Health

Group Seeks Funding for Cancer - Detecting PET Scan

By Gail Johnson

The future of early cancer diagnosis rests in the use of positron emission tomography, according to the president of the B.C. Cancer Agency. Oncologist Simon Sutcliffe says the organization is about to approach the provincial government with hopes that the powerful imaging technique—which is considered to be more effective than computerized axial tomography scans and magnetic resonance imaging, and which costs $2,500 per use—will soon be publicly funded.

Sutcliffe sits on the medical advisory committee of the Vancouver PETscan Centre, a private clinical scanning facility that’s owned by the Vancouver-based company International PET Diagnostics and that opened last fall. He recently gathered with a group of oncologists and nuclear-medicine clinicians from across North America at Canada’s first conference on the advanced technology.

“Our experience is very consistent with the American and European experience, and our experience leads us to conclude that PET is very valuable in certain indications of cancer,” Sutcliffe said at the June 11 meeting. “In many cases, this unique innovation will become the imaging modality of choice.”

The goal of the conference, which was held at the Morris J. Wosk Centre for Dialogue at SFU Harbour Centre, was to raise awareness of appropriate and effective uses of the technique and to come up with a detailed analysis of the scan’s applications to be submitted to the government within a month. So far, the cost of the scans for the neediest patients has been covered by a fund donated by a local philanthropist, but that money is drying up.

“There is no funding in B.C., and there never has been, so there is no precedent,” Sutcliffe told the Straight after the forum. “We’re starting from ground zero. If the indications support that this is a state-of-the-art practice and that there are medically justifiable health outcomes, it should be covered by MSP.” He added that the only province in which PET is fully covered is Quebec; limited coverage is available in Ontario and Alberta.

Edward Coleman, professor of radiology at North Carolina’s Duke University Medical Center, told the conference that although PET scans were introduced in the early ’70s, around the same time as MRIs—which went into rapid commercial development—it’s just been within the past decade that the use of PET has really taken off.

“Only in the last several years has the potential been demonstrated and the clinical applications [of PET] been well-accepted,” Coleman said. Unlike CATs, MRIs, X-rays, and ultrasound, which determine anatomy or body structure, PET images the body’s metabolic activity, or tissue function. Other advantages of positron emission tomography, Sutcliffe and others claim, are that it minimizes the need for exploratory surgery by providing specific information on disease and damaged organs. Traditionally, a biopsy is required to tell whether or not a tumour is cancerous, but a PET scan can often tell whether a tumour is benign or malignant, what stage the cancer is at, and whether or not the cancer has spread, as well as if the cancer treatment is working and if there are any abnormalities in the brain or heart.

The scan works through the use of a radioactive, glucose-based compound, called fluorodeoxyglucose, that’s injected into the patient. The tracer travels through the body, and because cancerous tissue aggressively feeds on glucose, the affected organ shows a concentration of FDG. A computer then assembles the signals into three-dimensional images, which show organ function. This can uncover abnormalities or tumours that could otherwise go undetected.

The scan provides an image from the head to the upper thighs and takes about two hours; results are available within 24 hours. Coleman noted that there are about 200 PET scanners in use in the U.S.; at Duke University, almost 2,700 people underwent PET scanning last year. The most common type of cancer being investigated was lung cancer, with 923 patients having scans, followed by brain cancer (345) and melanoma (300). Public funding of the scans is partial in the States, but coverage is provided there for certain stages of lung and colorectal cancer, lymphoma, and melanoma.

The conference did touch on one of the imaging system’s weaknesses, a fairly high false-positive rate for some cancers. However, Sutcliffe said incorrect test results will happen from time to time no matter what the technology. And PET scans remain highly specific and sensitive; he maintained that they are up to 35 percent more accurate than CATs or MRIs. Sutcliffe claimed that doctors using PET scans end up changing their treatment approach in up to 50 percent of cases. He maintained that the test can save money because it can eliminate unnecessary procedures such as surgery, chemotherapy, and radiation. Researchers are also investigating the use of PET scans in neurology, specifically in the areas of dementia, epilepsy, and stroke, and in cardiology, for such conditions as coronary-artery disease.

In the eight months since the Vancouver PETscan Centre opened at the B.C. Research and Innovation Complex at UBC, the number of patients undergoing scanning has jumped from 12 per month to 51. A doctor’s referral is necessary to get into the centre.

Sutcliffe said the cancer agency’s push for PET-scan funding would focus initially on the areas in which the technique is especially effective, such as lung, esophageal, and colorectal cancer, as well as lymphomas and melanomas. There is still not enough evidence of the test’s effectiveness in diagnosing breast, cervical, and ovarian cancer, he noted. If the private donor’s funds are used up, Sutcliffe said, the centre will try to avoid denying needy patients access by dipping into its own operating budget, seeking other donations, or asking for short-term coverage from the province until, as the agency hopes, firmer plans are established.

[Please note that this article has been taken from the electronic files of the Georgia Straight and so may vary slightly from the published version. Please note that this article may not be reproduced in any fashion without the permission of the author and a credit stating that it originally ran in the Georgia Straight.]

[From: The Georgia Straight, June 21-28]