Radiation Dosimetry of 68Ga in PET Imaging: Impact of Exposure Pathways and Age on Effective Dose and Organ-Specific Coefficients

Background The study investigated Positron Emission Tomography (PET), a diagnostic imaging technique employed in healthcare to evaluate physiological functions and detect abnormalities. It emphasized concerns regarding radiation dosimetry and potential risks, advocating for an evaluation of radiopharmaceuticals such as Gallium-68 ( ⁶⁸ Ga) to prioritize patient safety and prevent radiation exposure. The study determined effective doses and organ-specific dose coefficients, utilizing data from the Federal Guidance Report No. 13 Database (FGR13_DB) and the International Commission on Radiological Protection (ICRP) database, for ⁶⁸ Ga radiopharmaceutical employed in PET imaging, encompassing both internal and external exposure pathways. Results Younger individuals exhibited greater susceptibility to the effects of radionuclides, with internal exposure leading to significantly higher radiation doses. Consequently, incorporating age-specific coefficients is crucial when assessing the effects and risks associated with radiation exposure. The dose coefficients for ⁶⁸ Ga exhibited variability depending on the exposure scenario. Furthermore, the organs exhibiting the highest sensitivity to radiation were determined based on the specific exposure scenario. For external exposure, the skin, breast surface, and testes were the organs most susceptible to radiation. Regarding internal exposure, the stomach wall and small intestine wall were the organs most affected by ingestion, while the esophagus, stomach wall, and small intestine wall exhibited the highest sensitivity to radiation exposure via inhalation. With regard to the effective dose, it was found that the effective dose is higher when exposure is through1ingestion or the dietary route. Conclusion The collected specific data of dose estimates is important for characterizing patient doses, and specific dosimetric in formation assists in establishing the risk and optimization of PET.