Facteurs prédictifs de l’efficacité de l’irathérapie chez les patients porteurs de métastases pulmonaires de cancer différencié de la thyroïde de souche folliculaire

Abstract

Ten to 15% of patients with differentiated follicular thyroid carcinoma (DTC) develop micro- or macronodular lung metastases (LM). Iodine 131 is the key treatment of these metastases. The aim of the study was to assess the efficacy of radioiodine therapy in LM of DTC, and to identify predictive factors of response. This was a retrospective and descriptive study, including patients operated for DTC presenting synchronous or metachronous LM, between 1996 and 2019. The number of patients included was 29 (8 children and 21 adults). The mean age was 39 years (ranging from 5 to 82 years). Papillary carcinoma was the most frequent histological type. LM were miliary in 14 cases and nodular in 15. The administered activity was 3.7 GBq in 80% of cases. The number of courses of radioiodine therapy varied from 3 to 12, with an average of 6.1. The response to treatment was complete in 10 patients, partial in 4 others and absent in the last 15. The efficacy rate was 48%. Univariate analysis showed that young age at diagnosis, type of LM and initial iodine avidity were the most significant factors associated with therapeutic efficacy (P = 0.008; < 0.001 and < 0.001 respectively). Most LM of DTC respond to radioiodine therapy, either completely or partially, especially the iodine-avid micronodular metastases of young patients. Radioiodine therapy should be continued as long as lesions continue to present radioiodine uptake.