Radiotherapy Division, European Institute of Oncology, IEO IRCCS, Milan, Italy.
Department of Oncology and Hemato-oncology, University of Milan, Milan, Italy.
Pract Radiat Oncol. 2024 Nov-Dec;14(6):484-498. doi: 10.1016/j.prro.2024.05.012. Epub 2024 Jul 18.
Intraoperative radiation therapy with electrons (IOERT) may represent a viable choice for partial breast reirradiation after repeat quadrantectomy for local recurrence (LR) for primary breast cancer (BC) in lieu of mastectomy.
A database collecting data on partial breast reirradiation with IOERT from 8 Italian centers was set up in 2016 to 2018, providing data on cumulative incidence (CumI) of second LR and survival with a long follow-up.
From 2002 to 2015, 109 patients underwent the conservative retreatment. The median primary BC first LR interval was 11.1 years (range, 2.4-27.7). The median first LR size was 0.9 cm (range, 0.3-3.0), and 43.6% cases were luminal A. Median IOERT dose was 18 Gy (range, 12-21), and median collimator diameter was 4 cm (range, 3-6). Median follow-up duration was 11.7 years (IQR, 7.7-14.6). The second LR CumI was 12.2% (95% CI, 6.8%-19.2%) at 5 years and 32.3% at 10 years (95% CI, 22.8%-42.2%), occurring in the same site as the first LR in about half of the cases. Human epidermal growth factor receptor 2 status and collimator size were independent LR predictors. The 5- and 10-year overall survival rates were 95.2% and 88.3%, respectively, whereas 5- and 10-year BC-specific survival rates were 98% and 94.5%, respectively. The development of a second LR significantly reduced BC-specific survival (hazard ratio, 9.40; P < .001). Grade ≥3 fibrosis rate was 18.9%. Patient-reported cosmesis was good/excellent in 59.7% of the cases.
Second LR CumI was within the range of the literature but higher than expected, opening questions on radiation field extension and fractionation schedule. Because a second LR worsened the outcome, salvage modality must be carefully planned.
对于原发性乳腺癌（BC）局部复发（LR）后行象限切除术的患者，术中电子放射治疗（IOERT）可能是乳房局部重建的可行选择，而不是乳房切除术。
为了提供与 IOERT 相关的局部挽救性放疗的第二 LR 累积发生率（CumI）和长期随访生存数据，2016 年至 2018 年，我们建立了一个包含 8 个意大利中心数据的数据库。
2002 年至 2015 年间，有 109 例患者接受了保守性治疗。中位原发性 BC 首次 LR 间期为 11.1 年（范围，2.4-27.7）。首次 LR 大小的中位数为 0.9cm（范围，0.3-3.0），43.6%的病例为 luminal A 型。中位 IOERT 剂量为 18Gy（范围，12-21），中位准直器直径为 4cm（范围，3-6）。中位随访时间为 11.7 年（IQR，7.7-14.6）。5 年时第二 LR 的 CumI 为 12.2%（95%CI，6.8%-19.2%），10 年时为 32.3%（95%CI，22.8%-42.2%），约一半的病例发生在与首次 LR 相同的部位。人表皮生长因子受体 2 状态和准直器大小是 LR 的独立预测因素。5 年和 10 年的总生存率分别为 95.2%和 88.3%，5 年和 10 年的 BC 特异性生存率分别为 98%和 94.5%。第二 LR 的发生显著降低了 BC 特异性生存率（风险比，9.40；P<.001）。≥3 级纤维化率为 18.9%。59.7%的患者报告美容效果良好/优秀。
第二 LR 的 CumI 在文献范围内，但高于预期，这引发了对放射野扩展和分割方案的质疑。由于第二 LR 会恶化结局，因此必须仔细计划挽救性治疗方式。
