Giraud P, Antoine M, Larrouy A, Milleron B, Callard P, De Rycke Y, Carette M F, Rosenwald J C, Cosset J M, Housset M, Touboul E
Department of Radiation Oncology, Hôpital Tenon, Paris, France.
Int J Radiat Oncol Biol Phys. 2000 Nov 1;48(4):1015-24. doi: 10.1016/s0360-3016(00)00750-1.
One of the most difficult steps of the three-dimensional conformal radiotherapy (3DCRT) is to define the clinical target volume (CTV) according to the degree of local microscopic extension (ME). In this study, we tried to quantify this ME in non-small-cell lung cancer (NSCLC).
Seventy NSCLC surgical resection specimens for which the border between tumor and adjacent lung parenchyma were examined on routine sections. This border was identified with the naked eye, outlined with a marker pen, and the value of the local ME outside of this border was measured with an eyepiece micrometer. The pattern of histologic spread was also determined.
A total of 354 slides were examined, corresponding to 176 slides for adenocarcinoma (ADC) and 178 slides for squamous cell carcinoma (SCC). The mean value of ME was 2.69 mm for ADC and 1.48 mm for SCC (p = 0.01). The usual 5-mm margin covers 80% of the ME for ADC and 91% for SCC. To take into account 95% of the ME, a margin of 8 mm and 6 mm must be chosen for ADC and SCC, respectively. Aerogenous dissemination was the most frequent pattern observed for all groups, followed by lymphatic invasion for ADC and interstitial extension for SCC.
The ME was different between ADC and SCC. The usual CTV margin of 5 mm appears inadequate to cover the ME for either group, and it must be increased to 8 mm and 6 mm for ADC and SCC, respectively, to cover 95% of the ME. This approach is obviously integrated into the overall 3DCRT procedure and with other margins.
三维适形放疗（3DCRT）最困难的步骤之一是根据局部微观扩展（ME）程度来定义临床靶区（CTV）。在本研究中，我们试图对非小细胞肺癌（NSCLC）中的这种ME进行量化。
70例NSCLC手术切除标本，在常规切片上检查肿瘤与相邻肺实质之间的边界。用肉眼识别该边界，用记号笔勾勒，并用目镜测微计测量该边界外局部ME的值。还确定了组织学扩散模式。
共检查了354张切片，其中腺癌（ADC）176张，鳞状细胞癌（SCC）178张。ADC的ME平均值为2.69mm，SCC为1.48mm（p = 0.01）。通常的5mm边界覆盖了ADC的80%的ME和SCC的91%的ME。为了考虑95%的ME，ADC和SCC分别必须选择8mm和6mm的边界。气源性播散是所有组中最常见的模式，其次是ADC的淋巴浸润和SCC的间质扩展。
ADC和SCC的ME不同。通常5mm的CTV边界似乎不足以覆盖两组的ME，对于ADC和SCC，必须分别增加到8mm和6mm才能覆盖95%的ME。这种方法显然已融入整个3DCRT程序以及其他边界中。
