Department of Medical Oncology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
J Nucl Med. 2017 Jun;58(6):905-910. doi: 10.2967/jnumed.116.183475. Epub 2017 Jan 12.
Currently, biomarkers that predict the efficacy of everolimus in metastatic renal cell carcinoma (mRCC) patients are lacking. Everolimus inhibits vascular endothelial growth factor A (VEGF-A) expression. We performed PET scans on mRCC patients with Zr-bevacizumab, a VEGF-A-binding antibody tracer. The aims were to determine a change in tumor tracer uptake after the start of everolimus and to explore whether Zr-bevacizumab PET can identify patients with early disease progression. Zr-bevacizumab PET was done before and 2 and 6 wk after the start of everolimus, 10 mg/d, in mRCC patients. Routine CT scans were performed at baseline and every 3 mo thereafter. Tumor tracer uptake was quantified using SUV The endpoints were a change in tumor tracer uptake and treatment response on CT after 3 mo. Thirteen patients participated. The median SUV of 94 tumor lesions was 7.3 (range, 1.6-59.5). Between patients, median tumor SUV varied up to 8-fold. After 2 wk, median SUV was 6.3 (1.7-62.3), corresponding to a mean decrease of 9.1% ( < 0.0001). Three patients discontinued everolimus early. At 6 wk, a mean decrease in SUV of 23.4% compared with baseline was found in 70 evaluable lesions of 10 patients, with a median SUV of 5.4 (1.1-49.4, < 0.0001). All 10 patients who continued treatment had stable disease at 3 mo. Everolimus decreases Zr-bevacizumab tumor uptake. Further studies are warranted to evaluate the predictive value of Zr-bevacizumab PET for everolimus antitumor efficacy.
目前，缺乏预测依维莫司在转移性肾细胞癌（mRCC）患者中的疗效的生物标志物。依维莫司抑制血管内皮生长因子 A（VEGF-A）的表达。我们对使用 Zr-贝伐单抗（一种 VEGF-A 结合抗体示踪剂）的 mRCC 患者进行了 PET 扫描。目的是确定依维莫司开始后肿瘤示踪剂摄取的变化，并探讨 Zr-贝伐单抗 PET 是否可以识别早期疾病进展的患者。在 mRCC 患者中，每天 10mg 依维莫司开始后 2 周和 6 周进行 Zr-贝伐单抗 PET，基线和此后每 3 个月进行一次常规 CT 扫描。使用 SUV 定量肿瘤示踪剂摄取。终点是 3 个月后 CT 上肿瘤示踪剂摄取的变化和治疗反应。13 名患者参加了这项研究。94 个肿瘤病变的 SUV 中位数为 7.3（范围 1.6-59.5）。在患者之间，肿瘤 SUV 的中位数差异高达 8 倍。2 周后，SUV 中位数为 6.3（1.7-62.3），平均下降 9.1%（<0.0001）。3 名患者早期停止了依维莫司治疗。在 10 名可评估的患者的 70 个病变中，在 6 周时发现与基线相比 SUV 平均下降 23.4%，SUV 中位数为 5.4（1.1-49.4，<0.0001）。所有继续治疗的 10 名患者在 3 个月时均表现为疾病稳定。依维莫司降低了 Zr-贝伐单抗肿瘤摄取。需要进一步研究来评估 Zr-贝伐单抗 PET 对依维莫司抗肿瘤疗效的预测价值。
