Room: ePoster Forums
Purpose: To compare intensity-modulated proton therapy (IMPT) plans generated by the in-house developed treatment planning system (TPS) (Solo) and our commercial TPS (cTPS) for advanced stage non-small cell lung carcinoma (NSCLC).
Methods: We selected 6 lung cancer patients. Two IMPT plans were created using multi-field optimization (MFO) in Solo and cTPS. The plans were designed to deliver the prescription doses to internal target volumes (ITV) on averaged 4D-CTs. Solo plans were imported back to cTPS and recalculated to get the final dose distributions in cTPS for fair comparison. Both plans of each patient were further verified in inhalation and exhalation phases and all plans met the clinical requirements. Plan robustness on all phases was quantified using dose-volume-histograms (DVH) band method. Interplay effects were evaluated by the in-house developed software for every plan, which randomized starting phases of each field per fraction. DVH indices were compared using Wilcoxon rank sum test.
Results: Compared to plans generated by cTPS, in the nominal scenario Solo plans delivered significantly lower esophagus V60Gy[RBE] and cord Dmax with better plan robustness in target coverage, homogeneity, and hot spots. In inhalation and exhalation phases, Solo plans had better ITV coverage and cord Dmax with comparable plan robustness. In term of interplay effects, Solo plans had statistically better target coverage, hot spots, homogeneity, and lower cord Dmax.
Conclusion: Solo was able to generate IMPT plans of higher quality, better or comparable plan robustness in exhalation and inhalation phases, and reduced interplay effects. The approximations used in our commercial TPS might lead to suboptimal IMPT plans for lung cancer patients.
Not Applicable / None Entered.