Percutaneous image-guided spinal lesion biopsies: Factors affecting higher diagnostic yield

OBJECTIVE. The objectives of this study were to determine the diagnostic yield of percutaneous biopsy of osseous spinal lesions under CT and fluoroscopy guidance and to analyze lesion-related and technical factors affecting higher diagnostic yield. MATERIALS AND METHODS. We retrospectively reviewed 247 consecutive percutaneous spinal biopsies and recorded the following information: Size, anatomic location, and bone matrix of lesions; guiding modality; years of attending physicians' experience; number of approaches; pathologic result of initial biopsy; and final diagnosis. The pathologic results of the initial biopsies were classified as diagnostic or nondiagnostic. All variables were compared using Pearson chi-square test or Fisher exact test. Multivariate logistic regression was also conducted. RESULTS. Of the initial 247 biopsies, 197 (80%) biopsies were diagnostic. On multivariate analysis, size, bone matrix, and final diagnosis of lesion were significant factors affecting biopsy yield. Biopsies of large lesions (≥ 20 mm) showed higher diagnostic yield than biopsies of small lesions (p = 0.006). Biopsies of lytic lesions had the highest diagnostic yield (88%), followed by biopsies of mixed (84%), sclerotic (67%), and isodense lesions (61%). Differences were significant for diagnostic yields of biopsies of lytic versus sclerotic lesions (p = 0.004) and lytic versus isodense lesions (p = 0.031). Biopsies of metastases had significantly highest diagnostic yield (97%), followed by biopsies of primary malignancies (84%) and benign lesions (39%) (p < 0.05). CONCLUSION. For percutaneous image-guided biopsies of spinal tumorous lesions, diagnostic yield was 80%. Size, bone matrix, and final diagnosis of lesions affected diagnostic yield of percutaneous image-guided biopsies.