比较多个肺部病变的立体定向全身放射治疗(SBRT)中体积调制电弧治疗(VMAT)和强度调制质子治疗(IMPT)的剂量学差异,并确定基于正常组织并发症概率(NTCP)模型的决策策略,以确定患者将使用哪种治疗方式。回顾性选择了41例患者进行本研究。1-6个病灶的患者数分别为5、16、7、6、3和4。对每个病变给予10分的70个GyRBE的处方剂量。使用VMAT和IMPT生成SBRT计划。所有的IMPT计划使用具有±3.5%范围不确定性和5mm设置不确定性的鲁棒性优化。放射性肺炎(RP)的剂量学指标和预测的NTCP值,食管炎,分析了心包炎和心包炎,以评估不同计划组之间的潜在临床获益.此外,使用受试者工作特征曲线确定PTV与肺比率的阈值(%),以确定患者是否会从IMPT中获益。所有计划均达到目标覆盖率(V70GyRBE≥95%)。与VMAT相比,IMPT导致大多数胸部正常组织的剂量显着降低。对于1-2、3-4和5-6病变组,肺V5为29.90±9.44%,58.33±13.35%,VMAT为81.02±5.91%,11.34±3.11%(p<0.001),21.45±3.80%(p<0.001),IMPT为32.48±4.90%(p<0.001),分别。肺V20为12.07±4.94%,25.57±6.54%,VMAT和43.99±11.83%,6.76±1.80%(p<0.001),13.14±2.27%(p<0.01),IMPT为19.62±3.48%(p<0.01)。全肺的Dmean为7.65±2.47GyRBE,14.78±2.75GyRBE,VMAT和21.64±4.07GyRBE,3.69±1.04GyRBE(p<0.001),7.13±1.41GYRBE(p<0.001),IMT为10.69±1.81GyRBE(p<0.001)。此外,在VMAT组中,放射性肺炎的最大NTCP值为73.91%,而IMPT组则显著较低,为10.73%。我们基于NTCP模型的决策模型的准确性,结合了病变数量和PTV/肺(%),为97.6%。该研究表明,MPTSBRT对多发性肺病变的剂量学结果令人满意,即使病变数量达到6。我们研究中提出的基于NTCP模型的决策策略可以作为临床实践中的有效工具。帮助选择VMAT和IMPT之间的最佳治疗方式。
To compare the dosimetric differences in volumetric modulated arc therapy (VMAT) and intensity modulated proton therapy (IMPT) in stereotactic body radiation therapy (SBRT) of multiple lung lesions and determine a normal tissue complication probability (NTCP) model-based decision strategy that determines which treatment modality the patient will use. A total of 41 patients were retrospectively selected for this study. The number of patients with 1-6 lesions was 5, 16, 7, 6, 3, and 4, respectively. A prescription dose of 70 GyRBE in 10 fractions was given to each lesion. SBRT plans were generated using VMAT and IMPT. All the IMPT plans used robustness optimization with ± 3.5% range uncertainties and 5 mm setup uncertainties. Dosimetric metrics and the predicted NTCP value of radiation pneumonitis (RP), esophagitis, and pericarditis were analyzed to evaluate the potential clinical benefits between different planning groups. In addition, a threshold for the ratio of PTV to lungs (%) to determine whether a patient would benefit highly from IMPT was determined using receiver operating characteristic curves. All plans reached target coverage (V70GyRBE ≥ 95%). Compared with VMAT, IMPT resulted in a significantly lower dose of most thoracic normal tissues. For the 1-2, 3-4 and 5-6 lesion groups, the lung V5 was 29.90 ± 9.44%, 58.33 ± 13.35%, and 81.02 ± 5.91% for VMAT and 11.34 ± 3.11% (p < 0.001), 21.45 ± 3.80% (p < 0.001), and 32.48 ± 4.90% (p < 0.001) for IMPT, respectively. The lung V20 was 12.07 ± 4.94%, 25.57 ± 6.54%, and 43.99 ± 11.83% for VMAT and 6.76 ± 1.80% (p < 0.001), 13.14 ± 2.27% (p < 0.01), and 19.62 ± 3.48% (p < 0.01) for IMPT. The Dmean of the total lung was 7.65 ± 2.47 GyRBE, 14.78 ± 2.75 GyRBE, and 21.64 ± 4.07 GyRBE for VMAT and 3.69 ± 1.04 GyRBE (p < 0.001), 7.13 ± 1.41 GyRBE (p < 0.001), and 10.69 ± 1.81 GyRBE (p < 0.001) for IMPT. Additionally, in the VMAT group, the maximum NTCP value of radiation pneumonitis was 73.91%, whereas it was significantly lower in the IMPT group at 10.73%. The accuracy of our NTCP model-based decision model, which combines the number of lesions and PTV/Lungs (%), was 97.6%. The study demonstrated that the IMPT SBRT for multiple lung lesions had satisfactory dosimetry results, even when the number of lesions reached 6. The NTCP model-based decision strategy presented in our study could serve as an effective tool in clinical practice, aiding in the selection of the optimal treatment modality between VMAT and IMPT.