Evaluation of SharePlan

Abstract: Introduction: SharePlanTM is a new type of treatment planning system produced by RaySearch Laboratories AB for TomoTherapy Inc. SharePlan enables transfer of treatment plans generated with the TomoTherapy Hi∙Art® system to plans deliverable at conventional linacs. The main reason for this is to ensure continuous patient treatment if the TomoTherapy unit “goes down”, e.g. at clinics with only one TomoTherapy unit. The purpose of this work was to evaluate SharePlan. The work consists primarily of beam-commissioning and an in depth comparison between IMRT plans generated with SharePlan to IMRT plans generated with Oncentra MasterPlan (OMP) (Nucletron).Material and Methods: The beam commissioning involves input of general properties of the linac being modelled, importing measured profiles and depth dose curves for a specific energy and the auto-modelling of the beam properties. Some manual tuning of the model is required. To evaluate the accuracy of the beam-model the methods proposed by Venselaar et al. and by Palta et al. were used. To further check the beam-model; dose calculations performed in Shareplan were compared to calculations performed in OMP and measurements were conducted with MapCheckTM (Sun Nuclear Corporation, USA), at the commissioned linac. The quality of the plans generated in SharePlan were compared to the ones generated in OMP; for three cases with the use of Pareto optimal fronts, for eight clinical cases by letting radiation oncologists and physicist look at the generated plans and deciding which ones they prefer. The “efficient planning time” spent when generating plans for the clinical cases were compared for the different treatment planning systems. The experience needed for planning in the different treatment planning systems was considered.Results: The comparisons and measurements confirmed the accuracy of the beam-model. Plans generated in SharePlan were of equal or superior quality than plans generated with OMP for the three cases compared, using Pareto optimal fronts. For the eight clinical cases; the SharePlan generated plans were preferred over the plans generated in OMP. Planning in SharePlan was a lot faster than planning in OMP. The planning experience needed to generate high quality IMRT plans in SharePlan was minimal.Conclusions: SharePlan works well for making backup plans. It is extremely timesaving and easy to use. Based on the results of this dissertation, SharePlan should prove to be a very useful and time saving complement, especially for clinics having a single TomoTherapy unit among its conventional linacs.