J Nucl Med. 2007; 48 (Supplement 2):431P
Instrumentation & Data Analysis: Instrumentation
Practical technique for the PET image-guided, minimally-invasive biopsy of breast abnormalities
Edward Anashkin1 and
1 R&D, Naviscan PET Systems, Inc., Rockville, Maryland
Objectives: Positron Emission Mammography (PEM) with F18-FDG has been shown to be useful in planning breast surgery and accurately depicting ductal carcinoma in situ (DCIS). In current clinical practice imaging abnormalities identified on PEM are often sampled under the ultrasound (US) guidance. Since some lesions, in particular linear distributions associated with DCIS, may be poorly visualized under US, a procedure employing PEM for needle guidance was previously proposed. Here we report the refinement of the technique to perform PEM-guided breast biopsies, using tools available for the MRI-guided localizations. A phantom study was carried out to confirm the ability of PEM to guide sampling of masses and linear distributions of activity. Methods: Ten breast phantoms were constructed containing physiologic amount of F18-FDG (0.01-0.1uCi/cc). Each phantom contained an 8 mm "hot" mass connected to a "hot" linear extension 3 mm in cross-section, 5cm in length. Both the mass and the linear extension were filled with F18-FDG to create the lesion-to-background ratio of 8:1. Mass, extension, and background were differently colored. The phantom was immobilized between the paddles of the PEM scanner. A ten minute PEM scan was performed, and the resulting image was used to plan biopsy of both the mass and linear extension. The needle guide accessory was installed according to software instructions. The needle track was made and a Germanium-68 line source, encapsulated in a sterile casing, was used to visualize the position of the needle track relative to the targeted abnormality on the PEM image. Imaging abnormalities were sampled using a 9Ga vacuum-assisted core biopsy device. Samples were visually inspected for the presence of the appropriately colored material. Results: All ten attempts at biopsy of primary lesions and linear extensions were successful. Conclusions: The developed localization technique can aid in sampling of masses and linear distributions of activity seen on Positron Emission Mammography. Clinical application of the biopsy method is planned.