Risk factors of non-diagnostic percutaneous liver tumor biopsy: a single-center retrospective analysis of 938 biopsies based on cause of error.

Purpose: To evaluate the risk factors of non-diagnostic results based on cause of error in liver tumor biopsy.

Materials and methods: This single-institution, retrospective study included 843 patients [445 men, 398 women; median age, 67 years] who underwent a total of 938 liver tumor biopsies between April 2018 and September 2022. An 18-G cutting biopsy needle with a 17-G introducer needle was used. Ultrasound was used as the first choice for image guidance, and computed tomography was alternatively or complementarily used only for tumors with poor ultrasound visibility. Non-diagnostic biopsies were divided into two groups depending on the cause of error, either technical or targeting error. Biopsies in which the biopsy needle did not hit the target tumor were classified as technical error. Biopsies in which insufficient tissue was obtained due to necrosis or degeneration despite the biopsy needle hitting the target tumor were classified as targeting error. This classification was based on pre-procedural enhanced-imaging, intro-procedural imaging, and pathological findings. Statistical analysis was performed using binary logistic regression.

Results: The non-diagnostic rate was 4.6%. Twenty-six and seventeen biopsies were classified as technical and targeting errors, respectively. In the technical error group, tumor size ≤ 17 mm and computed tomography-assisted biopsy due to poor ultrasound visibility were identified as risk factors (p < 0.001 and p = 0.021, respectively), and the tumors with both factors had a significantly high risk of technical error compared to those without both factors (non-diagnostic rate: 17.2 vs 1.1%, p < 0.001). In the targeting error group, tumor size ≥ 42 mm was identified as a risk factor (p = 0.003).

Conclusion: Tumor size ≤ 17 mm and computed tomography-assisted biopsy due to poor ultrasound visibility were risk factors for technical error, and tumor size ≥ 42 mm was a risk factor for targeting error in liver tumor biopsies.