Bones and Tissues

ANSTO’s irradiation facility is used to treat various types of bone and soft tissue to ensure they are sterile for grafting and transplants. Irradiation is the best method for destroying any residual bacteria on bones and tissues.

At ANSTO we irradiate bones or tendons while frozen (under dry ice) in eskies/coolers and carefully monitor the radiation dose with calibrated dosimeters. A range of different sized eskies are available that have been dosemapped to determine the dose distribution throughout the product in the esky volume. The dosemapping establishes processing parameters for routine irradiation, in particular, the dose uniformity ratio (ratio of maximum to minimum doses to the product). We apply the worst case dose uniformity to the final result to ensure the entire product has received at least the minimum dose required. Generally the dose uniformity ratio will be greater for bone (higher density) than soft tissue (lower density).

Available eskies range from a volume of 25 L with a dose uniformity ratio from 1.15 to a 50 L esky with a dose uniformity ratio of less than 1.4. If for example, the minimum dose received was 25 kGy, then for a dose uniformity ratio of 1.4, the maximum dose would be 35 kGy. The majority of the product would receive doses between these extremes.

While radiation is commonly used to sterilise bone grafts, high doses are detrimental to bone and soft tissues. ANSTO provides researchers with the ability to test ideas such as the biocompatibility and structural integrity of bone grafts over a range of radiation doses with the aim of ensuring reliability for use.
 

Contact: Justin Davies