Prospective economic evaluation of image-guided radiation therapy for prostate cancer in the framework of the national programme for innovative and costly therapies assessment

Purpose. - The main objective of the economical study was to prospectively and randomly assess the additional costs of daily versus weekly patient positioning quality control in image-guided radiotherapy (IGRT), taking into account the modalities of the 3D-imaging: tomography (CBCT) or gold seeds implants. A secondary objective was to prospectively assess the additional costs of 3D versus 2D imaging with portal imaging for patient positioning controls. Patients and methods. - Economics data are issued from a multicenter randomized medico-economics trial comparing the two frequencies of patient positioning control during prostate IGRT. A prospective cohort with patient positioning control with PI (control group) was constituted for the cost comparison between 3D (IGRT) versus 2D imaging. The economical evaluation was focused to the radiotherapy direct costs, adopting the hospital's point of view and using a micro-costing method applied to the parameters that may lead to cost differences between evaluated strategies. Results. - The economical analysis included a total of 241 patients enrolled between 2007 and 2011 in seven centres, 183 in the randomized study (128 with CBCT and 55 with fiducial markers) and 58 in the control group. Compared to weekly controls, the average additional cost per patient of daily controls was euros 847 (CBCT) and euros 179 (markers). Compared to PI, the average additional cost per patient was euros 1392 (CBCT) and euros 997 (fiducial markers) for daily controls; euros 545 (CBCT) and euros 818 (markers) in case of weekly controls. Conclusion. - A daily frequency for image control in IGRT and 3D images patient positioning control (IGRT) for prostate cancer lead to significant additional cost compared to weekly control and 2D imaging (PI). Long-term clinical assessment will permit to assess the medico-economical ratio of these innovative radiotherapy modalities. (authors)