Stimulation with 0.3-mg recombinant human thyrotropin prior to iodine 131 therapy to improve the size reduction of benign nontoxic nodular goiter: a prospective randomized double-blind trial.
BACKGROUND
Use of recombinant human thyrotropin increases the thyroid radioiodine (iodine 131 [(131)I]) uptake and may have a role in the context of (131)I therapy of benign goiter.


METHODS
In a double-blind, placebo-controlled trial, 57 patients with nodular nontoxic goiter (51 women and 6 men) were randomized to receive either 0.3 mg of recombinant human thyrotropin (n = 28) or placebo (n = 29) 24 hours before (131)I therapy. The (131)I dose was calculated based on thyroid size (measured by ultrasound), thyroid (131)I uptake, and (131)I half-life. The follow-up period was 1 year and included measurements of thyroid size and function and patient satisfaction.


RESULTS
Baseline median goiter volume was 51 mL (range, 20-99 mL) in the placebo group and 59 mL (range, 25-92 mL) in the thyrotropin group (P = .75). At 12 months, the mean +/- SEM relative goiter reduction was 46.1% +/- 4.0% in the placebo group and 62.1% +/- 3.0% in the thyrotropin group (P = .002 between groups). The difference was most pronounced among patients with large goiters. Within each group, there was no significant correlation between retained thyroid (131)I dose and goiter reduction. Adverse effects were significantly more frequent in the thyrotropin group (34 vs 12 events; P<.001). Permanent hypothyroidism developed in 3 patients (11%) in the placebo group compared with 16 patients (62%) in the thyrotropin group (P<.001). Patient satisfaction was high and uninfluenced by the use of recombinant human thyrotropin.


CONCLUSIONS
Stimulation with recombinant human thyrotropin prior to (131)I therapy improves thyroid size reduction by 35%, with a 5-fold higher rate of hypothyroidism. These effects are, at least partially, mediated through mechanisms other than an increase in retained (131)I thyroid dose. Further recombinant human thyrotropin dose-finding studies are warranted before routine use.
Nielsen
Viveque Egsgaard
VE
Department of Endocrinology and Metabolism, Odense University Hospital, Odense, Denmark. viveque.egsgaard@ouh.fyns-amt.dk
Bonnema
Steen Joop
SJ
Boel-Jørgensen
Henrik
H
Grupe
Peter
P
Hegedüs
Laszlo
L
D000328:Adult; D000368:Aged; D013956:Antithyroid Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D018450:Disease Progression; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006044:Goiter, Nodular / Q000097:blood / Q000000981:diagnostic imaging / Q000188:drug therapy*; D006801:Humans; D007457:Iodine Radioisotopes / Q000008:administration & dosage* / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction; D011446:Prospective Studies; D013963:Thyroid Hormones / Q000008:administration & dosage* / Q000627:therapeutic use; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D016896:Treatment Outcome; D014284:Triiodothyronine / Q000097:blood; D014463:Ultrasonography
D013956:Antithyroid Agents; D007457:Iodine Radioisotopes; D013963:Thyroid Hormones; D014284:Triiodothyronine; C004227:thyroidin; D013972:Thyrotropin; D013974:Thyroxine