SU-E-T-544: Commissioning and Clinical Evaluation of a Secondary Check Software for 3D Conformal and IMRT Treatment Plans.

PURPOSE The increasing complexities of the geometry of 3D radiation treatment plans possess challengesto the monitor unit (MU) and dose verification in clinical routine. In this work, the commissioningof the DIAMOND software (PTW-Freiburg Germany) for two Siemens linear accelerators(Primus & Artiste) along with the evaluation of its performance is described. METHODS DIAMOND employs the modified Clarkson integration method for dose computation and a pointeye-view (PEV) method for scatter calculation on collimators by a geometrical back-projectinginto the collimation system from the view of the source. During the commissioning process, themachine data (geometrical set up) and dosimetry base data such as the percentage depth dose(PDD), head scatter factor Sc as well as total scatter factor Sc,p, off-axis profiles are entered into the software. A comprehensive validation process is performed following the provided protocol.For evaluation purposes, twelve 3D conformal treatment plans and two prostate IMRT plans arecalculated with DIAMOND and the results are compared to the values from the treatmentplanning system (TPS). RESULTS The deviations of the MU for 3D conformal treatment plans computed with the DIAMONDsoftware are within ±3%. For IMRT plan verification, the dose at a point in the target volume iscomputed for every treatment beam, with deviations within 0.40% to 3.28%. The typical time forsingle dose point verification is less than a minute, thus minimizing the clinical workload of theverification process. For dose matrices calculation at certain plane, a relative longercomputation time is needed depending on a field dimension. CONCLUSIONS In this work, we have demonstrated the ability of the DIAMOND software to compute MU anddose at a point for 3D conformal and IMRT plans. Its speed and accuracy implies that DIAMOND can be implemented as independent secondary check software in the clinical routine.