Measurements of dose rate constant corrected for self attenuation from patients injected with 18F (FDG)
Conference Paper
K.Soliman, A.Alenezi, . 2016
نوع عمل المنشور:
E.Poster 004
رابط المنشور على الويب:
اسم المؤتمر:
1st European Congress of Medical Physics
عنوان المؤتمر:
Athene, Greece
تاريخ المؤتمر:
الخميس, أيلول (سبتمبر) 1, 2016
مستخلص المنشور:
Introduction
Variations in FDG biodistribution and organ uptake levels are patient specific and vary with organs sizes and disease types. Radiation self-attenuation and scatter characteristics are assumed to be patient specific and may have comparable variations among populations. A new study from different population type or race could positively contribute to the overall average value applicable in clinical practice.
Purpose
The aim of this paper is to recommend a value for the radiation dose rate constant measured at one meter from patients injected with 18F-FDG to be applied in clinical practice.
Materials and methods
We have measured the dose rates from 67 patients all injected with 18F-FDG just before voiding using a calibrated ionization chamber; The injected activity was corrected for decay and used to calculate the dose rate per unit activity constant. The injected activity range was [147–485] MBq and we found an average dose rate constant of 96 ± 14 μSv h−1 GBq−1.
Results
we recommend the use of 96 μSv h−1 GBq−1 as radiation dose rate constant evaluated at one meter from patients; this result is in agreement with the current literature in 18F-FDG PET/CT imaging practice. We have examined the geometrical factors affecting the measured dose rate values, specifically the point and line source models.
Conclusion
We have presented an overview of the literature that reports dose rate constant values calculated using different assumptions, and suggest the most appropriate one to be used in the case of occupational radiation dose estimates without performing actual dose rate measurements on the patient.