Relationship between serum thyroglobulin and 18FDG-PET/CT in 131I-negative differentiated thyroid carcinomas.

Abstract

BACKGROUND:

The purpose of this study was to assess the relationship between [(18) F]-fluorodeoxyglucose ((18) FDG)-positron emission tomography/CT ((18) FDG-PET/CT) and serum thyroglobulin (Tg) in patients with recurrent differentiated thyroid carcinoma (DTC).

METHODS:

Forty-two patients with recurrent DTC and negative Tg antibodies were included in the study. All patients underwent (131) I therapy due to an increasing serum Tg with a corresponding negative (131) I posttreatment whole body scan. The (18) FDG-PET/CT scans were then performed on all patients, serum Tg was measured concurrently, and respective results were compared.

RESULTS:

Sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), and accuracy of the (18) FDG-PET/CT examination were 93%, 84%, 93%, 84%, and 90%, respectively. The sensitivity of (18) FDG-PET/CT significantly increased in patients with serum Tg levels ≥4.6 ng/mL (96%) in comparison with patients having lower levels (25%; p < .001). Nonetheless, 3 of 27 patients (11%) with a true-positive (18) FDG-PET/CT still had a Tg <4.6 ng/mL.

CONCLUSION:

Although (18) FDG-PET/CT scans are more likely to be positive with pretest Tg levels ≥4.6 ng/mL, 11% of patients with DTC with a lower serum Tg level will still have a positive scan. Our findings are in contrast with the American Thyroid Association (ATA) guidelines, which only recommend to perform (18) FDG-PET/CT in patients with Tg levels >10 ng/mL.

• Authors: Luca Giovanella, Luca Ceriani, Diego De Palma, Sergio Suriano, Massimo Castellani, Frederik A Verburg
• Journal: Head & neck (Head Neck) Vol. 34 Issue 5 Pg. 626-31 (May 2012) ISSN: 1097-0347 [Electronic] United States
• PMID: 21850699 (Publication Type: Journal Article)
• Copyright: Copyright © 2011 Wiley Periodicals, Inc.

Chemical References

• Iodine Radioisotopes
• Radiopharmaceuticals
• Fluorodeoxyglucose F18
• Thyroglobulin

Topics

• Adenocarcinoma, Follicular (diagnostic imaging, therapy)
• Adult
• Aged
• Carcinoma, Papillary (diagnostic imaging, therapy)
• Female
• Fluorodeoxyglucose F18
• Humans
• Iodine Radioisotopes (therapeutic use)
• Lymphatic Metastasis (diagnosis)
• Male
• Middle Aged
• Multimodal Imaging
• Neoplasm Recurrence, Local (diagnosis)
• Positron-Emission Tomography
• Predictive Value of Tests
• ROC Curve
• Radiopharmaceuticals
• Sensitivity and Specificity
• Thyroglobulin (blood)
• Thyroid Neoplasms (diagnostic imaging, therapy)
• Tomography, X-Ray Computed
• Young Adult