Molecular Imaging for Barwon Health
July 2009
The Federal and State Health Ministers recently announced funding for a PET/CT service at Barwon Health. This is very exciting news and it is expected that this system will become operational by mid-2010.
What are the clinical applications?
Positron Emission Tomography (PET) is a very powerful medical imaging tool. The most important and established indication for PET is in the detection and staging of cancer. PET scans assess tissue metabolism, which may alter before any structural changes are apparent. This means that many tumours can be detected before they can be 'seen' using other techniques such as CT or MRI. PET scans accurately show the extent of spread (or metastasis) of malignant tumours, and can discriminate malignant cancers from benign tumours and scar tissue. PET has received funded support from the Federal Government in the staging and assessment of lung cancer, melanoma, lymphoma, colorectal and, more recently, ovarian cancer.
Other indications for PET include the assessment of dementias, complex epilepsy and cardiac disease.
How does it work?
Positron emission tomography (PET) shows the chemical function or metabolism of an organ or tissue rather than its structure. PET requires the injection of small amounts of positron emitting radioactive chemicals (radionuclides) into a patient's bloodstream. The most important and widely used compound is F-18-fluorodeoxyglucose (FDG), which has a half-life of close to 1.5 hours. FDG is taken up in proportion to the metabolic activity in the tissue. The radioactive rays (gamma rays) emitted by radionuclide within these tissues are detected by a PET scanner.
When PET images are used in combination with CT or MRI, it enables the precise anatomical localisation of the distribution of the FDG throughout the body. The result is that functional metabolic images are superimposed or co-registered with high resolution anatomical images. The images produced are able to show areas of the body that are very metabolically active (such as cancers) and those not functioning satisfactorily (such as areas of the brain damaged by stroke or dementia).
PET/CT service for Barwon Health
Previously in Victoria, PET was only available in a handful of hospitals including Peter McCallum Cancer Institute and the Austin Hospital, therefore requiring patients to travel to Melbourne. Barwon Health has a major cancer treatment service, Andrew Love Cancer Centre, and PET is an essential diagnostic tool in the detection, staging and management of patients with cancer.
Barwon Health is planning to introduce a state-of-the-art PET/CT service, which combines functional PET images with high resolution structural images produced using CT. This technology will be among the most advanced available anywhere in Australia. It is anticipated that the PET/CT service be fully operational by mid 2010.
http://www.petscaninfo.com/zportal/portals/phys/clinical/pet_case_studies