PDF(Sci-hub)
Abstract：
UNASSIGNED: Pelvic reirradiation (re-RT) presents challenges due to concerns for late toxicity to tissues-at-risk including pelvic bone marrow (PBM). We routinely utilize a hyperfractionated, accelerated re-RT for recurrent rectal or anal cancer in the setting of prior radiation. We hypothesized that proton beam radiation (PBR) is uniquely suited to limit doses to pelvic non-target tissues better than photon-based approaches.
UNASSIGNED: All patients who received hyperfractionated, accelerated PBR re-RT to the pelvis from 2007 to 2017 were identified. Re-RT was delivered twice daily with a 6 h minimum interfraction interval at 1.5 Gray Relative Biological Effectiveness (Gy(RBE)) per fraction to a total dose of 39-45 Gy(RBE). Concurrent chemotherapy was given to all patients. Comparison photon plans were generated for dosimetric analysis. Dosimetric parameters compared using a matched-pair analysis and the Wilcoxon signed-rank test. Survival analysis was performed Kaplan Meier curves.
UNASSIGNED: Fifteen patients were identified, with a median prior pelvic RT dose of 50.4 Gy (range 25-80 Gy). Median time between the initial RT and PBRT re-RT was 4.7 years (range 1.0-36.1 years). In comparison to corresponding photon re-RT plans, PBR re-RT plans had lower mean PBM dose, and lower volume of PBM getting 5 Gy, 10 Gy, 20 Gy, and 30 Gy (p < 0.001, p < 0.001, p < 0.001, and p = 0.033, respectively).With median 13.9 months follow-up after PBR re-RT, five patients had developed local recurrences, and four patients had developed distant metastases. One-year overall survival following PBR re-RT was 67.5% and one-year progression free survival was 58.7%. No patients developed acute or late Grade 4 toxicity.
UNASSIGNED: PBR re-RT affords improved sparing of PBM compared with photon-based re-RT. Clinically, PBR re-RT is well-tolerated. However, given modest control rates with definitive re-RT without subsequent surgical resection, a multidisciplinary approach should be favored in this setting when feasible.
UNASSIGNED: All patients who received hyperfractionated, accelerated PBR re-RT to the pelvis from 2007 to 2017 were identified. Re-RT was delivered twice daily with a 6 h minimum interfraction interval at 1.5 Gray Relative Biological Effectiveness (Gy(RBE)) per fraction to a total dose of 39-45 Gy(RBE). Concurrent chemotherapy was given to all patients. Comparison photon plans were generated for dosimetric analysis. Dosimetric parameters compared using a matched-pair analysis and the Wilcoxon signed-rank test. Survival analysis was performed Kaplan Meier curves.
UNASSIGNED: Fifteen patients were identified, with a median prior pelvic RT dose of 50.4 Gy (range 25-80 Gy). Median time between the initial RT and PBRT re-RT was 4.7 years (range 1.0-36.1 years). In comparison to corresponding photon re-RT plans, PBR re-RT plans had lower mean PBM dose, and lower volume of PBM getting 5 Gy, 10 Gy, 20 Gy, and 30 Gy (p < 0.001, p < 0.001, p < 0.001, and p = 0.033, respectively).With median 13.9 months follow-up after PBR re-RT, five patients had developed local recurrences, and four patients had developed distant metastases. One-year overall survival following PBR re-RT was 67.5% and one-year progression free survival was 58.7%. No patients developed acute or late Grade 4 toxicity.
UNASSIGNED: PBR re-RT affords improved sparing of PBM compared with photon-based re-RT. Clinically, PBR re-RT is well-tolerated. However, given modest control rates with definitive re-RT without subsequent surgical resection, a multidisciplinary approach should be favored in this setting when feasible.
摘要：
■由于担心对包括骨盆骨髓（PBM）在内的高危组织的后期毒性，骨盆再照射（re-RT）面临挑战。我们通常利用超分割，在既往放疗的情况下，复发性直肠癌或肛门癌的加速再放疗。我们假设质子束辐射（PBR）比基于光子的方法更适合将剂量限制到骨盆非目标组织。
■所有接受超分割的患者，确定了2007年至2017年骨盆的加速PBR再RT。每天两次递送Re-RT,以每分份1.5Gy相对生物有效性(Gy(RBE))的最小间隔6小时,达到39-45Gy(RBE)的总剂量。所有患者均给予同期化疗。生成比较光子计划用于剂量测定分析。使用配对分析和Wilcoxon符号秩检验比较剂量学参数。采用KaplanMeier曲线进行生存分析。
■确定了15名患者，前盆腔RT剂量中位数为50.4Gy（范围25-80Gy）。初始RT和PBRT再RT之间的中位时间为4.7年（范围为1.0-36.1年）。与相应的光子重RT计划相比，PBR再RT计划的平均PBM剂量较低，和较低的PBM体积得到5Gy，10Gy,20Gy,和30Gy(分别为p<0.001、p<0.001、p<0.001和p=0.033)。PBR再RT后的中位随访时间为13.9个月，五名患者出现局部复发，4例患者发生远处转移。PBR再RT后一年总生存率为67.5%，一年无进展生存率为58.7%。无患者出现急性或晚期4级毒性。
■与基于光子的re-RT相比，PBRre-RT提供了改进的PBM备用。临床上,PBR再RT耐受性良好。然而,考虑到适度的控制率和明确的再RT，没有随后的手术切除，在可行的情况下，应在这种情况下采用多学科方法。
■所有接受超分割的患者，确定了2007年至2017年骨盆的加速PBR再RT。每天两次递送Re-RT,以每分份1.5Gy相对生物有效性(Gy(RBE))的最小间隔6小时,达到39-45Gy(RBE)的总剂量。所有患者均给予同期化疗。生成比较光子计划用于剂量测定分析。使用配对分析和Wilcoxon符号秩检验比较剂量学参数。采用KaplanMeier曲线进行生存分析。
■确定了15名患者，前盆腔RT剂量中位数为50.4Gy（范围25-80Gy）。初始RT和PBRT再RT之间的中位时间为4.7年（范围为1.0-36.1年）。与相应的光子重RT计划相比，PBR再RT计划的平均PBM剂量较低，和较低的PBM体积得到5Gy，10Gy,20Gy,和30Gy(分别为p<0.001、p<0.001、p<0.001和p=0.033)。PBR再RT后的中位随访时间为13.9个月，五名患者出现局部复发，4例患者发生远处转移。PBR再RT后一年总生存率为67.5%，一年无进展生存率为58.7%。无患者出现急性或晚期4级毒性。
■与基于光子的re-RT相比，PBRre-RT提供了改进的PBM备用。临床上,PBR再RT耐受性良好。然而,考虑到适度的控制率和明确的再RT，没有随后的手术切除，在可行的情况下，应在这种情况下采用多学科方法。
