Comparative real-world analysis of stereotactic body radiotherapy versus conventional radiotherapy for Chinese patients with low- to intermediate-risk localised prostate cancer.

Abstract

Introduction: This study evaluated the 5-year biochemical progression-free survival (bPFS) rate and late toxicities associated with conventional radiotherapy (CRT) and stereotactic body radiotherapy (SBRT) in Chinese patients with low-to intermediate-risk prostate cancer.

Methods: A retrospective analysis was conducted in patients with low- to intermediate-risk prostate cancer who received CRT (76 Gy in 38 fractions) or SBRT (36.25 Gy in 5 fractions) between 2015 and 2019 at a hospital in Hong Kong. The primary endpoint was 5-year bPFS. Post-radiotherapy biochemical recurrence was defined according to the Phoenix criteria. Secondary endpoints included clinician-reported late gastrointestinal (GI) and genitourinary (GU) toxicities, graded according to CTCAE (Common Terminology Criteria for Adverse Events) version 5.0.

Results: In total, 130 patients met the inclusion criteria: 99 (76.2%) received CRT and 31 (23.8%) received SBRT. After median follow-up of 65.7 months for CRT and 78.0 months for SBRT, the 5-year bPFS rates were 88.2% (95% confidence interval [95% CI]=76.6%-100%) for SBRT and 90.3% (95% CI=84.0%-97.1%) for CRT (P=0.9). Twenty-two (22.2%) patients in the CRT group and four (12.9%) in the SBRT group experienced grade ≥2 GU toxicities (P=0.258). For grade ≥2 GI toxicities, 29 (29.3%) patients in the CRT group and five (16.1%) in the SBRT group were affected (P=0.146). The incidence of these toxicities peaked between 2 and 3 years after treatment.

Conclusion: In this study, CRT and SBRT demonstrated comparable long-term effectiveness for low- to intermediate-risk prostate cancer; SBRT appeared to be associated with a non-significantly lower incidence of late GI and GU toxicities.