Searchable abstracts of presentations at key conferences in endocrinology
Endocrine Abstracts (2003) 5 P273

BES2003 Poster Presentations Thyroid (27 abstracts)

Conventional withdrawal of thyroid suppression in differentiated thyroid carcinoma: How frequently are adequately raised TSH levels attained?

CM McLaughlin 1 , SJ Hunter 1 , PM Bell 1 , DR McCance 1 , B Sheridan 2 & AB Atkinson 1

1Regional Centre for Endocrinology and Diabetes, Royal Victoria Hospital, Belfast, UK; 2Regional Endocrine Laboratory, Royal Victoria Hospital, Belfast, UK.

Radioactive iodine scanning and ablative radioactive therapy (RAI) are mainstays of follow-up and therapy in patients with differentiated thyroid carcinoma. TSH levels of 30 or greater are recommended as the levels required for effective use of RAI (see recent British Thyroid Association guidelines).
To clarify our own practice we have studied 20 consecutive patients undergoing ablative RAI for thyroid carcinoma (10 papillary, 8 follicular and 2 mixed). The fourteen who had been on thyroxine were switched to tertroxin 6 weeks prior to the estimation of TSH, and all had discontinued tertroxin 2 weeks before its measurement.
Of the 20, 17 had TSH levels > 30 milliunits per litre while 3 had levels of 28, 21 and 18. Despite all 3 taking up RAI on post therapy scans 2 of the 20 would be considered as having suboptimal TSH levels which may have compromised the effectiveness of treatment. Our results do not agree with a recent study by Liel 1 in which thyroxine was simply withdrawn and the mean interval to achievement of thyroxine of >30 milliunits per litre was 17 days (range 11-28).
We recommend either an urgent measurement of TSH immediately before therapy after withdrawing thyroxine 6 weeks before and tertroxin 2 weeks before RAI (90% >25 milliunits per litre at this time). Alternatively the more expensive option is routine use of recombinant TSH in all cases to eliminate the need for thyroid hormone withdrawal. Straight withdrawal of thyroxine therapy is not associated with a predictable time to an adequately raised TSH levels.
1Liel Y, (2002) Clinical Endocrinology 57:523-527

Volume 5

22nd Joint Meeting of the British Endocrine Societies

British Endocrine Societies 

Browse other volumes

Article tools

My recent searches

No recent searches.