Prevalence of normal TSH value among patients with autonomously functioning thyroid nodule.
BACKGROUND
International guidelines significantly diverge on the effectiveness of thyroid scintigraphy (TS) in the initial work-up of thyroid nodules. In particular, the role of TS to detect or exclude the presence of autonomously functioning thyroid nodules (AFTN) in patients with normal serum thyrotropin (TSH) is still a matter to debate. Here, we aimed to review the literature on the prevalence of normal TSH value among patients with AFTN and meta-analyse data of the retrieved eligible papers.


METHODS
A comprehensive literature search of studies published from January 2000 to December 2014 on AFTN detected by TS was performed. Records reporting serum TSH values in AFTN were selected. Pooled prevalence of AFTN with normal TSH values was calculated on a per-patient analysis including 95% confidence intervals (95% CI).


RESULTS
Eight records including 2761 AFTN were selected for the meta-analysis. Pooled prevalence of AFTN with normal TSH detected by TS was 50% (95% CI: 32-68%). Selection bias in the included studies and heterogeneity among studies were potential limitations of the meta-analysis.


CONCLUSIONS
Present meta-analysis shows that about one in two patients with AFTN demonstrated by TS has a TSH value within normal references. As a consequence, TSH measurement may not be considered as effective as a single tool to detect or exclude AFTN, and TS remains mandatory.
Department of Nuclear Medicine and Thyroid Center, Oncology Institute of Southern Switzerland, Bellinzona, Switzerland.
Giorgio
G
Treglia
Department of Nuclear Medicine and Thyroid Center, Oncology Institute of Southern Switzerland, Bellinzona, Switzerland.|Section of Endocrinology and Diabetology, Ospedale Israelitico, Rome, Italy.
Pierpaolo
P
Trimboli
Department of Nuclear Medicine, RWTH University Hospital Aachen, Aachen, Germany.|Thyroid Committee, European Association of Nuclear Medicine, Vienna, Austria.
Frederik A
FA
Verburg
Thyroid Committee, European Association of Nuclear Medicine, Vienna, Austria.|Department of Nuclear Medicine, UKGM University Hospital Marburg, Marburg, Germany.
Markus
M
Luster
Department of Nuclear Medicine and Thyroid Center, Oncology Institute of Southern Switzerland, Bellinzona, Switzerland.|Thyroid Committee, European Association of Nuclear Medicine, Vienna, Austria.
Luca
L
Giovanella
D004812:Epidemiologic Methods; D006801:Humans; D011877:Radionuclide Imaging; D016606:Thyroid Nodule / Q000097:blood* / Q000000981:diagnostic imaging / Q000503:physiopathology; D013972:Thyrotropin / Q000097:blood*
D013972:Thyrotropin
Autonomously functioning thyroid nodule; meta-analysis; nodular goitre; scintigraphy; thyroid; thyroid-stimulating hormone