Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas.
Pract Radiat Oncol. 2018 Jan-Feb;8(1):58-65. doi: 10.1016/j.prro.2017.07.002. Epub 2017 Jul 8.
Reirradiation of thoracic malignancies is a treatment challenge, with concerns for toxicity and the inability to deliver definitive doses. Intensity modulated proton therapy (IMPT) may allow safe delivery of a higher dose of radiation to the tumor while minimizing toxicities.
Between 2011 and 2016, 27 patients who received IMPT for reirradiation of thoracic malignancies with definitive intent were retrospectively analyzed. Patients were included if they received a prior thoracic radiation course. All doses were recalculated to an equivalent dose in 2-Gy fractions (EQD2). Patients received IMPT to a median dose of 66 EQD2 Gy (range, 43.2-84 Gy) for recurrence of thoracic cancer (93%) or sequentially after a course of thoracic stereotactic ablative radiation therapy (7%).
Twenty-two patients (81%) were treated for non-small cell lung cancer. The median time to reirradiation was 29.5 months. At a median follow-up for all patients of 11.2 months (25.9 surviving patients), the median overall survival was 18.0 months, with a 1-year overall survival of 54%. Four patients (15%) experienced an in-field local failure (LF), with a 1-year freedom from LF rate of 78%. The 1-year freedom from locoregional failure and 1-year progression-free survival rates were 61% and 51%, respectively. Patients who received 66 EQD2 Gy or higher had improved 1-year freedom from LF (100% vs 49%; P = .013), 1-year freedom from locoregional failure (84% vs 23%; P = .035), and 1-year progression-free survival (76% vs 14%; P = .050). Reirradiation was well tolerated, with only 2 patients (7%) experiencing late grade 3 pulmonary toxicity, and none with grade 3 or higher esophagitis. There were no grade 4-5 toxicities.
These data represent the largest series of patients treated with IMPT for definitive reirradiation of thoracic cancers. They demonstrate that IMPT provided durable local control with minimal toxicity and suggest that higher doses may improve outcomes.
胸部恶性肿瘤的再放疗是一个治疗挑战，存在毒性和无法给予根治剂量的问题。强度调制质子治疗（IMPT）可能允许安全地给予肿瘤更高剂量的辐射，同时最大限度地减少毒性。
在 2011 年至 2016 年间，对 27 例因明确意向行胸部恶性肿瘤再放疗而接受 IMPT 的患者进行回顾性分析。如果患者接受过胸部放射治疗，则将其纳入研究。所有剂量均换算为等效剂量 2-Gy 分数（EQD2）。患者接受 IMPT 的中位剂量为 66 EQD2 Gy（范围为 43.2-84 Gy），用于治疗胸部癌症（93%）复发或在胸部立体定向消融放疗后序贯治疗（7%）。
22 例（81%）患者患有非小细胞肺癌。再放疗的中位时间为 29.5 个月。在所有患者的中位随访 11.2 个月（25.9 例存活患者）后，中位总生存期为 18.0 个月，1 年总生存率为 54%。4 例（15%）患者发生了场内局部失败（LF），1 年 LF 无失败率为 78%。1 年无局部区域失败和 1 年无进展生存率分别为 61%和 51%。接受 66 EQD2 Gy 或更高剂量的患者，1 年 LF 无失败率（100%比 49%；P=0.013）、1 年无局部区域失败率（84%比 23%；P=0.035）和 1 年无进展生存率（76%比 14%；P=0.050）均得到改善。再放疗耐受性良好，仅 2 例（7%）患者发生晚期 3 级肺毒性，无 3 级或更高级别的食管炎。无 4-5 级毒性。
这些数据代表了最大系列接受 IMPT 治疗明确再放疗的胸部癌症患者。它们表明 IMPT 提供了持久的局部控制，毒性最小，并表明更高的剂量可能改善结果。
