Analysis and utility of pretreatment and posttreatment total body iodine-131 scans in patients with thyroid carcinoma
e17031 Background: The purpose of this study was to evaluate the efficacy of post-I-131 treatment total body scans. Methods: The records of 108 consecutive patients with thyroid carcinoma treated by surgery and postoperative I-131 were reviewed. All patients underwent a postoperative diagnostic total body I-131 and post I-131 therapy scintigraphies .83% of patients were considered low risk according to AMES (age, metastasis, extracapsular extension, size) criteria. Results: The postoperative diagnostic total body I-131 scintigraphy revealed uptake in the neck in 95 out of 108 patients (88%). Three patients had lung and mediastinal uptake in known sites of metastatic disease. Additional foci of neck, mediastinal and lung uptake were revealed in the post-131 therapy total body scintigraphies in ten patients ( 9.3%). Variables found to correlate significantly with additional uptake on the post-I131 therapy total body scintigraphies were tumor size >4cm, lymph-node involvement and extracapsular extension. Conclusions: Post- I-131 therapy scans yielded additional information in 9.3% of the patients treated by postoperative I-131 for well differentiated thyroid carcinoma. The value of posttreatment scintigraphies is questionable in low risk patients. No significant financial relationships to disclose.