Department of Medical Oncology, Institut Jules Bordet, Brussels, Belgium.
Ann Oncol. 2012 Jul;23(7):1687-93. doi: 10.1093/annonc/mdr554. Epub 2011 Nov 23.
The study purpose was to assess the predictive value of 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography (PET)/computerized tomography (CT) metabolic response after a single course of chemotherapy in patients with metastatic colorectal cancer (mCRC).
FDG-PET/CT scans were carried out at baseline and on day 14 in 41 patients with unresectable mCRC treated with a biweekly regimen of chemotherapy. Metabolic nonresponse was defined by <15% decrease in FDG uptake in the dominant proportion of the patient's lesions or if a lesion was found metabolically progressive. The PET-based response was correlated with radiological response (primary end point) and patient's outcome (secondary end points).
RECIST response rate in metabolically responding patients was 43% (10 of 23) compared with 0% (0 of 17) in nonresponding patients (P=0.002). The metabolic assessment's predictive performance for RECIST response was sensitivity 100% [95% confidence interval (CI) 69% to 100%], specificity 57% (95% CI 37% to 75%), positive predictive value 43% (95% CI 23% to 66%), and negative predictive value 100% (95% CI 80% to 100%). Comparing metabolically responding versus nonresponding patients, the hazard ratio (HR) was 0.28 (95% CI 0.10-0.76) for overall survival and 0.57 (95% CI 0.27-1.21) for progression-free survival.
The metabolic response measured by FDG-PET/CT after a single course of chemotherapy in mCRC is able to identify patients who will not benefit from the treatment.
本研究旨在评估转移性结直肠癌（mCRC）患者接受单疗程化疗后，2-[氟-18]氟代-2-脱氧-D-葡萄糖（FDG）-正电子发射断层扫描（PET）/计算机断层扫描（CT）代谢反应的预测价值。
对 41 例接受两周一次化疗方案治疗的不可切除 mCRC 患者进行基线和第 14 天 FDG-PET/CT 扫描。代谢无反应定义为患者病变的优势比例中 FDG 摄取量减少<15%，或发现病变代谢进展。基于 PET 的反应与影像学反应（主要终点）和患者预后（次要终点）相关。
代谢反应患者的 RECIST 缓解率为 43%（23 例中有 10 例），而无反应患者为 0%（17 例中无 1 例）（P=0.002）。代谢评估对 RECIST 反应的预测性能为敏感性 100%[95%置信区间（CI）69%至 100%]，特异性 57%（95%CI 37%至 75%），阳性预测值 43%（95%CI 23%至 66%），阴性预测值 100%（95%CI 80%至 100%）。与代谢反应患者相比，代谢无反应患者的总生存和无进展生存的危险比（HR）分别为 0.28（95%CI 0.10-0.76）和 0.57（95%CI 0.27-1.21）。
在 mCRC 患者中，单次化疗后 FDG-PET/CT 测量的代谢反应能够识别出不能从治疗中获益的患者。
