Clinical relevance of ¹⁸F-FDG PET/CT in the postoperative follow-up of patients with history of medullary thyroid cancer

Abstract

BackgroundThe aim of the study was evaluation of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography with computed tomography (PET/CT) in the detection of active disease in the patients with suspected recurrence of the medullary thyroid carcinoma (MTC).Patients and methods18F-FDG PET/CT investigation was performed in 67 patients, investigated from 2010 to 2019. _ Follow up was performed from 6 to 116 months after surgery (median 16.5 months, x± SD = 29±28.9 months). Twenty five of 67 patients underwent 99mTc-dimercaptosuccinic acid (99mTc-DMSA) scintigraphy, 11 underwent somatostatin receptor scintigraphy (SRS) with 99mTc-HYNIC TOC while 11 123I-metaiodobenzylguanidine (MIBG) scintigraphy.ResultsFrom 67 patients, 35 (52.2%) had true positive 18F-FDG PET/CT findings (TP). Average maximal standardized uptake value (SUVmax) for all TP lesions was 5.01+3.6. In 25 (37.3%) patients findings were true negative (TN). Four (6%) patients had false positive (FP) findings while three (4.5%) were false negative (FN). Thus, sensitivity of the 18F-FDG PET/ CT was 92.11%, specificity 86.21%, positive predictive value 89.74%, negative predictive value 89.29% and accuracy 89.55%. In 27 patients (40%) 18F-FDG PET/CT finding influenced further management of the patient.Conclusions18F-FDG PET/CT has high accuracy in the detection of metastases/recurrences of MTC in patients after thyroidectomy as well as in evaluation and the appropriate choice of the therapy.

PET/CT with various radiopharmaceuticals in the complex diagnosis of medullary thyroid carcinoma: a review

“…ПЭТ/КТ с 18 F-ФДГ. Укорочение периода удвоения концентраций кальцитонина и РЭА до 24 месяцев и меньше свидетельствует о дедифференцировке опухоли и повышении ее злокачественного потенциала [29,31,[33][34][35]. Включение в план обследования пациентов ПЭТ/КТ c 18 F-ФДГ позволит оценить дальнейший прогноз течения заболевания: появление 18 F-ФДГ-позитивных очагов ассоциировано с неблагоприятным прогнозом [31,33].…”

Molecular Imaging and Therapy of Differentiated Thyroid Carcinoma in Adults

“…36,37 FDG PET has typically been considered of limited utility in patients with MTC, although one recent study reported sensitivity of 92% and specificity of 86% for detection of recurrent or metastatic MTC in a small cohort. 38 Low count rates and high energy/364 keV photon emissions degrade diagnostic imaging quality. However, the longer imaging interval improves background clearance.…”

“…FDG PET is recommended for initial staging of anaplastic thyroid carcinoma and may aid in prognostication 36,37 . FDG PET has typically been considered of limited utility in patients with MTC, although one recent study reported sensitivity of 92% and specificity of 86% for detection of recurrent or metastatic MTC in a small cohort 38 …”

Nuclear Medicine and Cancer Theragnostics: Basic Concepts

“…The sensitivity of 18 F-FDG PET for MTC metastases is moderate (59-69%) [25], with the highest yield among individuals with short tumor marker doubling periods (one year). A study of 18 F FDG PET indicated that in MTC with high calcitonin, the sensitivity was 92% and the specificity was 86%, with a significant impact on management decisions [26].…”