PT - JOURNAL ARTICLE AU - Deandreis, Désirée AU - Rubino, Carole AU - Tala, Hernan AU - Leboulleux, Sophie AU - Terroir, Marie AU - Baudin, Eric AU - Larson, Steve AU - Fagin, James A. AU - Schlumberger, Martin AU - Tuttle, R. Michael TI - Comparison of Empiric Versus Whole-Body/-Blood Clearance Dosimetry–Based Approach to Radioactive Iodine Treatment in Patients with Metastases from Differentiated Thyroid Cancer AID - 10.2967/jnumed.116.179606 DP - 2017 May 01 TA - Journal of Nuclear Medicine PG - 717--722 VI - 58 IP - 5 4099 - http://jnm.snmjournals.org/content/58/5/717.short 4100 - http://jnm.snmjournals.org/content/58/5/717.full SO - J Nucl Med2017 May 01; 58 AB - The optimal management of radioactive iodine (RAI) treatment in patients with metastatic thyroid cancer (TC) is still a matter of debate. Methods: We retrospectively analyzed 352 patients with RAI-avid metastatic well-differentiated TC treated with 131I by an empiric fixed activity of 3.7 GBq at Gustave Roussy (GR, n = 231) or by personalized activity (2.7–18.6 GBq) based on whole-body/-blood clearance (WB/BC) dosimetry at Memorial Sloan Kettering Cancer Center (MSKCC, n = 121). The primary endpoint was to compare overall survival (OS) in the 2 groups of patients by log-rank test. Results: Patients received a median cumulative activity of 14.8 GBq at GR and 24.2 GBq at MSKCC (P < 0.0001). The median follow-up after the diagnosis of metastases was 7.2 y (0.4−31 y). Five-year OS was 86.8% and 78.8% for patients treated at GR and at MSKCC, respectively (P < 0.01). However, there was no statistical difference in OS after correction for sex, age at the diagnosis of distant metastases, metastases site, and metastases extension between the 2 centers (P = 0.16). OS at 5 y was 96% and 96% for patients younger than 40 y with micrometastases, 70% and 65% for patients older than 40 y with macrometastases or multiple metastases, and 92% and 87% for younger patients with macrometastases or older patients with micrometastases treated at GR and MSKCC, respectively (P = not significant). Conclusion: Routine use of WB/BC dosimetry without lesional dosimetry provided no OS advantage when compared with empiric fixed RAI activity in the management of thyroid cancer patients with RAI-avid distant metastases.