Technique Streamlines Breast Biopsy Procedures

The system was attached to an ultrasound transducer, and biopsy needles were inserted through the guidance arm. Both experienced and inexperienced radiologists performed ultrasound-guided biopsy on simulated breast lesions with and without the guidance system; success rates were scored based on the presence of lesions in the core biopsy samples. The biopsy procedures were analyzed using procedure time and total needle tip travel distance before firing.

The researchers found that the success rate using the needle guidance system was 95.9%, compared to a success rate of 91.3% using the freehand technique. When using the freehand technique, experienced radiologists had a procedure time of approximately 31 seconds; but when using the needle guidance system, they had a reduced procedure time of approximately 10 seconds. Additionally, needle tip motion was significantly greater when using the freehand technique than using the guidance system. The study describing the new technique and the results of the experiments was published in the June 2009 issue of the American Journal of Roentgenology (AJR).

"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,” said lead author Aaron Fenster, M.D., of the Robarts Research Institute. "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.”

Freehand ultrasound-guided breast biopsy can present several difficulties in visualizing the biopsy needle within the scanning plane of the ultrasound image. Issues such as scanning plane and needle misalignment, an unknown needle insertion site (relative to the ultrasound image), a misaligned needle trajectory before insertion, and physician experience can all play a role in increasing the difficulty of performing these biopsy procedures.

Related Links:
Robarts Research Institute
University of Western Ontario
London Health Sciences Center