Adjuvant High-Dose Intensity-Modulated Radiotherapy after Radical Prostatectomy for Prostate Cancer: Clinical Results in 104 Patients

• Published in: European urology 2009-10, Vol.56 (4), p.669-677
• Main Authors: Ost, Piet, Fonteyne, Valérie, Villeirs, Geert, Lumen, Nicolaas, Oosterlinck, Willem, De Meerleer, Gert
• Format: Article
• Language: English
• Subjects: Aged; Humans; Male; Middle Aged; Prostatectomy; Prostatic Neoplasms - radiotherapy; Prostatic Neoplasms - surgery; Radiotherapy Dosage; Radiotherapy, Adjuvant; Retrospective Studies; Treatment Outcome; Urology
• ISSN: 0302-2838; 1873-7560
• DOI: 10.1016/j.eururo.2009.05.041

Abstract Background Approximately 25% of patients treated with adjuvant radiotherapy (RT) will develop a biochemical failure within 5 yr after RT when doses of 60–64 Gray (Gy) are used. Objective To report on the safety and biochemical outcome of adjuvant intensity-modulated RT (IMRT) with doses >70 Gy. Design, setting, and participants Between 1999 and 2008, 104 patients underwent radical prostatectomy (RP) followed by adjuvant IMRT with or without androgen deprivation (AD) with a median follow-up of 36 mo. Indications for adjuvant IMRT were capsule perforation, seminal vesicle invasion (SVI) and/or positive surgical margins at prostatectomy specimen. All patients were irradiated at a single tertiary academic centre. AD was initiated on the basis of SVI, a preprostatectomy prostate-specific antigen level >20 ng/ml, Gleason score ≥4 + 3 ( n = 36), or personal preference of the referring urologist ( n = 32). Intervention A median dose of 74 Gy was prescribed to the planning target volume using IMRT in all patients. AD consisted out of a luteinising hormone-releasing hormone analogue for 6 mo. Measurements We report on acute and late toxicity, biochemical relapse–free survival (bRFS), and clinical progression. The Kaplan-Meier method was used to estimate bRFS. Univariate analysis was used to examine the influence of patient- and treatment-related factors on bRFS. Results and limitations With respect to acute toxicity, no patients developed grade 3 gastrointestinal (GI) toxicity, and eight patients developed grade 3 genitourinary (GU) toxicity (8%). With respect to late toxicity, no patients developed grade 3 GI toxicity, and four patients (4%) developed grade 3 GU toxicity. A urethral stricture was observed in six patients (6%). The 3- and 5-yr actuarial bRFS was 93%. On univariate analysis, bRFS rates were worse when SVI ( p < 0.02), Gleason score ≥4 + 3 ( p < 0.02), or negative surgical margins ( p < 0.02) were present. AD did not influence bRFS. Six patients had a clinical relapse. Conclusions Adjuvant high-dose IMRT after prostatectomy is safe and bRFS is excellent.