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.