Dose Area Product
A measure of the total radiation dose delivered during a radiographic examination, calculated as the absorbed dose multiplied by the area of the X-ray beam, expressed in gray-centimetres squared (Gy·cm²).
Full Definition
Dose area product (DAP) is a quantity used in medical and dental radiology to estimate the total energy imparted to a patient during an X-ray examination. It is measured using an ionisation chamber mounted on the X-ray tube and expressed in units of gray-centimetres squared (Gy·cm²). DAP is particularly useful for comparing radiation output across different radiographic techniques and equipment, and it forms the basis of dose audit data in dental practices. Editors of radiation protection documentation must render the abbreviation as 'DAP' after spelling it out in full on first use and must ensure the correct SI unit (Gy·cm²) is used rather than obsolete or incorrect alternatives. DAP should not be confused with effective dose, which accounts for tissue radiosensitivity.
Usage
Usage note: Use 'Gy·cm²' (gray-centimetres squared) as the SI unit; do not abbreviate as 'Gycm2' or 'cGy·cm²' without explanation. Expand 'DAP' at first use.
In Context
- "The dose area product recorded for the panoramic examination was 67 mGy·cm², which was within the national diagnostic reference level." — Dose audit report
- "The editor ensured that 'dose area product (DAP)' appeared in full at first mention throughout the radiation protection policy document." — Radiation protection policy editing