Recombinant human TSH increases the efficacy of a fixed activity of radioiodine for treatment of multinodular goitre.
BACKGROUND
High doses of (131)I are usually needed in the treatment of multinodular goitre (MNG) for effective thyroid volume (TV) reduction. Recombinant human thyroid-stimulating hormone (rhTSH) is an adjuvant to enhance (131)I uptake, allowing a decrease in radiation activity and enhancing (131)I efficacy.


OBJECTIVE
To evaluate whether rhTSH increases the efficacy of a fixed activity of (131)I for the treatment of MNG.


METHODS
Two-year, observational, placebo-controlled study.


METHODS
Patients received 0.1 mg rhTSH (A), 0.005 mg rhTSH (B) or placebo (C). A fixed activity of 1.11 GBq of (131)I was administered 24 h after rhTSH or placebo.


METHODS
A total of 28 outpatients (26 females and two males) with MNG.


METHODS
TSH, free T4, T3, thyroglobulin (Tg) and TV.


RESULTS
Basal radioactive iodine uptake and TV values were comparable among all groups. After rhTSH or placebo, peak levels of TSH, free T4, T3 and Tg were higher in A than in B or in C (p < 0.05). Hyperthyroidism was observed in A (n = 2), B (n = 6) and C (n = 4). Thyroid enlargement was reported in A (n = 3) and B (n = 6). After 24 months, 10 patients developed hypothyroidism (four in A, three in B and three in C). TV reduction was similar between A and B (37.2 +/- 25.5% vs. 39.3 +/- 27.9%, p = 0.88), but different from the non-significant reduction in C (15.3 +/- 28.3%, p = 0.08).


CONCLUSIONS
Followed by 1.11 GBq, a very low dose of 0.005 mg rhTSH was equally safe and effective as 0.1 mg rhTSH. Both doses increased the efficacy of radioiodine. Adverse events were mild, transient and readily treatable.
Cubas
E R
ER
SEMPR - Serviço de Endocrinologia e Metabologia da Universidade Federal do Paraná, Curitiba, Brazil.
Paz-Filho
G J
GJ
Olandoski
M
M
Goedert
C A
CA
Woellner
L C
LC
Carvalho
G A
GA
Graf
H
H
D000368:Aged; D003131:Combined Modality Therapy; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006044:Goiter, Nodular / Q000628:therapy*; D006801:Humans; D007457:Iodine Radioisotopes / Q000009:adverse effects / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D011994:Recombinant Proteins / Q000627:therapeutic use; D013972:Thyrotropin / Q000009:adverse effects / Q000627:therapeutic use*; D016896:Treatment Outcome
D007457:Iodine Radioisotopes; D011994:Recombinant Proteins; D013972:Thyrotropin