This single-center, single-arm, phase II trial (ChiCTR2100050057) investigated the ability of ¹⁸F-labeled fibroblast activation protein inhibitor ([¹⁸F]AlF-NOTA-FAPI-04, denoted as ¹⁸F-FAPI) PET/CT to predict the response to neoadjuvant camrelizumab plus chemotherapy (nCC) in locally advanced esophageal squamous cell carcinoma (LA-ESCC). Methods: This study included 32 newly diagnosed LA-ESCC participants who underwent ¹⁸F-FAPI PET/CT at baseline, of whom 23 also underwent scanning after 2 cycles of nCC. The participants underwent surgery after 2 cycles of nCC. Recorded PET parameters included maximum, peak, and mean SUVs and tumor-to-background ratios (TBRs), metabolic tumor volume, and total lesion FAP expression. PET parameters were compared between patient groups with good and poor pathologic responses, and the predictive performance for treatment response was analyzed. Results: The good and poor response groups each included 16 participants (16/32, 50.0%). On ¹⁸F-FAPI PET/CT, the posttreatment SUVs were significantly lower in good responders than in poor responders, whereas the changes in SUVs with treatment were significantly higher (all P < 0.05). SUV_max (area under the curve [AUC], 0.87; P = 0.0026), SUV_peak (AUC, 0.89; P = 0.0017), SUV_mean (AUC, 0.88; P = 0.0021), TBR_max (AUC, 0.86; P = 0.0031), and TBR_mean (AUC, 0.88; P = 0.0021) after nCC were significant predictors of pathologic response to nCC, with sensitivities of 63.64%–81.82% and specificities of 83.33%–100%. Changes in SUV_max (AUC, 0.81; P = 0.0116), SUV_peak (AUC, 0.82; P = 0.0097), SUV_mean (AUC, 0.81; P = 0.0116), and TBR_mean (AUC, 0.74; P = 0.0489) also were significant predictors of the pathologic response to nCC, with sensitivities and specificities in similar ranges. Conclusion: ¹⁸F-FAPI PET/CT parameters after treatment and their changes from baseline can predict the pathologic response to nCC in LA-ESCC participants.

这项单中心、单臂、II 期试验 （ChiCTR2100050057） 研究了 ¹⁸F 标记的成纤维细胞活化蛋白抑制剂 （[¹⁸F]AlF-NOTA-FAPI-04，表示为 ¹⁸F-FAPI） PET/CT 预测局部晚期食管鳞状细胞癌 （LA-ESCC） 对新辅助卡瑞利珠单抗加化疗 （nCC） 的反应的能力。方法：这项研究包括 32 名新诊断的 LA-ESCC 参与者，他们在基线时接受了 ¹⁸次 F-FAPI PET/CT，其中 23 名在 2 个 nCC 周期后也接受了扫描。参与者在 2 个 nCC 周期后接受了手术。记录的 PET 参数包括最大、峰值和平均 SUV 以及肿瘤背景比 （TBR） 、代谢肿瘤体积和总病灶 FAP 表达。比较病理反应良好和较差的患者组之间的 PET 参数，并分析治疗反应的预测性能。结果：反应良好组和不良反应组各包括 16 名参与者 （16/32,50.0%）。在 ¹⁸F-FAPI PET/CT 中，治疗后 SUV 患者患者疗效好，治疗后 SUV 水平显著低于患者，而治疗后 SUV 患者的变化显著升高 （P值均 < 0.05）。SUV_max（曲线下面积 [AUC]，0.87;P = 0.0026）、SUV_峰值 （AUC，0.89;P = 0.0017），SUV_平均值 （AUC，0.88;P = 0.0021）、_{TBR 最大值} （AUC， 0.86;P = 0.0031）和 TBR_平均值 （AUC，0.88;P = 0.0021） 是 nCC 病理反应的重要预测因子，敏感性为 63.64%–81.82%，特异性为 83.33%–100%。SUV_max 的变化 （AUC，0.81;P = 0.0116）、SUV_峰值 （AUC， 0.82;P = 0.0097），SUV_平均值 （AUC，0.81;P = 0.0116）和 TBR_平均值 （AUC，0.74;P = 0.0489） 也是对 nCC 病理反应的重要预测因子，敏感性和特异性相似。结论： 治疗后 ¹⁸个 F-FAPI PET/CT 参数及其相对于基线的变化可以预测 LA-ESCC 参与者对 nCC 的病理反应。