Clinical utility of 18F-FDG PET/CT in the follow-up of a large cohort of patients with high-risk differentiated thyroid carcinoma

SummaryIn a previous paper, we published the impact of initial [18F]FDG PET/CT (FDG-PET/CT) in high-risk patients with differentiated thyroid cancer (DTC) and described the changes in therapy management. The aim of the present study was to evaluate the prognostic impact of the initial FDG-PET/CT on a patient’s follow-up over three years and the rate of complete remission. Patients, methods: This study included 109 DTC patients who underwent radioiodine treatment (RIT), including posttherapeutic whole-body scintigraphy with FDG-PET/CT and a follow-up over three years. The follow-up included high-resolution sonography of the neck and determination of serum Tg as well as Tg antibodies every six months. The results of initial FDG-PET/CT and whole-body scintigraphy were compared with the status after three years of follow-up. Results: 24/109 patients (22%) presented FDG-positive lesions, 22/109 patients (20%) only iodine-positive lesions, and 63/109 patients (58%) neither FDG-positive nor iodine-positive lesions. After three years, 83/109 patients (76%) revealed full remission, 15/109 patients (14%) tumour persistence and 11/109 patients (10%) a progressive disease. The negative predictive value (NPV) was calculated for patients without FDG-positive lesions (NPV 85%) and patients without any lesions (NPV 91%) regarding full remission in the follow-up. Conclusion: FDG-PET/CT has a high NPV (85% to 91%) in DTC patients regarding recurrence-free follow-up after three years. The change in patient management in patients with iodine-negative lesions can lead to a higher rate of full remissions in the follow-up after additional surgery. Therefore, FDG-PET/ CT should be performed in all high-risk DTC patients in the context of the first RIT to improve patient management and risk stratification.

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Rising serum thyroglobulin in the follow-up of patients with differentiated thyroid carcinoma: the role of FDG PET-CT

Endocrine Abstracts ◽

10.1530/endoabs.35.p1122 ◽

2014 ◽

Author(s):

Paulina Godlewska ◽

Elzbieta Bruszewska ◽

Grazyna Lapinska ◽

Agnieszka Fijolek-Warszewska ◽

Marek Dedecjus

Keyword(s):

Thyroid Carcinoma ◽

Fdg Pet ◽

Differentiated Thyroid Carcinoma ◽

Serum Thyroglobulin ◽

Pet Ct ◽

Fdg Pet Ct

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Rare renal metastases from differentiated thyroid carcinoma: early clinical detection and treatment based on radioiodine

Arquivos Brasileiros de Endocrinologia & Metabologia ◽

10.1590/0004-2730000002913 ◽

2014 ◽

Vol 58 (3) ◽

pp. 260-269 ◽

Cited By ~ 2

Author(s):

Zhong-Ling Qiu ◽

Yan-Li Xue ◽

Quan-Yong Luo

Keyword(s):

Thyroid Carcinoma ◽

Fdg Pet ◽

Imaging Modality ◽

Differentiated Thyroid Carcinoma ◽

Renal Lesions ◽

131I Treatment ◽

Pet Ct ◽

18F Fdg ◽

Renal Metastases ◽

Fdg Pet Ct

Objective : The aim of this study was to explore the clinical characteristics of renal metastatic cancer, the methods for its detection by radioiodine (131I), and the response to 131I treatment in fourteen patients with renal metastases from differentiated thyroid carcinoma (DTC).Subjects and methods : DTC patients (n = 2,955) that received treatment with 131I were retrospectively analyzed. Scans (131I-WBS, 31I-SPECT/CT and/or 18F-FDG-PET/CT) were performed after an oral therapeutic dose of 131I. Therapeutic efficacy was evaluated based on changes in Tg and anatomical imaging changes at renal lesions.Results : Among these 14 patients, 11 had avidity for 131I, but three patients did not accumulate 131I after 131I treatment. In the 11 131I-positive renal lesions, 10 cases were detected by 131I-SPECT/CT combined with another imaging modality and one case by 131I-WBS combined with ultrasonography (US). In the three 131I-negative renal lesions, two cases were detected by 18F-FDG-PET/CT and one case by computed tomography (CT). In 11 patients with 131I-avid renal metastases, Serum Tg levels in 81.82% (9/11) patients showed a gradual decline, and 18.18% (2/11) of the patients showed a significant elevation. There was no marked difference in serum Tg before the last 131I treatment (Z = 0.157; p = 0.875). Only one patient presented partial response, eight patients exhibited stable disease, and renal metastases progressed in two patients showing progressive disease. No patients reached complete response.Conclusion : 131I-SPECT/CT, combined with another imaging modality after 131I-WBS, can contribute to the early detection of renal metastases of DTC. 131I therapy is a feasible and effective treatment for most DTC renal metastases with avidity for 131I. Arq Bras Endocrinol Metab. 2014;58(3):260-9

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