Comparison of Fixed versus Calculated Activity of Radioiodine for the Treatment of Graves Disease in Adults.

BACKGROUND: Radioactive iodine as a treatment modality has been shown in several studies to be a safe and effective therapy for Graves disease. However, there is still no uniformity regarding optimal dosing method. The aim of this study is to compare the efficacy of calculated and fixed dosing of radioiodine for the treatment of Graves disease. METHODS: A hundred twenty-two patients diagnosed with Graves disease were randomized to receive either fixed or calculated dose of radioiodine. Those randomized to fixed activity received either low fixed activity at 9.9 mCi for thyroid gland size <40 g or high fixed activity at 14.9 mCi for thyroid gland size 40 to 80 g, and those grouped to calculated activity received 160 µCi/g of thyroid tissue adjusted for 24 hours radioiodine uptake. Thyroid function tests (free thyroxine [T4] and thyroid stimulating hormone [TSH]) were monitored at 10, 16, and 24 weeks after radioactive iodine therapy. The primary outcome, treatment failure was defined as persistently elevated free T4 and low TSH. RESULTS: Of the 122 patients randomized, 56 in the fixed dose group and 56 in the calculated dose group completed the follow-up. At the end of 6 months, the percentage of treatment failure was 37.50% in the calculated dose group versus 19.64% in the fixed dose group with a relative risk of 0.53 (95% confidence interval, 0.28 to 0.98) favoring the fixed dose group. CONCLUSION: Fixed dose radioiodine has a significantly lower incidence of persistent hyperthyroidism at 6 months post-radioactive therapy.

Effect of suppressive and replacement doses of levothyroxine on bone mineral density in Asian women

We performed this research to determine the prevalence of low bone mineral density in patients given levothyroxine and to investigate the effects of replacement and suppressive doses of levothyroxine, age, body mass index, and TSH level on bone mineral density. One hundred and ten Asian women taking levothyroxine for at least six months were grouped into levothyroxine replacement group (levothyroxine dose that will maintain TSH level of 0.5-5.0 ulU / mL) and TSH-suppressive group (dose that will maintain TSH level of less than 0.5 uIU/mL). Bone mineral density (BMD) was measured by dual-energy x-ray absorptiometry at the lumbar spine, femoral neck and total hip. The prevalence of low bone mineral density on levothyroxine replacement and TSH-suppressive groups were 58 % and 45.8%, respectively. In the levothyroxine replacement group significant associations between levothyroxine dose, as well as body mass index, and low BMD in both spine and femoral neck were detected. An inverse relationship between duration of therapy and low bone density was also observed. Even normal TSH level in this group correlated with low bone mass in the total hip. Age and menopausal status were also significantly associated with low bone density. In the group of patients taking TSH-suppressive doses of levothyroxine, only age showed an inverse correlation with BMD. This may be secondary to the small population size generated for this group.

Transarterial 188 rhenium-HDD-lipiodol conjugate in the treatment of inoperable hepatocellular carcinoma

This is a descriptive study to assess the safety and efficacy of 188 Rhenium-HDD-Lipiodol conjugate in treating patients with unresectable hepatocellular carcinoma. Eight patients with inoperable hepatocellular carcinoma with liver lesions ranging from 1.8 x 2.0 cm to 12.7 x 70 cm participated in the study. 188 Rhenium-HDD-Lipiodol conjugate was administered to the patients via femoral catheter based on the radioactivity that was eluted from the generator. Corresponding whole body scintigraphic images, which showed significant tracer uptake in the liver lesions, were obtained at 24, 48 and 72 hours after 188 Rhenium-HDD-lipiodol administration. Follow-up CT scans in six patients showed progressive disease in three patients and stable disease in three patients. Two patients had re-treatment due to progression of liver lesions. Follow-up scintigraphy after re-treatment showed decrease in tracer uptake in liver lesions on one patient, while the other showed diffuse tracer uptake. Post-ttherapy symptoms were minimal: mild to moderate epigastric pain in two, nausea and vomiting in one, while the rest are asymptomatic. Karnofsky performance status of patients three months after the therapy ranged from 20-90%. Two of the eight patients are still living at the time this paper was written. Radionuclide therapy aided in the prolongation of life and improvement of its quality for some patients. 188 Rhenium-HDD-Lipiodol radio conjugate provides promising results in treating inoperable hepatocellular carcinoma.

Value of post-therapy whole body scintigraphy in predicting the need for subsequent radioactive iodine therapy in patients with well-differentiated thyroid carcinoma

INTRODUCTION: Patients with well-differentiated thyroid carcinoma (WDTC) may require more than one session of radioactive iodine therapy (RAIT). This study was conducted to determine if post-therapy whole body scintigraphy (PTWBS) can identify patients who will require repeat RAIT due to persistent disease. METHOD: The records of patients with WDTC who were referred to the Philippine General Hospital for RAIT from 2005-2007 were reviewed in this retrospective cohort study. PTWBS results (number of remnants, area of remnants, and presence of metastasis) of patients who had repeat RAIT (based on laboratory and clinical evidence of persistent disease) were compared with those of patients who did not have repeat RAIT. Multiple logistic regression analysis was done. RESULTS: Forty-five of 99 patients in the study [45%, 95% Confidence Interval (CI): 35 had repeat RAIT. Thirty-six of 38 patients (95%) with metastases on PTWBS required repeat RAIT, while only 9 of 61 patients (15%) with no scan evidence of metastases required subsequent therapy. Controlling for age group (age), the odds ratio was 102 (95% CI: 20 . Positive and negative predictive values were 95 and 85% respectively. The same results were obtained using metastases alone as a predictor. Twenty-six patients had extra-cervical metastases by PTWBS and all required repeat RAIT. The number and aggregate size of thyroid remnants by PTWBS, however, were not found to be predictive of the need for repeat therapy. CONCLUSION: The presence of functioning metastases seen on PTWBS was highly predictive of the need for repeat RAIT.