Scattered Radiation Distribution Utilizing Three Different Cone-Beam Computed Tomography Devices for Maxillofacial...

Area of Science:

• Medical Physics
• Radiological Sciences
• Radiation Protection

Background:

• Cone-beam computed tomography (CBCT) is widely used in dentistry and medicine.
• Understanding scattered radiation is crucial for operator safety and optimizing imaging protocols.
• Current guidelines necessitate operators leaving the room during CBCT scans to minimize radiation exposure.

Purpose of the Study:

• To estimate scattered radiation and its spatial distribution around three different CBCT devices.
• To determine safe operator positions within the CBCT room during patient scans.
• To assess if scattered radiation levels permit operator presence near the X-ray gantry.

Main Methods:

• Measurements of scattered radiation were conducted on three CBCT devices (Morita Accuitomo, Newtom Giano HR, Newtom VGi).
• Radiation levels were assessed using an ionization chamber at various distances from the isocenter, simulating clinical conditions with an anthropomorphic phantom.
• Different exposure parameters (kVp, mA, FOV) were utilized to evaluate their impact on scattered radiation.

Main Results:

• A statistically significant difference (p < 0.001) in mean scattered radiation levels was observed among the three CBCT devices.
• Scattered radiation decreased with increasing distance from the X-ray gantry, with varying reduction rates per device (CBCT1: 0.047 μGy/m, CBCT2: 0.036 μGy/m, CBCT3: 0.079 μGy/m).
• At certain distances, scattered radiation levels fell below the 1 mGy public exposure limit.

Conclusions:

• Operator presence within the CBCT room during scans is feasible at specific distances from the X-ray source.
• The findings support revised radiation safety protocols, potentially allowing for closer operator supervision of patients during CBCT procedures.
• Device-specific radiation profiles are important for establishing safe operating distances and protocols.