Analysis of radiotracer uptake (in vivo PET/SPECT, biodistribution)
Radiotracer uptake is often expressed in percent of injected dose per weight of wet tissue (%ID/g). In in vivo PET/SPECT studies, Volumes or Regions of Interest (VOIs/ROIs) are drawn and regional activity data (Bq/cm3) is extracted from these VOIs/ROIs. The Time-Activity Curves are derived from the calculated data using image analysis software.
Kinetic modelling may be involved if sophisticated data is required for compartmental uptakes or clearance. In biodistribution studies, %ID/g values are calculated to express the uptakes of radiotracers in organs of interest. Ratios of target:non-target or organ:background uptakes are often calculated to serve as indications of radiotracer selectivity/specificity and clearance.
Contact scientist: Vu Nguyen
Radioligand stability studies
In vitro radioligand stability studies are often conducted in physiological solutions or body fluids (plasma/blood), mimicking physiological conditions to establish the tracer stability over time. In vivo radioligand stability studies are performed to examine the unchanged/changed fractions of the tracers in relevant organs or tissues, often the targets of the tracer. Both techniques involve activity extraction and/or analytical methodologies such as radio-HPLC, radio-TLC or appropriate chromatography methods.
ANSTO's Radiation Technology group operates 60Co irradiators for small scale irradiation studies to a wide range of doses and dose rates. Our unique capabilities enable us to accurately deliver high doses of radiation with a precision not achievable in industrial-scale irradiators. Controlled dose rates and temperatures allow users to test ideas, develop applications and perform irradiations under non-standard conditions.
The range of applications provided by our service include:
- Low doses for seed mutation studies (10Gy) or sterile insect technique (70 Gy)
- Product qualification studies (for medical products ISO 11137 )
- Temperature staging irradiations (chilled & frozen conditions)
- Long irradiations for polymer and degradation studies
The Sterile Insect Technique is the primary pest management program to contain and eradicate Queensland fruit fly (Q-fly) outbreaks. SIT is the only alternative to cover-spray applications of toxic pesticides when eradication is required. In Australia, this program was developed in collaboration with ANSTO in the 1980’s. ANSTO’s Radiation Technology group continues to irradiate these insects for the Tri-State SIT program (NSW, VIC and SA) to protect citrus, stone fruit, pome fruit, grapes and other crops.
While radiation is commonly used to sterilise bone grafts, high doses are detrimental to bone and soft tissues. ANSTO's Radiation Technology capabilities provides researchers with the ability to test ideas such as the bio-compatibility and structural integrity of bone grafts over a range of radiation doses with the aim of ensuring reliability for use.