Abstract：
This study aimed to investigate whether the RapidPlan (RP) model configured by volumetric modulated arc therapy (VMAT) plans of nasopharyngeal carcinoma (NPC) could be used to assist in the optimization of HT plans and improve their quality. An RP model was trained using 100 clinically accepted VMAT plans of NPC patients. The predicted dose constraints of the VMAT trained RP model were used to reoptimize 25 consecutive clinically accepted HT plans (HT_clinical) and perform new VMAT plans based on the same computed topography (CT). The dosimetric quality of the reoptimized HT plans (HT_reoptimized), HT_clinical, and VMAT group were compared. The minimum dose encompassing 2% target (D2%), the minimum dose encompassing 98% target (D98%), homogeneity index (HI) and conformity index (CI) were similar for most targets between the HT_clinical and HT_reoptimized plans, although certain targets in the HT_reoptimized plans had higher D2% and HI and lower D98%. The HT_reoptimized plans outperformed the HT_clinical plans in the Dmax and D1cc of the spinal cord, V40Gy of the left temporal lobe, Dmean and V30Gy of the oral cavity, Dmean of the larynx and thyroid, and the differences were statistically significant. HT plans had higher CI and HI than VMAT plans. HT plans outperformed VMAT plans in the Dmax of the spinal cord and lenses, V30Gy of the oral cavity and parotids, and V40Gy of the temporal lobes, but underperformed in the Dmax and D1cc of the brainstem, D1cc of the spinal cord and Dmean of the oral cavity. The VMAT-based RP model can be used to assist in the planning of HT plans and improve the dosimetry quality of HT plans.
摘要：
本研究旨在探讨由鼻咽癌（NPC）的体积调制电弧治疗（VMAT）计划配置的RapidPlan（RP）模型是否可用于辅助HT计划的优化并提高其质量。使用100名临床接受的NPC患者的VMAT计划训练RP模型。VMAT训练的RP模型的预测剂量约束用于重新优化25个连续的临床接受的HT计划(HT_clinical),并基于相同的计算形貌(CT)执行新的VMAT计划。重新优化的HT计划(HT_重新优化)的剂量学质量，HT_临床，与VMAT组进行比较。包含2%目标的最小剂量(D2%)，包含98%目标的最小剂量（D98%），在HT_临床和HT_重新优化计划之间，大多数目标的同质性指数(HI)和符合性指数(CI)相似，尽管HT_重新优化计划中的某些目标具有较高的D2％和HI和较低的D98％。在脊髓的Dmax和D1cc中，HT_重新优化的计划优于HT_临床计划，左颞叶V40Gy,Dmean和V30Gy的口腔，喉和甲状腺的均值，差异有统计学意义。HT计划的CI和HI高于VMAT计划。HT计划在脊髓和晶状体的Dmax中优于VMAT计划，口腔和腮腺的V30Gy，颞叶的V40Gy，但是在脑干的Dmax和D1cc中表现不佳，脊髓的D1cc和口腔的Dmean。基于VMAT的RP模型可用于辅助HT计划的规划,提高HT计划的剂量学质量。
