Monte Carlo validation of EYEPLAN proton therapy treatment planning

Protons, thanks to their physical features, offer the dosimetric advantage of an highly conformal dose region and the possibility of covering the tumor volume with an elevated accuracy. On the other hand, their precision has to match with the accuracy in the patient positioning and in the dose distributions calculated by the Treatment Planning Systems (TPSs). One of the major application of proton therapy is the treatment of ocular melanoma. In this case the software EYEPLAN is commonly adopted as TPS. In this work we verified the EYEPLAN dose calculations via the GEANT4 Monte Carlo toolkit quantitatively evaluating the agreement between dose distribution curves. The generally accepted parameters, as Distance to Agreement (DTA) and Dose Difference (DD), were adopted for the comparisons. The maximum differences between profiles were 5% for the Dose Difference and 1.2 mm for the Distance To Agreement. These results eventually demonstrated that a Monte Carlo approach can be considered the most accurate method to verify the dose distribution planned by a TPS.