Kibar Ali, Sager Sait, Sahin Onur Erdem, Asa Sertac, Uslu-Besli Lebriz, Demirci Nebi Serkan, Onur Irem, Ozturk Tulin, Teksoz Serkan, Sonmezoglu Kerim, Sayman Haluk Burcak
Department of Nuclear Medicine.
Division of Medical Oncology, Department of Internal Medicine.
Nucl Med Commun. 2025 Aug 1. doi: 10.1097/MNM.0000000000002036.
Radioactive iodine-refractory differentiated thyroid cancer (RAIR-DTC) is associated with challenges in both imaging and treatment due to resistance to I-131. The aim of this study is to compare the lesion detection rates of [18F] fluorodeoxyglucose (FDG) PET/computed tomography [CT] and [68Ga]Ga-prostate specific membrane antigen (PSMA)-11 PET/CT, and to investigate the theranostic potential of PSMA in RAIR-DTC.
Thirty-eight RAIR-DTC patients followed between 2022 and 2024 underwent [18F]FDG PET/CT and [68Ga]Ga-PSMA-11 PET/CT. Lesions with uptake exceeding background activity were considered positive, while physiological uptake areas and benign-appearing foci were excluded. Lesion maximum standardized uptake value (SUVmax), tumor-to-background ratio (TBR), and detection rates were calculated and compared.
[18F]FDG PET/CT detected more lesions overall than [68Ga]Ga-PSMA-11 PET/CT (96.8 vs. 60.1%), particularly in the thyroid bed, lymph nodes, and lungs. However, both modalities identified the same number of bone lesions. While [18F]FDG PET/CT was superior in most patients, [68Ga]Ga-PSMA-11 PET/CT detected more lesions in a subset of patients and performed better in the pure classic papillary thyroid carcinoma subtype compared to other subtypes (71.7 vs. 50.3%). SUVmax and TBR values were higher on [18F]FDG PET/CT, yet in 14 patients (36.8%), [68Ga]Ga-PSMA-11 PET/CT identified lesions with SUVmax exceeding liver SUVmax, indicating potential eligibility for PSMA-based radionuclide therapy.
Although [18F]FDG PET/CT demonstrated superior overall lesion detection, [68Ga]Ga-PSMA-11 PET/CT identified more lesions in a subset of patients. [68Ga]Ga-PSMA-11 PET/CT appears to be more beneficial in the pure classic subtype compared to other histological variants. Notably, [68Ga]Ga-PSMA-11 PET/CT demonstrated high uptake in a considerable number of patients and may provide theranostic value in RAIR-DTC patients with limited treatment options.
放射性碘难治性分化型甲状腺癌（RAIR-DTC）由于对I-131耐药，在成像和治疗方面均面临挑战。本研究的目的是比较[18F]氟脱氧葡萄糖（FDG）PET/计算机断层扫描（CT）和[68Ga]Ga-前列腺特异性膜抗原（PSMA）-11 PET/CT的病灶检出率，并探讨PSMA在RAIR-DTC中的诊疗潜力。
对2022年至2024年期间随访的38例RAIR-DTC患者进行了[18F]FDG PET/CT和[68Ga]Ga-PSMA-11 PET/CT检查。摄取超过本底活性的病灶被视为阳性，同时排除生理性摄取区域和表现为良性的病灶。计算并比较病灶的最大标准化摄取值（SUVmax）、肿瘤与本底比值（TBR）及检出率。
总体而言，[18F]FDG PET/CT检测到的病灶比[68Ga]Ga-PSMA-11 PET/CT更多（96.8%对60.1%），尤其是在甲状腺床、淋巴结和肺部。然而，两种检查方式发现的骨病灶数量相同。虽然在大多数患者中[18F]FDG PET/CT更具优势，但[68Ga]Ga-PSMA-11 PET/CT在一部分患者中检测到更多病灶，并且在纯经典乳头状甲状腺癌亚型中比其他亚型表现更好（71.7%对50.3%）。[18F]FDG PET/CT的SUVmax和TBR值更高，但在14例患者（36.8%）中，[68Ga]Ga-PSMA-11 PET/CT发现了SUVmax超过肝脏SUVmax的病灶，表明有接受基于PSMA的放射性核素治疗的可能性。
虽然[18F]FDG PET/CT在总体病灶检测方面表现更优，但[68Ga]Ga-PSMA-11 PET/CT在一部分患者中发现了更多病灶。与其他组织学变异型相比，[68Ga]Ga-PSMA-11 PET/CT在纯经典亚型中似乎更具优势。值得注意的是，[68Ga]Ga-PSMA-11 PET/CT在相当数量的患者中显示出高摄取，并且可能为治疗选择有限的RAIR-DTC患者提供诊疗价值。
