V4-03: CT/MRI-US Fusion Guided Renal Mass Biopsy: Initial Experience
The Real-time Virtual Sonography (RVS) system allows image-fusion of real-time live US with pre-operative contrast-enhanced CT/MRI. Both real-time US and fused-image of CT are real-timely displayed in parallel in US-machine. The objectives are to assess the feasibility and safety of a pilot study for offie RVS-guided renal mass biopsy (RMB)._x000D_
Pre-operative: After 8 hours of fasting, the patient is placed in prone position in outpatient facility and monitored. US/CT registration: The DICOM data of a previous CT scan or MRI is loaded into the RVC system. The image is rotate to be at the same orientation of the patient. The kidney of interest and the plane with a reference point that a shows a good window to puncture the renal mass is selected.The kidney of interest is then US-scanned and the images are compared with the CT scan. When the images match to each other the plane with the reference point is fused with pre-operative contrast CT scan using the RVS system. The kidney is scanned and the best location to target the renal mass is selected. Co-axial needle technique: A 17G hollow needle is connected to a needle-guide under 21-degree inclination and attached to the US probe. Under local anesthesia, a 17G hollow-needle, is first placed along the planned puncturing dotted-line toward the renal mass up to the Gerota&[prime]s fascia. Biopsy: A 18G biopsy-gun is inserted through the co-axial-outersheath, advanced along the planned puncturing dotted-line upto the tumor and is fired to obtain the biopsy-tissue from the tumor. Usually two to three cores are taken, all through the hollow needle.
From April to June of 2014, 13 patients underwent RMB. Only single-use of local anesthesia was required in all cases. Co-axial needle technique facilitated (i) visualization of the biopsy-needle in live US, (ii) multiple-sampling through it, and (iii) decreasing the seeding risk of malignant cells. RVS system facilitated targeting the contrast-enhanced lesion, as it improved visualization of important anatomical landmarks. Intra-operatively accompanied pathology-team was important to determine the adequacy of tissue-sampling. Biopsy histology was concordant with surgical specimen in 7 of 10 patients undergoing surgery. Additionally, 2 patients with histology of oncocytoma chose active surveillance. There were no complications.
Outpatient RMB performed by urologist is safe and promising. This was achieved using local anesthesia, co-axial needle technique, and intra-operative co-operation with pathology-team, and introduction of real-time image-fusion technology of live US with contrast CT/MRI.