A new breast biopsy technique that uses a passive mechanical arm to guide the needle for the biopsy and has a braking system to allow for accurate placement of the needle and to avoid needle motion, could lead to decreased procedure times and reduced patient discomfort and morbidity. Photo Credit: Video GrabJune 24, 2009, (Sawf News) - A new breast biopsy technique that uses a passive mechanical arm to guide the needle for the biopsy and has a braking system to allow for accurate placement of the needle and to avoid needle motion, could lead to decreased procedure times and reduced patient discomfort and morbidity.
The mechanical arm is attached to an ultrasound transducer and biopsy needles are inserted through the guidance arm.
The objective of this study was to compare the freehand technique which is currently in use with the use of a needle guidance system that limits needle motion to within the ultrasound scanning plane for breast biopsy.
The biggest drawback of the freehand ultrasound-guided breast biopsy is difficulty in needle visualization within the scanning plane of the ultrasound image. Scanning plane and needle misalignment, an unknown needle insertion site (relative to the ultrasound image), needle trajectory before insertion, and physician experience play roles in the difficulty of these biopsy procedures.
Breast biopsy procedures, using both methods, were performed on phantoms during the study.
"Our results showed that biopsy success rates were greater when using our new guidance system," said Aaron Fenster, MD, lead author of the study performed at Roberts Research Institute, the University of Western Ontario and London Health Sciences Centre, London, ON, Canada.
"We also showed that experienced and inexperienced radiologists performed a biopsy significantly faster when using our needle guidance system," said Dr. Fenster. The success rate using the needle guidance system was 95.9% compared to a success rate of 91.3% using the freehand technique. Using the freehand technique, experienced radiologists had a procedure time of approximately 31 seconds. Using the needle guidance system, experienced radiologists had a procedure time of approximately 10 seconds.
"Techniques for improving biopsy procedures are needed to make the procedures more efficient and reduce the variability due to physician experience and size of the target lesion. Breast biopsy using the developed needle guidance system is feasible and I believe it will enable physicians to diagnose early-stage carcinomas more efficiently and accurately, thus decreasing patient morbidity," said Dr. Fenster.
"The system we designed is a prototype and is required to be redesigned for routine clinical use. Tests with human subjects are planned for the fall of 2009," he said.
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