Interrupted 131I Procedures for Patients With Differentiated Thyroid Cancer: Comparing Thyroxine Withdrawal With Recombinant Thyrotropin Preparation Techniques.
OBJECTIVE
In patients with differentiated thyroid carcinoma scheduled to receive doses of I 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 I procedures between January 2012 and June 2015 were retrospectively reviewed. Patients were 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 rh-TSH. 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 THW in preparation for I 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.


METHODS
Retrospective cohort-Level III.
From the Divisions of *Nuclear Medicine, and †Endocrinology, Jewish General Hospital, Montreal, Québec, Canada.
Shawn
S
Karls
Gad
G
Abikhzer
Michael
M
Tamilia
Stephan
S
Probst
D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000532:radiotherapy; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D019275:Radiopharmaceuticals / Q000627:therapeutic use*; D011878:Radiotherapy / Q000379:methods; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000532:radiotherapy; D013972:Thyrotropin / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D013974:Thyroxine / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use
D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; D013972:Thyrotropin; D013974:Thyroxine