Stereotactic Radiotherapy and Androgen Deprivation Therapy for Localized Prostate Cancer: A Retrospective Mono-institutional Experience

Abstract

Background/aim: Stereotactic radiotherapy (SRT) is an effective treatment for localized prostate cancer. However, is it not clear whether the addition of androgen deprivation therapy (ADT) to SRT is beneficial. The aim of this study was to analyze the outcomes of a series of patients treated with SRT plus ADT for localized prostate cancer.

Patients and methods: Patients were treated with SRT with 42 Gy in 7 fractions with volumetric-modulated arc therapy plus Image Guided Radiotherapy (V-MAT IGRT) technique. ADT was administered to patients with intermediate unfavorable- and high-risk disease. Study endpoints were biochemical disease-free survival (bDFS), overall survival (OS), acute and late toxicity and patient-reported outcomes (PROs) using international prostate cancer symptoms scale (IPSS) and international index of erectile function (IIEF).

Results: A total of 170 consecutive patients were identified, of which 49 (28.8%) with low-risk, 15 (8.8%) with favorable intermediate-risk 76 (44.7%) with unfavorable intermediate-risk and 30 (17.6%) with high-risk class. All patients of unfavorable intermediate- and high-risk groups were administered LHRH analogue concurrently to SRT and for at least 6 months. Patients with unfavorable intermediate- and high-risk presented a 5-year bDFS of 81.7% and 76.9%, respectively.

Conclusion: SRT consisting of 42 Gy in seven fractions with short-term ADT represents a safe and effective treatment for unfavorable intermediate and high risk prostate cancer. Our results support the need of high quality studies to test the efficacy of ADT combined with SRT for unfavorable intermediate- and high-risk localized prostate cancer.

Keywords: Prostate cancer; androgen deprivation therapy; high risk prostate cancer; stereotactic radiotherapy; unfavorable intermediate risk prostate cancer.