Document Type : Regular Paper


1 Department of Medical Physics, Illawarra Cancer Care Centre, Crown St, Wollongong, N.S.W, 2500, Australia

2 Dept. of Physics and Materials Science, City University of Hong Kong, Kowloon Tong, Hong Kong

3 Center for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia


– Gafchromic XRCT radiochromic film is a self developing high sensitivity radiochromic film
product which can be used for assessment of delivered radiation doses which could match applications such
as Computed Tomography (CT) dosimetry. The dose response of Gafchromic XRCT radiochromic film has
been measured with reflectance spectrophotometry and desktop scanners. The film automatically changes
colour upon irradiation, changing from a yellow to a green/brown colour. Results show a high sensitivity to
delivered dose compared to other conventional radiochromic films which is well suited to CT applications
where lower applied doses are delivered. Sensitivity is found for this film with a 1cGy applied dose,
producing an approximate net optical density change of 0.3 at 636nm and 0.2 net OD using broad band white light. This high sensitivity combined with its relatively energy independent nature around the 100kVp to
150kVp x-ray energy range provides a unique enhancement in dosimetric measurement capabilities over
currently available dosimetry films for CT applications.