Bassam, Abdulkarim, research, cancer, tomotherapy, Alberta
Dr. Bassam Abdulkarim's research at the Alberta Cancer Board
A gentler approach to radiation therapy
Radiation therapy has been a standard cancer treatment for almost a century. Over time, it’s become an incredibly effective tool for killing cancers cells and shrinking tumours.
But the cure has often come at a cost—radiation can inflict damage on the normal, healthy tissues surrounding a tumour.
A new technology, known as tomotherapy, is promising to make radiation therapy a safer and more effective treatment option for the next generation of cancer patients.
Unlike traditional radiation therapy systems, in which beams project onto the tumour from only a few directions, tomotherapy rotates the beam source around the patient, thereby allowing the beam to enter the patient from multiple angles in succession. As a result, the cancer is targeted more precisely and the healthy tissue surrounding the tumour is subjected to much lower doses of radiation.
One of only two centres in Canada to employ a prototype tomotherapy machine, Edmonton’s Cross Cancer Institute has just embarked on a three-year project to test the effectiveness of using tomotherapy on patients following a lumpectomy (a partial mastectomy). In particular, researchers are hoping to see a significant reduction in the incidence of skin fibrosis—a common side-effect of radiation in which breast tissue becomes more fibrous, less stretchy and more tender to the touch.
According to Bassam Abdulkarim, co-leader of the Edmonton study, skin fibrosis is observed in about 45 per cent of breast cancer patients following radiation therapy, with about one-in-10 patients exhibiting severe symptoms. Using tomotherapy, Abdulkarim and his colleagues hope to demonstrate that it’s possible to reduce the overall incidence of skin fibrosis by about 20 per cent.
Before beginning treatment, 3-D images taken by a special CT (computerized tomography) scan reveal the exact location of the tumour as well as the sensitive organs or tissues that might be damaged by radiation. The CT scan also shows how best to position the patient within the machine.
With that information in hand, it’s possible to determine how much radiation the tumour should receive as well as the acceptable levels for the surrounding areas.
The tomotherapy device then calculates the appropriate pattern, position and intensity of the radiation beam to be delivered to match that prescription.
“There’s a real advantage in being able to see how the dose is being delivered,” says Abdulkarim. “We can monitor it and do more control. And we expect to decrease the levels of radiation on healthy areas—on the skin, lung, heart and contours of the breast.”
The potential benefits of tomotherapy are not limited to treating breast cancer. Abdulkarim, who is a member of the Brain Tumour Group at the University of Alberta’s department of oncology, says the technology is already being applied to brain tumours and prostate cancer and could be used for many other types of cancer.
For Abdulkarim, who was born in Lebanon and did his medical and oncology training in France, the project represents a good example of how research can lead to tangible improvements in patient care.
“What we learn here,” he says, “could, in the future, help tailor treatment so those who are most prone to radiation toxicity receive lower doses or are offered other options. There’s also the potential to reduce the average length of radiation therapy. These are all very good things.”
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Dr. Bassam Abdulkarim is researching tomotherapy to lower radiation doses while increasing effectiveness.
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