An evaluation of deviation from the international atomic energy agency-international commission on radiological protection proposed equation for calculation of radiation dose rate emanating from the patients with differentiated thyroid cancer undergoing radioiodine (I-131) therapy

Abstract

The main purpose of this study was to investigate dose rate emanating from patients treated with 131I to evaluate which of the theoretical formulas, inverse-square law (ISL) and International Atomic Energy Agency-International Commission on Radiological Protection (IAEA-ICRP) suggested equation, can provide a sufficiently close approximation of the measured dose rate. Measurements were performed based on the IAEA safety report No. 63 method at 0, 12, 24, and 48 h after administration of radioiodine at a distance of 1 m for 69 patients and for the rest of 67 patients, dose rate was measured at 2, 4, 24, and 48 h at a distance of 2 m. Results revealed that the ISL formula gained better approximation of measured dose rates than the IAEA-ICRP equation with the lesser error. The ISL formula is still more reliable than the novel method of dose calculation in the vicinity of patients. This finding reminded us the prime importance of distance as a radiation protection principle.

The Nuclear Medicine Patient as a Line Source: The Source Length Is Certainly Not the Patient Height, But It Is a Reasonable Approximation

“…We retrieved seven studies (Barrington et al 1996; Willegaignon et al 2007; Sudbrock et al 2009; Yi et al 2013; Liu et al 2014; Dehkordi et al 2017; Mat Nawi et al 2020) providing the required data; the number of patients per study was between 3 and 231. We defined three categories of measurement time: “day 0,” “day 1,” and “day 2.” The first category (six studies) was for measurements taken immediately after injection or on the injection day, the second and third categories each included data from three studies.…”

“…131 I treatment of thyroid remnants. We retrieved seven studies (Barrington et al 1996;Willegaignon et al 2007;Sudbrock et al 2009;Yi et al 2013;Liu et al 2014;Dehkordi et al 2017;Mat Nawi et al 2020) providing the required data; the number of patients per study was between 3 and 231. We defined three categories of measurement time: "day 0," "day 1," and "day 2."…”