Radiation therapy has been used to treat cancer for over a century. But the potentially harmful tools used in the therapy’s early days (such as basic X-rays and radium) have been replaced, thanks to advances in technology that have totally revamped the process.
Today, radiation is more effective and has less deleterious side-effects, according to Chris Birk, radiation therapy manager at the Cross Cancer Institute.
“With new machines, we get new abilities. Our field is ever-evolving,” Birk says.
Understanding Radiation Therapy and its Effects
Radiation therapy is one of the four key treatment modalities for cancer (the others are surgery, chemotherapy and immunotherapy). In most cases it uses high-energy rays to kill the cancer cells of soft-mass tumours by damaging their DNA. It damages healthy cells, too, but they have the capacity to recover.
Radiation may also be recommended before surgery to shrink and/or downstage a tumour (reducing the tumour’s clinical diagnosis from a higher-risk stage 4 to a stage 3, for example), thus allowing for a less-invasive procedure
and a better outcome. After surgery, radiation can also eradicate microscopic cancer cells that might remain in the surrounding tissue.
The most pronounced side-effect of radiation therapy is fatigue. This is often in combination with the stress-related fatigue from travelling and/or being away from family or work that many patients report experiencing. Skin may also be damaged by radiation therapy, especially in moist parts of the body, such as tumours of the mouth. Other effects — like swelling or nausea — are temporary and site-specific.
Currently, Alberta has four cancer centres that offer radiation — Edmonton, Calgary, Red Deer and Lethbridge. Radiation services at the Grande Prairie Cancer Centre are projected to open in 2019.
Since 2011, the Cross has replaced five out of eight linear accelerator (Linac) machines used to deliver external radiation therapy to patients. New versions provide something called “rapid arc treatment.” It rotates around the patient and speedily emits pencil-beams of high-dose radiation directly at the tumour.
“This was a big change for us,” says Birk. “When you get more focused radiation to the cancerous tissues, you can also spare some of that normal tissue.”
The Cross also has three brachytherapy units that use radiation sources for additional personalized treatment options. Note: if you were treated with older machines, do not worry. “Treatment delivery and planning techniques have changed,” Birk explains. “But maximizing tumour dose and limiting the impact on normal tissue has always applied.”
Today, all machines also have “on-board imaging,” which allows for more accurate patient positioning. Previously, imaging focused on where the tumour was relative to the nearest bone structure, like the rib or spinal column. With better imagining, therapists can provide these higher-dosage treatments (called stereotactic therapy) to the tumour and deliver fewer, more focused treatments. For example, brain cancer patients who are treated with gamma knife radiation stereotactic therapy may only need a single treatment session. The latest Linac-MR machine, which was being built and developed this past spring, will use more sophisticated magnetic resonance imaging to provide sharper soft tissue contrast than the X-ray technology used in older models.
The radiation therapy team has even examined the importance of aesthetics in improving the patient experience — now, when you are getting treatment, you can look at soothing images, like forests or skies, which are fixed, static images on the walls of the treatment vault.
Improving Patient Quality Of Life
Although there are no guarantees that radiation therapy will cure cancer, advances like these — resulting in lower-grade side-effects — ensure better quality of life for patients. They will be able to get back to their real lives faster and with more hopeful outlooks than ever before.
Radiation Therapy At The Cross Cancer Institute By The Numbers
4,500 patients seen for treatment annually
63,793 sessions delivered annually
15 minutes (less than) time frame of average treatment
20 to 25 sessions over four to five weeks is the average number per patient
13 number of treatment machines in the program
85 number of radiation therapists in the program
$3.5 million cost of the latest Lina