Abstract
148
Objectives rhTSH use to aid RRA in patients with DTC allows LT4 therapy and euthyroidism at the time of RRA. By preserving baseline renal and bowel function, rhTSH lowers RRA-related whole-body irradiation by ~1/3 on average relative to thyroid hormone withholding (THW). Only 1 relatively small published study addressed the impact of this finding on treatment room length-of stay; no study empirically addressed impact on treatment room utilization.
Methods We retrospectively reviewed charts of all DTC patients ablated at our tertiary referral center from Jan. 2003 to Mar. 2008 and treatment room records during that time. We calculated mean ± SD length-of-stay and median ablation activity for the rhTSH and THW groups and compared these values using the Student t test. We also calculated the mean patients/wk ablated for each method.
Results Eighty-eight patients received rhTSH-RRA, 50 patients, THW-RRA. Median (range) ablation activity was 3.74 (3.33-7.40) GBq/ 101 (90-200) mCi I-131 for rhTSH, 3.57 (2.20-3.70) GBq/96 (59-100) mCi for THW (P = 0.026). Unless medically contraindicated, patients left the treatment room when whole-body count measured <60 mSv/h at 50 cm, the radioprotection ward discharge threshold in Spain. Despite the significantly higher median RRA activity for the rhTSH group, mean ± SD treatment room length-of-stay was 1.47 ± 0.75 d for rhTSH vs 1.98 ± 0.74 d for THW (P <0.005). The mean pats. ablated/wk (5 workdays) was 33% higher with rhTSH vs THW.
Conclusions Relative to RRA with THW, RRA with rhTSH significantly decreases treatment room length-of-stay and markedly increases the number of patients ablated/wk. Since radioprotection ward staffing is largely a fixed cost, increasing the number of pats. ablated/wk. decreases the staffing cost per procedure; together with the shorter hospital stay itself, this substantially reduces the cost per RRA