Risk factors and stratification for recurrence of patients with differentiated thyroid cancer, elevated thyroglobulin and negative I-131 whole-body scan, by restaging 18F-FDG PET/CT
Hellenic Journal of Nuclear Medicine, cilt.19, sa.3, ss.208-217, 2016 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 19 Sayı: 3
- Basım Tarihi: 2016
- Dergi Adı: Hellenic Journal of Nuclear Medicine
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Sayfa Sayıları: ss.208-217
- Anahtar Kelimeler: Elevated thyroglobulin 18level - F-FDG PET/CT-Negative I-131 whole-body scan -recurrent thyroid cancer
- Sağlık Bilimleri Üniversitesi Adresli: Evet
Özet
Objective: In nearly 20%-30% of patients with differentiated thyroid carcinoma (DTC) relapse and 7% of them die during the next 10 years after initial diagnosis. In 10%-30% of patients with DTC after ablation therapy during the follow-up show a negative iodine-131 (131l) whole-body screening test (131 l WBS) and increased serum thyroglobulin (Tg) level. Loss of ability of DTC metastatic lesions to trap 1311 is associated with pure survival and often aggressivedisease. Several studies haveshown that in DTC cases non trapping 131l,fluorine-18-fluorodeoxyglucose positron emissiontomography (18F-FDG PET) can detect recurrence or metastases with high sensitivity (80%-90%). The purpose of this study was to investigate the clinicopathologic features and other related risk factors of patients with DTC having elevated Tg levels and negative 1311 WBS in which recurrence was detected by 18F-FDG PET/CT. We tried to study and stratify patients in this grey zone who could benefit from 18F-FDG PET/CT for the detection of metastasis/recurrence according to predefined risk factors not investigated by other researchers. Subjects and Methods: We studied retrospectively 165 DTC patients with elevated Tg levels and a negative 131l WBS during their fol low-up between 2004-2015. Metastases/recu rrence was fou nd i n 49% of the patients on restaging with 18F-FDG PET/CTand were compared with nonmetastatic group according to predefined risk factors. These factors were also evaluated in true positive and false negative cases. Results:The sensitivity and specificity of 18F-FDG PET/CT for detecting recurrent/metastatic disease were 90% and 98.5%, respectively. No apparent predefined riskfactor impacting a false negative ,!iF-FDG PET/CT was found. Findingsin follicular carcinoma, Hurtle cell carcinoma and papillary carcinoma were not different from positive PET findings. The variants of papillary carcinoma also had no statistically difference with regard to 18F-FDG results. Conclusion: The most important factors affecting a true positive 18F-FDG PET/CT study were: ETE, high total 131l dose and the SU Vmax valuesover 4.5.