Bral Samuel, Duchateau Michaël, De Ridder Mark, Everaert Hendrik, Tournel Koen, Schallier Denis, Verellen Dirk, Storme Guy
Department of Radiation Oncology, Universitair Ziekenhuis Brussel, Belgium.
Radiother Oncol. 2009 Jun;91(3):438-42. doi: 10.1016/j.radonc.2009.03.015.
To study the feasibility of measuring volumetric changes in the primary tumor on megavoltage-computed tomography (MVCT) during chemoradiation and to examine the correlation with local response.
Fifteen consecutive patients with stage III, inoperable, locally advanced non-small cell lung cancer (NSCLC) were treated in a prospective dose escalation study protocol of concurrent chemoradiation. They were monitored for acute toxicity and evaluated with daily MVCT imaging. The volumetric changes were fitted to a negative exponential resulting in a regression coefficient (RC). Local response evaluation was done with positron emission tomography using the radio-labeled glucose analogue F18 fluorodeoxyglucose (FDG-PET).
The mean volume decrease (+/-standard deviation) was 73% (+/-18%). With a mean treatment time of 42days this treatment schedule resulted in a mean decrease of 1.74%/day. Of the 13 evaluable patients seven developed a metabolic complete remission (MCR). The mean RC of the patients with MCR is 0.050 versus a mean RC of 0.023 in non-responders (p=0.0074). Using a proposed cut-off value for the RC of 0.03 80% of the non-responders will be detected correctly while misclassifying 16.4% of patients who will eventually achieve an MCR. The total cumulative percentage of esophageal grade 3 or more toxicity was 46.7%.
The RC derived from volumetric analysis of daily MVCT is prognostic and predictive for local response in patients treated with chemoradiation for a locally advanced NSCLC. Because this treatment schedule is toxic in nearly half of the patient population, MVCT is a tool in the implementation of patient-individualized treatment strategies.
研究在放化疗期间利用兆伏级计算机断层扫描（MVCT）测量原发肿瘤体积变化的可行性，并检验其与局部反应的相关性。
15例连续的Ⅲ期、无法手术的局部晚期非小细胞肺癌（NSCLC）患者参加了一项同步放化疗的前瞻性剂量递增研究方案。对他们进行急性毒性监测，并通过每日MVCT成像进行评估。将体积变化拟合为负指数曲线，得出回归系数（RC）。使用放射性标记的葡萄糖类似物F18氟脱氧葡萄糖（FDG-PET）通过正电子发射断层扫描进行局部反应评估。
平均体积减少（±标准差）为73%（±18%）。平均治疗时间为42天，该治疗方案导致平均每天减少1.74%。在13例可评估患者中，7例出现代谢完全缓解（MCR）。MCR患者的平均RC为0.050，而无反应者的平均RC为0.023（p = 0.0074）。使用提议的RC临界值0.03，80%的无反应者将被正确检测出来，同时将最终实现MCR的患者误分类的比例为16.4%。食管3级或更高级别毒性的总累积发生率为46.7%。
从每日MVCT的体积分析得出的RC对局部晚期NSCLC放化疗患者的局部反应具有预后和预测价值。由于该治疗方案在近一半的患者中具有毒性，MVCT是实施个体化治疗策略的一种工具。
