Measurement of dose-area product with GafChromic XR Type R film.

Many of the newer X-ray machines are equipped with electronic means to provide dose-area product (DAP) information. For machines without that ability, an alternative method is to record radiation on a film that can handle a large amount of cumulative exposure. The use of GafChromic XR Type R film was investigated for this purpose by placing it at the X-ray tube assembly to record the radiation in interventional radiological procedures. Dose-area product was determined with a reflective densitometer and then with a flatbed scanner. Precisions were demonstrated to be 5% and 2%, respectively. In a comparison with the machine-recorded DAP, a regression analysis showed the validity of both techniques for values less than 1200 Gy-cm2.