Salvage intensity-modulated radiotherapy for rising PSA after radical prostatectomy

IntroductionThe aim was to prospectively evaluate both acute and late toxicity and biochemical non-evidence of disease (bNED) in patients treated with salvage intensity-modulated radiotherapy (IMRT) ± androgen deprivation (AD) for biochemical relapse after radical prostatectomy (RP).Materials and methodsIMRT was prescribed to a mean prescription dose to the planning target volume (PTV) of 75 Gy to be delivered in 37 fractions of 2 Gy. In total, 135 patients were treated with IMRT. Median age was 64 years. Median PSA level was 0.8 ng/ml. AD was initiated in 94 patients. Indications were perineural invasion, seminal vesicle invasion or Gleason score ⩾8 at RP.(1) Acute toxicity (n = 135). All patients were available for this analysis. Acute toxicity was scored using an in-house developed scoring system.(2) Late toxicity (n = 68). Only patients with a follow-up of at least 18 months were considered for late toxicity analysis. The RILIT score was used to register gastro-intestinal (GI) toxicity. An in-house developed scale was used to register genito-urinary (GU) toxicity.(3) bNED (n = 87). For bNED, all AD-naive patients (n = 38) together with the AD-positive patients with a follow-up ⩾18 months (n = 49) were considered.Factors influencing the results of salvage treatment were analyzed.Results(1) Acute toxicity (n = 135). No patient developed grade 3 GI toxicity. We observed grade 2 toxicity in 20 patients. Four patients developed grade 3 GU toxicity.(2) Late toxicity (n = 68). One patient developed grade 3 rectal blood loss. One patient developed grade 3 anal pain (anal fissure). We observed grade 2 GI toxicity in 9 patients. Two patients developed grade 3 GU toxicity. Twenty-one patients developed grade 2 GU toxicity. We observed an urethral stricture in 5 patients.(3) bNED (n = 87). The 3- and 5-year bNED was 67%. Gleason score at RP, perineural invasion and capsular perforation were significant predictors for bNED. PSA before IMRT (<1.0 vs. ⩾1.0 ng/ml) showed a trend in predicting bNED (p = 0.08).ConclusionIMRT to 75 Gy ± AD can be delivered with low levels of acute and late toxicity. In patients without perineural invasion and capsular invasion and with a Gleason score ⩽7 (3 + 4), IMRT offers very good 5-years bNED.