Department of Radiation Oncology, New York Proton Center and Memorial Sloan Kettering Cancer Center, New York, NY.
Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA.
Semin Radiat Oncol. 2020 Jul;30(3):253-261. doi: 10.1016/j.semradonc.2020.02.007.
Local and regional recurrences are common following an initial course of radiotherapy, yet management of these recurrences remains a challenge. Reirradiation may be an optimal treatment approach for providing durable tumor control and even offering select patients with locoregional recurrences or new primary tumors a chance of cure, but photon reirradiation can be associated with considerable risks of high grade acute and late toxicities. The high conformality and lack of exit dose with proton therapy offer significant advantages for reirradiation. By decreasing dose to adjacent normal tissues, proton therapy can more safely deliver definitive instead of palliative doses of reirradiation, more safely dose escalate reirradiation treatment, and more safely allow for concurrent systemic therapy in the reirradiation setting. In this case-based analysis, renowned experts in the fields of proton therapy and of reirradiation present cases for which they recently employed proton reirradiation. This manuscript focuses on case studies in patients with lung cancer, head and neck malignancies, and pelvic malignancies. Considerations for when to deliver proton therapy in the reirradiation setting and the pros and cons of proton therapy are discussed, and the existing literature supporting the use of proton reirradiation for these disease sites is assessed.
局部和区域性复发在初始放射治疗后很常见，但这些复发的治疗仍然是一个挑战。再放疗可能是提供持久肿瘤控制的最佳治疗方法，甚至为局部区域复发或新原发性肿瘤的患者提供治愈的机会，但光子再放疗可能会伴随着严重的高级别急性和迟发性毒性的风险。质子治疗的高适形性和无出口剂量为再放疗提供了显著优势。通过降低相邻正常组织的剂量，质子治疗可以更安全地提供确定性而不是姑息性的再放疗剂量，可以更安全地增加再放疗的剂量，并且可以更安全地在再放疗环境中同时进行全身治疗。在这个基于案例的分析中，质子治疗和再放疗领域的知名专家介绍了他们最近采用质子再放疗的案例。本文重点介绍了肺癌、头颈部恶性肿瘤和盆腔恶性肿瘤患者的病例研究。讨论了在再放疗中何时使用质子治疗的考虑因素以及质子治疗的优缺点，并评估了支持在这些疾病部位使用质子再放疗的现有文献。
