Radiotherapy is an integral component of multidisciplinary breast cancer care. Given how commonly radiotherapy is used in the treatment of breast cancer, many patients with recurrences have received previous radiotherapy. Patients with new primary breast cancer may also have received previous radiotherapy to the thoracic region. Curative doses and comprehensive field photon reirradiation (reRT) have often been avoided in these patients due to concerns for severe toxicities to organs-at-risk (OARs), such as the heart, lungs, brachial plexus, and soft tissue. However, many patients may benefit from definitive-intent reRT, such as patients with high-risk disease features such as lymph node involvement and dermal/epidermal invasion. Proton therapy is a potentially advantageous treatment option for delivery of reRT due to its lack of exit dose and greater conformality that allow for enhanced non-target tissue sparing of previously irradiated tissues. In this review, we discuss the clinical applications of proton therapy for patients with breast cancer requiring reRT, the currently available literature and how it compares to historical photon reRT outcomes, treatment planning considerations, and questions in this area warranting further study. Given the dosimetric advantages of protons and the data reported to date, proton therapy is a promising option for patients who would benefit from the added locoregional disease control provided by reRT for recurrent or new primary breast cancer.
放射治疗是多学科乳腺癌综合治疗的重要组成部分。鉴于放疗在乳腺癌治疗中的广泛应用，许多复发患者既往曾接受过放疗。新发原发性乳腺癌患者也可能曾接受过胸廓区域的放射治疗。由于担心对心脏、肺、臂丛神经及软组织等危及器官造成严重毒性反应，临床通常避免对这些患者实施根治性剂量和大范围光子再程放疗。然而，许多患者可能从根治性再程放疗中获益，特别是具有淋巴结受累、真皮/表皮侵犯等高危疾病特征的患者。质子治疗因其无出射剂量和更高的适形性，能够更好地保护既往照射过的非靶区组织，成为实施再程放疗的潜在优势选择。本综述探讨质子治疗在需要再程放疗的乳腺癌患者中的临床应用、现有文献证据及其与传统光子再程放疗结果的比较、治疗计划设计考量，以及该领域亟待进一步研究的问题。基于质子治疗的剂量学优势和现有数据，对于可通过再程放疗获得局部区域疾病控制的复发性或新发原发性乳腺癌患者，质子治疗是一种前景广阔的治疗选择。
Proton Reirradiation for High-Risk Recurrent or New Primary Breast Cancer
肿瘤(癌症)患者之家