Skin blood flow after transdermal S-nitrosothio-acetylglucose

THE LANCET

studies preferably comparing 131I and thyroxine, we suggest that radioiodine be used in selected patients in whom thyroxine treatment has been inadequate and in patients with contraindications to or refusal of surgery.

100

Thyroid volume (mL)

80

1

60 2

40

3

20

4

Normal range 5

0 0

3

6

9

12

Time (months) Mean (SE) thyroid volume before and after radioiodine therapy of diffuse non-toxic goitre

Hegedüs L, Hansen JM. Radioactive iodine for thyrotoxicosis. Lancet 1986; ii: 339–40. Hegedüs L, Hansen BM, Knudsen N, Hansen JM. Reduction of size of thyroid with radioactive iodine in multinodular non-toxic goitre. BMJ 1988; 297: 661–62. Nygaard B, Hegedüs L, Gervil M, Hjalgrim H, Søe-Jensen P, Hansen JM. Radioiodine treatment of multinodular non-toxic goitre. BMJ 1993; 307: 828–32. Perrild H, Hansen JM, Hegedüs L, et al. Triiodothyronine and thyroxine treatment of non-toxic diffuse goitre evaluated by ultrasonic scanning. Acta Endocrinol (Copenh) 1982; 100: 382–87. Faber J, Galloe AM. Changes in bone mass during prolonged subclinical hyperthyroidism due to L-thyroxine treatment: a metaanalysis. Eur J Endocrinol 1994; 13: 350–56.

Department of Endocrinology M, Odense University Hospital, DK-5000 Odense C, Denmark (L Hegedüs)

Shaded area represents normal range.

goitre with 131I. All patients had a diffuse goitre by palpation as well as on 99mTc pertechnetate thyroid scintiscan and ultrasonography. All had pressure symptoms and seven had cosmetic complaints; all refused surgery. Six had tried thyroxine treatment without adequate effect; they had stopped thyroxine at least 3 months before being given 131I therapy. Informed consent was obtained from all patients. Serum thyroxine, triiodothyronine, and thyrotropin concentrations, triiodothyronine resin uptake, and the size of the thyroid on ultrasonography were determined before treatment as well as 1, 2, 3, 6, 9, and 12 months after treatment. 131I was given at a dose of 3·7 MBq/g total thyroid mass corrected to a 100% 131I uptake in 24 h. A maximum outpatient dose of 600 MBq was set and none was treated as an inpatient. Since the radioiodine uptake is generally low in non-toxic goitre and some had a large goitre, the 131I dose had to be reduced in seven of 11 patients, which led to a median dose of 600 (range 400–600) MBq. All patients received only one 131I dose. Mean thyroid volume (normal range 9–28 mL) decreased gradually from 72·9 (SE 7·2) mL to 27·8 (6·0) mL at 12 months (figure; p=0·003, Wilcoxon’s test for paired data). Two patients developed permanent hypothyroidism 6 months after treatment. None developed radiation thyroiditis. Thyroid autoantibodies were present pretreatment in two patients (antithyroid peroxidase antibodies in both cases) in low concentrations (287 and 489 U/mL, normal