Intraoperative radiotherapy for locally advanced prostate cancer: The experience of the European institute of oncology

INTRODUCTION AND OBJECTIVE: To present the technique adopted for intraoperative radiotherapy (IORT) for locally advanced prostate cancer. METHODS: Between June 2005 and February 2007, 24 patients (pts) with non-metastatic prostate cancer were treated with IORT before prostatectomy as part of their surgical procedure. Median DJHZDV\HDUVUDQJH7HQSWVZHUHFODVVL¿HGDV 7FSWVDV•77KHPHGLDQL36$ZDVQJPODQGWKH median bioptic Gleason Score was 7. According to NCCN 2007, risk group distribution was as follows: intermediate risk 2 pts (8.33%) and high risk 22 pts (91.67%). A total of 11 pts (45.83%) were treated with neoadjuvant hormones. Immediately before IORT prostate dimensions and rectum depth were measured with intraoperative ultrasound. IORT was delivered by a mobile linear accelerator in the operating room. The prescribed dose was 12 Gy at the 90% isodose. In vivo dosimetry was performed. Three months later, postoperative external beam radiotherapy (EBRT) of 45-50,4 Gy in 25-28 fractions was prescribed to the prostatic bed alone and whole pelvis in case of pT3-4 pN0 and pN1, respectively. RESULTS: According to the MSKCC nomograms, the mean SUHRSHUDWLYHSUREDELOLW\RIRUJDQFRQ¿QHGGLVHDVHH[WUDFDSVXODUGLVHDVH and lymph node involvement were 8%, 40% and 25% respectively. 3RVWRSHUDWLYHKLVWRORJLFDO¿QGLQJVZHUHDVIROORZVPHGLDQ*6UDQJH 6-9), pT2 7 pts (29,2%), pT3 14 pts (58,3), pT4 3 (12,5%), pN0 12 pts, S1SWV2UJDQFRQ¿QHGGLVHDVHS7S15ZDVGLDJQRVHGLQ pts (16.6%) and no further radiation treatment was prescribed. Based RQWKHGH¿QLWLYHKLVWRORJLFDOUHSRUWVSRVWRSHUDWLYHSHOYLFDQGSURVWDWLF bed EBRT is planned in 12 and 8 pts, respectively. After a median follow up of 9.2 months (range 3.3-15.7) only 1 patient had evidence of biochemical relapse. No patients had major acute rectal toxicity. No acute urinary toxicity was observed in 6 patients, 17 patients had G1 toxicity. No increased risk of urinary incontinence was recorded. CONCLUSIONS: IORT delivered before prostatectomy appeared a feasible and safe approach for prostate cancer, showing a satisfactory dose coverage to the prostate bed with relatively low rectal wall dose. Longer follow-up is needed to evaluate late toxicity and clinical control.