From the Departments of Surgery.
Radiation Oncology.
Clin Nucl Med. 2022 Jun 1;47(6):496-502. doi: 10.1097/RLU.0000000000004191. Epub 2022 Apr 5.
Patients with esophageal cancer can develop distant metastases between the start of neoadjuvant chemoradiotherapy (nCRT) and planned surgery (ie, interval distant metastases). 18F-FDG PET/CT restaging after nCRT detects interval distant metastases in ~8% of patients. This study aimed to identify patients for whom 18F-FDG PET/CT restaging after nCRT could be omitted using an existing prediction model predicting for interval distant metastases or by using clinical stage groups.
Patients with locally advanced esophageal cancer who underwent baseline and restaging 18F-FDG PET/CT, nCRT, and were planned for esophagectomy between 2017 and 2021 were eligible for inclusion in this retrospective study. The primary outcome was the existing model's external performance (ie, discrimination and calibration) for predicting interval distant metastases. The existing model predictors included tumor length, cN status, squamous cell carcinoma histology, and baseline SUVmax. The secondary outcome determined the clinical stage groups (AJCC/UICC eighth edition) for adenocarcinoma and squamous cell carcinoma for which the incidence of interval distant metastases was <10%.
In total, 127 patients were included, of whom 17 patients developed interval distant metastases (13%; 95% confidence interval [CI], 8%-21%) and 9 patients were deemed to have false-positive lesions on 18F-FDG PET/CT (7%; 95% CI, 2%-11%). Applying the existing model to this cohort yielded a discriminatory c-statistic of 0.56 (95% CI, 0.40-0.72). The calibration of the existing model was poor (ie, mostly underestimating the actual risk). The incidence of true-positive versus false-positive interval distant metastases for patients with clinical stage II disease was 5% versus 0%; clinical stage III, 14% versus 8%; and clinical stage IVa, 22% versus 9%.
The existing prediction model cannot reliably identify patients at risk for developing interval distant metastases after nCRT for esophageal cancer. Omission of 18F-FDG PET/CT restaging after nCRT could be considered in patients with clinical stage II esophageal cancer.
接受新辅助放化疗（nCRT）和计划手术（即间隔远处转移）之间，食管癌患者可能会发生远处转移。nCRT 后 18F-FDG PET/CT 再分期检测到约 8%的患者存在间隔远处转移。本研究旨在通过使用现有的预测间隔远处转移的模型或使用临床分期组，确定哪些患者可以省略 nCRT 后 18F-FDG PET/CT 再分期。
本回顾性研究纳入了 2017 年至 2021 年间接受基线和 18F-FDG PET/CT 再分期、nCRT 并计划行食管切除术的局部晚期食管癌患者。主要结局是现有模型预测间隔远处转移的外部表现（即鉴别力和校准度）。现有的模型预测因子包括肿瘤长度、cN 状态、鳞状细胞癌组织学和基线 SUVmax。次要结局确定了腺癌和鳞状细胞癌的临床分期组（AJCC/UICC 第八版），这些分期组的间隔远处转移发生率<10%。
共纳入 127 例患者，其中 17 例患者发生间隔远处转移（13%；95%置信区间 [CI]，8%-21%），9 例患者在 18F-FDG PET/CT 上被认为存在假阳性病变（7%；95%CI，2%-11%）。将现有模型应用于该队列，得出的鉴别 c 统计量为 0.56（95%CI，0.40-0.72）。现有模型的校准情况较差（即，大多低估了实际风险）。临床分期 II 期患者的真阳性与假阳性间隔远处转移发生率分别为 5%与 0%；临床分期 III 期分别为 14%与 8%；临床分期 IVa 期分别为 22%与 9%。
对于接受 nCRT 的食管癌患者，现有的预测模型不能可靠地识别发生间隔远处转移的风险患者。在临床分期 II 期食管癌患者中，可考虑省略 nCRT 后 18F-FDG PET/CT 再分期。
