Session Item

Saturday
August 01
11:40 - 12:00
Training The Next Generation of Brachytherapists
465
Plenary Session
14:23 - 14:31
Radiotherapy of prostate cancer:impact of treatment characteristics on the incidence of second tumor
PH-0648

Abstract

Radiotherapy of prostate cancer:impact of treatment characteristics on the incidence of second tumor
Authors: Cammelli|, Silvia(1)*[silvia.cammelli2@unibo.it];Ntreta|, Maria(1);Scirocco|, Erica(1);Macchia|, Gabriella(2);Deodato|, Francesco(2);Bisello|, Silvia(1);Siepe|, Giambattista(1);Alitto|, Anna Rita(3);Cilla|, Savino(4);Valentini|, Vincenzo(3);Morganti|, Alessio Giuseppe(1);Buwenge|, Milly(1);
(1)Radiation Oncology Center, Department of Experimental- Diagnostic and Specialty Medicine - DIMES-Azienda Ospedaliera-Universitaria S.Orsola-Malpighi, Bologna, Italy;(2)Fondazione "Giovanni Paolo II", UO di Radioterapia- Università Cattolica del Sacro Cuore, Campobasso, Italy;(3)Fondazione Policlinico Universitario A. Gemelli- IRCCS, UOC di Radioterapia- Dipartimento di Scienze Radiologiche- Radioterapiche ed Ematologiche, Roma, Italy;(4)Fondazione "Giovanni Paolo II", UO di Fisica Sanitaria- Università Cattolica del Sacro Cuore, Campobasso, Italy;
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Purpose or Objective

It has been hypothesized that radiotherapy (RT) techniques delivering radiations to larger volumes (IMRT, VMAT) are potentially associated with a higher risk of second primary tumors. The aim of this study was to analyse the impact of RT technique (3D-CRT vs IMRT/VMAT) on the incidence of second tumors in prosate cancer (PCa) patients.  

Material and Methods

A retrospective study on 2526 previously irradiated PCa patients was performed. Patients were treated with 3D-CRT (21.3%), IMRT (68.1%), or VMAT (10.6%). Second tumors incidence was analysed in 3 categories: pelvic, pelvic and abdominal, and “any site”. The correlation with RT technique was analysed using log-rank test and Cox’s proportional hazard method.

Results

With a median follow-up of 72 months (range: 9-185), 92 (3.6%) cases of second tumors were recorded with 48 months (range: 9-152) median interval from RT. Actuarial 10-year second tumor free survival (STFS) was 87.3%. Ten-year STFS in patients treated with 3D-CRT and IMRT/VMAT was 85.5% and 84.5%, respectively (p: .627). A significantly higher 10-year cumulative incidence of second tumors in the pelvis was registered in patients treated with IMRT/VMAT compared to 3D-CRT (10.7% vs 6.0%; p: .033). This lower incidence of second pelvic cancers in patients treated with 3D-CRT was confirmed at multivariable analysis (HR: 2.42, 95%CI: 1.07-5.47, p: .034). 

Conclusion

The incidence of second pelvic tumors after RT of PCa showed a significant correlation with treatment technique. Further analyses in larger series with prolonged follow-up are needed to confirm these results.