Physical dosimetric reconstruction of a case of large area back skin injury due to overexposure in an interventional procedure

Abstract

To estimate the physical dose of skin and key organs in a case of overexposure during a cardiac interventional procedure. Methods: The female patient aged 50 suffered from overexposure during cardiac interventional therapy in a hospital, Xinxiang city, Henan province, China in January 2020. The mesh-type phantom for the patient was constructed based on the adult mesh-type reference computational phantoms (MRCPs) released by the International Commission on Radiological Protection Publication 145 (ICRP145) and phantom deformation technology. Models of exposure scenario were constructed and simulated with particle and heavy ion transport code system (PHITS) according to exposure conditions. Results: The maximum absorbed dose of key organs/tissues under irradiation in posteroanterior (PA) and 30° left anterior oblique directions(LOA) was 632.4 and 305.6 ​mGy, respectively. The left lung, heart, and left mammary gland received a larger dose under both irradiation conditions. The ratio of the absorbed dose with and without shielding was calculated, and the relative difference in most organs was <1% between two directions. The iso-dose curve of the back skin revealed the distribution of the absorbed dose (0.1 −5.2 ​Gy). The dose estimate of key tissues/organs was higher than the conventional level, especially the local skin, up to 5.2 ​Gy. Conclusions: The interventional procedure in this case resulted in a higher dose. Monte Carlo codes combined with the MRCPs can be employed to estimate physical dose to individuals in concrete irradiation scenarios.

Keywords

• Physical dose
• Dose reconstruction
• Digital subtraction angiography
• Monte Carlo codes
• Particle and heavy ion transport code system (PHITS)
• Mesh-type phantoms