2 years was 3.7 %.Conclusion: Developed and tested on a linear accelerator, SBRT should be recognized as an effective method for the radical treatment of localized PCa. A high level of biochemical control with a tolerable safety profile was achieved without the use of gold fiducials or biodegradable perirectal spacers.