Abstract
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 empiric fixed activity of 3.7 GBq at Gustave Roussy (GR, n = 231) or by personalized activity (2.8 to 18.6 GBq) based on whole body/blood clearance dosimetry (WB/BC) at Memorial Sloan Kettering Cancer Center (MSKCC, n = 121). The primary endpoint was to compare Overall Survival (OS) in the two 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, respectively (p< 0.0001). Median follow-up after the diagnosis of metastases was 7.2 years (0.4 -31). Median OS was 86.8 % and 78.8 % at 5 years 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 two centers (P = 0.16). OS at 5 years was 96 % and 96% for patients < 40 ys with micrometastases, 70% and 65% for patients > 40 ys with macro or multiple metastases, 92% and 87% for younger patients with macrometastases or older patients with micrometastases treated at GR and MSKCC, respectively (P = NS). CONCLUSION: Routine use of WB/BC dosimetry without lesional dosimetry provided no OS advantage when compared to empiric fixed RAI dosing in the management of thyroid cancer patients with RAI-avid distant metastases.
- Copyright © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.