RADIO-IODINE THERAPY IN HYPERTHYROIDISM- A STUDY OF 50 CASES

The use of radioiodine-131 for the treatment of hyperthyroidism is a very simple and cheap form of therapy and highly effective and is now the predominant definitive therapy both as primary treatment and following relapse after anti thyroid drugs. This study was carried out in Khulna medical college from January 2002 to January 2003 to assess the degree of effectiveness of radioiodine therapy in case of hyperthyroidism. This was a prospective study of 50 patients with hyperthyroidism (28 female,22 male, mean age 39.87 years) treated with radioiodine-131 and followed up for a period of one year. The dose of radioiodine-131 ranged from 7-10 mci. Out of 50 patients 38 (76%) were found to have diffuse toxic goitre, 5(10%) have solitary toxic nodule 1(2%) have multi nodular toxic goitre, 4(8%) have impalpable gland with thyrotoxicosis and 2(4%) with relapsing thyrotoxicosis received oral radioiodine therapy. Serum T3 was elevated in 43(86%) and was normal in 7(14%) cases. Serum T4 was normal in 4 (8%) cases that were T3 thyrotoxicosis and rose in 46(92%) cases. Serum TSH was reduced in all cases. Thyroid scan shows warm/ diffuse uptake in 44 (88%) and hot nodule in 6(12%) cases. Post therapy clinical and biochemical evaluation of thyroid function was done at 3 months, 6 months, 9 months and 12 months interval. The patient was classified as cured if the biochemical status was either euthyroid or hypothyroid at one year without further treatment by antithyroid drugs or radioiodine. The incidence of euthyroid, hypothyroidism and hyperthyroidism within one year was 60.00%, 35.60% and 4.40% and the cure rate was 95.6%. From this study we found that radioiodine-131 therapy is a simple, safe and effective means to normalize thyroid function status in patients with hyperthyroidism. 1. MD Student (Nephrology-Thesis), Bangabandhu Shaiekh Mujib Medical University. 2. MD Student, Internal Medicine (Thesis), Dhaka Medical College Hospital. 3. Assistant Professor, Department of Anatomy, Bangladesh Medical College. 4. Assistant Professor (Endocrinology), Dhaka Medical College, Dhaka. 5. Medical Officer, SPRC Hospital, New Eskaton Road, Dhaka 6. Professor of Medicine, Dhaka Medical College, Dhaka. drugs.1, 4, 5 In Bangladesh a few studies have been done on this topic which show radioiodine therapy is an effective means of treatment, although those are not still sufficient to cover the topic in our country. We have done this study in Khulna medical college hospital from January 2002 to January 2003. It was undertaken to find out the effectiveness of radio-iodine therapy in controlling hyperthyroidism & to observe the short term outcome of radio-iodine treatment. Materials and Methods: Fifty cases of hyperthyroidism diagnosed by usual clinical and biochemical criteria including raised T3, T4 & suppressed TSH from Khulna Medical College Hospital (KMCH) and Centre for Nuclear Medicine & Ultrasound, Khulna, were selected for the study. Radio J MEDICINE 2008; 9 : 27-30


Introduction:
Disorders of thyroid gland result primarily from autoimmune processes that either stimulates the overproduction of thyroid hormone (Hyperthyroidism) or cause glandular destruction and under production of thyroid hormone (hypothyroidism). 1 Both the conditions are not uncommon and hyperthyroidism is an important disorder in our country. 2The conventional treatment of hyperthyroidism includes antithyroid drugs, surgery and radioiodine-131 therapy.Each form of treatment has specific indications, advantages & disadvantages. 3Radioiodine has the advantage if being a very simple and cheap form of therapy and highly effective and is now the predominant definitive therapy both as primary treatment and following relapse after antithyriod

Abstract:
The use of radioiodine-131 for the treatment of hyperthyroidism is a very simple and cheap form of therapy and highly effective and is now the predominant definitive therapy both as primary treatment and following relapse after anti thyroid drugs.This study was carried out in Khulna medical college from January 2002 to January 2003 to assess the degree of effectiveness of radioiodine therapy in case of hyperthyroidism.This was a prospective study of 50 patients with hyperthyroidism (28 female,22 male, mean age 39.87 years) treated with radioiodine- 131 and followed up for a period of one year.The dose of radioiodine- 131  drugs. 1,4,5 I Bangladesh a few studies have been done on this topic which show radioiodine therapy is an effective means of treatment, although those are not still sufficient to cover the topic in our country.We have done this study in Khulna medical college hospital from January 2002 to January 2003.It was undertaken to find out the effectiveness of radio-iodine therapy in controlling hyperthyroidism & to observe the short term outcome of radio-iodine treatment.Elderly patients and all those with cardiac disease and severe hyperthyroidism were pretreated with a short course of antithyroid drugs in full dosages until they were clinically and biochemically euthyroid.Antithyroid drugs were stopped 3 days before radioiodine administration.No patient had posttreatment antithyroid drugs during follow-up period.Before administering radioiodine, the nature of treatment, the importance of precautionary measures and follow-up necessity was explained to the patients.

Results:
Out of fifty patients the maximum age was 75 years and the minimum age 17 years.The mean age was 39.87 years.Of these patients (Table I) females were more sufferer 28 (56%) than the male 22 (44%).Male (22) and female (28) ration was 1:1.   9 Hypothyroidism is an inevitable consequence of the treatment of hyperthyroidism with radioactive iodine and almost certainly would occur in all patients if they lived long enough. 10,11In our study 16(35.6%)patients became hypothyroid after therapy.Hypothyroidism that occurs in the first year following radioactive iodine therapy is related to dose, while the subsequent occurrence is due to a combination of radiation-mediated injury and underlying autoimmunity. 12Hence current practice guidelines, recommend large single dose because attempting to achieve permanent euthyroidism with radioactive iodine is nearly impossible. 13,14 ugh due to small sample size with short follow up period which preclude any firm conclusion of long term effects of radioiodine therapy.In our observation hyperthyroidism was controlled with single dose of 1-131 in most of the cases as an effective means of treatment with change of essentially unavoidable hypothyroidism.Further long term research is needed in this regard.

:
Fifty cases of hyperthyroidism diagnosed by usual clinical and biochemical criteria including raised T 3 , T4 & suppressed TSH from Khulna Medical College Hospital (KMCH) and Centre for Nuclear Medicine & Ultrasound, Khulna, were selected for the study.Radio J MEDICINE 2008; 9 : 27-30 .nuclide scan was performed in all cases, post therapy follow up was done at 3 months, 6 months, 9 months, 1 year.Clinical & biochemical evaluation was assessed in each follow up visit.Serum T 3 and T 4 was measured by radioimmunoassay technique and TSH by immuno radiometric assay technique.
2 The highest number of patient belongs to 30-34 and 40-44 age groups and least number belongs to 20-24 age group (Fig 1).

Table - I
Sex distribution of studied patient(n=50)