LaRiviere Michael J, Dreyfuss Alexandra, Taunk Neil K, Freedman Gary M
Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania.
Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York.
Adv Radiat Oncol. 2021 May 9;6(4):100710. doi: 10.1016/j.adro.2021.100710. eCollection 2021 Jul-Aug.
Local-regional recurrence (LRR) of breast cancer after prior adjuvant radiation (RT) can present a clinical challenge. Proton therapy is recommended by the American Society for Radiation Oncology in cases where reirrradiation is needed; however, data are limited. We present the toxicity and outcomes after reirradiation for local-regional recurrence of breast cancer with proton therapy.
A single-institution retrospective review identified patients with the following criteria: LRR of breast cancer, prior photon radiation to the same region, proton beam reirradiation, and definitive intent. Surgery or systemic therapy at the time of recurrence was used when indicated. The log-rank test was used to compare Kaplan-Meier survival estimates. Kruskal-Wallis tests were performed to compare worst reported toxicities with clinical variables.
The population included 27 patients with a history of prior radiation and treated with proton therapy for LRR between 2012 and 2019. The median interval between courses was 9.7 years. Proton reirradiation regimens included whole breast/chest wall (WB/CW) with regional nodal RT (22/27), nodal RT alone (2/27), or WB/CW alone (3/27). The median dose was 51 Gy, and the most common fractionation was 1.5 Gy twice daily. Median follow-up after reirradiation was 16.6 months. Acute grade 3 toxicities included dermatitis in 2 patients and breast pain in 2 patients. Grade 2 or higher late toxicities included 6 G2 rib fractures and 1 G2 brachial plexopathy, 1 G3 dermatitis, 1 G3 breast pain, and 1 G4 dermatitis. Twelve patients had new documented recurrences of which 1 was a second in-field LRR, and there were 7 deaths.
Proton salvage reirradiation to median 51 Gy in 1.5 Gy twice daily appears to be safe with acceptable acute and late toxicity, and effective with >95% local-regional control.
既往接受辅助放疗后乳腺癌的局部区域复发（LRR）可能带来临床挑战。美国放射肿瘤学会建议在需要再次放疗的情况下采用质子治疗；然而，相关数据有限。我们报告了质子治疗乳腺癌局部区域复发再次放疗后的毒性反应和治疗结果。
一项单机构回顾性研究纳入符合以下标准的患者：乳腺癌局部区域复发、既往对同一区域进行过光子放疗、质子束再次放疗且为根治性治疗目的。复发时根据指征采用手术或全身治疗。采用对数秩检验比较Kaplan-Meier生存估计值。进行Kruskal-Wallis检验以比较报告的最严重毒性反应与临床变量。
该队列包括27例有既往放疗史且在2012年至2019年间接受质子治疗以处理局部区域复发的患者。疗程之间的中位间隔时间为9.7年。质子再次放疗方案包括全乳/胸壁（WB/CW）联合区域淋巴结放疗（22/27）、单纯淋巴结放疗（2/27）或单纯WB/CW放疗（3/27）。中位剂量为51 Gy，最常用的分割方式是每日两次，每次1.5 Gy。再次放疗后的中位随访时间为16.6个月。急性3级毒性反应包括2例患者出现皮炎，2例患者出现乳腺疼痛。2级或更高等级晚期毒性反应包括6例2级肋骨骨折、1例2级臂丛神经病变、1例3级皮炎、1例3级乳腺疼痛和1例4级皮炎。12例患者出现新的复发记录，其中1例为第二次野内局部区域复发，7例患者死亡。
每日两次，每次1.5 Gy，中位剂量达51 Gy的质子挽救性再次放疗似乎安全，急性和晚期毒性反应可接受，且局部区域控制率>95%，效果良好。
