From the Departments of Nuclear Medicine.
Surgical Gastroenterology, Jawaharlal Institute of Post Graduate Medical Education and Research, Puducherry, India.
Clin Nucl Med. 2023 Jun 1;48(6):e281-e288. doi: 10.1097/RLU.0000000000004641. Epub 2023 Apr 5.
Preliminary studies showed good expression of fibroblast activating protein inhibitor (FAPI) in hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC). Our aims were to study the diagnostic performance of 68 Ga-FAPI PET/CT in diagnosing the primary hepatobiliary malignancies and to compare its performance with 18 F-FDG PET/CT.
Patients suspected to have HCC and CC were recruited prospectively. FDG and FAPI PET/CT studies were completed within 1 week. Final diagnosis of malignancy was achieved by tissue diagnosis (either histopathological examination or fine-needle aspiration cytology) and radiological correlation from conventional modalities. Results were compared with final diagnosis and expressed as sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy.
Forty-one patients were included. Thirty-one were positive for malignancy and 10 were negative. Fifteen were metastatic. Of 31, 18 were CC and 6 were HCC. For overall diagnosis of the primary disease, FAPI PET/CT performed exceptionally compared with FDG PET/CT with sensitivity, specificity, and accuracy of 96.77%, 90%, and 95.12%, respectively, versus 51.61%, 100%, and 63.41% for FDG PET/CT. FAPI PET/CT clearly outperformed FDG PET/CT for the evaluation of CC with sensitivity, specificity, and accuracy of 94.4%, 100%, and 95.24%, respectively, whereas for FDG PET/CT sensitivity, specificity, and accuracy were 50%, 100%, and 57.14%, respectively. Diagnostic accuracy of FAPI PET/CT was 61.54% for metastatic HCC compared with 84.62% for FDG PET/CT.
Our study highlights the potential role of FAPI-PET/CT in evaluating CC. It also ascertains its usefulness in the cases of mucinous adenocarcinoma. Although it showed a higher lesion detection rate than FDG in primary HCC, its diagnostic performance in the metastatic setting is questionable.
初步研究表明，成纤维细胞激活蛋白抑制剂（FAPI）在肝细胞癌（HCC）和胆管细胞癌（CC）中表达良好。我们的目的是研究 68Ga-FAPI PET/CT 诊断原发性肝胆恶性肿瘤的诊断性能，并将其与 18F-FDG PET/CT 进行比较。
前瞻性招募疑似患有 HCC 和 CC 的患者。FDG 和 FAPI PET/CT 研究在 1 周内完成。恶性肿瘤的最终诊断通过组织诊断（组织学检查或细针穿刺细胞学检查）和常规影像学检查进行。结果与最终诊断进行比较，并表示为敏感性、特异性、阳性预测值、阴性预测值和诊断准确性。
共纳入 41 例患者。31 例为恶性肿瘤阳性，10 例为阴性。15 例为转移性。31 例中，18 例为 CC，6 例为 HCC。对于原发性疾病的总体诊断，FAPI PET/CT 的表现优于 FDG PET/CT，其敏感性、特异性和准确性分别为 96.77%、90%和 95.12%，而 FDG PET/CT 分别为 51.61%、100%和 63.41%。FAPI PET/CT 对 CC 的评估明显优于 FDG PET/CT，其敏感性、特异性和准确性分别为 94.4%、100%和 95.24%，而 FDG PET/CT 分别为 50%、100%和 57.14%。FAPI PET/CT 对转移性 HCC 的诊断准确性为 61.54%，而 FDG PET/CT 为 84.62%。
本研究强调了 FAPI-PET/CT 在评估 CC 中的潜在作用。它还证实了其在黏液性腺癌中的有用性。虽然它在原发性 HCC 中的病变检出率高于 FDG，但在转移性疾病中的诊断性能仍存在疑问。
