Problems of Radiation Medicine and Radiobiology

Chumak V., Morgun A., Bakhanova E., Loganovsky K., Loganovska T., Marazziti D.

Problems following hippocampal irradiation in interventional radiologists – doses and potential effects: a Monte Carlo simulation

Objective: This study aimed at investigating radiation exposure of hippocampus in interventional medical professionals irradiated in the operating room, and to compare doses in the hippocampus with the effective dose (protection quantity), as well as with the doses measured by individual dosimeter, in order to estimate probability of reaching levels of radiation-induced cognitive and other neuropsychiatric alterations during their working career, through a Monte Carlo simulation.
Materials and methods: A Monte Carlo simulation of hippocampal exposure was used by means of a hybrid voxel-mathematical phantom of a doctor irradiated in typical angiographic projections and energy spectra inherent to interventional cardiology procedures.
Results: The results showed that cranial irradiation was very heterogeneous and depended on the projection: doses of left and right hippocampi may be different up to a factor of 2.5; under certain conditions, the dose of the left hippocampus may be twice the effective dose, estimated by conventional double dosimetry algorithm.
Conclusions: The professional span doses of the irradiated hippocampus may overcome the threshold able to provoke possible cognitive and emotional-behavioral impairment. Therefore, in-depth studies of the effects of brain irradiation in occupationally-exposed interventional medical personnel appear urgently needed and crucial.

Key words: Monte Carlo simulation, interventional radiology, radiation exposure, dose, hippocampus, brain effects, cognitive impairments.

Problems of radiation medicine and radiobiology. 2015;20:241-256.