Recombinant human thyrotropin-stimulated radioiodine therapy of nodular goiter allows major reduction of the radiation burden with retained efficacy.
OBJECTIVE
Stimulation with recombinant human TSH (rhTSH) before radioiodine (131I) therapy augments goiter volume reduction (GVR). Observations indicate that rhTSH has a preconditioning effect beyond increasing thyroid (131)I uptake. We test the hypothesis that an equivalent GVR might be obtained by an absorbed thyroid dose well below what has been used previously.


METHODS
In a double-blinded setup, 90 patients (78 women; median age, 52 yr; range, 22-83) with a nontoxic nodular goiter (median size, 63 ml; range, 25-379 ml) were randomized to either 0.1 mg rhTSH (n=60) followed by a thyroid dose of 50 Gy or placebo followed by 100 Gy (n=30).


RESULTS
At 12 months, the mean relative GVR in the placebo and the rhTSH group was identical (35+/-3%; P=0.81). The median administered 131I-activity was 170 MBq (45-1269) in the rhTSH group and 559 MBq (245-3530) in the placebo group (70% reduction, P<0.0001). According to the official radiation regulation, hospitalization was required in 14 patients in the placebo group vs. one patient in the rhTSH group (P<0.0001). In both groups, goiter-related symptoms were effectively relieved in the majority of patients. The prevalence of myxedema (10%) did not differ among groups.


CONCLUSIONS
This is the first study to demonstrate that rhTSH not only increases the thyroid 131I uptake, but per se potentiates the effect of 131I-therapy, allowing a major reduction of the 131I-activity without compromising efficacy. This approach is attractive in terms of minimizing posttherapeutic restrictions and in reducing the potential risk of radiation-induced malignancy.
Department of Endocrinology and Metabolism, Odense University Hospital, DK-5000 Odense C, Denmark. Soeren.Fast@ouh.regionsyddanmark.dk
Søren
S
Fast
Laszlo
L
Hegedüs
Peter
P
Grupe
Viveque Egsgaard
VE
Nielsen
Christa
C
Bluhme
Lars
L
Bastholt
Steen Joop
SJ
Bonnema
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D004307:Dose-Response Relationship, Radiation; D004311:Double-Blind Method; D005260:Female; D006044:Goiter, Nodular / Q000532:radiotherapy*; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction; D011829:Radiation Dosage; D011994:Recombinant Proteins / Q000627:therapeutic use*; D013960:Thyroid Function Tests; D013972:Thyrotropin / Q000627:therapeutic use*; D016896:Treatment Outcome
D007457:Iodine Radioisotopes; D011994:Recombinant Proteins; D013972:Thyrotropin