A novel semi-robotized device for high-precision (18)F-FDG-guided breast cancer biopsy.

Abstract Purpose To assess the 3D geometric sampling accuracy of a new PET-guided system for breast cancer biopsy (BCB) from areas within the tumour with high 18 F-FDG uptake. Materials and methods In the context of the European Union project MammoCare, a prototype semi-robotic stereotactic prototype BCB-device was incorporated into a dedicated high resolution PET-detector for breast imaging. The system consists of 2 stacked rings, each containing 12 plane detectors, forming a dodecagon with a 186 mm aperture for 3D reconstruction (1 mm 3 voxel). A vacuum-assisted biopsy needle attached to a robot-controlled arm was used. To test the accuracy of needle placement, the needle tip was labelled with 18 F-FDG and positioned at 78 target coordinates distributed over a 35 mm × 24 mm × 28 mm volume within the PET-detector field-of-view. At each position images were acquired from which the needle positioning accuracy was calculated. Additionally, phantom-based biopsy proofs, as well as MammoCare images of 5 breast cancer patients, were evaluated for the 3D automated locating of 18 F-FDG uptake areas within the tumour. Results Needle positioning tests revealed an average accuracy of 0.5 mm (range 0–1 mm), 0.6 mm (range 0–2 mm), and 0.4 mm (range 0–2 mm) for the x / y / z -axes, respectively. Furthermore, the MammoCare system was able to visualize and locate small ( 18 F-FDG uptake within the tumour suitable for PET-guided biopsy after being located by the 3D automated application. Conclusions Accuracy testing demonstrated high-precision of this semi-automatic 3D PET-guided system for breast cancer core needle biopsy. Its clinical feasibility evaluation in breast cancer patients scheduled for neo-adjuvant chemotherapy will follow.