Radiology：张丽娟等非实性肺癌肿瘤负荷定量研究获进展

近日，中科院深圳先进技术研究院生物医药与健康工程所医学成像研究中心副研究员张丽娟在非实性肺癌肿瘤负荷的定量研究方面取得进展，发现其肿瘤的影像密度值每增加100单位，肿瘤负荷约增加10%。研究成果发表在国际期刊《放射学》（Radiology）杂志上。

据介绍，倍增时间在判断肿瘤的性质及预后方面有重要临床意义。 不同于实性肿瘤，非实性肺癌在体积增加之前常存在一段不确定的“内生长”期，即肿瘤组织向肺泡内空间填充，组织学上表现为癌细胞沿肺泡表面的增殖，而肿瘤的径线并无改变。 这种生长方式使得经典倍增时间计算方法不再适用，长期以来该疾病的临床诊疗也因此颇受困扰。

医学影像技术的发展使得使用计算机辅助断层成像在体估算肿瘤负荷成为可能。 深圳先进院的这项研究结合应用医学病理及影像的方法，全面分析了非实性肺癌的内生长模式，并对其肿瘤负荷作了定量分析，首次发现肿瘤的影像密度值每增加100单位，肿瘤负荷约增加10%。

据介绍，这项研究为非实性肺肿瘤的生长提供了有效的评估方法，对肺癌的诊疗有重要临床应用价值。 同时，也为丰富肺癌的WHO（世卫组织）分期提供了新思路。

doi:10.1148/radiol.11101372
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Internal Growth of Nonsolid Lung Nodules: Radiologic-Pathologic Correlation

Lijuan Zhang, MD, David F. Yankelevitz, MD, Darryl Carter, MD, Claudia I. Henschke, PhD, MD, Rowena Yip, MPH and Anthony P. Reeves, PhD

Purpose: To determine whether computed tomographic (CT) attenuation values correlate with the histologic measurements of a lung cancer manifesting as a nonsolid nodule and to quantify the extent to which the tumor replaces the airspace within the nodule.

Materials and Methods: Informed consent was obtained to analyze images from CT and pathologic examination under an institutional review board–approved protocol. Fifteen patients who had undergone resection of nonsolid lung cancer were evaluated. On the basis of the CT attenuation values of nonsolid nodules, nonneoplastic lung, soft tissue, and air, the overall proportion of soft tissue in the nodule and nonneoplastic lung and the difference between these two measures were calculated. The analogous measures were obtained from a representative digitized histologic slide. The area of each nodule and the proportion of air within it were measured, and the proportion of soft tissue in the nodule and nonneoplastic lung and the difference between the two were calculated. The difference between the two proportions at CT and histologic examination are the proportions attributable to the cancer on the basis of CT and histologic examinations, respectively. Linear regression was performed to assess the relationship between these measures.

Results: The average proportions of soft tissue in the nodule at CT and histologic examination were 48% and 69%, respectively, and they showed significant correlation with each other (P = .02); in addition, each showed significant correlation with the attenuation of the nodule (P < .0001 and P = .02, respectively). The difference between the proportions of soft tissue in nodule and nonneoplastic lung at CT and histologic examination were 37% and 30%, respectively, and both were independent of the tumor diameter (P = .26 and P = .41).

Conclusion: The proportion of soft tissue within a nonsolid nodule is correlated with attenuation at CT. This allows for measurement of change within the nodule. An increase of 100 HU in nodule attenuation represents an approximately 10% increase in tumor volume.