Percutaneous CT-guided Biopsy of Focal Liver Lesions - Long- term Experience with more than 300 Procedures.

Background and aims: Despite the undeniable ongoing development of cross-sectional imaging methods, not all focal liver lesions (FLLs) have a typical pattern. An image-guided biopsy using a percutaneous approach might safely provide a final histological diagnosis of the FLLs. We aimed to evaluate the accuracy, efficiency, complication rate, technical features, and relationships between the followed parameters of computed tomography (CT)-guided percutaneous biopsies of FLLs using a retrospective approach.

Methods: 303 percutaneous biopsy procedures in 295 patients were carried out in patients with suspected or indeterminate FLLs over a 10-year period. The median size of the tumors was 44 mm (15 - 144 mm). Median age of patients was 67 years (25 to 87 years). Skin-to-lesion distance was variable, from 30 mm to 138 mm (median length 59 mm). In 200 procedures (66%) malignant disease was known from the patients´ clinical history.

Results: In 288 biopsies (95%) the results were true positive or true negative; 15 procedures (4.95%) resulted in a histologically false negative and had to be confirmed using other approaches. Metastatic disease to hepatic parenchyma of various origins was the most frequent histological diagnosis (55.4%). Cholangiocarcinoma was the most common individual result (13.5%). In total 14 complications (4.6%) were confirmed, 4 of which were severe haemorrhages that needed angiographic treatment and in one case surgical revision. The mortality rate in our group was 0.3%. A statistically significant relationship between lesion size and diagnostic accuracy (p < 0.01) was revealed. The use of a 16 G needle calibre and at least two samples were suitable for hypo- and hypervascular lesions without a significant increase in the complication rate.

Conclusions: Core needle biopsy using a percutaneous approach and a CT-guidance performed on patients with indetermined FLLs had a high overall accuracy in determining the final histological diagnosis including subtyping. Concurrently, the complication incidence was low.