Feddock Jonathan, Cleary Ryan, Arnold Susanne, Shelton Brent, Sinha Partha, Conrad Gary, Chen Li, Rinehart John, Mcgarry Ronald
Department of Radiation Medicine, University of Kentucky, Lexington, Kentucky, USA.
Department of College of Medicine, University of Kentucky, Lexington, Kentucky, USA.
J Radiosurg SBRT. 2013;2(3):235-242.
A prospective single institution study evaluating the feasibility of conventional chemoradiation (CRT) followed by SBRT as a means of dose escalation for patients with stage II-III NSCLC with residual disease recently completed accrual. Two patients enrolled developed unexpected fatal pulmonary hemorrhages. A post-hoc analysis was performed to evaluate for an association between protocol therapy and this grade 5 toxicity.
17 patients enrolled on the protocol with medial tumors according to the RTOG 0813 definitions, were selected for analysis. Protocol therapy consisted of SBRT boost consisting of 10Gy times two or 6.5Gy times three fractions, after completing initial CRT. Chi-square and ANOVA associations were performed using patient-specific and dosimetric characteristics, particularly volume and point doses to mediastinal structures.
After a median follow-up of 13 months, 2 patients developed a grade V pulmonary hemorrhage, in the setting of recurrent disease. Cumulative biological effective doses (BED) were calculated using an α/β 3.0 for the pulmonary vasculature and bronchial wall. No volumetric or point doses administered seemed to correlate with the risk for pulmonary hemorrhage, despite an average maximum pulmonary artery dose of 175 Gy BED. The only significant association with fatal hemorrhage was local recurrence (p = 0.0441).
SBRT boost does not appear to increase the risk for fatal pulmonary hemorrhage. A cumulative maximum BED to the pulmonary artery less than 175 Gy appears to be safe.
一项前瞻性单机构研究评估了对于II - III期非小细胞肺癌（NSCLC）残留病灶患者，采用传统放化疗（CRT）后序贯立体定向放疗（SBRT）作为剂量递增手段的可行性。该研究最近完成了入组。两名入组患者发生了意外的致命性肺出血。进行了事后分析以评估方案治疗与这种5级毒性之间的关联。
根据RTOG 0813定义，选择17名入组该方案且肿瘤位于中央的患者进行分析。方案治疗包括在完成初始CRT后进行SBRT推量，推量为10Gy×2次或6.5Gy×3次分割。使用患者特异性和剂量学特征，特别是纵隔结构的体积和点剂量，进行卡方检验和方差分析关联。
中位随访13个月后，2例患者在疾病复发的情况下发生了V级肺出血。使用肺血管和支气管壁的α/β 3.0计算累积生物等效剂量（BED）。尽管平均最大肺动脉剂量为175 Gy BED，但似乎没有给予的体积剂量或点剂量与肺出血风险相关。与致命出血唯一显著相关的是局部复发（p = 0.0441）。
SBRT推量似乎不会增加致命性肺出血的风险。肺动脉累积最大BED小于175 Gy似乎是安全的。
