BY NORM TOLLINSKY
The Thunder Bay Regional Research Institute (TBRRI) has received funding for a cyclotron that will produce radioisotopes for molecular imaging and earlier detection of cancer.
The $3 million unit will produce a range of radioisotopes, including Fluorine-18 (F-18), which will be used with Thunder Bay Regional’s 64-slice Positron Emission Tomography/CT scanner, said Michael Campbell, TBRRI’s manager of cyclotron and radiopharmacy operations. Currently, Thunder Bay receives fluorine-18 from the Centre for Probe Development and Commercialization in Hamilton.
The radioactive fluorine is combined with a sugar molecule to form fluorodeoyglucose, a radiopharmaceutical that is injected into a patient and zeros in on cancer cells.
The Thunder Bay cyclotron will be one of approximately 10 such units across Canada and the only one in Northern Ontario.
“The future of health care is tied to enhanced diagnostics to ensure diagnosis of cancer at the earliest stage possible,” said Michael Power, TBRRI’s CEO and vice president, regional cancer and diagnostic services at Thunder Bay Regional Health Sciences Centre.”
Molecular imaging can also be used during a course of chemotherapy to confirm its effectiveness.
“We’re moving away from anatomical images using CT and MRI scanners which take pictures of bone and muscle with shadows representing tumours, to imaging that more precisely identifies disease at the cellular level,” said Power. “The radioisotopes allow us to enhance the way we take images and do more with the information produced.”
With conventional CT and MRI scanning, the cancer has to be a certain size and certain density to be detected. PET scanning, on the other hand, takes advantage of the fact that cancer cells are hyperactive and metabolize glucose at a faster rate than healthy cells.
This means “we’re able to see cells based on how they function, not how big they are, so it lets us detect cancer at a much earlier stage,” explained Campbell. “It also gives us a very quick indication if the chemotherapy is working because you can tell after a few courses of treatment if the cells are getting knocked back even before the tumour has started to shrink.”
The enhanced diagnostics made possible by PET scanning with radioisotopes can help oncologists make better treatment decisions.
“There are many examples of lung cancer patients who undergo a very expensive and very invasive thorocotomy to take out a lung only to find out that the cancer has metastasized, but has not yet shown up on traditional CT scans,” said Power. With PET scanning, the patient would be spared the trauma of major surgery and treated with chemotherapy or provided with palliative care.
Using cyclotrons to produce radioisotopes will alleviate the dependence of the health care system on the likes of Atomic Energy of Canada’s Chalk River Laboratories, which produces close to half of the world’s medical isotopes.
The risk of relying on facilities like Chalk River became obvious when a heavy water leak forced a shutdown of AECL’s National Research Universal reactor from May 2009 to August 2010, resulting in a worldwide shortage of isotopes.
Diversified supply
“There’s a very strong push for the idea of a diversified supply chain versus having one central supplier,” said Campbell. “When everything is working great, the reactors are able to produce isotopes quite efficiently, but it’s when one goes down that there’s such a huge impact on the system.”
Ultimately, the thinking is that there would be a network of cyclotrons, each of which would supply isotopes, including technetium, to hospitals within their respective regions. This could mean that Thunder Bay would supply hospitals in Sudbury, Sault Ste. Marie, Timmins, North Bay and even Winnipeg.
Thunder Bay Regional Research Institute received funding commitments of $5.5 million for the cyclotron, including $4 million from the province and $1.5 million from the city, in 2010. In March, the federal government agreed to match the provincial contribution, bringing the total amount raised to $9.5 million.
The price tag for the cyclotron itself is $3 million. The rest of the money will be used for the acquisition of radiopharmacy technologies and for construction to accommodate the 22-tonne device at Thunder Bay Regional.
“The cyclotron we’re getting is a mid-energy unit that’s very efficient at producing F-18 for routine PET scanning, but also lets us produce other isotopes, including Iodine 123, which is a highly desired isotope for other types of medical imaging,” said Power.
The federal government plans to cease production of medical isotopes from AECL’s National Research Universal reactor by 2016 and is counting on new cyclotron-based technologies for producing technetium-99m beyond that date.
The Thunder Bay Regional Research Institute is one of several research groups working toward this goal.
Research in Thunder Bay will also focus on the development of new imaging agents that not only detect cancer, but also tell us “what kind of cancer it is and what the best drug is to treat it,” said Campbell.
www.tbrri.com
