Analysis of ¹³¹I therapy and correlation factors of Graves' disease patients: a 4-year retrospective study.
OBJECTIVE
To analyze the correlation therapeutic effects of first sufficiency ¹³¹I therapy in Graves' disease patients and improve its one-time curative ratio.


METHODS
Seven hundred and sixty-six patients (age range 12-77 years, mean 40.46 ± 13.12 years), including 237 men (range 12-77 years, 40.98 ± 12.64 years) and 529 women (range 14-75 years, 40.22 ± 13.34 years), who received the first I treatment were studied. The relevant examinations were performed before ¹³¹I therapy: the maximal radioactive iodine uptake of thyroid (RAIUmax), the effective half-life (EHL), the ultrasound of thyroid to calculate its weight, thyroid imaging with single-photon emission computed tomography and serum-free triiodothyronine (FT₃), free thyroxine (FT₄), sensitive thyroid-stimulating hormone (sTSH), anti-thyrotrophin receptor antibody (TRAb), thyroid-stimulating immunoglobulin, thyroglobulin antibody (TgAb), and anti-thyroid microsome antibody (TMAb). After the ¹³¹I dosage was determined, all the patients took ¹³¹I once orally. The ¹³¹I dosage range was 74-592 MBq (221.63 ± 100.64 MBq). A clinical and laboratory assessment was performed at 1, 3, 6, and 12 months after ¹³¹I therapy. Patients were divided into the clinically recovered group (symptoms and signs disappeared, free thyroid hormone levels were within or below the normal range, and sTSH was within or above the normal range) and the clinically unhealed group (symptoms and signs disappeared partially, free thyroid hormone levels were still above the normal range or within the normal range for a time and then increased again, and sTSH was constantly below the normal range). Data were analyzed by the unpaired t-test, the independent samples t-test, the χ² test, logistic regression, and Pearson bivariate correlation.


RESULTS
The one-time curative ratio of ¹³¹I therapy was 78.7% (including euthyroidism and hypothyroidism). Multiplicity in healing patients fit the logistic regression equation. The accuracy of discrimination of the equation was 79.5%. The influential factors of ¹³¹I therapy were age, RAIUmax, EHL, TRAb, and TgAb. RAIUmax and EHL were the protecting factors. Age, TRAb, and TgAb were the risk factors. TRAb influenced the one-time curative ratio between patients with negative and positive TRAb, which was higher in men (2.836 times) than in women (1.438 times).


CONCLUSIONS
¹³¹I therapy is an effective intervention for Graves' disease. The higher the RAIUmax and (or) the longer the EHL, the higher the possibility of a one-time cure. Elder patients or patients with a positive TRAb and (or) TgAb have a lower possibility of a one-time cure. Women with a positive TRAb should be administered an increased ¹³¹I dose to improve the curative effect.
Department of Nuclear Medicine, Tianjin Medical University General Hospital, Tianjin, China.
Wei
W
Zheng
Tan
T
Jian
Zhang
Z
Guizhi
Meng
M
Zhaowei
Wang
W
Renfei
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006111:Graves Disease / Q000097:blood / Q000532:radiotherapy*; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D015899:Tomography, Emission-Computed, Single-Photon; D016896:Treatment Outcome; D055815:Young Adult
D015415:Biomarkers; D007457:Iodine Radioisotopes