Background. Prostate cancer (PCa) is the second most common cancer worldwide. Current methods of definitive treatment of PCa provide good recurrence-free survival in patients with low and intermediate risk of progression, and yet about a third of men will face the local recurrence in the next 10 years of life. Today, there is a great need to find optimal technologies for treating local relapses of PCa.
Aim. To analyze the efficiency and toxicity of salvage high dose-rate (HDR) brachytherapy in the treatment of local recurrences of prostate cancer after various types of primary treatment.
Materials and methods. A total of 98 patients with local relapse of PCa after various types of radical treatment were included in the study. The age of the patients was on average 68 years (minimum 53 years, maximum 84 years) [95% CI = 66.9-69.7 years]. Recruitment of patients was carried out from January 2015 to December 2022 at the Federal State Budgetary Institution Russian Scientific Center for Radiology of the Ministry of Health of Russia. After a comprehensive examination, all patients underwent salvage HDR brachytherapy. The study included 34 patients after radical prostatectomy and 64 patients after radiation treatments (EBRT, brachytherapy).
Results. The median follow-up was 36 months (3–84 months). Depending on the previous treatment, the patients were divided into 2 groups. Group I (n=34) included patients after radical prostatectomy, while in group II (n=64) there were men after radiation treatment (EBRT, brachytherapy). The 5-year PSA-progression-free survival in group I was significantly higher than in group II and was 88.2 and 67.2%, respectively (p=0.023). The incidence of late genitourinary toxicity of grades 1, 2, 3 in both groups was 22.4, 10.2, and 4.1%, respectively, and late gastrointestinal toxicity of grades 1 and 2 were 10.2 and 1%, respectively. Severe complications of grades 2 and 3, both from the urinary system and from the rectum, were observed only in group II.
Conclusion. HDR brachytherapy is an effective salvage treatment option for local relapses of PCa after previous radiation and surgical treatment.

Keywords: high dose brachytherapy, salvage brachytherapy, radical prostatectomy, prostate cancer, recurrence