Hoover D, Reid R H, Rodrigues G, Wong E, Stitt L, Yaremko B P
London Regional Cancer Program, Department of Physics and Engineering.
The University of Western Ontario, Department of Radiology.
Med Phys. 2012 Jul;39(7Part4):4640-4641. doi: 10.1118/1.4740190.
To investigate whether functionally-weighted dose-volume histogram (DVH) parameters are more predictive of radiation-induced pneumonitis (RP) than standard parameters such as V20 and mean lung dose (MLD).
A retrospective chart review identified 26 patients who received curative-intent radiation therapy for primary carcinoma of the lung. Prior to treatment, all patients received single photon emission computed tomography (SPECT) to assess both lung ventilation and lung perfusion. Patients were assessed for clinical RP using standard criteria and were separated into a non-RP group (RP grade < 2) and an RP-group (RP grade ≥ 2). Standard DVH parameters (V10, V20, V30, MLD) and their function-weighted counterparts (for perfusion: pF10, pF20, pF30, pMLD; for ventilation: vF10, vF20, vF30, vMLD) were evaluated for each group. Receiver operating characteristics (ROC) curves were created and the area under the curve (AUC) computed.
7 of 26 patients had grade ≥ 2 pneumonitis. Both pF20 (p=0.022) and vF20 (p=0.036) were significantly different between the 2 groups; V20 was not (p=0.06). Both pF30 (p=0.008) and vF30 (p=0.025) were significantly different between groups while V30 failed to reach significance (p=0.072). Standard MLD (p=0.011), pMLD (p=0.001), and vMLD (p=0.011) were all significantly different. The ROC curves indicated that both the perfusion-weighted parameters and the ventilation-weighted parameters outperformed the standard DVH parameters as predictors of RP grade ≥2.
SPECT-based, function-weighted DVH parameters appear to be useful as predictors of RP.
研究功能加权剂量体积直方图（DVH）参数是否比诸如V20和平均肺剂量（MLD）等标准参数更能预测放射性肺炎（RP）。
一项回顾性病历审查确定了26例接受原发性肺癌根治性放疗的患者。治疗前，所有患者均接受单光子发射计算机断层扫描（SPECT）以评估肺通气和肺灌注。根据标准标准对患者进行临床RP评估，并分为非RP组（RP分级<2）和RP组（RP分级≥2）。对每组评估标准DVH参数（V10、V20、V30、MLD）及其功能加权对应参数（灌注：pF10、pF20、pF30、pMLD；通气：vF10、vF20、vF30、vMLD）。绘制受试者操作特征（ROC）曲线并计算曲线下面积（AUC）。
26例患者中有7例发生≥2级肺炎。两组之间pF20（p = 0.022）和vF2（p = 0.036）均有显著差异；V20无显著差异（p = 0.06）。两组之间pF30（p = 0.008）和vF30（p = 0.025）均有显著差异，而V30未达到显著差异（p = 0.072）。标准MLD（p = 0.011）、pMLD（p = 0.001）和vMLD（p = 0.011）均有显著差异。ROC曲线表明，作为RP分级≥2的预测指标，灌注加权参数和通气加权参数均优于标准DVH参数。
基于SPECT的功能加权DVH参数似乎可作为RP的预测指标。
