A Self-Consistent Monte Carlo Validation Procedure for Hadron Cancer Therapy Simulation

Accelerated heavy ions (3He, 12C, among others) nowadays provide an advanced non-invasive procedure for radiotherapy of tumors with risky or impossible access, henceforth called Hadron Cancer Therapy (Kraft 1990), (Durante 2008). Moreover heavy-ion beams naturally optimize the physical depth-dose profile (known as Bragg curve) with an increased relative biological efficiency in the target volume that as a consequence minimizes damage in the healthy tissue. A further advantage of heavy ions over protons is the positron production from a by-product of nuclear reactions and subsequent decays (Pshenichnov et al. 2005), (Pshenichnov et al. 2006). Thus positron emission tomography (PET) allows for dose verification in real-time. The raster-scan technology was developed at the GSI facility (Gademann et al. 1990), (Kraft et al. 1991) and today is, and in the close future will be implemented in several cancer treatment centers all over Europe. While treatment planning in the pioneer stage of the developments was done by experiments with phantoms, in the consolidation phase these may be substituted by computerized treatment planning engines that make use of physical and radio-biological data obtained at GSI and other places. The state of the art so far permits us to treat skull base tumors and tumors close to the spinal chord (Debus et al. 2000), (Durante and Loeffler 2010), (Schardt et al. 2010).