Avaliação computacional da exposição ocupacional durante quimioembolização hepática

Abstract

Hepatocellular carcinoma (HCC) is considered the third deadliest cancer worldwide. One treatment alternative is through an interventional radiology (IR) procedure, transcatheter arterial chemoembolization (TACE). This technique uses ionizing radiation for visualizing structures, known as fluoroscopy. The activation of X-rays raises concerns regarding the doses received by occupationally exposed individuals (OEIs), who need to remain in the room during the procedure. The dose values received by the professionals can vary according to the experience of the team, the parameters used, and the total duration of the procedure. In this study, the equivalent and effective dose values for OEIs during a hepatic chemoembolization procedure were obtained through computer simulation using the Monte Carlo method. An IR room containing three virtual male phantoms (MASH3) to represent the main physician, the assistant, and the patient was simulated using two projections: Postero-Anterior (PA) and right anterior oblique, 26° (RAO26), with a field of 35 cm × 35 cm and applied X-ray tube voltages of 70 kV and 80 kV. Scenarios were simulated where the OEIs used collective protection equipment (CPE) against radiation, such as lead curtains and suspended shields, but did not use personal protective equipment (PPE) like brain and thyroid protectors, aprons, and lead eyewear. Scenarios with all PPE and CPE, each with 0.5 mmPb protection, were also simulated to evaluate the efficiency of these equipment during the procedure evaluated in this study. Due to the discomfort caused by the weight of lead aprons on professionals, alternative materials for their composition are available. To verify the shielding differences according to material variation, two different compositions (WSi and tungsten rubber) were simulated in addition to the conventional material, lead. It was observed that the highest dose values received by the OEIs were for the RAO26 projection when an 80 kV voltage was applied, highlighting the need to reduce the voltage value if possible. Considering the scenario without the use of PPE, the effective dose received by the primary physician was 266.82 µSv and by the assistant 30.27 µSv. When all PPE and CPE were used, the doses for these professionals were reduced to 24.12 µSv and 1.16 µSv, respectively. The dose reduction caused using protective equipment emphasizes the importance of using these devices.