Department of Radiation Oncology, Albert Einstein College of Medicine-Montefiore Medical Center, Bronx, New York.
Department of Radiation Oncology, Albert Einstein College of Medicine-Montefiore Medical Center, Bronx, New York; Institute for Onco-Physics, Albert Einstein College of Medicine-Montefiore Medical Center, Bronx, New York.
Int J Radiat Oncol Biol Phys. 2018 Nov 15;102(4):1036-1045. doi: 10.1016/j.ijrobp.2018.03.059. Epub 2018 Apr 6.
To evaluate whether a response assessment using mid-treatment computed tomography (CT) scans during definitive radiation therapy (RT) for oropharyngeal head and neck cancer can predict for locoregional recurrence (LRR).
Head and neck cancer patients who receive RT at our institution undergo CT repeat scans at the 15th fraction, with treatment replanning in the case of an inadequate dose to gross disease or an increased dose to organs at risk. A retrospective cohort analysis was performed of 96 consecutive patients with oropharyngeal cancer treated from 2007 to 2015 with mid-treatment repeat CT scans available. The primary disease volume and involved lymph node volume were delineated on the pre- and mid-treatment CT scans. Univariable and multivariable Cox proportional hazards regression analyses were used to evaluate the efficacy of the mid-treatment reduction in tumor volume as a predictor of LRR. Risk stratification was performed by dichotomizing the patients into high- and low-risk groups according to the mid-treatment response and p16 status and smoking history.
With a median follow-up of 34 months, 14 patients experienced LRR. The median reduction in the total tumor volume was 18.7% (interquartile range 8.4%-30.9%). A reduction in total tumor volume greater than the median was an independent predictor of LRR (hazard ratio 0.22, 95% confidence interval 0.05-0.89; P = .020). The reduction in primary tumor volume was an even stronger predictor of LRR (hazard ratio 0.11, 95% confidence interval 0.02-0.57; P = .002). Stratifying patients into a high-risk group for those with a reduction in the total tumor volume at mid-treatment at or less than the median, p16 negative status, and smoking status of >10 pack-years and a low-risk group for those without these factors, we found a clear separation in Kaplan-Meier curves, with actuarial 3-year locoregional control, progression-free survival, and overall survival rates for the high-risk patients of 45.7%, 38.2%, and 71.8% compared with 90.7%, 70.6%, and 89.8% for low-risk patients, respectively (P ≤ .021 for all).
Our results have shown that the treatment response from an early assessment using mid-treatment CT scans is an independent predictor of LRR and can be used to effectively distinguish high- and low-risk patients, allowing for risk-adaptive treatment stratification at the midway point.
评估在头颈部癌症根治性放疗中使用治疗中程计算机断层扫描（CT）对局部区域复发（LRR）的预测价值。
在我们机构接受放疗的头颈部癌症患者，在第 15 次分次时进行 CT 重复扫描，如果疾病总剂量不足或危及器官剂量增加，则进行治疗计划调整。对 2007 年至 2015 年间接受中程重复 CT 扫描的 96 例咽后区头颈部癌症患者进行回顾性队列分析。在治疗前和中程 CT 扫描上勾画原发肿瘤体积和受累淋巴结体积。采用单变量和多变量 Cox 比例风险回归分析评估肿瘤体积治疗中程缩小作为 LRR 预测因子的功效。根据治疗中程反应、p16 状态和吸烟史将患者分为高风险和低风险组进行风险分层。
中位随访 34 个月后，14 例患者发生 LRR。总肿瘤体积的中位缩小率为 18.7%（四分位距 8.4%-30.9%）。肿瘤总体积缩小大于中位数是 LRR 的独立预测因子（风险比 0.22，95%置信区间 0.05-0.89；P=0.020）。原发肿瘤体积缩小更是 LRR 的强烈预测因子（风险比 0.11，95%置信区间 0.02-0.57；P=0.002）。将患者分为治疗中程肿瘤总体积缩小小于或等于中位数、p16 阴性状态和吸烟量大于 10 包年的高风险组，以及无这些因素的低风险组，我们发现 Kaplan-Meier 曲线明显分离，高风险患者的 3 年局部区域控制、无进展生存率和总生存率分别为 45.7%、38.2%和 71.8%，而低风险患者分别为 90.7%、70.6%和 89.8%（P≤0.021）。
我们的结果表明，使用中程 CT 扫描进行早期评估的治疗反应是 LRR 的独立预测因子，并可有效区分高风险和低风险患者，从而在治疗中期实现风险适应性治疗分层。
