Purpose

Accurate assessment of residual disease of tumor and lymph nodes after neoadjuvant immunochemotherapy is crucial in the active surveillance for patients with pathological complete response (pCR) and the optimal extent of lymphadenectomy for patients with non-pCR. This post hoc analysis aimed to evaluate the performance of ¹⁸F-FDG PET/CT to predict the pathological response to neoadjuvant immunochemotherapy for esophageal squamous cell carcinoma (ESCC).

Methods

Fifty-eight resectable ESCC patients received two cycles of camrelizumab in combination with chemotherapy and were enrolled in the final analysis. The ¹⁸F-FDG PET/CT scans were acquired at baseline (scan-1) and after immunochemotherapy but prior to surgery (scan-2). Maximum standardized uptake value (SUV_max), mean standardized uptake value (SUV_mean), tumor-to-blood pool SUV_max ratio (SUV_TBR), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were evaluated for their association with the pathological response to immunochemotherapy.

Results

Nineteen patients (32.8%, 19/58) had pCR and thirty-nine patients (67.2%, 39/58) had non-pCR after two doses of camrelizumab and chemotherapy. At scan-2, the SUV_max, SUV_mean, SUV_TBR, TLG, and MTV were significantly lower in pCR than in non-pCR patients. Decrease in TLG and MTV between scan-2 and scan-1 of the same patient was significantly higher in the pCR than in the non-pCR group. In the receiver operating characteristic curve analysis, SUV_max, SUV_mean, SUV_TBR, TLG, and MTV in scan-2 showed excellent predictive value for the pCR of primary tumors. Furthermore, SUV_max in scan-2 were higher in positive lymph nodes than in negative ones, suggesting a high negative predictive ability (98.6%) with a cut-off value at 1.4.

Conclusion

The parameters of ¹⁸F-FDG PET/CT have the excellent performance for predicting pCR after the combined neoadjuvant immunochemotherapy in resectable ESCC.

Trial registration

ChiCTR2000028900. Registered on January 6, 2020.

中文翻译：

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18F-FDG PET/CT 在预测新辅助 PD-1 阻断联合化疗治疗可切除食管鳞癌病理反应中的作用

目的

准确评估新辅助免疫化疗后肿瘤和淋巴结的残留病灶对于病理完全缓解（pCR）患者的主动监测和非pCR患者淋巴结清扫的最佳范围至关重要。该事后分析旨在评估¹⁸ F-FDG PET/CT 预测食管鳞状细胞癌 (ESCC) 新辅助免疫化疗的病理反应的性能。

方法

58 名可切除的 ESCC 患者接受了两个周期的 camrelizumab 联合化疗，并被纳入最终分析。18 F-FDG PET/CT 扫描是在基线 (scan-1) 和免疫化疗后但在手术前 (scan-2) 获得的^。评估最大标准化摄取值 (SUV _max )、平均标准化摄取值 (SUV _mean )、肿瘤与血池 SUV_最大比率 (SUV _TBR )、代谢肿瘤体积 (MTV) 和总病变糖酵解 (TLG)与免疫化疗的病理反应有关。

结果

19 名患者 (32.8%, 19/58) 在两次剂量的 camrelizumab 和化疗后获得 pCR，39 名患者 (67.2%, 39/58) 获得非 pCR。在扫描 2 时，pCR 患者的 SUV_最大值、SUV_平均值、SUV _TBR、TLG 和 MTV 显着低于非 pCR 患者。同一患者的 scan-2 和 scan-1 之间 TLG 和 MTV 的降低在 pCR 组中显着高于非 pCR 组。在受试者工作特征曲线分析中，scan-2 中的 SUV _max、SUV _mean、SUV _TBR、TLG 和 MTV 对原发肿瘤的 pCR 显示出极好的预测价值。此外，SUV _max在 scan-2 中，阳性淋巴结高于阴性淋巴结，表明具有较高的阴性预测能力 (98.6%)，截止值为 1.4。

结论

¹⁸ F-FDG PET/CT的参数在预测可切除 ESCC 联合新辅助免疫化疗后的 pCR 方面具有出色的性能。

试用注册

ChiCTR2000028900。2020 年 1 月 6 日注册。