Effect of lithium and oral thyrotrophin-releasing hormone (TRH) on serum thyrotrophin (TSH) and radioiodine uptake in patients with well differentiated thyroid carcinoma.
Oral thyrotrophin-releasing hormone (TRH) and lithium were given to patients on follow-up for well-differentiated thyroid carcinoma to see their effect on serum thyrotrophin level (TSH) and radioiodine (I-131) uptake (RAIU). The study was randomised and doubled-blinded and consisted of a total of 19 patients in 3 groups. Group 1 received placebo and TRH, group 2 received lithium and placebo, and group 3 received lithium and TRH. Serum TSH and RAIU at 24 hours were measured before, and after treatment, with TRH, lithium, and/or placebo. In group 1, mean (+/-SEM) TSH increased from 48.9 (+/-15.2) mU/l to 148.2 (+/-48.0) mU/l (p < 0.05); in group 2, the change of 24.9 (+/- 15.9) mU/l to 31.7 (+/-14.1) mU/l in TSH was not statistically significant; and in group 3, TSH increased from 108.1 (+/-13.8) mU/l to 187.0 (+/-39.1) mU/l (p < 0.05). However, despite the significant change in TSH, there was no significant increase in I-131 uptake in any group: 7.70% to 10.43%, 7.15% to 7.43% and 2.49% to 2.61%, in groups 1, 2 and 3 respectively (p > 0.05). We conclude that while oral TRH will increase endogenous serum TSH significantly, there is no significant increase in I-131 uptake. Lithium was not an useful adjunct in increasing serum TSH or I-131 uptake in these patients.
Ang
E S
ES
Department of Nuclear Medicine, Singapore General Hospital, Singapore.
Teh
H S
HS
Sundram
F X
FX
Lee
K O
KO
D018263:Adenocarcinoma, Follicular / Q000097:blood / Q000000981:diagnostic imaging* / Q000188:drug therapy; D000328:Adult; D002291:Carcinoma, Papillary / Q000097:blood / Q000000981:diagnostic imaging* / Q000188:drug therapy; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D007089:Image Enhancement; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics; D016651:Lithium Carbonate / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D012680:Sensitivity and Specificity; D013964:Thyroid Neoplasms / Q000097:blood / Q000000981:diagnostic imaging* / Q000188:drug therapy; D013972:Thyrotropin / Q000097:blood*; D013973:Thyrotropin-Releasing Hormone / Q000008:administration & dosage*
D007457:Iodine Radioisotopes; D016651:Lithium Carbonate; D013973:Thyrotropin-Releasing Hormone; D013972:Thyrotropin