Isik Emine Goknur, Has Simsek Duygu, Gul Nurdan, Erturk Sukru Mehmet, Buyukkaya Fikret, Soyluk Selcukbiricik Ozlem, Iscan Ahmet Yalin, Özkan Zeynep Gözde, Sanli Yasemin, Mudun Ayse, Kuyumcu Serkan
From the Department of Nuclear Medicine.
Department of Endocrinology.
Clin Nucl Med. 2024 Nov 19. doi: 10.1097/RLU.0000000000005558.
We aimed to compare the diagnostic performance of 68Ga-FAPI-04 (FAPI) in comparison to 68Ga-DOTATATE (SSTR) PET/CT for patients presenting with recurrent medullary thyroid carcinoma (MTC).
Sixteen MTC patients with elevated calcitonin levels (>150 pg/mL) underwent FAPI and SSTR PET/CT. Two nuclear medicine physicians evaluated all images, categorizing lesions into locoregional metastases, mediastinal lymph nodes (LNs), liver, and bone metastases. SUVmax and tumor-to-background ratio were recorded. PET modalities were compared using the McNemar test. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of FAPI and SSTR PET were calculated.
The cohort comprised 16 patients (50% female; mean age 50 ± 17 years). Median calcitonin and CEA levels were 6234 pg/mL and 17.3 ng/mL, respectively. In patient-based analysis, SSTR exhibited higher diagnostic sensitivity compared with FAPI (88% vs 81%), resulting a statistically significant difference (P = 0.004). Mean SUVmax and tumor-to-background ratio values were 10.3 and 5.35 for FAPI, and 9.7 and 11.9 for SSTR PET, respectively. In lesion-based analyses, FAPI demonstrated higher accuracy than SSTR for cervical LNs (91.9% vs 50%), mediastinal LNs (94.9% vs 54.4%), and liver metastases (57.4% vs 7.3%), respectively. Notably, 31% of patients (n = 5) with FAP-expressing liver lesions showed no uptake on SSTR imaging. MRI confirmed liver metastases in 3 of these patients; however, 2 FAP-expressing lesions were confirmed as hemangiomas. False-positive findings of DOTA primarily included reactive LNs and bone hemangiomas.
FAPI PET presents promising outcomes in detecting metastases in recurrent MTC patients. Although its diagnostic performance matches SSTR on a per-patient basis, FAPI PET exhibits superior sensitivity and accuracy in lesion-based analyses, notably for liver and bone metastases.
我们旨在比较68Ga-FAPI-04（FAPI）与68Ga-DOTATATE（SSTR）PET/CT对复发性甲状腺髓样癌（MTC）患者的诊断性能。
16例降钙素水平升高（>150 pg/mL）的MTC患者接受了FAPI和SSTR PET/CT检查。两名核医学医师评估了所有图像，将病变分为局部区域转移、纵隔淋巴结（LNs）、肝脏和骨转移。记录SUVmax和肿瘤与背景比值。使用McNemar检验比较PET检查方式。计算FAPI和SSTR PET的敏感性、特异性、阳性预测值、阴性预测值和准确性。
该队列包括16例患者（50%为女性；平均年龄50±17岁）。降钙素和癌胚抗原水平的中位数分别为6234 pg/mL和17.3 ng/mL。在基于患者的分析中，SSTR与FAPI相比表现出更高的诊断敏感性（88%对81%），差异具有统计学意义（P = 0.004）。FAPI的平均SUVmax和肿瘤与背景比值分别为10.3和5.35，SSTR PET分别为9.7和11.9。在基于病变的分析中，FAPI在检测颈部LNs（91.9%对50%）、纵隔LNs（94.9%对54.4%）和肝转移（57.4%对7.3%）方面比SSTR表现出更高的准确性。值得注意的是，31%（n = 5）有FAP表达的肝脏病变患者在SSTR成像上无摄取。MRI在其中3例患者中证实有肝转移；然而，2个FAP表达病变被证实为血管瘤。DOTA的假阳性结果主要包括反应性LNs和骨血管瘤。
FAPI PET在检测复发性MTC患者的转移灶方面显示出有前景的结果。虽然其在基于患者的诊断性能上与SSTR相当，但FAPI PET在基于病变的分析中表现出更高的敏感性和准确性，特别是对于肝转移和骨转移。
