Recurrence detection in differentiated thyroid cancer patients with elevated serum level of antithyroglobulin antibody: special emphasis on using (18)F-FDG PET/CT.

Abstract

OBJECTIVE:

A clinical challenge is presented by differentiated thyroid cancer (DTC) patients who show increased serum antithyroglobulin antibody (TgAb) level with undetectable thyroglobulin (Tg) and negative radioiodine whole body scan (I-WBS). The aim of this study is to investigate the recurrence in DTC patients with elevated TgAb by using (18)F-FDG PET/CT (PET/CT) in addition to I-WBS and neck ultrasonography (USG).

SUBJECTS AND DESIGN:

A total of 276 TgAb+ patients were enrolled. Recurrence was assessed and compared between TgAb+ and TgAb- patients. TgAb+ patients were further categorized into two groups of 35-140 U/ml (Group A) and 140 U/ml or greater (Group B), according to receiver operating characteristic (ROC) curve analysis. Tumoural status was evaluated regarding the TgAb positivity and the degree of increase of TgAb.

RESULTS:

Thirty-seven (13.4%) of 276 TgAb+ patients were finally diagnosed with recurrence, compared with 21 (13.5%) of 156 TgAb- patients (P = 0.987). There was a correlation between TgAb level and recurrence (P = 0.032). Recurrence was more common in Group B than Group A (27.8% and 9.9%, respectively, P = 0.001). Recurrence was found in 37.5% of 24 TgAb+/Tg- patients who showed a gradually increasing tendency in serial measurements of TgAb. Sixteen cervical foci (21.1%) missed on neck USG and 17 lesions (22.4%) located outside the neck were additionally detected with PET/CT in TgAb+ patients.

CONCLUSIONS:

TgAb plays a complementary role to Tg in the detection of recurrence of DTC. Tumour recurrence was more frequent in patients with elevated TgAb level over 140 U/ml or a trend toward increasing levels. PET/CT could provide additional information to I-WBS and neck USG in detecting tumour recurrence in patients with elevated TgAb.

• Authors: Ji Hyoung Seo, Sang Woo Lee, Byeong-Cheol Ahn, Jaetae Lee
• Journal: Clinical endocrinology (Clin Endocrinol (Oxf)) Vol. 72 Issue 4 Pg. 558-63 (Apr 2010) ISSN: 1365-2265 [Electronic] England
• PMID: 19744107 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Autoantibodies
• anti-thyroglobulin
• Fluorodeoxyglucose F18
• Thyroglobulin

Topics

• Adolescent
• Adult
• Aged
• Aged, 80 and over
• Autoantibodies (blood)
• Female
• Fluorodeoxyglucose F18
• Humans
• Male
• Middle Aged
• Neoplasm Recurrence, Local (diagnosis, diagnostic imaging)
• Positron-Emission Tomography
• Prevalence
• Thyroglobulin (blood, immunology)
• Thyroid Neoplasms (diagnosis, diagnostic imaging)
• Tomography, X-Ray Computed
• Whole Body Imaging