Massachusetts General Hospital, Boston, MA.
J Clin Oncol. 2019 Oct 20;37(30):2778-2785. doi: 10.1200/JCO.18.02366. Epub 2019 Aug 26.
To evaluate the safety and efficacy of proton beam radiation therapy (RT) for patients with breast cancer who require regional nodal irradiation.
Patients with nonmetastatic breast cancer who required postoperative RT to the breast/chest wall and regional lymphatics and who were considered suboptimal candidates for conventional RT were eligible. The primary end point was the incidence of grade 3 or higher radiation pneumonitis (RP) or any grade 4 toxicity within 3 months of RT. Secondary end points were 5-year locoregional failure, overall survival, and acute and late toxicities per Common Terminology Criteria for Adverse Events (version 4.0). Strain echocardiography and cardiac biomarkers were obtained before and after RT to assess early cardiac changes.
Seventy patients completed RT between 2011 and 2016. Median follow-up was 55 months (range, 17 to 82 months). Of 69 evaluable patients, median age was 45 years (range, 24 to 70 years). Sixty-three patients (91%) had left-sided breast cancer, two had bilateral breast cancer, and five had right-sided breast cancer. Sixty-five (94%) had stage II to III breast cancer. Sixty-eight (99%) received systemic chemotherapy. Fifty (72%) underwent immediate reconstruction. Median dose to the chest wall/breast was 49.7 Gy (relative biological effectiveness) and to the internal mammary nodes, 48.8 Gy (relative biological effectiveness), which indicates comprehensive coverage. Among 62 surviving patients, the 5-year rates for locoregional failure and overall survival were 1.5% and 91%, respectively. One patient developed grade 2 RP, and none developed grade 3 RP. No grade 4 toxicities occurred. The unplanned surgical re-intervention rate at 5 years was 33%. No significant changes in echocardiography or cardiac biomarkers after RT were found.
Proton beam RT for breast cancer has low toxicity rates and similar rates of disease control compared with historical data of conventional RT. No early cardiac changes were observed, which paves the way for randomized studies to compare proton beam RT with standard RT.
评估质子束放射治疗（RT）在需要区域淋巴结照射的乳腺癌患者中的安全性和疗效。
符合条件的患者为患有非转移性乳腺癌，需要术后对乳房/胸壁和区域淋巴结进行 RT，且被认为不适合常规 RT。主要终点是 RT 后 3 个月内发生 3 级或更高级别的放射性肺炎（RP）或任何 4 级毒性的发生率。次要终点为 5 年局部区域失败、总生存率以及根据常见不良事件术语标准（第 4.0 版）评估的急性和迟发性毒性。在 RT 前后进行应变超声心动图和心脏生物标志物检查，以评估早期心脏变化。
70 例患者于 2011 年至 2016 年间完成 RT。中位随访时间为 55 个月（范围，17 至 82 个月）。69 例可评估患者中，中位年龄为 45 岁（范围，24 岁至 70 岁）。63 例（91%）为左侧乳腺癌，2 例为双侧乳腺癌，5 例为右侧乳腺癌。65 例（94%）为 II 期至 III 期乳腺癌。68 例（99%）接受了全身化疗。50 例（72%）进行了即刻重建。胸壁/乳房的中位剂量为 49.7 Gy（相对生物效应），内乳淋巴结的中位剂量为 48.8 Gy（相对生物效应），这表明有全面覆盖。在 62 例存活患者中，5 年局部区域失败和总生存率分别为 1.5%和 91%。1 例患者发生 2 级 RP，无 3 级 RP。未发生 4 级毒性。5 年时无计划的再次手术干预率为 33%。RT 后未发现超声心动图或心脏生物标志物有明显变化。
与常规 RT 的历史数据相比，质子束 RT 治疗乳腺癌的毒性发生率低，疾病控制率相似。未观察到早期心脏变化，为比较质子束 RT 与标准 RT 的随机研究铺平了道路。
