Researchers at Western University, London Health Sciences Centre, and Lawson Health Research Institute, all in Canada, have developed and tested a new 3D ultrasound system. Designed to improve the accuracy of interstitial brachytherapy, a technique in which tiny sources of radiation are placed inside tumors, the new ultrasound may help physicians to significantly improve their targeting accuracy.
The technology is particularly useful in transvaginal procedures, such as those initiated to attack vaginal, cervical, and uterine cancers, since physicians typically don’t have a clear view of the anatomical features they’re working with. Right now, doctors have to manually feel the relevant anatomy and the tumors they’re targeting, which happens under anesthesia and the targeting is verified using CT scanning.
The new 3D ultrasound scanner offers a more nuanced approach, allowing for a comprehensive assessment of where the needles used to deliver the radiation beads are in relation to the tumors being treated. “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 Aaron Fenster, PhD, the lead author of the study appearing in Journal of Medical Imaging.
To validate the ultrasound device, which provides a 360 degree look inside the vagina, the researchers tested it on six patients at the London Health Sciences Centre, finding that “landmark anatomical features and all needles were clearly visible,” according to the study authors. Moreover, they believe that the new ultrasound “provides a technique for visualizing needles and OARs [organs at risk] intraoperatively during interstitial gynecologic brachytherapy, enabling implants to be assessed and providing the potential for image guidance.”
Study in the Journal of Medical Imaging: Intraoperative 360-deg three-dimensional transvaginal ultrasound during needle insertions for high-dose-rate transperineal interstitial gynecologic brachytherapy of vaginal tumors