Accuracy, safety, and diagnostic prediction of percutaneous renal mass biopsy and subsequent changes in treatment

Introduction
The incidence of renal tumours is increasing annually, and imaging alone cannot meet the diagnostic needs.

Aim
This single-centre study aimed to evaluate the predictors of diagnostic imaging-guided percutaneous renal mass biopsy (PRMB), its accuracy and safety, and subsequent changes to the treatment plan.

Material and methods
We retrospectively collected the clinical data of patients who had undergone PRMB. The diagnosis rate, pathological data, and complications were analysed. Potential predictors of a diagnostic PRMB were evaluated using logistic regression analysis. Changes to the treatment plan due to PRMB results were also analysed.

Results
A total of 158 patients were included in this study. The univariate analysis showed that higher tumour diameter (OR = 1.223, 95% CI: 1.018–1.468, p = 0.031) and number of biopsy cores ≥ 2 (OR = 6.125, 95% CI: 2.006–18.703, p = 0.001) were significantly associated with diagnostic biopsy, and multivariate analysis results showed that higher tumour diameter (OR = 1.215, 95% CI: 1.008–1.463, p = 0.041) was an independent predictor of diagnostic biopsy. A nomogram including tumour diameter and number of biopsy cores was constructed to predict diagnostic biopsy. Compared with postoperative pathology, the concordance between biopsy and postoperative pathology at identifying malignancies, histologic type, and histologic grade were 100% (47/47), 85.1% (40/47), and 54.1% (20/37), respectively. The treatment plans of 15 patients (9.5%) changed based on the PRMB results. Fourteen patients (8.9%) had minor complications (Clavien-Dindo classification < 2).

Conclusions
Our results suggest that tumour diameter was an independent predictor of diagnostic biopsy. Furthermore, PRMB can be accurately and safely performed and may guide clinical decision-making for patients with renal tumours.