Memorial Sloan Kettering Cancer Centger.
J Appl Clin Med Phys. 2016 May;17(3):371-379. doi: 10.1120/jacmp.v17i3.6199.
The presence of two intact lungs makes it challenging to reach a tumoricidal dose with hemithoracic pleural intensity-modulated radiation therapy (IMRT) in patients with malignant pleural mesothelioma (MPM) who underwent pleurectomy/decortications or have unresectable disease. We developed an anatomy-based model to predict attainable prescription dose before starting optimization. Fifty-six clinically delivered IMRT plans were analyzed regarding correlation of prescription dose and individual and total lung volumes, planning target volume (PTV), ipsilateral normal lung volume and ratios: contralateral/ipsilateral lung (CIVR); contralateral lung/PTV (CPVR); ipsilateral lung /PTV (IPVR); ipsilateral normal lung /total lung (INTLVR); ipsilateral normal lung/PTV (INLPVR). Spearman's rank correlation and Fisher's exact test were used. Correlation between mean ipsilateral lung dose (MILD) and these volume ratios and between prescription dose and single lung mean doses were studied. The prediction models were validated in 23 subsequent MPM patients. CIVR showed the strongest correlation with dose (R=0.603,p<0.001) and accurately predicted prescription dose in the validation cases. INLPVR and MILD as well as MILD and prescription dose were significantly correlated (R=-0.784,p<0.001 and R=0.554,p<0.001, respectively) in the training and validation cases. Parameters obtainable directly from planning scan anatomy predict achievable prescription doses for hemithoracic IMRT treatment of MPM patients with two intact lungs. PACS number(s): 87.55.de, 87.55.dk.
在接受胸膜切除术/剥脱术或患有不可切除疾病的恶性胸膜间皮瘤 (MPM) 患者中，由于存在两个完整的肺，因此很难通过半胸部胸膜强度调制放射治疗 (IMRT) 达到肿瘤杀伤剂量。我们开发了一种基于解剖结构的模型，以便在开始优化之前预测可达到的处方剂量。分析了 56 个临床交付的 IMRT 计划，以研究处方剂量与个体和总肺体积、计划靶区 (PTV)、同侧正常肺体积和比值之间的相关性：对侧/同侧肺 (CIVR)；对侧肺/PTV (CPVR)；同侧肺/PTV (IPVR)；同侧正常肺/总肺 (INTLVR)；同侧正常肺/PTV (INLPVR)。使用 Spearman 等级相关和 Fisher 确切检验。研究了平均同侧肺剂量 (MILD) 与这些体积比之间以及处方剂量与单肺平均剂量之间的相关性。在随后的 23 名 MPM 患者中验证了预测模型。CIVR 与剂量相关性最强 (R=0.603,p<0.001)，并在验证病例中准确预测了处方剂量。在训练和验证病例中，INLPVR 和 MILD 以及 MILD 和处方剂量均呈显著相关性 (R=-0.784,p<0.001 和 R=0.554,p<0.001)。直接从计划扫描解剖结构获得的参数可预测具有两个完整肺的 MPM 患者半胸部 IMRT 治疗的可实现处方剂量。PACS 号：87.55.de, 87.55.dk。
