Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York.
Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York.
Int J Radiat Oncol Biol Phys. 2019 Jul 15;104(4):859-866. doi: 10.1016/j.ijrobp.2019.02.050. Epub 2019 Mar 7.
Most studies examining accelerated partial breast irradiation (APBI) have used twice-daily fractionation. Cosmesis with this approach has produced mixed results, and the optimal fractionation scheme remains unknown. We sought to evaluate the safety and efficacy of APBI with a total dose of 40 Gy in 10 daily fractions.
Between 2010 and 2014, we prospectively enrolled 106 patients to receive APBI after lumpectomy for invasive or in situ node-negative breast cancer. Radiation was administered via 3-dimensional conformal techniques.
The median age was 62 years (range, 39-85), and all patients underwent APBI per protocol. With a median follow-up of 58 months, we evaluated patient-reported local toxicity and recurrence outcomes. Of 106 patients, 16 (15%) experienced grade ≥2 skin toxicity. The most common significant toxicities were acute cutaneous changes at 4 to 9 weeks after radiation therapy, including grade 2 erythema in 2 patients (1.8%) and skin color changes in 4 patients (3.8%). Only 2 instances of grade 3 toxicity were reported, including 1 patient with acute moist desquamation after radiation therapy and another with fibrosis at 2 years. Planning target volume and breast V were significantly predictive of skin/subcutaneous toxicity, with evidence that limiting breast V to <45% may improve tolerability. Overall, 3 breast cancer recurrences arose: 1 local recurrence in the original quadrant (3 years after APBI), 1 in a different ipsilateral quadrant (5 years after APBI), and 1 with distant disease 2 years after APBI.
In an appropriately selected group of patients with early stage breast cancer, APBI to a dose of 40 Gy in 10 daily fractions was well tolerated, with most patients (99%) reporting excellent/good cosmesis. Planning target volume and breast V should be carefully constrained to limit local morbidity. Longer follow-up will be needed to establish efficacy and subsequent local recurrence rates.
大多数研究检查加速部分乳房照射（APBI）使用了每日两次分割。这种方法的美容效果产生了混合的结果，最佳分割方案仍不清楚。我们试图评估 40Gy 总剂量分 10 次每日分割的 APBI 的安全性和有效性。
在 2010 年至 2014 年期间，我们前瞻性地招募了 106 例接受保乳手术后浸润性或原位淋巴结阴性乳腺癌的患者接受 APBI。辐射通过三维适形技术进行。
中位年龄为 62 岁（范围 39-85），所有患者均按方案接受 APBI。中位随访 58 个月后，我们评估了患者报告的局部毒性和复发结果。在 106 例患者中，有 16 例（15%）发生了≥2 级皮肤毒性。最常见的显著毒性是放射治疗后 4 至 9 周的急性皮肤变化，包括 2 例患者（1.8%）出现 2 级红斑和 4 例患者（3.8%）出现皮肤颜色改变。仅报告了 2 例 3 级毒性，包括 1 例患者在放射治疗后出现急性湿性脱皮，另 1 例患者在 2 年后出现纤维化。计划靶区和乳房 V 是皮肤/皮下毒性的显著预测因子，证据表明将乳房 V 限制在<45%可能会提高耐受性。总的来说，有 3 例乳腺癌复发：1 例在 APBI 后 3 年在原象限发生局部复发，1 例在 APBI 后 5 年在同侧象限发生，1 例在 APBI 后 2 年发生远处疾病。
在适当选择的早期乳腺癌患者组中，40Gy 总剂量分 10 次每日分割的 APBI 耐受性良好，大多数患者（99%）报告美容效果极好/良好。应仔细限制计划靶区和乳房 V，以限制局部发病率。需要更长时间的随访才能确定疗效和随后的局部复发率。
