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AIM: To study the absorption and excretion of CT-707 in healthy male subjects. METHODS: Six healthy male subjects received a single 300 mg (120 μCi) oral dose of radio-labeled CT-707 as a suspension in a fasted state. Blood, urine and feces were collected. Radioactivity concentrations were measured by liquid scintillation counting (LSC). The pharmacokinetic parameters of total radioactivity in plasma were calculated by WinNonlin (Pharsight version 8.1) software according to the non-compartment model. The recovery rate of total radioactivity in urine and feces was calculated according to the weight and radioactivity concentration of urine and feces collected at each time interval. RESULTS: After a single 300 mg oral of radio-labeled CT-707 552 h (23 d) as a suspension in a fasted state, the mean AUC
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To improve the efficacy of radioactive iodine (RAI) therapy for differentiated thyroid cancer patients, a low-iodine diet (LID) prior to the therapy is recommended. In iodine-rich areas such as Korea, however, a strict LID is very difficult to maintain. We experienced the cases of three patients showing low adherence to the LID before initial RAI therapy, and analyzed the main food source supplying iodine during the LID, and examined the influence of the poorly maintained LID on the efficacy of RAI therapy. The dietary intake during the LID periods were assessed using three-day dietary records and remnant thyroid activity after the second RAI administration was also evaluated. All patients' mean daily iodine intake during two-week LID periods exceeded the 100 microg guideline set by the Korean Thyroid Association (median 110.9 microg, ranges 100.4-117.0 microg). Although the typical food sources of iodine intake are seaweeds in Korea, salted vegetables were the main contributor to the patients' iodine intake during the LID periods. Remnant thyroid activity was shown on a follow-up scan in all of 3 patients suggesting low efficacy of RAI therapy. In summary, the patients with low adherence to the LID guideline showed unsuccessful remnant ablation, and the main food source of iodine was salted vegetables. Further studies are necessary to examine the relationship between adherence of the LID and RAI efficacy according to dietary iodine intake levels, as well as food sources that cause low adherence to the LID. These data can then be used to develop more practical LID guidelines.