Department of Surgery, Hoag Memorial Hospital Presbyterian, Newport Beach, CA, USA.
Department of Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
Ann Surg Oncol. 2023 Oct;30(10):6079-6088. doi: 10.1245/s10434-023-13897-3. Epub 2023 Jul 18.
Randomized trials have shown that risk-adapted intraoperative radiation therapy (IORT) after breast-conserving surgery for low-risk breast cancer patients is a safe alternative to whole-breast radiation therapy (WBRT). The risk-adapted strategy allows additional WBRT for predefined high-risk pathologic characteristics discovered on final histopathology. The greater the percentage of patients receiving WBRT, the lower the recurrence rate. The risk-adapted strategy, although important and necessary, can make IORT appear better than it actually is.
Risk-adapted IORT was used to treat 1600 breast cancers. They were analyzed by the intention-to-treat method and per protocol to better understand the contribution of IORT with and without additional whole-breast treatment. Any ipsilateral breast tumor event was considered a local recurrence.
During a median follow-up period of 63 months, local recurrence differed significantly between the patients who received local treatment and those who received whole-breast treatment. For 1393 patients the treatment was local treatment alone. These patients experienced 79 local recurrences and a 5-year local recurrence probability of 5.95 %. For 207 patients with high-risk final histopathology, additional whole-breast treatment was administered. They experienced two local recurrences and a 5-year local recurrence probability of 0.5 % (p = 0.0009).
Whole-breast treatment works well at reducing local recurrence, and it is a totally acceptable and necessary addition to IORT as part of a risk-adapted program. However, the more whole-breast treatment that is given, the more it dilutes the original plan of simplifying local treatment and the less we understand exactly what IORT contributes to local control as a stand-alone treatment.
随机试验表明，对于低危乳腺癌患者，保乳手术后适应性术中放疗（IORT）是全乳放疗（WBRT）的一种安全替代方案。适应性策略允许对最终组织病理学发现的预定高危病理特征进行额外的 WBRT。接受 WBRT 的患者比例越高，复发率越低。尽管适应性策略很重要且必要，但它可能会使 IORT 看起来比实际情况更好。
采用适应性 IORT 治疗 1600 例乳腺癌。通过意向治疗和方案进行分析，以更好地了解有无额外全乳治疗的 IORT 的贡献。任何同侧乳房肿瘤事件均被视为局部复发。
在中位随访 63 个月期间，接受局部治疗和接受全乳治疗的患者之间局部复发率存在显著差异。对于 1393 例接受局部治疗的患者，这些患者发生了 79 例局部复发，5 年局部复发率为 5.95%。对于 207 例具有高危最终组织病理学的患者，给予了额外的全乳治疗。他们发生了 2 例局部复发，5 年局部复发率为 0.5%（p=0.0009）。
全乳治疗在降低局部复发方面效果良好，作为适应性方案的一部分，它是对 IORT 的完全可接受且必要的补充。然而，给予的全乳治疗越多，就越能淡化最初简化局部治疗的计划，我们对 IORT 作为独立治疗在局部控制方面的贡献的了解就越少。
