Multiple Bone Metastases in a Patient with Differentiated Thyroid Cancer (DTC): Complete resolution following thyroidectomy and four ablation doses of I-131.

Multiple bone metastases from a differentiated thyroid cancer are usually incurable. We report the case of a young Omani woman who presented with 8 discrete skeletal lesions three years after a total thyroidectomy. Following four ablation doses of I-131 she has remained in clinical and biochemical remission for over five years. An extraordinary aspect of this case was the persistent refusal of her husband to use contraception either for himself or his wife. This resulted in her treatment being delayed for more than 6 years during which time the patient delivered and breastfed four additional healthy babies.

Radiation exposure levels in family members of omani patients with thyrotoxicosis treated with radioiodine (I) as outpatients.

OBJECTIVES: This study was conducted to assess whether the radiation exposure levels of Omani family members of thyrotoxic patients, if treated with radioiodine therapy as outpatients, are within the international and local radiation dose limits in order to allow them to be treated as outpatients. METHODS: The study included 86 family members of 22 self-dependent thyrotoxic patients (29 children ≤ 16 yrs and 57 adults including 11 spouses and 8 parents). The mean age of the family members was 26.6 years (range 17 months - 75 years).They were treated with (131)I as outpatients and monitored for 10 days in 2007-2008 for radiation exposure using thermoluminescent dosimeters (TLDs). The mean administered activity of (131)I to patients (±SD) was 610 ±79MBq in the range 520-862 MBq. Oral and written radiation safety instructions were given to patients and family members before leaving the hospital. RESULTS: The radiation doses received by family members were less than the annual recommended dose limit for general public of 1mSv, except for four children aged 19 months, 12, 13 and 15 years, who received radiation doses of 2.9, 1.2, 1.2 and 1.2 mSv respectively. CONCLUSION: In view of the low radiation doses received by the family members, we recommend treating thyrotoxic patients undergoing radioiodine therapy with administered activities up to 800 MBq as outpatients.

Radioactive iodine in the treatment of Graves' disease.

OBJECTIVES: This study was performed to evaluate the efficacy of radioactive iodine 131I therapy of Graves' hyperthyroidism at Sultan Qaboos University Hospital, Oman and to determine the optimal dose of 131I needed to achieve the euthyroid or hypothyroid status. METHODS: The medical records of 366 patients with Graves hyperthyroidism who received a single dose of 131I at Sultan Qaboos University Hospital, Oman between 1991 and 1999 were reviewed. The diagnosis was based on clinical, biochemical grounds and 99mTc thyroid scintigraphy. The patients were followed up for a minimum period of 12 months. For the analysis, the patients were divided into 6 groups according to the 131I dose administered: Dose one (350-399), dose 2 (400-449), dose 3 (450-499), dose 4 (500-549), dose 5 (550-599) and dose 6 (> or = 600) MBq. RESULTS: Fifty-eight percent of all the patients were hypothyroid after 3 months. Three hundred and twenty two patients (88%) were treated by a single dose of 131I in 12 months (85.5% hypothyroid and 2.5% euthyroid). Forty-one patients (11.2%) required a 2nd 131I dose and only 3 patients required 3 doses of 131I. The best cure rate (93%) was observed in group dose 5 (574.0 +/- 16.4 MBq) which however, was not significantly different from other dosage levels. The female to male ratio was 2:1 and the cure rates were not gender or age related. CONCLUSION: Treatment of Graves' hyperthyroidism from a single 131I dose is our aim, rather than avoidance of hypothyroidism. Our results indicate that cure rates are higher with larger doses of 131I except in group dose 6 (special category of patients). In the future, fixed doses would be adopted in our radioactive iodine treatment practice guidelines. As the majority of our patients were hypothyroid at 3 months regular monthly follow-up is essential. Whenever appropriate, physicians are encouraged to consider early referral of Graves' hyperthyroidism patients for radioactive iodine treatment as it is cheap, effective, easy to administer and free from serious side effects.

Are scintigraphy and ultrasonography necessary before fine-needle aspiration cytology for thyroid nodules?

OBJECTIVE: To evaluate the efficacy of scintigraphy, ultrasound and fine-needle aspiration in thyroid nodules and to establish the best diagnostic pathway in detecting thyroid cancer. METHOD: Two hundred and sixteen patients with thyroid nodules were examined using high-resolution ultrasonography, 99mTc thyroid scintigraphy and ultrasound-guided fine-needle aspiration. Of these, 113 patients subsequently underwent thyroidectomy. The remaining 103 were followed up for two years without any evidence of malignancy. RESULTS: Cytopathology classified 71% of the aspirate as benign, 3% as positive for malignancy, 21% as suspected neoplasia and 5% as unsatisfactory. Fine-needle aspiration cytology had a sensitivity of 87.5% and specificity of 80%. On ultrasound 33% of malignant nodules were hypo-echoic and on scintigraphy 16% of solitary cold nodules were malignant. Neither test could reliably diagnose thyroid cancer. CONCLUSION: Ultrasound-guided fine-needle aspiration cytology should be the first test performed in euthyroid patients with a thyroid nodule. Scintigraphy and ultrasound imaging should be reserved for follow-up studies and patients who have suppressed levels of thyroid stimulating hormone.