Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, Massachusetts, USA.
Department of Radiation Oncology, Brigham and Women's Hospital, Harvard Medical School, Boston, USA.
Ann Nucl Med. 2018 Apr;32(3):165-174. doi: 10.1007/s12149-018-1229-0. Epub 2018 Jan 13.
The aim of this prospective pilot study was to investigate the potential of serial FLT-PET/CT compared to FDG-PET/CT to provide an early indication of esophageal cancer response to concurrent neoadjuvant chemoradiation therapy.
Five patients with biopsy-proven esophageal adenocarcinomas underwent neoadjuvant chemoradiation (Tx) prior to minimally invasive esophagectomy. The presence of residual tumor was classified histologically using the Mandard et al. criteria, categorizing patients as pathologic responders and non-responders. Participants underwent PET/CT imaging 1 h after intravenous administration of FDG and of FLT on two separate days within 48 h of each other. Each patient underwent a total of 3 scan "pairs": (1) pre-treatment, (2) during treatment, and (3) post-treatment. Image-based response to therapy was measured in terms of changes in SUVmax (ΔSUV) between pre- and post-therapeutic FLT- and FDG-PET scans. The PET imaging findings were correlated with the pathology results after surgery.
All tumors were FDG and FLT avid at baseline. Lesion FLT uptake was lower than with FDG. Neoadjuvant chemoradiation resulted in a reduction of tumor uptake of both radiotracers in pathological responders (n = 3) and non-responders (n = 2). While the difference in the reduction in mean tumor FLT uptake during Tx between responders (ΔSUV = - 55%) and non-responders (ΔSUV = - 29%) was significant (P = 0.007), for FDG it was not, [responders had a mean ΔSUV = - 39 vs. - 31% for non-responders (P = 0.74)]. The difference in the reduction in tumor FLT uptake at the end of treatment between responders (ΔSUV = - 62%) and non-responders (ΔSUV = - 57%) was not significant (P = 0.54), while for FDG there was a trend toward significance [ΔSUV of responders = - 74 vs. - 52% in non-responders (P = 0.06)].
The results of this prospective pilot study suggest that early changes in tumor FLT uptake may be better than FDG in predicting response of esophageal adenocarcinomas to neoadjuvant chemoradiation. These preliminary results support the need to corroborate the value of FLT-PET/CT in a larger cohort.
本前瞻性初步研究旨在探讨 FLT-PET/CT 系列检查相对于 FDG-PET/CT 检查在提供食管腺癌患者接受新辅助放化疗后早期疗效评估方面的潜在作用。
5 例经活检证实的食管腺癌患者在接受微创食管切除术前先接受新辅助放化疗（Tx）。采用 Mandard 等标准进行组织学评估，根据残留肿瘤的存在情况将患者分为病理缓解者和非缓解者。在 48 小时内的两天内，参与者分别在静脉注射 FDG 和 FLT 后 1 小时接受 PET/CT 成像。每位患者总共进行 3 对扫描：（1）治疗前，（2）治疗中，和（3）治疗后。根据治疗前后 FLT 和 FDG-PET 扫描中 SUVmax（ΔSUV）的变化来衡量肿瘤对治疗的反应。PET 成像结果与术后病理结果相关联。
所有肿瘤在基线时均为 FDG 和 FLT 摄取阳性。病灶 FLT 摄取低于 FDG。在病理缓解者（n=3）和非缓解者（n=2）中，新辅助放化疗均导致两种示踪剂摄取的肿瘤减少。在治疗过程中，缓解者（ΔSUV=-55%）和非缓解者（ΔSUV=-29%）之间肿瘤 FLT 摄取减少的差异具有统计学意义（P=0.007），但对于 FDG 则不然[缓解者的平均 SUV 下降为-39%，而非缓解者为-31%（P=0.74）]。在治疗结束时，缓解者（ΔSUV=-62%）和非缓解者（ΔSUV=-57%）之间肿瘤 FLT 摄取减少的差异无统计学意义（P=0.54），而对于 FDG，则存在统计学意义[缓解者的 SUV 下降为-74%，而非缓解者为-52%（P=0.06）]。
本前瞻性初步研究结果表明，肿瘤 FLT 摄取的早期变化可能优于 FDG，可预测食管腺癌对新辅助放化疗的反应。这些初步结果支持在更大的队列中验证 FLT-PET/CT 价值的必要性。
