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On the basis of erroneous and incomplete data, the authors (1) suggest algorithms for the diagnostic evaluation of the thyroid, which cannot be applied in their current form—at least not in Germany, (formerly) a region with iodine deficiency.
The specificity of scintigraphy was given as 5%; this is not correct—the three citations are not conclusive: a 20-year-old study from Ireland and two review articles without concrete data.
Furthermore, the article contains some technical inconsistencies.
Firstly, the cited European guideline was introduced in 2006 and the others even later, which means they had not been published at the time of data collection. The procedural recommendations of the German Society of Nuclear Medicine of 2003 (2), which were coordinated with the German Society of Endocrinology and the German Society for Surgery and deposited with the Association of the Scientific Medical Societies in Germany (Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften, AWMF) were not cited.
Secondly, the authors combined their data with a figure from the AACE/AME/ETA guideline, which was published only in 2010, two years after the collection of data.
Thirdly, how would it have been common knowledge that 94% of patients who underwent scintigraphy also had a low concentration of thyroid stimulating hormone (TSH) or multinodular goiter? Scintigraphy in (euthyroid) uninodular goiter was “done in accordance with the guideline.” According to the valid German guideline (2), indications for thyroid scintigraphy are amongst others:
- Palpable and/or sonographically distinct focal findings (nodules of 1 cm or larger).
- Suspected focal/diffuse autonomy in manifest/latent hyperthyroidism.
- After definitive therapy in order to document therapeutic success.
- If required during the course of untreated functional autonomy.
The depicted algorithm can therefore not be applied to the situation in Germany. A single nodule ≥ 1 cm would directly undergo fine-needle aspiration cytology (FNAC) without scintigraphic investigation. For a hyperfunctional and therefore benign nodule, the cytopathological finding often is “follicular neoplasia,” and the patient would probably have unnecessary surgery because scintigraphy was not done. A recent German study found no decreased TSH concentration in 70% of all cases of focal autonomy (3).
Lastly, the cited article (Fast et al.) on thyroid hormone administration in the treatment of goiter studied the long abandoned concept of TSH suppressive administration of levothyroxine; but a recent, methodologically superior German study remains unmentioned (4).
On behalf of the working group for thyroid diseases of the German Society of Nuclear Medicine:
Dr. med. Michael C. Kreißl
Klinik für Nuklearmedizin, Klinikum Augsburg/Klinik für Nuklearmedizin,
Prof. Dr. med. Dr. rer. nat. Andreas Bockisch
Klinik für Nuklearmedizin, Universitätsklinikum Essen
Prof. Dr. med. Markus Dietlein
Klinik für Nuklearmedizin, Universitätsklinikum Köln
Prof. Dr. med. Frank Grünwald
Klinik für Nuklearmedizin, Universitätsklinikum Frankfurt am Main
Prof. Dr. med. Markus Luster
Klinik für Nuklearmedizin, Universitätsklinikum Gießen und Marburg GmbH, Marburg
Conflict of interest statement
Prof. Grünwald has received speaker honoraria from Sanofi/Henning, Merck, Thermofischer, GE. The other authors declare that no conflict of interest exists.
|1.||Wienhold R, Scholz M, Adler JB, Günster C, Paschke R. The management of thyroid nodules—a retrospective analysis of health insurance data. Dtsch Arztebl Int 2013; 110(49): 827–34. VOLLTEXT|
|2.||Dietlein M, Dressler J, Eschner W, Leisner B, Reiners C, Schicha H; Deutsche Gesellschaft für Nuklearmedizin; Deutsche Gesellschaft für Medizinische Physik: Leitlinie zur Schilddrüsendiagnostik (Version 2). Nuklearmedizin 2003; 42: 120–2.|
|3.||Graf D, Helmich-Kapp B, Graf S, Veit F, Lehmann N, Mann K: Funktionelle Aktivität fokaler Schilddrüsenautonomien in Deutschland. Dtsch Med Wochenschr 2012; 137: 2089–92 CrossRef MEDLINE|
|4.||Grussendorf M, Reiners C, Paschke R, Wegscheider K; LISA Investigators: Reduction of thyroid nodule volume by levothyroxine and iodine alone and in combination: a randomized, placebo-controlled trial. J Clin Endocrinol Metab 2011; 96: 2786–95 CrossRef MEDLINE PubMed Central|