Background
Salvage radiotherapy (SRT) is utilized for biochemical progression of prostate cancer after radical prostatectomy (RP).
Objective
To report the outcomes of the SAKK 09/10 trial comparing conventional and dose-intensified SRT.
Design, setting, and participants
SAKK 09/10 was a randomized, multicenter, phase 3 trial that recruited men with biochemical progression after RP.
Intervention
Patients were randomly assigned to conventional-dose (64 Gy) or dose-intensified SRT (70 Gy) to the prostate bed without hormonal therapy.
Outcome measurements and statistical analysis
The primary endpoint was freedom from biochemical progression (FFBP). Secondary endpoints included clinical progression-free survival (PFS), time to hormonal treatment, overall survival (OS), acute and late toxicity (Common Terminology Criteria for Adverse Events v4.0), and quality of life (QoL).
Results and limitations
Between February 2011 and April 2014, 350 patients were randomly assigned to 64 Gy (n = 175) or 70 Gy (n = 175). Median prostate-specific antigen at randomization was 0.3 ng/ml. After median follow-up of 6.2 yr, the median FFBP was 8.2 yr in the 64 Gy arm and 7.6 in the 70 Gy arm (log-rank p = 0.4), with a hazard ratio of 1.14 (95% confidence interval 0.82–1.60). The 6-year FFBP rates were 62% and 61%, respectively. No significant differences in clinical PFS, time to hormonal treatment, or OS were observed. Late grade 2 and 3 genitourinary toxicity was observed in 35 (21%) and 13 (7.9%) patients in the 64 Gy arm, and 46 (26%) and seven (4%) in the 70 Gy arm, respectively (p = 0.8). Late grade 2 and 3 gastrointestinal toxicity was observed in 12 (7.3%) and seven patients (4.2%) in the 64 Gy arm, and 35 (20%) and four (2.3%) in the 70 Gy arm, respectively (p = 0.009). There were no significant differences in QoL.
Conclusions
Conventional-dose SRT to the prostate bed is sufficient in patients with early biochemical progression of prostate cancer after RP.
