Extracranial stereotactic radiotherapy as a treatment for oligometastatic prostate cancer

Abstract

OBJECTIVE: To report preliminary results of our experience with stereotactic body radiation therapy (SBRT) in patients with oligometastatic prostate cancer (OMPC). METHOD: observational study of 23 individuals with CPO treated with SBRT between 2019-2025. RESULTS: Median age 65 years. Eleven patients (47.8%) had de novo oligometastatic prostate cancer, two (8.7%) had oligoprogression, four (17.4%) had oligopersistence, and six (26.1%) had oligorelapse. Twenty patients (86.95%) underwent positron emission tomography (PET-CT/PSMA) for staging. All patients received androgen deprivation therapy (ADT). The most frequently used technique was VMAT (73.9%); the most frequently used fractionation was 3000 cGy in five fractions. Biochemical response (BR) was 91.3%, with complete response in 82.6% and partial response in 8.69%, and biochemical progression in 4.35%. The biochemical progression-free survival (BFS) at one and five years was 93.8 ± 6.1. The cause-specific survival (CSS) at 1 year was 95% ± 4.9 and at 5 years was 86.4% ± 9.4. Grade I acute genitourinary toxicity was reported in 17.40% of patients and Grade II in 13.04%. Grade I acute gastrointestinal toxicity was reported in 17.40% and Grade II in 4.35%. No acute or chronic complications were observed during metastasis-directed therapies. The median follow-up was 17.63 months, with a mean of 26.36 months and a range of 68.8–4.57 months. CONCLUSION: SBRT is a safe and effective treatment in terms of RB, SLPB, SCE and toxicity for patients with oligometastatic prostate cancer.