Modelling of organ-specific radiation-induced secondary cancer risks following particle therapy.

Radiation-induced cancer is a serious late effect that may follow radiotherapy. A considerable uncertainty is associated with carcinogenesis from photon-based treatment, and even less established when including relative biological effectiveness (RBE) for particle therapy. The aim of this work was therefore to estimate and in particular explore relative risks (RR) of secondary cancer (SC) following particle therapy as applied in treatment of prostate cancer.

RRs of radiation-induced SC in the bladder and rectum were estimated using a bell-shaped dose-response model incorporating RBE and fractionation effects. The risks from volumetric modulated arc therapy (VMAT) were compared to intensity-modulated proton therapy (IMPT) and scanning carbon ions for ten patients.

The mean estimated RR (95% CI) of SC for VMAT/C-ion was 1.31 (0.65-2.18) for the bladder and 0.58 (0.41-0.80) for the rectum. Corresponding values for VMAT/IMPT were 1.72 (1.06-2.37) and 1.10 (0.78-1.43). The radio-sensitivity parameter α had the strongest influence on the results with decreasing RR for increasing values of α.

Based on the wide spread in RR between patients and variations across the included parameter values, the risk profiles of the rectum and bladder were not dramatically different for the investigated radiotherapy techniques.

Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology. 2016 Jul 13 [Epub ahead of print]

Camilla H Stokkevåg, Mai Fukahori, Takuma Nomiya, Naruhiro Matsufuji, Grete May Engeseth, Liv B Hysing, Kristian S Ytre-Hauge, Eivind Rørvik, Artur Szostak, Ludvig P Muren

Department of Oncology and Medical Physics, Haukeland University Hospital, Bergen, Norway; Department of Physics and Technology, University of Bergen, Norway. Electronic address: ., Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba, Japan., Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba, Japan; Department of Radiation Oncology, Kanagawa Cancer Center, Yokohama, Japan., Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba, Japan., Department of Oncology and Medical Physics, Haukeland University Hospital, Bergen, Norway., Department of Oncology and Medical Physics, Haukeland University Hospital, Bergen, Norway., Department of Physics and Technology, University of Bergen, Norway., Department of Physics and Technology, University of Bergen, Norway., Department of Physics and Technology, University of Bergen, Norway., Department of Medical Physics, Aarhus University/Aarhus University Hospital, Denmark.

E-Newsletters

Newsletter subscription

Free Daily and Weekly newsletters offered by content of interest

The fields of GU Oncology and Urology are rapidly advancing. Sign up today for articles, videos, conference highlights and abstracts from peer-review publications by disease and condition delivered to your inbox and read on the go.

Subscribe