UT DRO Physicians are changing the way we treat prostate cancer

Over the ten years since its inception in September 2001, the HDR Brachytherapy program at the Odette Cancer Centre has garnered a lot of attention for its innovation. The program, which treats three to six patients per week, has accomplished two ‘firsts’: the first cancer centre to perform High Dose Rate (HDR) brachytherapy treatment for prostate in one visit, and the first to use ultrasound imaging instead of CT to plan the procedure.

Set apart from other treatments by its minimal invasiveness and ability to deliver the highest dose possible while sparing surrounding organs, HDR treatment is ideal for patients with intermediate disease who may not be interested in or eligible for surgery. Dr. Hans Chung explains “It’s a higher dose, so there’s a higher chance of curing the cancer. Because we can pinpoint the tumour, less radiation is delivered to surrounding areas, so there are fewer side effects. The advantage is that the treatment is minimally invasive, with only temporary placement of needles, and a cure rate comparable to surgery.” Presently, the treatment is given as a boost preceding external beam radiation therapy (EBRT).

Traditional treatment with HDR brachytherapy involved two fractions, or treatments, one week apart in addition to five weeks of external beam radiation therapy. Dr. Gerard Morton, Associate Professor in the UT DRO, explains his interest in treating with only one HDR ‘boost’: “Two fractions worked very well, but the problem was that it meant all our patients had to go through two procedures one week apart. It was not convenient for patients and involved a lot of additional resources.”

With the team’s vision focused on the long-term, they began to research new ways to improve the treatment process and, subsequently, patient outcomes. Dr. Morton explains, “Our real interest was to see if we could come up with a better approach, and instead of having to do two fractions, do one. Instead of five weeks of EBRT, could we get away with a shorter course of radiation? What we’ve done is come up with a novel way of delivering HDR brachytherapy consisting of a single HDR treatment and combining it with three weeks of external beam. We calculated that, in theory, this would be equivalent to what we were giving before. It should have lower acute side effects for the patient and the same or better chance of controlling the cancer.”

Current data for this treatment now dates back five years and supports the hypothesis Dr. Morton and his colleagues put forward a few years ago. He explains, “Data confirms that our new, novel single fraction protocol works very well and very favourably compares with what we, and everybody else, had been doing previously.” Dr. Chung adds, “the disease-free survival rates are very good. There’s more and more data coming out. Recent reports suggest 90% biochemical control rates for intermediate-risk disease.” The novel procedure has since been adopted by many other centres across Canada, the US, and Europe as the standard way of doing HDR brachytherapy for prostate cancer.

In late 2009, the program broke ground for a second time, using ultrasound to both guide the needles and plan the dose: “The patient comes to the operating room, is put under general anesthesia, has needles inserted via ultrasound, and right there and then we create a plan using the same ultrasound images. Treatment is given without having to move the patient. Because the patient isn’t moved, we know the treatment given is very precise and accurate. The average length of time from start to finish, including treatment, is about one and a half hours compared to nearly six hours when we planned using CT images. Since we introduced this, we’ve treated approximately 250 patients. We are prospectively collecting patient quality of life data and outcome data to compare with what we were doing previously.”

The team has no intention of stopping here. Dr. Morton explains that the “next step is to determine if we really need EBRT in addition to HDR and to develop protocols for treatment with HDR only.” There is a lot of excitement about the future of treatment when a patient might come in, undergo a ninety minute procedure in the operating room, and have his cancer completely treated. This is something that Dr. Morton hopes to see come to fruition in the next 18 months: “It’s part of some work we’re doing now. We have a number of pieces in the puzzle, and a number of research projects ongoing looking at different types of ultrasound and MRI imaging to map out the tumour location. Our goal is to put all this information together so we can very precisely identify the timing of brachytherapy, locate the cancer, and selectively boost in that area. With some ongoing clinical trials, we’ll start reducing the amount of external beam we’re giving and hopefully get rid of it all together.”

Check out more feature articles from our 2010-2011 Annual Report.