Mammographic practice and dosimetry in Britain

Area of Science:

• Radiology
• Medical Physics
• Diagnostic Imaging

Background:

• Mammography is a key breast cancer screening tool.
• Variations in mammographic techniques and dosimetry exist across healthcare centers.
• Optimizing image quality while minimizing radiation dose is crucial.

Purpose of the Study:

• To survey mammographic techniques and dosimetry in UK National Health Service (NHS) centers.
• To assess the relationship between physical parameters, dosimetry, image quality, and radiation dose.
• To compare different mammographic equipment combinations (target/receptor) for efficacy and safety.

Main Methods:

• Conducted a survey of 61 NHS centers in Britain.
• Measured physical parameters: tube output, half-value thickness, peak kilovoltage, surface dose, percentage depth dose.
• Employed ionization and thermoluminescence dosimetry; assessed image quality using a test phantom.
• Calculated absorbed doses for a standardized breast model under different technique combinations.

Main Results:

• Molybdenum/xerox (Mo/X) yielded the best phantom images but the highest mean dose (3.26 cGy) for cranio-caudad (c-c) views.
• Molybdenum/film (Mo/F) with low-dose film achieved a mean dose of 0.95 cGy for c-c views.
• Tungsten/xerox (W/X) provided superior image quality with a mean dose of 0.89 cGy.
• Tungsten/film (W/F) produced the poorest image quality.

Conclusions:

• The Mo/X technique's high dose may not be justified for asymptomatic screening.
• The W/X combination offers a favorable balance of superior image quality and lower radiation dose.
• Continued use of the W/F combination in mammography is questionable due to poor image quality.