A Definite No Brainer
Dr. Sossi used this opportunity to captivate students with an in-depth tour that addressed radiotracer usage for brain imaging (e.g. Parkinson’s Disease) at UBC Hospital.
The Positron Emission Tomography (PET) program is the result of over thirty years of collaboration between TRIUMF and the University of British Columbia, a bond solidified by a 2.5-kilometer underground pipeline titled the rabbit line connecting the two facilities. TRIUMF produces the radioisotopes using the TR-13 medical cyclotron and radiotracer preparation is done at TRIUMF's chemistry labs before they are sent for patient use at UBC hospital via the rabbit line traveling at speeds of over 100km/hr.
A PET transmission scan begins with a rotating positron-emitter source with and without patient in order to calculate the attenuation correction factor. The patient is injected, and placed in the machine for up to one hour. Molded masks are used to help patients remain still during the scan, while infrared camera monitor head motions for further data correction. Two most important positron-emitter radioisotopes used in PET imaging are 18F (t1/2 =110 min) and 11C (t1/2 =20 min). Because of their biological significance, a great number of biological radiotracers have been developed to study the function of biological systems. Dr. Sossi states that currently 15 radiotracers are produced routinely for imaging studies in this facility such as 18F‐fluorodopa and 11C‐PBR28 for dopaminergic and inflammation tests. Determining the amount of injected radiotracer is a trade-off between minimizing the noise and getting useful data, while giving as low as possible dose to the patient. The effective dose is comparable to the dose of whole body CT scan (2-10 mSV).
Patients for human brain research in the PET imaging facility are volunteer subjects with specific types of disease who are selected for diverse research studies. One study focuses on genetic alterations associated with the development of Parkinson disease; patients with a genetic mutation are approached to volunteer, then imaged before any clinical symptoms to understand how early the disease may occur. The success of the tour comes in the form of ideas. Dr. Sossi exposed each participant to no less than three PET scanners (including a small-animal PET camera used for preclinical imaging). Access to PET imaging facility at the UBC Hospital was a unique opportunity that gave each student a better understanding of the breadth of diversity isotopes in the science and medicine fields. Taking in this tour was definitely a no brainer.
~ Zeynab Nosrati, IsoSiM MA student
~ Nic Zdunich, IsoSiM Communications Assistant