Estimated Dose Rates for Pediatric Patient Release Criteria for 131I Therapy
Abstract
Radioactive iodine (RAI) therapy using 131I can be used to treat patients with thyroid dysfunction such as hyperthyroidism and differentiated thyroid cancer (DTC). In the case of DTC, cells in the thyroid gland, mainly follicular cells, continue to grow irregularly, forming a mass in one or both lobes of the thyroid that appear microscopically similar to normal thyroid tissue. Hyperthyroidism refers to when the thyroid is overstimulated and produces excess thyroxine hormone (T4) that adversely accelerates the body’s metabolism causing many symptoms, including the worsening of a DTC prognosis. While much work has been conducted focused on adult patients and adult members of the public with respect to radiation protection standards and patient release criteria, little has been considered in regard to age-specific pediatric patient cases, both as patients and exposed public. An evaluation of patient bioretention of RAI resulting in estimated exposure rates and effective dose to all members of the public from adult and pediatric patients receiving RAI therapy has been conducted to better inform patient release radiation protection guidelines or patients and exposed family members. The improvements to public protection and patient release criteria account for age-dependent analysis (both patient and public) are proposed in harnessing radiation transport simulations of age-specific phantoms correlated with biokinetics post-administration of RAI therapy. Results demonstrated current patient release regulatory guidelines overestimated dose to patients and members of the public at minimum by a factor of 2 across age groups, indicating that time-dependent age-specific models more accurately determined the time at which release can occur to is potentially sooner than current tools provided in regulatory guidelines to licensees.
Subject
I-131 patient releasecomputational dosimetry
thyroid 7- Monte Carlo
Radiation dosimetry & risk
Uptake kinetics
20-Radiopharmaceutical therapy
Anthropomorphic dosimetry phantoms
Dose estimation-Monte Carlo
Safety
QA
risk analysis and radiation protection 24-Phantoms for dosimetric measurement
Citation
Aziz, Landon (2021). Estimated Dose Rates for Pediatric Patient Release Criteria for 131I Therapy. Master's thesis, Texas A&M University. Available electronically from https : / /hdl .handle .net /1969 .1 /193267.