Hunter G J, Hamberg L M, Choi N, Jain R K, McCloud T, Fischman A J
Department of Radiology, Massachusetts General Hospital, Boston 02129, USA.
Clin Cancer Res. 1998 Apr;4(4):949-55.
The management of primary lung cancer relies on sophisticated imaging methods to assist in the diagnosis, staging, and evaluation of tumor regression during treatment. The information provided is generally anatomical in nature, except for that provided by positron emission tomography with [18F]fluorodeoxyglucose, a modality that yields physiological data that have been shown to be useful in identifying neoplasia, based on an elevated glucose metabolic rate. Because the metabolism of malignant tissue depends intimately on neovascularization to provide oxygen and glucose in sufficient quantities to allow tumor growth, the characterization of tumor vascular physiology could be an important tool for assessing and predicting the likely effectiveness of treatment. Our goal was to show the feasibility and practical value of parameters of tumor vascular physiology obtained using dynamic T1-weighted magnetic resonance imaging (MRI), to correlate them with glucose metabolism and to demonstrate changes in these parameters during and after treatment in patients with lung cancer. Parameters of vascular physiology [permeability-surface area (PS) product and extracellular contrast agent distribution volume] and glucose metabolism were assessed in 14 patients with lung cancer. Glucose metabolism was measured by using [18F]fluorodeoxyglucose-positron emission tomography. Vascular physiology was assessed by dynamic T1-weighted, contrast-enhanced MRI. The mean PS product in tumor was 0.0015 +/- 0.0002 s(-1) (n = 13) before, 0.0023 +/- 0.0003 s(-1) (n = 3, P = 0.053) midway through, and 0.00075 +/- 0.0002 s(-1) (n = 5, P < 0.03) 2 weeks after treatment. Values for the extracellular contrast distribution space were 0.321 +/- 0.03 before, 0.289 +/- 0.02 midway through, and 0.195 +/- 0.02 (P < 0.01) 2 weeks after therapy. The glucose metabolic rate was significantly correlated with the PS product (P < 0.01) but not with the extracellular contrast distribution space. Our results demonstrate that tumor PS product correlates with glucose metabolism, that chemo- and radiotherapy induce observable and quantifiable changes in these parameters, and that such changes can be measured by in vivo dynamic MRI. Quantitative dynamic T1-weighted MRI of tumor vascular physiology may have a useful role in the clinical management of lung cancer.
原发性肺癌的治疗依赖于先进的成像方法，以辅助诊断、分期以及评估治疗期间肿瘤的消退情况。所提供的信息通常本质上是解剖学信息，但正电子发射断层扫描结合[18F]氟脱氧葡萄糖所提供的信息除外，这种检查方式能产生生理数据，基于升高的葡萄糖代谢率，已证明这些数据在识别肿瘤形成方面很有用。由于恶性组织的代谢密切依赖于新血管形成，以提供足够的氧气和葡萄糖来支持肿瘤生长，因此肿瘤血管生理学特征可能是评估和预测治疗可能效果的重要工具。我们的目标是展示使用动态T1加权磁共振成像（MRI）获得的肿瘤血管生理学参数的可行性和实用价值，将它们与葡萄糖代谢相关联，并证明肺癌患者治疗期间及治疗后这些参数的变化。对14例肺癌患者评估了血管生理学参数[通透表面积（PS）乘积和细胞外对比剂分布容积]以及葡萄糖代谢。通过[18F]氟脱氧葡萄糖-正电子发射断层扫描测量葡萄糖代谢。通过动态T1加权对比增强MRI评估血管生理学。肿瘤的平均PS乘积在治疗前为0.0015±0.0002 s-1（n = 13），治疗中期为0.0023±0.0003 s-1（n = 3，P = 0.053），治疗后2周为0.00075±0.0002 s-1（n = 5，P < 0.03）。细胞外对比剂分布空间的值在治疗前为0.321±0.03，治疗中期为0.289±0.02，治疗后2周为0.195±0.02（P < 0.01）。葡萄糖代谢率与PS乘积显著相关（P < 0.01），但与细胞外对比剂分布空间无关。我们的结果表明，肿瘤PS乘积与葡萄糖代谢相关，化疗和放疗可诱导这些参数出现可观察到的和可量化的变化，并且这些变化可通过体内动态MRI测量。肿瘤血管生理学的定量动态T1加权MRI在肺癌的临床管理中可能具有重要作用。
