Calculation of backscatter factors for diagnostic radiology using Monte Carlo methods

Area of Science:

• Medical Physics
• Radiological Dosimetry
• Computational Physics

Background:

• Accurate dosimetry is crucial for diagnostic radiology.
• Backscatter factors are essential for dose calibration in X-ray imaging.
• Standardized calibration methods ensure consistent radiation measurements.

Purpose of the Study:

• To determine backscatter factors for X-ray beams used in diagnostic radiology.
• To evaluate the suitability of phantom sizes for dosimeter calibration.
• To propose a standard set of backscatter factors for diagnostic reference dose measurements.

Main Methods:

• Utilized Monte Carlo methods for simulating X-ray interactions.
• Investigated a cuboid phantom (30x30 cm2 front surface, 15 cm depth) as a suitable calibration tool.
• Examined backscatter factor variations across different phantom media (water, PMMA, ICRU tissue) and source geometries (field size, source-to-phantom distance).

Main Results:

• Established backscatter factors for relevant diagnostic radiology X-ray beams.
• Identified a specific phantom size as optimal for dosimeter calibration and representative of adult patients.
• Quantified the influence of phantom material and beam geometry on backscatter factors.

Conclusions:

• The proposed phantom size and selected backscatter factors can serve as a standard for dosimeter calibration.
• These findings contribute to improved accuracy in diagnostic reference dose measurements.
• Standardization of backscatter factors enhances the reliability of radiation dosimetry in medical imaging.