The worker in a white lab coat grips the handles dangling by her shoulders and stares through the window into an orange glow.
With the pinch of a finger and the push of a button, she manoeuvres the mechanical arm at the end of the hose like a dropping-claw arcade game. But instead of a teddy bear, she deftly picks up a tiny vial, unscrews its lid and dumps its contents into a goblet.
Twenty kilometres away, nuclear medicine specialist Dr. Eugene Leung watches a multi-screened computer monitor in a darkened room at the Civic Campus of the Ottawa Hospital.
A blob of colours shifts and stirs, glowing yellow, orange, red, blue and green as it glides and rolls across the screen.
The blob is an egg sandwich being digested in a stomach.
Leung can see it because the sandwich has been mixed with a minuscule amount of something made from what was in the vial being manipulated by the worker in the lab coat.
That something is radioactive molybdenum-99.
After the substance arrives at the MDS Nordion facility in Kanata, Ont., it is brought in through the back of the machine with the dropping claw, which is a hot cell shielded with lead to protect the workers from radiation.
The highly trained technicians manipulate the machine with tools that look complicated but do not require much automation, because the radiation levels would damage more technologically sophisticated equipment.
Forward. Back. Fill. Empty. They are testing it for product quality before it will be loaded into specialized shipping containers — vials inside metal cylinders inside a layer of foam inside a bigger metal drum — and distributed to radiopharmaceutical companies around the world.
The molybdenum-99 is then loaded onto a generator where it will begin to decay into technetium-99m, which is used in the majority of nuclear medicine procedures. The generators are delivered to hospitals, where the technetium-99m is extracted to be used in diagnostic tests and treatments.
The nuclear medicine department at the Ottawa Hospital does about 30,000 such procedures a year, says its manager, Alan Thibeau. They begin with a patient being injected with, inhaling or, in the case of the egg sandwich, ingesting some technetium-99m or an alternative medical isotope and then (usually) going home to wait for it to crawl through the blood or digestive system or whatever organ the doctor wants to examine.
When the patient returns, he or she will be brought in to lie down on a machine called a gamma camera, which is circled by a gantry, a large ring that moves up, down and, at least on the newer models, all around the body.
The gantry, Thibeau explains, contains a thin crystal made of sodium iodine with a bit of another medical isotope, thallium. The high-frequency, short-wavelength electromagnetic radiation called a gamma ray hits the crystal, which then emits a small flash of light, multiplied thousands of times by electronic circuitry in the camera.
A graphical tool called a positioning matrix figures out exactly where the gamma camera took its “picture” and recreates the image on the computer.
The test finished, a nuclear medicine specialist such as Leung examines the images in the dark room to look for any problems.
The radioactive egg sandwich that appears as a colourful blob is a test to see how well, or how poorly, the stomach digests food. A slower rate can be an indication of diabetes, Leung explains.
Another image on his giant monitor shows a grey skeleton against a white background, covered in black spots, the biggest and darkest one surrounding the groin.
Leung says this patient has prostate cancer and the test was to see whether it had spread to other parts of the body. The dark patches do not represent the tumours themselves, but rather show where the bones are reacting to the presence of cancerous cells. The test finds the fire by looking for the smoke.
Joanna Smith
Ottawa Bureau