SU-F-T-597: Modeling and Evaluation of RapidPlan for Simultaneous Integrated Boost NPC Cases




The evaluation of using RapidPlan to generate the model of simultaneous integrated boost (SIB) VMAT plans for nasopharyngeal carcinoma (NPC).


In this study, the training models were established for SIB NPC cases in RadpidPlan system. The knowledge database was created from 46 VMAT plans for NPC with two dose level targets. CTV212 received 69.96 Gy in 33 fractions at 2.12 Gy per fraction. PTV164 received 54.12 Gy at 1.64 Gy per fraction. To validate the models, we generated plans with model-estimated objectives on four new NPC cases that were not included in the model-training database. Among these four cases, there were two cases with advanced stage NPC, which the targets invaded into eye level region. A comparison of results between the models and the clinical treatment plans were analyzed.


For typical cases, the model plans resulted in slightly superior V95% of targets than the clinical treatment plans by up to 2%. Conformity indices for targets were 1.05 and 1.22 for clinical and model plans, respectively. Homogeneity indices for targets were 1.25 and 1.21 for clinical and model plans, respectively. For advanced stage cases, the results of clinical treatment plans had better V95% coverage of targets than that of model plans by approximately 3%. Conformity indices for targets were 1.19 and 1.21, for clinical and model plans, respectively. Homogeneity indices for targets were 1.36 and 1.15 for clinical plans and model plans, respectively. In general, there was no significant difference between model and clinical plans observed.


RapidPlan models are powerful dynamic tools to meet the clinical needs. It is user-friendly and allows for standardization of planning process. This approach has the potential to improve the efficiency of the treatment planning process while ensuring that good quality plans are developed.