Molecular imaging and radionuclide therapy
Combined Maximum Tolerated Activity and Lesion-based Dosimetry for Personalized Radioiodine Therapy in Metastatic Differentiated Thyroid Carcinoma: An Early Institutional Experience
By Razak NA, Lee HMJ, Mathew A and 2 others.
Abstract
Objectives
Empirical fixed-activity radioiodine (RAI) therapy remains widely used in differentiated thyroid carcinoma (DTC), despite substantial inter-patient variability in iodine kinetics. Pre-therapeutic dosimetry offers a personalised approach by estimating radiation exposure to organs at risk as well as to tumour lesions. To describe our institutional experience with combined maximum tolerated activity (MTA) and lesion-based dosimetry in patients with metastatic or recurrent DTC, and to evaluate its impact on clinical decision-making.
Methods
A retrospective case series of six DTC patients undergoing pre-therapeutic Iodine-131dosimetry over two years was recorded. Whole-body and blood-based dosimetry were used to calculate MTA, while lesion-based dosimetry was calculated via estimated absorbed lesion-based dose per administered activity (LDpA). Treatment decisions were made following multidisciplinary discussion.