Estimating (131)I biokinetics and radiation doses to the red marrow and whole body in thyroid cancer patients: probe detection versus image quantification.

Objective: To compare the probe detection method with the image quantification method when estimating (131)I biokinetics and radiation doses to the red marrow and whole body in the treatment of thyroid cancer patients.

Materials And Methods: Fourteen patients with metastatic thyroid cancer, without metastatic bone involvement, were submitted to therapy planning in order to tailor the therapeutic amount of (131)I to each individual. Whole-body scans and probe measurements were performed at 4, 24, 48, 72, and 96 h after (131)I administration in order to estimate the effective half-life (Teff) and residence time of (131)I in the body.