Jin William H, Mellon Eric A, Frakes Jessica M, Murimwa Gilbert Z, Hodul Pamela J, Pimiento Jose M, Malafa Mokenge P, Hoffe Sarah E
University of South Florida Morsani College of Medicine, Tampa, FL, USA.
Moffitt Cancer Center, Tampa, FL, USA.
J Gastrointest Oncol. 2018 Feb;9(1):24-34. doi: 10.21037/jgo.2017.09.13.
Total psoas area (TPA), a marker of sarcopenia, has been used as an independent predictor of clinical outcomes in gastrointestinal (GI) cancers as a proxy for frailty and nutritional status. Our study aimed to evaluate whether TPA, in contrast to traditional measurements of nutrition like body mass index (BMI) and body surface area (BSA), was predictive of outcomes in borderline resectable pancreatic cancer (BRPC) and locally advanced pancreatic cancer (LAPC) patients receiving stereotactic body radiation therapy (SBRT).
Retrospective analysis of an institutional review board approved database of 222 BRPC and LAPC treated with SBRT from 2009-2016 yielded 183 patients that met our selection criteria of pre-SBRT computed tomography (CT) imaging with an identifiable L4 vertebra. Once the L4 vertebral level was identified, the bilateral psoas muscles were manually contoured. This area was normalized by patient height, with units described in mm/m. Receiver operating characteristic (ROC) curves were generated for TPA, BMI, and BSA to elicit clinically relevant cutoffs. Regression and Kaplan-Meier analyses were used to correlate toxicity with survival functions.
Low TPA (OR =1.903, P=0.036) was predictive of acute toxicities, and only TPA was predictive of Grade 3 or higher acute toxicities (OR =10.24, P=0.007). Both findings were independent of tumor resectability. Pain (P=0.003), fatigue (P=0.040), and nausea (P=0.039) were significantly associated with low TPA. No association was identified between any measurement of nutritional status and the development of late toxicities, overall survival, local progression or local recurrence. However, BRPC patients survived longer (median =21.98 months) than their LAPC (median =16.2 months) counterparts (P=0.002), independent of nutritional status.
TPA measurement is readily available and more specific than BMI or BSA as a predictor of acute radiotoxic complications following SBRT in BRPC/LAPC patients. A TPA of <500 mm/m is a clinically relevant cutoff that can direct physicians to address expected complications of pain, fatigue, and nausea. However, tumor resectability remains as the only predictor of overall survival in this cohort.
腰大肌总面积（TPA）作为肌肉减少症的一个指标，已被用作胃肠道（GI）癌症临床结局的独立预测因子，以代表虚弱和营养状况。我们的研究旨在评估与体重指数（BMI）和体表面积（BSA）等传统营养测量指标相比，TPA是否能预测接受立体定向体部放射治疗（SBRT）的临界可切除胰腺癌（BRPC）和局部晚期胰腺癌（LAPC）患者的结局。
对2009年至2016年期间接受SBRT治疗的222例BRPC和LAPC患者的机构审查委员会批准的数据库进行回顾性分析，得到183例符合我们选择标准的患者，即有可识别的L4椎体的SBRT前计算机断层扫描（CT）图像。一旦确定L4椎体水平，手动勾勒双侧腰大肌轮廓。该面积通过患者身高进行标准化，单位为mm/m。生成TPA、BMI和BSA的受试者工作特征（ROC）曲线，以得出临床相关的临界值。使用回归分析和Kaplan-Meier分析将毒性与生存函数相关联。
低TPA（OR = 1.903，P = 0.036）可预测急性毒性，且只有TPA可预测3级或更高等级的急性毒性（OR = 10.24，P = 0.007）。这两个发现均与肿瘤可切除性无关。疼痛（P = 0.003）、疲劳（P = 0.040）和恶心（P = 0.039）与低TPA显著相关。未发现任何营养状况测量指标与晚期毒性、总生存期、局部进展或局部复发之间存在关联。然而，BRPC患者的生存期（中位数 = 21.98个月）比LAPC患者（中位数 = 16.2个月）更长（P = 0.002），与营养状况无关。
在BRPC/LAPC患者中，TPA测量易于获得，并且作为SBRT后急性放射毒性并发症的预测因子比BMI或BSA更具特异性。TPA < 500 mm/m是一个临床相关的临界值，可指导医生处理预期的疼痛、疲劳和恶心并发症。然而，肿瘤可切除性仍然是该队列中总生存期的唯一预测因子。
