Radioactive isotopes crucial in cancer diagnosis

With the possibly prolonged shutdown of Canada’s nuclear reactor at Chalk River, many hospitals and private clinics are facing a shortage of radioactive isotopes for medical imaging.

TORONTO — With the possibly prolonged shutdown of Canada’s nuclear reactor at Chalk River, many hospitals and private clinics are facing a shortage of radioactive isotopes for medical imaging.

But what will that mean for Canadian patients? And just what the heck is a medical isotope anyway?

One might imagine the substance as a tiny green glob that glows in the dark, but the reality is far less dramatic.

A radioactive isotope preparation is actually a clear, odourless liquid that is injected into a vein in the patient’s arm, similar to getting a needle for hooking up an IV or having blood drawn.

Depending on what chemical it is combined or “tagged” with, the isotope travels to a targeted area of the body, where it emits gamma rays that are picked up by a special camera.

That allows doctors to capture pictures in detail that can’t necessarily be obtained by other imaging techniques such as X-rays or CT and MRI scans.

Isotopes are also safer for patients because they involve less radiation. In fact, nuclear medicine technologists do not have to stay behind a leaded barrier while administering the tests, as they would with other imaging techniques.

“What we do in nuclear medicine is we inject radioactive isotopes to look at different processes within the body,” says Yasmin Somani, an imaging technologist at Sunnybrook Health Sciences Centre in Toronto.

“So if you are a cancer patient and we need to see if the tumours have spread to any of your bones, we can do a bone scan,” says Somani, explaining that the isotope is tagged with a phosphate compound that is attracted to bone.

“So we can actually see that phosphate being attached to bone, and if there is a disease in the bone, more of that stuff will get there and basically we’re just lighting it up.”

The radio-isotope will collect in high concentrations in areas where there is increased bone cell activity, which would occur in tumour growth, for instance.

These hot spots on the scan show whether cancer cells have spread — a vital piece of information needed for the treatment of patients, says Somani. Bone scans can also identify fractures and detect infection after a hip or knee replacement.

Medical isotopes allow doctors to peer into numerous areas of the body to see if they are functioning improperly.

Those directed at the heart, for instance, can determine if a heart attack has caused damage to the organ or whether a coronary artery may be blocked.

Isotopes can also tell doctors whether a patient’s kidneys have proper blood flow and urine output; one tagged to the gastric system can show whether the stomach is emptying correctly; another that targets the lungs can pick up a pulmonary embolism, a potentially deadly blood clot.

“There are actually a couple of different radioactive isotopes we use in nuclear medicine, but the one that’s most scarce at the moment is technetium,” says Dawn-Marie King, director of clinical operations at the University Health Network, which comprises several Toronto hospitals.

Technetium, pronounced teck-NEES-e-um, is produced from molybdenum-99, the raw isotope created by Atomic Energy of Canada in its Chalk River reactor.

Chalk River supplies about half of the world’s supply of moly-99.

Using a special generator that captures technetium from moly-99, hospital technicians produce a quantity of the isotope each morning for that day’s imaging needs.

“Because technetium only has a six-hour half-life, we can only use it for that day,” says King.

But with the Chalk River generator down for repairs, UHN and the affiliated downtown hospitals it supplies are running out of the means to make technetium. (Sunnybrook uses a different supplier.)

King says UHN has enough moly-99 for full-scale imaging only until Wednesday, then reduced amounts for Thursday and Friday.

Technicians are looking for ways to stretch the supply by cutting the amount per patient, which would mean taking longer to acquire images.

“We’re also trying to prioritize the patients that we do because there are some scans” for which there is no alternative, she says.

“Any elective patients we’re trying to book further into the future, into July, so we make sure we have enough radioactivity for the urgent patients.”

Radiologist Dr. Marc Freeman, head of nuclear medicine at UHN, said the administration is trying to tap into alternative sources of moly-99 while Chalk River is out of commission.

“The problem is a Catch-22 because everyone else, whether it be university centres or independent health centres, needs the radio-isotopes to perform the scans,” he says.

“So the bottom line is not everyone is going to be able to get their capacity and it’s going to significantly impair our function as a department.”

Just Posted

Walk raises awareness, money for overdose awareness in Red Deer

More than 90 people gathered in Red Deer to break the stigma… Continue reading

Ponoka RCMP looking for missing man

Ponoka RCMP is asking the public to help find a man who… Continue reading

Woman killed in collision west of Rocky Mountain House

A 42-year-old woman is dead after a two-vehicle collision in Clearwater County… Continue reading

Rough camper “tree house” found hidden in Red Deer woods

“This took a bit of work,” says man who discovered it

Central Alberta has one less peacekeeper with death of Nobel Prize-winning vet

The late Wayne Coubrough and Wayne Bevis helped diffuse tensions in the Middle East

WATCH: Snakes, lizards and more at the Western Canadian Reptile Expo in Red Deer

The 10th annual Western Canadian Reptile Expo is this weekend in Red… Continue reading

Your community calendar

Tuesday and Sept. 3 The Tony Connelly Singers provide an opportunity to… Continue reading

Regina police officer charged with impaired driving after hit-and-run

Regina police say a member of the force has been charged after… Continue reading

Groups ready campaign to help young voters identify ‘fake news’ in election

OTTAWA — Samantha Reusch is aiming to help young Canadians identify misinformation… Continue reading

Trade to dominate Trudeau-Trump bilateral meeting during G7 summit

BIARRITZ, France — Prime Minister Justin Trudeau arrived Friday for this weekend’s… Continue reading

Brazil military begins operations to fight Amazon fires

RIO DE JANEIRO — Backed by military aircraft, Brazilian troops on Saturday… Continue reading

Economic storm clouds hovering over Trump and global leaders

BIARRITZ, France — Under the threatening clouds of a global economic slowdown,… Continue reading

‘Red flag laws’ offer tool for preventing some gun violence

After a white supremacist discussed plans on Facebook for a mass shooting… Continue reading

Hong Kong police and protesters clash, ending violence lull

Hong Kong protesters threw bricks and gasoline bombs at police, who responded… Continue reading

Most Read