ESTRO 2020 Abstract Book

S788 ESTRO 2020

based on the benchmark dose calculated by the integrated Feasiblity module from PlanIQ, Sun Nuclear. The clinical Auto-Planning template was used as starting point for personalized planning, where we set the dose volume histogram (DVH) parameters for rectal wall, anal wall based on feasibility-value (F-value) of 0 and for the bladder an F-value of 0.1. A stop-watch was used to measure the total planning time. Results We compared the plan quality for 10 prostate plan cases using our current automated planning and personalized automated planning. All plans met the clinical criteria. The planning time is reduced from 30 min to about 10 min for each case using personalised planning including some warm restarts for PTV coverage. Figure 1 shows an example of the current and new dose distribution and the DVH results.

Table 1: Differences in mean dose, percentages for 30 Gy and 60 Gy volumes for rectal wall, anal wall and bladder and monitor units (MUs). Positive values indicate that these dose metric values were improved compared to the clinical plan. The average mean dose to the rectal wall and bladder were improved with 2.8 and 2.0 Gy, respectively. The average V30 and V60 for the rectal wall was improved with 3.4% and 0.8%, respectively. The other dose metrics did not significantly improve. The MUs were slightly higher and were on average 728 MUs. Conclusion We showed that this GIDD application can be used to improve the plan quality by using a personalized template technique for VMAT prostate cases. The application is independent of the TPS applied and can be used for all different sites. Reference 1. Kentaro et al. Medica 2019 57:115-122. PO-1470 Personalized Planning for prostate radiotherapy in Pinnacle Evolution improves planning efficiency M. Kusters 1 , L. Bouwmans 2 , K. Bzdusek 2 , P. Van Kollenburg 1 , L. Abbenhuis 1 , R.J. Smeenk 1 , R. Monshouwer 1 1 Radboud university medical center, Radiation Oncology, Nijmegen, The Netherlands ; 2 Philips Healthcare, Radiation Oncology Solutions, Fitchburg, USA Purpose or Objective In this study we compare our current automated planning approach for volumetric art therapy (VMAT) prostate radiotherapy plans, using a single treatment technique template in the Auto-Planning module in Pinnacle 16.0.2 (Philips Healthcare, Fitchburg, WI, USA), with automated planning algorithms in Personalized Planning in Pinnacle Evolution. We investigate the plan quality and planning efficiency of Data of 10 automatically generated clinical prostate patient dose-plans were used to compare the single template technique with the personalized template optimization. In all these plans two VMAT arcs were used (95 to 265 o ) CW and CCW, to deliver 70 Gy in 28 fractions of 2.5 Gy. For the current single template technique for the Auto-Planning module objectives for organs at risk (OARs) that are dictated by the clinical goals were used. In Pinnacle Evolution a personalized template can be made the plans in this study. Material and Methods

Figure 1 shows the axial dose distribution and DVHs between current auto-planning (solid line) and new personalized automated planning (dashed lines) approach. The plan quality between clinical plans and the personalized plans are comparable in general. Table 1 shows the differences for all cases for each OAR.