William Chu: Leading Innovations in Radiation Medicine
THIS IS AN EXCERPT FROM THE 2015-2016 ANNUAL REPORT.
According to Dr. William Chu, “treatment techniques can always be made better and re-assembled to improve patient outcome.” He is referring to his latest efforts to combine MR imaging with therapeutic ultrasound and radiation to treat patients with recurrent rectal cancer.
William Chu is an Assistant Professor at UTDRO and a Radiation Oncologist at the Odette Cancer Centre. Following his residency and fellowship in Radiation Oncology at UTDRO, he joined Odette as a Radiation Oncologist specializing in gastro-intestinal and genitourinary malignancies.
The innovation was to combine high-intensity focused ultrasound with real-time MR imaging to heat the tumour.
It was his interest in imaging that led to his latest innovative therapeutic intervention, MR-guided high intensity focused ultrasound (MRg-HIFU) hyperthermia for recurrent rectal cancer. “We know that heating a tumour makes it more sensitive to radiation therapy,” William explained. “So we use ultrasound to heat the tumour with the help of real-time MR guidance for targeting visualization and thermometry; we then treat the tumour with radiation.”
Patients with recurrent rectal cancer are traditionally treated with a combination of radiation and chemotherapy, and surgery when possible. For tumours that cannot be treated surgically, MRg-HIFU hyperthermia potentially increases the likelihood of the tumour responding to chemotherapy and radiation. This may reduce the need for ongoing treatment for patients with recurrent rectal cancer.
William noted that heating tumours to increase their response is not a new concept. The innovation was to combine HIFU with real-time MR imaging to heat the tumour. “We worked with our technology partner, Philips Healthcare,” William said. “They helped us refine the MR imaging table with an ultrasound transducer so that we could heat a target deep in the body while visualizing and measuring the heat intensity.” The MRg-HIFU unit was optimized to administer lower heat over a longer period of time. This gentle heating is safer for the surrounding tissues and is then followed by radiation therapy to the tumour.
“With MR imaging, we are obtaining real-time information about the tumour,” William explained. “We can verify that we are hitting the target and precisely measuring its temperature in three-dimensions – all of this information was not available to us with previous hyperthermia treatment platforms.”
William’s team, comprised of researchers at Philips and the Sunnybrook Research Institute, recently launched the first phase of a feasibility study of this treatment for patients with recurrent rectal cancer. If the results of the study are positive, William hopes to extend this technology to the clinic to treat patients with newly diagnosed rectal cancer and other tumour types.
In addition to this study, William is busy as the Canadian lead of an international phase III clinical trial of stereotactic ablative body radiotherapy (SABR) for prostate cancer. The Prostate Advances in Comparative Evidence (PACE) study is being led by the Royal Marsden and is taking place at 15 cancer centres across Canada. “This trial will define the next step in the evolution of prostate cancer treatment,” William said. Instead of the standard 20 to 39 treatments of radiation, the team is delivering five treatments with higher doses. Studies to date have shown SABR to be a promising and effective treatment with no increase in damage to the tissues around the prostate. “This treatment is potentially a new standard for prostate cancer care,” William added.
William credits UTDRO for enabling his research. “We have the opportunity to ‘move the needle’ in Radiation Medicine. We are very fortunate at UTDRO to have the infrastructure and resources to take the next steps to discover new and innovative treatments.”
Image Credit: Horst Herget Photography