New technology developed at Western is providing an improved way for radiation oncologists to deliver treatment to women with gynaecological cancers, including vaginal, cervical and uterine.
By transforming a conventional ultrasound probe, already found in most clinics, the technology can provide a 360-degree, 3D view of surgical tools and surrounding tissue and organs. It provides a clearer and more accurate picture in the operating room for clinicians who need to precisely insert needles into the tumour for a procedure called interstitial brachytherapy, a type of targeted radiation therapy that uses intense energy to kill cancer cells in the tumour from the inside out.
“The problem with the procedure the way it is now is that doctors don’t have a great way of seeing where those needles are going while they are placing them,” said Jessica Rodgers, a PhD candidate at the Schulich School of Medicine & Dentistry and lead author on a feasibility study of the technology. “If they can’t place the needles precisely, they may not be placed optimally for giving treatment and may be impinging on organs that are nearby that you don’t want to over irradiate.”
Schulcih professor Aaron Fenster, the study’s principal investigator, has been developing 3D ultrasound technology for more than three decades. He says this technology has potential to be practice-changing.
“The short term goal is to reduce complication rates – ensure that the needles don’t go into the bladder or the rectum, which creates complications, and in addition, something we are hypothesizing, is if the needles are placed correctly they will provide an improved dose pattern distribution to the tumour and surrounding tissue,” said Fenster, a Robarts Research Institute scientist.
Before the introduction of this technology, clinicians would use pre-operative imaging to place the needles using ‘feel’ while a patient is under anesthesia. They would then check the needle placement afterward with CT once the patient is awake. The new technology was tested by radiation oncologists on six patients at London Health Sciences Centre (LHSC) with very promising results.
“This technology provides the operator live feedback and visualization of the needle placement in real time, and allows for needles to be adjusted while the patient is still asleep,” said Schulich professor Dr. Vikram Velker, an LHSC radiation oncologist.
Schulich professor Dr. David D’Souza, also an LHSC radiation oncologist, likens the technology to a backup camera on your car.
“Interstitial needles allow a radioactive source to go directly into the tumour tissue resulting in a better dose of radiation, which is hoped to translate into better chances of eradicating the cancer. The 360-degree, 3D ultrasound is an additional tool to guide the placement of the needles in an accurate manner,” D’Souza said.
One of the other benefits of using ultrasound technology is the accessibility and wide application globally in places where resources are scarce.
“Access to high-end imaging systems like CT and MRI to diagnose and treat diseases is difficult in some places in the world. So for that reason, we’ve been focusing on ultrasound which is widely available everywhere in the world and can be used for a variety of applications,” Fenster said.
The feasibility study, Intraoperative 360-deg three-dimensional transvaginal ultrasound during needle insertions for high-dose-rate transperineal interstitial gynecologic brachytherapy of vaginal tumors, was published this week in the Journal of Medical Imaging.