Department of Radiation Oncology, Cleveland Clinic, Cleveland, Ohio.
Department of Radiation Oncology, Cleveland Clinic, Cleveland, Ohio.
Pract Radiat Oncol. 2019 Mar;9(2):e187-e195. doi: 10.1016/j.prro.2018.11.011. Epub 2018 Dec 7.
Dosimetric parameters to limit chest wall toxicity (CWT) are not well defined in single-fraction (SF) stereotactic body radiation therapy (SBRT) phase 2 trials. We sought to determine the relationship of tumor location and dosimetric parameters with CWT for SF-SBRT.
From a prospective registry of 1462 patients, we identified patients treated with 30 Gy or 34 Gy. Gross tumor volume was measured as abutting, ≤1 cm, 1 to 2 cm, or >2 cm from the chest wall. CWT was prospectively graded according to Common Terminology Criteria for Adverse Events version 3.0, with grade 2 requiring medical therapy, grade 3 requiring procedural intervention, and grade 4 being disabling pain. Grade 1 CWT or radiographic rib fracture was not included. Logistic regression analysis was used to identify the parameters associated with CWT and calculate the probability of CWT with dose.
This study included 146 lesions. The median follow-up time was 23.8 months. The 5-year local control, distant metastasis, and overall survival rates were 91.8%, 19.2%, and 28.7%, respectively. Grade 2 to 4 CWT was 30.6% for lesions abutting the chest wall, 8.2% for ≤1 cm from the chest wall, 3.8% for 1 to 2 cm from the chest wall, and 5.7% for >2 cm from the chest wall. Grade ≥3 CWT was 1.4%. Tumor abutment (odds ratio [OR]: 6.5; P = .0005), body mass index (OR: 1.1; P = .02), rib D1cc (OR: 1.01/Gy; P = .03), chest wall D1cc (OR: 1.08/Gy; P = .03), and chest wall D5cc (OR: 1.10/Gy; P = .01) were significant predictors for CWT on univariate analysis. Tumor abutment was significant for CWT (OR: 7.5; P = .007) on multivariate analysis. The probability of CWT was 15% with chest wall D5cc at 27.2 Gy and rib D1cc at 30.2 Gy.
The rate of CWT with SF-SBRT is similar to the rates published for fractionated SBRT, with most CWT being low grade. Tumor location relative to the chest wall is not a contraindication to SF-SBRT, but the rates increase significantly with abutment. Rib D1cc and chest wall D1cc and D5cc may be used as predictors of CWT.
在单次分割（SF）立体定向体放射治疗（SBRT）的 2 期试验中，限制胸部壁毒性（CWT）的剂量学参数尚未得到很好的定义。我们旨在确定肿瘤位置和剂量学参数与 SF-SBRT 的 CWT 之间的关系。
从 1462 例患者的前瞻性登记中，我们确定了接受 30 Gy 或 34 Gy 治疗的患者。大体肿瘤体积测量为紧贴、≤1 cm、1 至 2 cm 或>2 cm 来自胸壁。根据通用不良事件术语标准 3.0 前瞻性分级 CWT，2 级需要药物治疗，3 级需要手术干预，4 级为致残性疼痛。1 级 CWT 或放射性肋骨骨折不包括在内。逻辑回归分析用于确定与 CWT 相关的参数，并计算剂量的 CWT 概率。
本研究共纳入 146 个病灶。中位随访时间为 23.8 个月。5 年局部控制、远处转移和总生存率分别为 91.8%、19.2%和 28.7%。紧贴胸壁的病变 CWT 为 30.6%，距胸壁≤1 cm 的病变为 8.2%，距胸壁 1 至 2 cm 的病变为 3.8%，距胸壁>2 cm 的病变为 5.7%。≥3 级 CWT 为 1.4%。肿瘤紧贴（优势比[OR]：6.5；P =.0005）、体质指数（OR：1.1；P =.02）、肋骨 D1cc（OR：1.01/Gy；P =.03）、胸壁 D1cc（OR：1.08/Gy；P =.03）和胸壁 D5cc（OR：1.10/Gy；P =.01）是 CWT 的单变量分析的显著预测因素。肿瘤紧贴是 CWT 的多变量分析的显著预测因素（OR：7.5；P =.007）。胸壁 D5cc 为 27.2 Gy 时，肋骨 D1cc 为 30.2 Gy 时，CWT 的概率为 15%。
SF-SBRT 的 CWT 发生率与分割 SBRT 的报告发生率相似，大多数 CWT 为低级别。肿瘤相对于胸壁的位置并不是 SF-SBRT 的禁忌症，但随着紧贴程度的增加，发生率显着增加。肋骨 D1cc 和胸壁 D1cc 和 D5cc 可作为 CWT 的预测因子。
