Gulstene Stephanie, Raziee Hamid
Department of Radiation Oncology, University of Western Ontario, London, ON, Canada.
Department of Radiation Oncology, BC Cancer Surrey, University of British Columbia, Vancouver, BC, Canada.
Front Oncol. 2020 Jun 26;10:772. doi: 10.3389/fonc.2020.00772. eCollection 2020.
Adding a boost to whole breast radiation (WBI) following breast-conserving surgery (BCS) may help improve local control, but it increases the total cost of treatment and may worsen cosmetic outcomes. Therefore, it is reserved for patients whose potential benefit outweighs the risks; however, current evidence is insufficient to support comprehensive and consistent guidance on how to identify these patients, leading to a potential for significant variations in practice. The use of a boost in the setting of close margins and hypofractionated radiotherapy represents two important areas where consensus guidelines, patterns of practice, and current evidence do not seem to converge. Close margins were previously routinely re-excised, but this is no longer felt to be necessary. Because of this recent practice change, good long-term data on the local recurrence risk of close margins with or without a boost is lacking. As for hypofractionation, although there is guidance recommending that the decision to add a boost be independent from the whole-breast fractionation schedule, it appears that patterns-of-practice data may show underutilization of a boost when hypofractionation is used. The use of a boost in these two common clinical scenarios represents important areas of future study for the optimization of adjuvant breast radiation.
保乳手术（BCS）后增加全乳放疗（WBI）剂量可能有助于改善局部控制，但会增加治疗总成本，且可能使美容效果变差。因此，它仅适用于潜在获益大于风险的患者；然而，目前的证据不足以支持关于如何识别这些患者的全面且一致的指导意见，导致实际操作中可能存在显著差异。在切缘接近和采用大分割放疗的情况下增加放疗剂量，是两个重要领域，在这些领域中，共识性指南、实践模式和现有证据似乎并未趋同。切缘接近时以前常规会再次切除，但现在认为没有必要这样做。由于最近的这种实践变化，缺乏关于切缘接近时无论是否增加放疗剂量的局部复发风险的良好长期数据。至于大分割放疗，尽管有指南建议增加放疗剂量的决定应独立于全乳分割方案，但实践模式数据似乎显示，使用大分割放疗时增加放疗剂量的情况可能未得到充分利用。在这两种常见临床情况下增加放疗剂量，是未来优化辅助性乳腺放疗的重要研究领域。
