Acute Toxicity And Early Quality Of Life After Dose Intensified Salvage Radiotherapy For Biochemically Recurrent Prostate Cancer After Prostatectomy: First Results Of The Randomized Trial Sakk 09/10.

5038 Background: Patients (pts) with biochemical recurrence after radical prostatectomy may benefit from dose intensified salvage radiotherapy (RT) of the prostate bed. We performed a randomized phase III trial assessing dose intensification. In this first report we report acute toxicity and early quality of life (QoL). Methods: Pts with biochemical recurrence but without evidence of macroscopic disease were enrolled in this randomized phase III trial. Pts were randomly assigned to either 64 Gy (32 daily fractions) or 70 Gy (35 daily fractions). Three-dimensional conformal RT (3D-CRT) or intensity-modulated RT (IMRT, or equivalent rotational techniques) were accepted techniques. The primary endpoint was freedom from biochemical recurrence. Secondary endpoints included acute toxicity according to the CTCAE v4.0 and QoL using the EORTC QLQ-C30 and PR25. Results: We enrolled 350 pts between 02/2011 and 04/2014. Three pts withdrew consent and three were not eligible, resulting in 344 pts in the safety population. Thirty (8.7%) and two (0.6%) pts had grade 2 and 3 genitourinary (GU) baseline symptoms. Acute grade 2 and 3 GU toxicity was observed in 22 (13.0%) and 1 (0.6%) with 64 Gy and 29 (16.6%) and 3 (1.7%) with 70 Gy, being not significantly different (p = 0.2). Baseline grade 2 gastrointestinal (GI) toxicity was observed in 1 (0.6%) patient. No baseline grade 3 GI toxicity was observed. Acute grade 2 and 3 GI toxicity was observed in 27 (16.0%) and 1 (0.6%) with 64 Gy and 27 (15.4%) and 4 (2.3%) with 70 Gy, again not significantly different (p = 0.8). Changes in QoL were marginal. However, pts receiving 70 Gy reported a more pronounced and clinically relevant worsening in urinary symptoms (mean difference between arms 3.6, p = 0.02). There was no significant difference between 3D-CRT and IMRT/rotational techniques. Conclusions: Dose-intensified salvage RT was associated with a low rate of grade 2 and 3 GU and GI toxicities. The impact of dose intensified salvage RT on QoL was marginal, with the exception of a worsening in urinary symptoms after 70 Gy. Clinical trial information: NCT01272050.