Radiotherapy and Radiosurgery Department, Humanitas Clinical and Research Center IRCCS, Milan-Rozzano, Italy.
Radiotherapy and Radiosurgery Department, Humanitas Clinical and Research Center IRCCS, Milan-Rozzano, Italy.
Clin Breast Cancer. 2020 Dec;20(6):527-533. doi: 10.1016/j.clbc.2020.06.005. Epub 2020 Jun 20.
The purpose of this study was to evaluate the impact of breast size on long-term toxicity and cosmesis in patients with breast cancer treated with hypofractionated simultaneous integrated boost (SIB) using volumetric modulated arc therapy (VMAT).
Patients with early stage breast cancer were treated with 3-week hypofractionated SIB-VMAT to the whole breast (40.5 Gy) and tumor bed (48 Gy). Two cohorts were identified: small/medium- (< 1000 cm) and large- (> 1000 cm) breasted patients. Acute and late (at 2 and 5 years) skin toxicity and cosmetic data were analyzed. Univariate and multivariate analysis evaluated associations between toxicity and dosimetric/anatomical variables.
From August 2010 to March 2017, a total of 1160 patients were treated; 831 had at least 2 years of follow-up and were analyzed. Treated skin area (TSA) receiving at least 20 Gy > 400 cm and V > 5 cm were significant predictors for acute skin toxicity. Multivariate analysis at 2 years was significant for boost volume > 70 cm, TSA > 400 cm, and breast size > 1500 cm. At 5 year analysis (352 patients), none of the analyzed variables was significant. For cosmetic outcome, only the breast size (> 1000 cm) and the boost size > 70 cm at 2 and 5 years, respectively, confirmed significance.
The TSA > 400 cm resulted as a significant predictor of both acute and late skin toxicity at 2 years; however, at 5 years, no breast size or dosimetric parameter suggested indications for increased toxicity. A worse cosmetic outcome was recorded at the 2-year follow up for large breasts, but was not confirmed at the 5-year follow-up. These long-term data suggest that hypofractionated SIB-VMAT is a viable modality also in large-breasted patients.
本研究旨在评估使用容积调强弧形治疗（VMAT）进行 3 周短程分割同步整合推量（SIB）治疗乳腺癌患者的乳房大小对长期毒性和美容效果的影响。
早期乳腺癌患者接受 3 周短程分割 SIB-VMAT 治疗全乳（40.5Gy）和肿瘤床（48Gy）。确定了两个队列：小/中乳房（<1000cm）和大乳房（>1000cm）患者。分析了急性和晚期（2 年和 5 年）皮肤毒性和美容数据。单变量和多变量分析评估了毒性与剂量学/解剖学变量之间的关联。
2010 年 8 月至 2017 年 3 月，共治疗了 1160 例患者；其中 831 例至少有 2 年的随访并进行了分析。至少接受 20Gy 的治疗皮肤面积（TSA）>400cm 和 V>5cm 是急性皮肤毒性的显著预测因素。2 年时的多变量分析表明，推量体积>70cm、TSA>400cm 和乳房大小>1500cm 有显著意义。在 5 年分析（352 例患者）中，分析的变量均无统计学意义。对于美容结果，仅在 2 年和 5 年时，乳房大小（>1000cm）和推量大小>70cm 分别确认有意义。
TSA>400cm 是 2 年时急性和晚期皮肤毒性的显著预测因素；然而，在 5 年时，没有乳房大小或剂量学参数提示毒性增加。大乳房患者在 2 年随访时记录到较差的美容结果，但在 5 年随访时未得到证实。这些长期数据表明，短程分割 SIB-VMAT 也是大乳房患者的可行治疗方式。
