Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan.
Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan.
Int J Radiat Oncol Biol Phys. 2021 Jun 1;110(2):566-573. doi: 10.1016/j.ijrobp.2020.12.018. Epub 2020 Dec 24.
Predicting individual patient sensitivity to radiation therapy (RT) for tumor control or normal tissue toxicity is necessary to individualize treatment planning. In head and neck cancer, radiation doses are limited by many nearby critical structures, including structures involved in swallowing. Previous efforts showed that imaging parameters correlate with RT dose; here, we investigate the role of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) blood volume (BV) changes in predicting dysphagia.
This study included 32 patients with locally advanced oropharyngeal squamous cell carcinoma treated with definitive chemoradiation on an institutional protocol incorporating baseline and early midtreatment DCE-MRI. BV maps of the pharyngeal constrictor muscles (PCM) were created, and BV increases midtreatment were correlated with the following parameters at 3 and 12 months post-RT: RT dose, Dynamic Imaging Grade of Swallowing Toxicity swallow score, aspiration frequency, European Organisation for Research and Treatment of Cancer HN35 patient-reported outcomes, physician-reported dysphagia, and feeding tube (FT) dependence.
The mean BV to the PCMs increased from baseline to fraction 10, which was significant for the superior PCM (P = .006) and middle PCM (P < .001), with a trend in the inferior PCM where lower mean doses were seen (P = .077). The factors associated with FT dependence at 3 months included BV increases in the total PCM (correlation, 0.48; P = .006) and middle PCM (correlation, 0.50; P = .004). A post-RT increase in aspiration was associated with a BV increase in the superior PCM (correlation, 0.44; P = .013),and the increase in the total PCMs was marginally significant (correlation, 0.34; P = .06). The best-performing models of FT dependence (area under the receiver operating curve [AUC] = 0.84) and aspiration increases (AUC = 0.78) included BV increases as well as a mean RT dose to middle PCM.
Our results suggest that midtreatment BV increases derived from DCE-MRI are an early predictor of dysphagia. Further investigation of these promising imaging markers to assess individual patient sensitivity to treatment and the patient's subsequent risk of toxicities is warranted to improve personalization of RT planning.
预测肿瘤控制或正常组织毒性的个体患者对放射治疗（RT）的敏感性，对于个体化治疗计划是必要的。在头颈部癌症中，由于存在许多临近的关键结构，包括参与吞咽的结构，因此限制了辐射剂量。先前的研究表明，成像参数与 RT 剂量相关；在这里，我们研究了动态对比增强磁共振成像（DCE-MRI）的血容量（BV）变化在预测吞咽困难中的作用。
本研究纳入了 32 名局部晚期口咽鳞状细胞癌患者，他们按照机构方案接受了根治性放化疗，该方案纳入了基线和早期中期 DCE-MRI。创建了咽缩肌（PCM）的 BV 图，并将中期治疗时的 BV 增加与 RT 后 3 个月和 12 个月的以下参数相关联：RT 剂量、吞咽毒性动态成像分级（Dynamic Imaging Grade of Swallowing Toxicity，DIGEST）吞咽评分、吸频率、欧洲癌症研究与治疗组织（European Organisation for Research and Treatment of Cancer，EORTC）HN35 患者报告的结果、医生报告的吞咽困难以及依赖饲管（feeding tube，FT）。
PCM 的平均 BV 从基线增加到第 10 次，其中上咽缩肌（P =.006）和中咽缩肌（P <.001）有统计学意义，而下咽缩肌的趋势则较低（P =.077）。与 3 个月时依赖 FT 相关的因素包括总 PCM（相关系数，0.48；P =.006）和中咽缩肌（相关系数，0.50；P =.004）的 BV 增加。RT 后出现的吸频率增加与上咽缩肌的 BV 增加相关（相关系数，0.44；P =.013），而总 PCM 的增加则具有边缘统计学意义（相关系数，0.34；P =.06）。FT 依赖的最佳性能模型（曲线下面积 [area under the receiver operating curve，AUC] = 0.84）和吸频率增加的最佳性能模型（AUC = 0.78）均包括 DCE-MRI 得出的治疗中期的 BV 增加以及中咽缩肌的平均 RT 剂量。
我们的研究结果表明，DCE-MRI 得出的治疗中期的 BV 增加是吞咽困难的早期预测指标。进一步研究这些有前途的影像学标志物，以评估个体患者对治疗的敏感性和随后发生毒性的风险，这对于提高 RT 计划的个体化具有重要意义。
