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April 16th, 2009

Tackling cancer with physics

Orléans researcher takes aim at tumours

Article online since February 12nd 2009, 11:51

An Orléans resident has been awarded two research grants to develop an efficient technique to target cancer tumours.

Carleton University assistant professor Dr. Tong Xu received $130,000 from the National Sciences and Engineering Research Council of Canada. A further $120,000 was awarded by the Canadian Foundation for Innovation . The grants will be used to renovate Carleton’s physics laboratory and purchase new equipment to conduct Xu’s unique research.

As a student, Xu worked on the Large Hadron Collider (LHC) project in Switzerland where the conditions of the ‘big bang’ are expected to be replicated this summer.

“Particle physics experiments such as LHC use techniques that can determine the mass, charge, and location of unknown particles from the radiation that they produce, without actually seeing them,” said Xu. “We use a similar idea to determine the location of the tumour without actually seeing it from outside of the patient.”

Radiation therapy is about precisely focusing X-ray beams on the tumour. However, if the tumour moves due to involuntary patient motion, such as breathing, the treatment’s outcome may be significantly compromised.

Current cancer treatment methods expose large areas of the body to irradiate tumours, yet simultaneously damage healthy tissues and organs around it. Xu will isolate tumours by tracking their movement and delivering precise shots of radiation.

“A tiny radioactive marker will be inserted into the tumour,” explained Xu. “By detecting the radiation emitted from the marker, the location of the marker can be determined, which indicates the location of the tumour.”

Designed mainly for lung cancer, Xu’s technique can be used to treat other forms of cancer where motion is an issue.

“(Our goal) is to have our techniques used at hospitals to benefit patients,” said Xu.

While he conducts his research, Xu teaches Carleton’s next generation of scientists how physics can be used to better diagnose and treat disease.

“Carleton University is an excellent place to perform medical physics research,” said Xu. “The department of physics in Carleton University is one of the tops in the field of particle physics.”

Xu’s laboratory forms a part of Carleton University’s research centre, the Ottawa Medical Physics Institute (OMPI). He will work on this project in partnership with other Ottawa-area medical physicists.

“Collectively, the medical physics community in Ottawa is one of the strongest and most diverse in Canada, spanning imaging physics, cancer therapy physics, medical biophysics and health physics,” said Xu. “It provides an ideal environment to perform medical physics researches and collaborations.”

Since moving to Orléans in 2007, Xu has discovered many benefits to living in the community.

“Orléans is a family-oriented community, nice schools, convenient transportation,” said Xu. “But most important, the best neighbours we ever had.”

For more information regarding OMPI visit: www.physics.carleton.ca

– By Riaz Sidi

**story originally appeared in the Winchester Press on January 14, 2009

By Riaz Sidi

Carleton University professor Dr. Jeff Dawson hangs up a white bed sheet across his garage at night while bright ultra-violet lights are pointed towards it.

“I’m actually surprised my neighbours haven’t come over asking me what I’m doing – or called the OPP thinking some alien aircraft has landed in my backyard,” he says.

By day, you may see the new Winchester resident strolling down the street with a butterfly net in hand. Dawson knows he may look like a bit of a “nutter” to his neighbours, but one of the perks to moving to the community is the ability to catch a plentiful number of specimen right in his own backyard. The way insects fly fascinates him and as humans have mastered traditional aviation, a new theory on flight is being developed.

“Insects are amazing aerial acrobats!” says Dawson.  “But, here’s the problem — insects have very unique aerodynamics; they simply don’t fly by the same rules that keep airplanes in the air.”

However, this will not stop Dawson from trying to understand how insects break the conventional rules of aerodynamics. His curiosity and passion for insects have led to an innovative view on flight and this has been supported by a $233,570 grant from the Canada Foundation for Innovation (CFI) and the Ontario Ministry of Research and Innovation to conduct his ground-breaking research at Carleton University.

Dawson envisions small vehicles mimicking the flight of moths or locusts outfitted with cameras, microphones and sensors. A countless number of applications in society could exist with ‘entomopters’, as they would be called, flying around. One such purpose would be as an inspection tool to disengage weapons or access and survey a rescue site without threat to human life.

Entomopters could analyze air quality, deliver aid packages to victims of war or be used to further space exploration. With the grant, Dawson hopes to discover more applications as he will work to unravel the mystery behind insect flight. Dawson plans to use the funding to create a state-of-the-art laboratory at Carleton University with instruments capable of measuring the aerodynamic shape of insects. By using scaled replicas, he will study insects without the unpredictable nature of their movement.

“We make robotic versions of the real insects that are larger than the real thing and we operate them under water rather than in air,” says Dawson. “Because they’re under water we make the robotic wings flap slower than the real insect.”

He then uses a coloured dye to track the movement of the specimen’s wings in water and calculate their different trajectories.

Dr. Dawson will be gradually cataloguing the insect population in the Winchester area, so when he does collect real insects, the community is an ideal location.

“Since Winchester is such a rich agricultural area, I’m able to obtain a lot of crop-pest species,” says Dawson.

At the same time, Dawson hopes an understanding of the population levels of each insect in the region will help to better prepare for saving certain species from extinction.

“We’re losing insect species at an alarming rate and it would be good to know what is here now for future reference,” says Dawson. “This is particularly valuable in case something new shows up that is or could become a new pest.”

According to Dawson, insects need more recognition for the fundamental role they play in every day life.

“A lot of people think that insects are just pests – that they eat our food, they spread or even cause disease, they annoy us in the summer and ruin our picnics,” says Dawson. “I think many don’t understand that insects are crucial to human survival; they’re a cornerstone of our environment.”

“Think about pollination – a lot of plants, especially many crops, wouldn’t be possible without bees, beetles and flies,” he says. “They give us products and materials for industry, medicines and alternative treatments for our health, and provide food for other animals and even humans.”

Dr. Dawson was first inspired to study insects as an undergraduate student at the University of Toronto. He became passionate about understanding the biology of insects and is always interested in sharing with others what he has learned himself.

“Now that I am a professor, I like to think I’m doing the same for my students at Carleton,” he says.

To get his innovative research underway, Dr. Dawson is getting students and faculty involved in his project.  Currently, Dawson supervises four graduate students and six undergraduate honours thesis students. He has also partnered with colleagues in the Department of Mechanical and Aerospace Engineering, at the National Research Council and the Canadian Museum of Nature.

“It is important to remember that most research done today is not done by a single person, but rather by teams of people,” says Dawson.”This is especially important when research spans many very different disciplines – my research requires experts in math, physics, electronics, robotics, insects, flight, neurobiology, biomechanics and more.”

The collaborative effort will take place at Dawson’s laboratory at Carleton University where innovation continues along the many disciplines required to complete his research. Dawson appreciates the Carleton community across these disciplines, primarily between the Faculty of Science and Faculty of Engineering, for working in unison to cooperate on the project.

“Carleton is perhaps the best place to build this facility and to do this research,” says Dawson. “I can’t think of any other University at which I would rather be.”

At Carleton University, Dr. Dawson works on trying to understand how animals move and adapt to their environment. As a neuroethologist, someone who studies the basis of an animal’s behaviour in its environment, how insects fly is just one of his many areas of interest.

“Many insects are eaten by bats – so I also study bats and how they catch insects, and how insects are able to detect bats and avoid being captured,” says Dawson. “Many people don’t realize that many of the insects that fly at night have ears that can detect the calls that bats use for navigating in the dark — a process called echolocation – so I’m also interested in insect hearing.”

Since moving with his wife Sabrina to Winchester last May, Dr. Dawson has been taken back by the friendly people he has met.

“We’re also enjoying a great sense of community too – with Dairy Fest, the Parade of Lights, local fairs and markets,” he says.

Dawson and his wife are expecting their first child in May and are looking forward to raising their family in Winchester. As he continues to conduct his research at Carleton, it is unlikely he will soon put down his butterfly net. With the help of his colleagues, Dawson will be able to fully explore the limits of insect flight with confidence.

“The department of Biology at Carleton is somewhat unique in Canada in having a cohort of professors and adjunct professors studying insects,” says Dawson. “This provides daily interactions, a great knowledge base and attracts students and collaborators to my doorstep.”