Prior carbimazole therapy has no effect on the outcome of radioiodine therapy in pediatric Graves' disease

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: SAT 622-631-Pediatric Endocrinology: Thyroid
Saturday, June 15, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board SAT-622
C S Bal*1, Sanjana Ballal2, Punit Sharma2, Nishikant Damle3 and Ramya Soundararajan4
1Dept of Nuclear Medicine, New Delhi, India, 2All India Institute of Medical sciences, New Delhi, India, 3All India Institute of Medical Sciences, new delhi, India, 4All India Institute of Medical Sciences, New delhi, India
Context: Therapeutic options for pediatric Graves’ disease as per ATA/AACE guideline recommendation 50 include antithyroid drugs (ATD), surgery and radioiodine (RAI 131I) [1]. Common practices include ATD therapy as the first line treatment and 131I therapy as the second line treatment option. However, till date only few studies have addressed the issue of prior carbimazole therapy effect on the RAI success rate in the treatment of pediatric Graves’ disease, thus creating a significant controversy [2-3].

Objective: To evaluate the effect of prior carbimazole therapy on the outcome of RAI in pediatric Graves’ disease.

Design: Retrospective analysis

Study design: Medical records of 126 children treated with fixed doses of 185 MBq 131I for Graves’ disease between 1995-2012  with a mean follow- up of 25.7 months (range: 2-120 mo) were scrutinized. 12 patients were excluded due to lack of sufficient clinical and biochemical data. We identified a total of 114 patients (84 girls and 30 boys, range: 4-20 y, mean 24 hr RAIU 58.4 % ± 18) among which 74/114 had prior carbimazole (group 1) and 40/114 were drug naïve (group 2). Multiple variables including gender, prior ATD therapy and its duration, outcome after first dose of RAI, thyroid size, total dose received, 24 hr RAIU values and TSH were used as the predictive factors for the development of euthyroidism (eu) or hypothyroidism after treatment.

Results: Cure rate after 131I therapy was defined as a sustained biochemical euthyroid or hypothyroid status. Over all cure rate after first dose of RAI was attained in 81 children (71%) and remaining 33 (29%) children required 2 or more doses. On further analysis: 66% of children in Gr1 and 80% of children in Gr2 were cured with the first dose of radioiodine (p= 0.178). Cure rate achieved at 1 year of follow-up and at a mean follow-up of 25.7 months in group 1 and 2 were 81% and 87% (p=0.407) and 90% & 91% (p=0.926), respectively. Other predictive factors were found statistically not significant.

Conclusions: There was a trend showing lower success rate with group1 children compared to drug naïve group2, however, it was statistically not significant. Thus we conclude that prior carbimazole therapy has no effect on the outcome of radioiodine therapy in pediatric Graves’ disease.

1. Bahn RS et al,Thyroid 21:593–646. (2). Leu SW et al., Acta Paediatr Taiwan. 2003 ;44(4):220-6. (3). Ward L et al., Clin Invest Med.;22(4):132-9.

Nothing to Disclose: CSB, SB, PS, ND, RS

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