The efficacy of patient-dependent practices on exposure rate in patients undergoing iodine-131 ablation.

The authors investigated the efficacy of the patient-dependent practices (micturition, defecation, and taking a shower) after I ablation therapy in patients with thyroid cancer. Exposure rates were measured from a 1-m distance at 2, 4, and 24 h after the I administration. The comparisons for 2-4 h and 2-24 h time intervals were carried out among the patients with good and poor compliance, according to the relative amount of the patient-dependent practices, over mean values calculated for an effective half-life (h) or exposure rate decline ratio (%). In the 2-4 h interval, the mean values for good versus poor compliance were found to be: 4.16 h versus 8.14 h and 31% versus 17% in micturition; 5.70 h versus 6.84 h and 26% versus 21% in defecation; and 6.68 h versus 5.69 h and 24% versus 24% in taking a shower. Among patients with good versus poor compliance during a 2-24 h interval, the mean values were: 11.63 h versus 16.62 h and 74% versus 61% in micturition; 12.75 h versus 15.88 h and 71% versus 63% in defecation; and 13.77 h versus 14.21 h and 68% versus 67% in taking a shower.