Department of Radiation Oncology, Winship Cancer Institute, Emory University, Atlanta, Georgia, USA.
Int J Radiat Oncol Biol Phys. 2013 Feb 1;85(2):309-14. doi: 10.1016/j.ijrobp.2012.06.008.
Locoregional control is associated with breast cancer-specific and overall survival in select women with breast cancer. Although several patient, tumor, and treatment characteristics have been shown to contribute to locoregional recurrence (LRR), studies evaluating factors related to radiotherapy (XRT) technique have been limited. We investigated the relationship between LRR location and XRT fields and dose delivered to the primary breast cancer in women experiencing subsequent locoregional relapse.
We identified 21 women who were previously treated definitively with surgery and XRT for breast cancer. All patients developed biopsy-result proven LRR and presented to Emory University Hospital between 2004 and 2010 for treatment. Computed tomography (CT) simulation scans with XRT dose files for the initial breast cancer were fused with (18)F-labeled fluorodeoxyglucose positron emission tomography (FDG PET)/CT images in DICOM (Digital Imaging and Communications in Medicine) format identifying the LRR. Each LRR was categorized as in-field, defined as ≥95% of the LRR volume receiving ≥95% of the prescribed whole-breast dose; marginal, defined as LRR at the field edge and/or not receiving ≥95% of the prescribed dose to ≥95% of the volume; or out-of-field, that is, LRR intentionally not treated with the original XRT plan.
Of the 24 identified LRRs (3 patients experienced two LRRs), 3 were in-field, 9 were marginal, and 12 were out-of-field. Two of the 3 in-field LRRs were marginal misses of the additional boost XRT dose. Out-of-field LRRs consisted of six supraclavicular and six internal mammary nodal recurrences.
Most LRRs in our study occurred in areas not fully covered by the prescribed XRT dose or were purposely excluded from the original XRT fields. Our data suggest that XRT technique, field design, and dose play a critical role in preventing LRR in women with breast cancer.
局部区域控制与特定于乳腺癌的生存和总体生存相关，在选择的乳腺癌患者中。尽管已经显示出几种患者、肿瘤和治疗特征与局部区域复发（LRR）有关，但评估与放射治疗（XRT）技术相关的因素的研究受到限制。我们研究了在经历局部区域复发后，LRR 位置与 XRT 射野和原发性乳腺癌接受的剂量之间的关系。
我们确定了 21 名之前接受过手术和 XRT 治疗的女性。所有患者均经活检证实发生 LRR，并于 2004 年至 2010 年期间在埃默里大学医院就诊。使用 XRT 初始乳腺癌剂量文件与（18）F-标记的氟脱氧葡萄糖正电子发射断层扫描（FDG PET）/CT 图像融合在 DICOM（数字成像和通信医学）格式中，以确定 LRR。每个 LRR 分为以下几类：① 场内，定义为≥95%的 LRR 体积接受≥95%的规定全乳剂量；② 边缘，定义为在射野边缘的 LRR 和/或未接受≥95%的规定剂量至≥95%的体积；③ 场外，即有意不使用原始 XRT 计划治疗的 LRR。
在确定的 24 个 LRR 中（3 名患者发生了 2 个 LRR），3 个为场内，9 个为边缘，12 个为场外。3 个场内 LRR 中有 2 个是额外的加量 XRT 剂量的边缘漏量。场外 LRR 包括 6 个锁骨上和 6 个内乳淋巴结复发。
在我们的研究中，大多数 LRR 发生在未完全覆盖规定 XRT 剂量的区域，或故意排除在原始 XRT 射野之外的区域。我们的数据表明，XRT 技术、射野设计和剂量在预防乳腺癌患者的 LRR 中起着关键作用。
