局部晚期和复发性乳腺癌患者区域淋巴结转移分布特点及靶区勾画意义

Distribution of involved regional lymph nodes in recurrent and locally advanced breast cancer and itsimpact on target definition

目的通过对局部晚期和区域复发性乳腺癌患者区域淋巴结累及范围的分析，探讨常规区域淋巴结放疗技术对淋巴引流区照射的合理性，并为合理的靶区勾画原则提供临床证据。方法搜集2003--2009年本院收治的影像和临床资料完整的局部晚期和局部一区域复发性乳腺癌患者11l例胸部CT片。将淋巴结引流区分为以下亚结构：锁骨上内侧组（sc—M）、锁骨上外侧组（sc—L）、第1站腋窝淋巴结（ALN—I）、第Ⅱ站腋窝淋巴结（ALN-Ⅱ）、第Ⅲ站腋窝淋巴结（ALN-Ⅲ）、锁骨下淋巴结（IFN），肌间淋巴结（RN）、内乳淋巴结（IMN）。统计各亚结构累及淋巴结频率及解剖特征。结果共111例患者199处亚结构进入分析，其中sc—M33处，sc—L21处，ALN—I30处，ALN-Ⅱ25处，ALN-Ⅲ和IFN35处，RN27处，IMN28处。锁骨上及腋窝是累及频率最高区域，达72．3％。SC中心平均深度分别为内侧组33．48mm（〉3cm者51．5％），外侧组45．62mm（〉3cm者71．4％）。局部晚期患者和术后患者淋巴结在腋静脉头侧与脚侧比分别为5：20和64：28。IMN除2处外余26处均位于1～3肋间。复发IMN中心距表皮和体中线平均距离分别为24．23mm和29．38mm，与内乳血管横向距离为6．19mm，纵向距离为5．73mm。结论区域淋巴结个体差异变化较大，传统固定野照射技术无法达到合理的剂量覆盖，建议采用CT定位为基础的三维适形计划优化。

Objective The frequency and the anatomic distribution of involved regional nodes in recurrent and locally advanced breast cancer were analyzed, in order to evaluate the rational of conventional regional node radiation technique and provide evidence for target definition of breast cancer . Methods Patients with recurrent or locally advanced breast cancer who were treated in our hospital from August 2003 to December 2009 were included in this study. 1 l 1 patients had contrast enhanced chest CT images of the whole regional nodes before treatment. The regional nodes were categorized into 8 anatomical substructures including medial and lateral supraclavieular nodes （SC-M, SC-L）, axilla nodes （ALN）-I, Ⅱ, Ⅲ, infraclavicular nodes （IFN）, Rotter＇s nodes （RN） and internal mammary nodes （IMN）. The frequency of involvement and anatomical distribution of the involved nodes on CT images were analyzed. Results A total of 111 patients were enrolled this study and 199 anatomical substructures with involved nodes were identified. The frequency of involvement were：SC-M 33, SC-L 21, ALN- I 30, ALN- l] 25, ALN-l]I ＋ IFN 35, RN 27, IMN 28. Supraclavicular region and axilla were the most frequently involved area （72. 3% ）. The average depth of the SC-M and SC-L nodes was 33.48 mm _＋ 10. 57 mm and 45.62 mm ± 20.45 ram, and 51.5% and 71.4% of the SC-M and SC-L nodes were located more than 3 cm deep from the skin. The axilla nodes were located cranial and caudal to the axillary vein in 5 and 20 locally advanced breast cancer patients and in 64 and 28 patients who received prior axillary dissection. The majority of involved IMN was located within the first 3 intercostal spaces （26/28）. The average distance between the center of involved IMN and chest skin was 24.23 mm± 10.28 ram. The average distance between the center of involved IMNand midline of the body was 29. 38 mm ± 6. 7 mm. The center of involved IMN was 6.19 mm ± 5.73 mm lateral and 5.73 mm ± 4. 56 mm posterior to the internal mammary vessels. Conclusions Conventional field design is unlikely to provide sufficient dose to the entire risk region because of individual differences. Individualized treatment planning based on CT would become feasible with increasing knowledge of natural risk of nodal involvement.