Renal Tracer Elimination in Thyroid Cancer Patients Treated With 131-Iodine

Relationship Between Estimated Glomerular Filtration Rate and Biological Half-life of 131I. Prospective Analysis in Patients With Differentiated Thyroid Carcinoma.

Correlation analysis between estimated renal function and biological half life of 131-I during radioiodine treatment of patients with differentiated thyroid cancer.

131-I during radioiodine treatment of patients with differentiated thyroid cancer is mainly renally excreted. It is advised in the clinical guidelines that serum creatinine should be determined before applying 131-I and if necessary the administered dose should be reduced. Nevertheless no guideline gives advice in what extent the dose should be decreased. The adjustment is at the discretion of the attending physician.

Aim of this prospective study is to correlate the biological half life of 131-I with the renal function to give objective recommendations concerning the reduction of the applied dose in patients with limited renal function.

Inclusion Criteria:

• patients with differentiated thyroid carcinoma
• stationary for treatment or diagnostic with radioiodine
• state after thyroidectomy
• written consent of the patient
• minimum age 18 years

Exclusion Criteria:

• no written consent of the patient
• patients with large residual thyroid tissue (iodine uptake > 10%)
• children under 18 years of age
• inclusion in concurrent interventional studies
• patients without TSH-stimulation by rhTSH