Phase II multi-institutional clinical trial on a new mixed beam RT scheme of IMRT on pelvis combined with a carbon ion boost for high-risk prostate cancer patients.

Definition of the optimal treatment schedule for high-risk prostate cancer is under debate. A combination of photon intensity modulated radiotherapy (IMRT) on pelvis with a carbon ion boost might be the optimal treatment scheme to escalate the dose on prostate and deliver curative dose with respect to normal tissue and quality of dose distributions. In fact, carbon ion beams offer the advantage to deliver hypofractionated radiotherapy (RT) using a significantly smaller number of fractions compared to conventional RT without increasing risks of late effects.

This study is a prospective phase II clinical trial exploring safety and feasibility of a mixed beam scheme of carbon ion prostate boost followed by photon IMRT on pelvis. The study is designed to enroll 65 patients with localized high-risk prostate cancer at 3 different oncologic hospitals: Istituto Europeo di Oncologia, Fondazione IRCCS Istituto Nazionale dei Tumori, and Centro Nazionale di Adroterapia Oncologica. The primary endpoint is the evaluation of safety and feasibility with acute toxicity scored up to 1 month after the end of RT. Secondary endpoints are treatment early (3 months after the end of RT) and long-term tolerability, quality of life, and efficacy.

The study is not yet recruiting; in silico studies are ongoing and we expect to start recruitment by 2017.

The present clinical trial aims at improving the current treatment for high-risk prostate cancer, evaluating safety and feasibility of a new RT mixed-beam scheme including photons and carbon ions. Encouraging results are coming from carbon ion facilities worldwide on the treatment of different tumors including prostate cancers. Carbon ions combine physical properties allowing for high dose conformity and advantageous radiobiological characteristics. The proposed mixed beam treatment has the advantage to combine a photon high conformity standard of care IMRT phase with a hypofractionated carbon ion RT boost delivered in a short overall treatment time.

Tumori. 2016 Dec 02 [Epub ahead of print]

Giulia Marvaso, Barbara A Jereczek-Fossa, Barbara Vischioni, Delia Ciardo, Tommaso Giandini, Azusa Hasegawa, Federica Cattani, Mauro Carrara, Mario Ciocca, Nice Bedini, Sergio Villa, Sara Morlino, Stefania Russo, Dario Zerini, Sarah Pia Colangione, Costanza Maria Vittoria Panaino, Cristiana Fodor, Luigi Santoro, Emanuele Pignoli, Francesca Valvo, Riccardo Valdagni, Ottavio De Cobelli, Roberto Orecchia

Department of Radiotherapy, European Institute of Oncology, Milan - Italy., Clinical Division, National Center of Oncological Hadrontherapy, Pavia - Italy., Medical Physics, Fondazione IRCCS Istituto Nazionale Tumori, Milan - Italy., Department of Medical Physics, European Institute of Oncology, Milan - Italy., Medical Physics Division, National Center of Oncological Hadrontherapy, Pavia - Italy., Division of Radiation Oncology, IRCCS Istituto Nazionale Tumori, Milan - Italy., Department of Epidemiology and Biostatistics, European Institute of Oncology, Milan - Italy., Department of Urology, European Institute of Oncology, Milan - Italy., Scientific Direction, European Institute of Oncology, Milan - Italy.