Abstract No. 513 Magnetic resonance imaging–guided renal biopsy: tertiary cancer center experience

Abstract

To investigate the technical success and outcome of magnetic resonance imaging (MRI)-guided renal biopsies using a closed-bore, high magnetic- field (1.5-T) MRI unit. We retrospectively reviewed all percutaneous MRI-guided renal biopsies performed at our institution over the last 4 years (May 2013-July 2017). For each patient, we recorded: demographics, tumor characteristics, MRI sequence, biopsy technique, complications (immediate or delayed), pathological outcome and reviewed follow up imaging. A total of 43 biopsies for 43 lesions (20 right kidney and 23 left kidney) were performed in 42 patients (22 Male and 20 females, average of 62 years old). Of the 43 biopsies, 13 biopsies were associated with renal cryoablation in the same setting. The average tumor size was 3 cm (range1-14 cm). All the lesions were solid except 3 lesions with cystic components. A fat saturation steady state free precession sequence was most commonly used for guidance during the biopsy procedures (62%). All biopsies were performed using coaxial technique with a 16F guide needle, 18 gauge side cutting core, and 22 gauge chiba for fine-needle aspiration (FNA). Samples were obtained using both FNA and cores in 20 biopsies (46.5%), cores only in 22 (51%) lesions and FNA only in one (2.5%) lesion. Samples were diagnostic in 41/43 (95.5%) lesions. Thirty three lesions (77%) were renal cell carcinoma. A single patient had perinephric hematoma managed conservatively. None of the patients developed major complications. The average follow up with imaging was 2.27 years (0.04-5.03 years) and none of the patients developed tumor seeding. Magnetic resonance imaging–guided biopsy in a closed-bore, high-field-strength magnet is a safe and effective technique for sampling of renal lesions with favorable diagnostic yield and low complication rate.