Self-correcting robotic system ensures accurate CT-guided needle placement
A robotic needle-placement system outfitted with correction software to improve its accuracy in mechanizing computed tomography (CT)-guided needle placement, according to a study published ahead of print in the Journal of Vascular and Interventional Radiology.
“Procedure success during percutaneous image-guided therapies almost invariably hinges on both adequate visualization and targeting,” corresponding author Eliel Ben-David, MD, and colleagues wrote in their report. “In the clinical setting, the accuracy of needle placement even for well-visualized lesions is often hindered by multiple variables, including difficult or steep approach, respiratory motion, peristalsis and changing target location.”
Radiologists have attempted to solve accuracy issues with CT- and MRI-guided needle placement, Ben-David et al. said, but robotics aren’t standard—or reliable, in many cases— in the radiologic community. The authors wrote that while most needle placement snags can be corrected with manual manipulation and a stepwise iterative path-correction approach, many radiologists don’t possess the meticulous skill that hands-on placement requires.
“Large robot-assisted procedures have become a standard of care in several fields, including urologic and gynecologic surgery,” Ben-David and co-authors wrote. “This precise, albeit expensive, option has been reported to be particularly beneficial when critical structures must be avoided or carefully resected to preserve neurovascular function.”
The researchers developed a small, patient-mounted CT-guided robot placement system for their trial, which included controlled needle placement in the retroperitoneum, kidneys and livers of eight Yorkshire pigs. Bronchial bifurcations were also targeted in the pigs’ lungs.
The authors said their robotic system had a 5-degree motion span, and after scanning the “patient” and marking a target, physicians were able to use choose a path for the needle and predetermine checkpoints along the way. A computer-based adaptation of the iterative path-correction approach for manual needle placement eclipsed any fear of shaky hands if needles needed to be redirected.
“With this feature, the robot is able to manipulate the needle tip and make the necessary corrections to steer it toward a chosen target, potentially overcoming the hurdles that have prohibited clinical application in the past,” Ben-David and colleagues wrote.
The team reported almost perfect placement post-study—out of 45 needle insertions, just two were unsuccessful due to technical problems. The accuracy of targeting the 17- to 19-gauge needles was 1.2 to 1.4 millimeters for kidneys, retroperitoneum and lungs, with 2.9-millimeter accuracy in the liver.
“This study confirms the potential advantage of a robotic system that includes correction software to improve targeting accuracy for CT-guided needle placement,” the authors said. “Stepwise checks with corrective angulation can potentially overcome issues of target movement during a procedure from organ deformity and other causes.”
After graduating from Indiana University-Bloomington with a bachelor’s in journalism, Anicka joined TriMed’s Chicago team in 2017 covering cardiology. Close to her heart is long-form journalism, Pilot G-2 pens, dark chocolate and her dog Harper Lee.