Department of Radiation Oncology, Peking University First Hospital, Beijing, China.
Department of Pathology, China-Japan Friendship Hospital, Beijing, China.
Thorac Cancer. 2021 Jul;12(13):1973-1982. doi: 10.1111/1759-7714.14000. Epub 2021 May 24.
The identification of the clinical target volume (CTV) is particularly important in the precise radiotherapy of lung cancer. The purpose of this study was to determine the extension margin from gross tumor volume (GTV) to CTV in primary small cell lung cancer (SCLC) and lung adenocarcinoma (ADC) by microscopic extension (ME).
The data of 25 cases of SCLC and 29 cases of ADC from August 2015 to August 2020 were analyzed. The measurement of tumor size between preoperative thoracic computed tomography (CT) and postoperative macroscopic specimens was compared, and the ME range of tumor cells was measured under a microscope to determine its correlation with clinical features and pathological manifestations.
A total of 217 slides were examined, corresponding to 103 slides for SCLC and 114 slides for ADC. The radiologic sizes of the tumors in SCLC and ADC were 12.8 and 7.9 mm, respectively (p = 0.09), and the macroscopic sizes were 12.5 and 8.5 mm, respectively (p = 0.07). There was a significant correlation between the radiologic and macroscopic size of the same tumor sample (r = 0.886). Compared with ADC, more SCLC tumor cells infiltrated through vascular or lymphatic dissemination (16% vs. 9%, p = 0.047). The mean ME value was 2.81 mm for SCLC and 2.02 mm for ADC (p = 0.012). To take into account 95% of the ME, a margin of 8 and 7.7 mm must be expanded for SCLC and ADC, respectively. The ME value of the tumor was related to the presence of atelectasis, the location of the tumor, and the Ki-67 cell proliferation index.
The GTV of the tumor was contoured according to CT images, which was basically consistent with the actual tumor size. The GTVs of SCLC and ADC should be expanded by 8 and 7.7 mm, respectively, to fully cover the subclinical lesions in 95% of cases.
在肺癌的精确放疗中，临床靶区（CTV）的确定尤为重要。本研究旨在通过微观扩展（ME）确定原发性小细胞肺癌（SCLC）和肺腺癌（ADC）的大体肿瘤体积（GTV）至 CTV 的扩展边界。
分析了 2015 年 8 月至 2020 年 8 月期间 25 例 SCLC 和 29 例 ADC 的病例数据。比较了术前胸部计算机断层扫描（CT）和术后大体标本之间的肿瘤大小测量，并在显微镜下测量肿瘤细胞的 ME 范围，以确定其与临床特征和病理表现的相关性。
共检查了 217 张切片，对应于 SCLC 的 103 张切片和 ADC 的 114 张切片。SCLC 和 ADC 的肿瘤影像学大小分别为 12.8 和 7.9mm（p=0.09），大体大小分别为 12.5 和 8.5mm（p=0.07）。同一肿瘤样本的影像学和大体大小之间存在显著相关性（r=0.886）。与 ADC 相比，更多的 SCLC 肿瘤细胞通过血管或淋巴扩散浸润（16%比 9%，p=0.047）。SCLC 的平均 ME 值为 2.81mm，ADC 为 2.02mm（p=0.012）。为考虑到 95%的 ME，SCLC 和 ADC 分别需要扩展 8 和 7.7mm 的边界。肿瘤的 ME 值与肺不张的存在、肿瘤的位置和 Ki-67 细胞增殖指数有关。
根据 CT 图像勾画肿瘤的 GTV，基本与实际肿瘤大小一致。SCLC 和 ADC 的 GTV 应分别扩大 8 和 7.7mm，以在 95%的情况下充分覆盖亚临床病变。
