Interrupted 131I Procedures for Patients With Differentiated Thyroid Cancer

Objective: In patients with differentiated thyroid carcinoma scheduled to receive doses of I-131 for diagnostic or therapeutic purposes, we compared patients prepared with thyroid hormone withdrawal (THW) versus recombinant human thyroid stimulating hormone (rh-TSH) to evaluate the incidence of cancelled procedures because of inadequate thyroid stimulation. Methods: Thyroid cancer patients after thyroidectomy who were scheduled for diagnostic or therapeutic 131I procedures between January 2012 and June 2015were retrospectively reviewed. Patientswere divided based on preparation modality (THW vs rh-TSH), and the incidence of cancelled procedures was compared. Results: Charts from 761 patients were reviewed, 292 THW and 569 rhTSH. A total of 10 patients (3.4%) in the THW group had cancelled procedures because of insufficient thyroid stimulation (TSH < 20 mU/ L). If a TSH threshold of 30 mU/L were used, 57 patients (17.1%) would have been cancelled. Comparing the groups with chi-squared analysis for both TSH thresholds yielded significantly more cancellations in the THW group (P < 0.001). Conclusions: Our study has shown that THWin preparation for 131I procedures leads to significantly more cancellations because of insufficient thyroid stimulation as compared with rh-TSH, which led to no cancellations. The added cost and inconvenience to this cancer population should therefore be considered when selecting a preparation modality. Level of Evidence: Retrospective cohort-Level III