Hypofractionated radiotherapy as salvage for rising prostate-specific antigen after radical prostatectomy

Abstract

To review the outcome of men receiving hypofractionated salvage radiotherapy for rising prostate-specific antigen (PSA) after radical prostatectomy. A retrospective analysis of 61 men referred for salvage radiotherapy for biochemical relapse after radical prostatectomy was conducted. Twenty-four men receiving hormonal therapy or with follow-up of less than 12 months were excluded. Thirty-seven men were identified, median age 64 years, median preoperative PSA 11 ng/ml (5.6-60 ng/ml), Gleason scores <7: 70%, Gleason scores > or = 7: 30%. Twenty-seven men had positive surgical resection margins, eight had seminal-vesicle involvement and one had lymph-node involvement. Diagnosis of failure after radical prostatectomy was made on rising PSA in all cases; 19 men also had positive magnetic resonance imaging, 11 abnormal digital rectal examination and nine positive biopsy. Radiotherapy was delivered conformally to the prostatic fossa, 50-52.5 Gy in 20 fractions over 4 weeks. Date of failure after radiotherapy was defined by the American Society for Therapeutic Radiology and Oncology (ASTRO) consensus criteria or as date of commencement of hormonal therapy for rising PSA. Median time from radical prostatectomy to radiotherapy was 30.6 months (8-68 months); median pre-radiotherapy PSA was 2.9 ng/ml (0.5-11.4 ng/ml). PSA response after radiotherapy was seen in 33 out of 37 (89%) patients. At median follow-up of 36 months (20-85 months), 28 out of 37 remained disease-free. Thirteen more patients have had two consecutive PSA rises. Actuarial 3-year disease-free survival is 74%. No patient has developed metastases or died of prostate cancer. Pre-radiotherapy PSA less than 2 ng/ml predicted disease-free survival (P = 0.027). No acute toxicity greater than Radiation Therapy Oncology Group (RTOG) G2 was observed. Salvage radiotherapy after radical prostatectomy achieved durable biochemical control in most patients. Outcome is improved if radiotherapy is delivered when PSA is less than 2 ng/ml. A policy of close monitoring after radical prostatectomy with early referral for salvage radiotherapy is advocated.