During 1981-1989, a total of 2,238 thyroid carcinoma patients were treated in limited accommodation in Iran with high-fixed ablation or therapeutic doses of I-131. For the 308 patients admitted in 1989, the external body exposure rate was measured sequentially at 2-4 d post-dose administration. Based on the exposure rate of 6.98 C kg(-1) h(-1) (1.8 mR h(-1)) at 1 m, cumulative percentages of patients ablated with 3.7 GBq of I-131 (268/308) and discharged from the hospital at 2, 3, and 4 d post-dose administration were 75%, 87%, and 95%, respectively. Likewise, for the group treated with 5.55 GBq (31/308), the cumulative percentages of patients discharged by day 2, 3, and 4 were 30%, 68%, and 79%, respectively. In the former, the remaining 5% (13 patients) had the external exposure rate less than 6.98 C kg(-1) h(-1) at one meter, before day seven PDA. In the latter, only 2 patients were released after day seven, that is at day 10, with the exposure rate less than 1.8 mR/hr at one meter, One patient, from the second group, with extensive melastatic disease was discharged at day 14 PDA with the external exposure rate of 5.81 C kg(-1) h(-1) (1.5 mR/hr) at one meter. By applying the above exposure rate as the requirement for the patient discharge, we changed the policy for release of patients from arbitrary 1-wk hospitalization to the discharge at the point when exposure rate dropped below 6.98 C kg(-1) h(-1) (1.8 mR h(-1)) at 1 m, which led to the significant (300%) increase in throughput of patients treated for thyroid carcinoma with I-131, within the same available space limitations.
