Imaging-Guided Biopsy, Percutaneous Ablation, and Active Surveillance for Small Renal Masses

The diagnosis rates of small renal masses less than 4 cm in diameter are increasing with the increasing number of CT and MRI examinations. Since these small renal masses include a high proportion of benign tumors and low-malignant renal cell carcinomas, image-guided biopsy plays an important role in facilitating accurate diagnosis, low-invasive percutaneous radiofrequency- or cryo-ablation, and active surveillance for these masses. Therefore, the diagnostic accuracy and safety of image-guided biopsy for small renal masses, but awareness of the technical aspects of image-guided percutaneous ablation and an understanding of active surveillance are crucial in establishing an adequate treatment plan. The purpose of this review is to present the basic knowledge and clinical usefulness of the diagnosis trends for small renal masses, discuss the diagnostic accuracy of imaging-guided biopsy, and assess the use of lowinvasive therapy with percutaneous ablation and active surveillance.