Electronic Letters to:

Article: Francesca Menconi, Michele Marinò, Aldo Pinchera, Roberto Rocchi, Barbara Mazzi, Marco Nardi, Luigi Bartalena, and Claudio Marcocci EFFECTS OF TOTAL THYROID ABLATION VS NEAR-TOTAL THYROIDECTOMY ALONE ON MILD TO MODERATE GRAVES' ORBITOPATHY TREATED WITH INTRAVENOUS GLUCOCORTICOIDS J Clin Endocrinol Metab 2007; 0: jc.2006-1800v1 [Abstract]

eLetters: Submit a response to this article

Electronic letters published:

Reply to Prof. Wiersinga's letter

Claudio Marcocci, Francesca Menconi, Michele Marinò, Roberto Rocchi, and Aldo Pinchera   (13 July 2007)

TOTAL THYROID ABLATION: IS IT USEFUL IN GRAVES’ ORBITOPATHY?

Wilmar M. Wiersinga   (27 June 2007)

Reply to Prof. Wiersinga's letter 13 July 2007
Claudio Marcocci, MD Dept Endocrinology, Univ of Pisa, Francesca Menconi, Michele Marinò, Roberto Rocchi, and Aldo Pinchera Send letter to journal: Re: Reply to Prof. Wiersinga's letter c.marcocci{at}endoc.med.unipi.it Claudio Marcocci, et al.	We thank Prof Wiersinga for giving us the opportunity to add further information on our study. We agree with him that it was disappointing not to ablation or thyroidectomy with methimazole, which is certainly a relevant issue that remains to be investigated. As far as the specific requests from Prof. Wiersinga are concerned, we answer as follows: 1. In the original version of the manuscript the “last observation carried forward” principle had been applied. However, as of the request of one of the reviewers, we used the “intention-to-treat” principle. Thus, findings at 9 months were included in the analysis regardless of whether patients had undergone additional treatments between 3 and 9 months. Nevertheless, this did not affect our results, as the proportion of patients who underwent additional therapies was similar in the two groups. In the end, statistical findings were similar regardless of whether the “intention-to-treat” or the “last observation carried forward” principle was applied. 2. Quantitative measures of the individual parameters of Graves’ orbitopathy were originally provided, but were removed on the request of one of the reviewers. As indicated below, some of these measures were more favorably affected by total thyroid ablation (TTA) than thyroidectomy alone (TX). In particular, changes in eyelid width (TTA: baseline 12.1±1.8 mm, 3 months 10.6±1.9 mm, 9 months 10.3±2.1 mm; TX: baseline 11.8±1.5 mm, 3 months 11.9±2.5 mm, 9-months 11.7±2.7 mm) and clinical activity score (TTA: baseline 2.9±0.9, 3 months 1.9±0.9, 9 months 1.3±1.0; TX: baseline 3.0±0.9, 3 months 2.2±1.2, 9 months 2.1±1.5) were significantly greater (P between groups by ANOVA for repeated measures: eyelid width=0.025; clinical activity score=0.023) in TTA patients. On the other hand, no statistically significant difference was observed for proptosis (TTA: baseline 23.2±2.3, 3 months 22.3±3.1, 9 months 22.1±3.1; TX: baseline 23.0±2.1, 3 months 22.9±2.5, 9-months 22.8±2.7. P=0.41). 3. As far as complications of surgery are concerned, none of the patients had laryngeal nerve paralysis. A total of two patients (3%) had permanent hypoparathyroidism.
TOTAL THYROID ABLATION: IS IT USEFUL IN GRAVES’ ORBITOPATHY? 27 June 2007
Wilmar M. Wiersinga, Endocrinologist Academic Medical Center, University of Amsterdam, The Netherlands Send letter to journal: Re: TOTAL THYROID ABLATION: IS IT USEFUL IN GRAVES’ ORBITOPATHY? w.m.wiersinga{at}amc.uva.nl Wilmar M. Wiersinga	I am writing with regard to the randomized clinical trial comparing effects of total thyroid ablation (near-total thyroidectomy + 30 mCi 131I) versus near-total thyroidectomy alone on mild to moderate Graves’ orbitopathy (1). The study is important because it tests the hypothesis that getting rid of all thyroid antigens will have a beneficial effect on the course of Graves’ orbitopathy. While the authors should be congratulated on completing such a demanding trial, it is a pity that the authors did not report or analyze further the original third antithyroid drug treatment study arm to address the debate on the preferred treatment of Graves’ hyperthyroidism (block-and-replace regimen or total thyroid ablation) in the presence of eye changes. To fully appreciate the study results, I have three questions to the authors: 1. The paper mentions a remarkable exacerbation of Graves’ orbitopathy between 3 and 9 months in five patients, necessitating other treatments. Are the results of these five patients incorporated in the final evaluation at 9 months (by the principle of last observation carried forward)? 2. The beneficial effect of total thyroid ablation is limited to the reduction of proptosis and eyelid width, but quantitative measurements of the extent of improvement are not provided, making it difficult to judge the clinical relevance of the improvements. 3. The authors do not mention the frequency of side effects of near-total thyroidectomy (like permanent vocal cord palsy and hypoparathyroidism), which could neutralize any improvement in the patients’ quality of life obtained by improved eye disease. Reference 1. Menconi F, Marino M, Pinchera A, Rocchi R, Mazzi B, Nardi M, Bartalena L, Marcocci C. 2007. Effects of total thyroid ablation versus near- total thyroidectomy alone on mild to moderate Graves' orbitopathy treated with intravenous glucocorticoids. J Clin Endocrinol Metab 92:1653-1658