Jamsek Jan, Hocevar Marko, Bergant Damijan, Zaletel Katja, Rep Sebastijan, Lezaic Luka
Department of Nuclear Medicine, University Medical Centre Ljubljana, Zaloska cesta 7, 1000, Ljubljana, Slovenia.
Faculty of Medicine, University of Ljubljana, Vrazov trg 2, 1000, Ljubljana, Slovenia.
Ann Nucl Med. 2021 Apr;35(4):429-437. doi: 10.1007/s12149-021-01579-7. Epub 2021 Feb 5.
Medullary thyroid cancer (MTC) is a challenging neuroendocrine malignancy where the role of nuclear medicine imaging is currently limited. This paper investigates the potential diagnostic value of [F]Fluorocholine PET/CT in primary MTC.
We prospectively enrolled 25 patients (10 male, 15 female) with suspicion for primary MTC based on fine-needle aspiration biopsy (FNAB). All patients had a baseline three phase [F]Fluorocholine PET/CT (2.5 MBq/kg): two regional head and neck and upper mediastinum studies at 5 min (first phase) and 120 min (third phase) and a whole-body PET/CT (from the skull vertex to mid-thighs) at 60 min (second phase). Any non-physiological radiotracer uptake was regarded as MTC positive. All patients referred to surgery had a preoperative neck-US. True lesion status was assessed using either histopathology, FNAB results or follow-up imaging and laboratory (calcitonin, CEA) results. Results with p < 0.05 were considered statistically significant.
Nineteen of 25 patients (76%) were surgically treated and histopathology reports were obtained. Patient-based sensitivity and positive predictive value for detection of any MTC lesion using [F]Fluorocholine PET/CT were both 100%. Neck-US was more specific (100% vs 70%; p = 0.002) and had a higher positive predictive value than [F]Fluorocholine PET/CT (100% vs 55%; p = 0.018) for N1a and N1b staging. [F]Fluorocholine PET/CT had a higher sensitivity (100% vs 50%; p = 0.025) and higher negative predictive value (100% vs 81%; p = 0.026) than neck-US for N1b staging. The optimal SUV cut-off to differentiate malignant from benign neck lesions at 60 and 120 min was 2.56. Patients with M1 stage on PET/CT had higher calcitonin (median of 5,372 vs 496.6 pg/ml; p = 0.005) and CEA concentrations (median of 95.8 vs 18.65 µg/l; p = 0.034) compared to patients with M0 disease.
[F]Fluorocholine PET/CT appears to be a promising radiotracer for primary staging of MTC by increasing diagnostic accuracy for N staging and detecting possible distant metastatic sites at initial presentation of disease.
甲状腺髓样癌（MTC）是一种具有挑战性的神经内分泌恶性肿瘤，目前核医学成像在其中的作用有限。本文研究[F]氟胆碱PET/CT在原发性MTC中的潜在诊断价值。
我们前瞻性纳入了25例基于细针穿刺活检（FNAB）怀疑为原发性MTC的患者（10例男性，15例女性）。所有患者均进行了基线三相[F]氟胆碱PET/CT检查（2.5 MBq/kg）：在5分钟（第一阶段）和120分钟（第三阶段）进行两次头颈部及上纵隔局部检查，在60分钟（第二阶段）进行一次全身PET/CT检查（从颅顶至大腿中部）。任何非生理性放射性示踪剂摄取均视为MTC阳性。所有接受手术治疗的患者术前均进行了颈部超声检查。使用组织病理学、FNAB结果或随访影像学及实验室检查（降钙素、癌胚抗原）结果评估真实病变状态。p < 0.05的结果被认为具有统计学意义。
25例患者中有19例（76%）接受了手术治疗并获得了组织病理学报告。基于患者的[F]氟胆碱PET/CT检测任何MTC病变的敏感性和阳性预测值均为100%。对于N1a和N1b分期，颈部超声更具特异性（100%对70%；p = 0.002），且阳性预测值高于[F]氟胆碱PET/CT（100%对55%；p = 0.018）。对于N1b分期，[F]氟胆碱PET/CT的敏感性（100%对50%；p = 0.025）和阴性预测值（100%对81%；p = 0.0
