Abstract No. 89 Safety, Technical Success, and Clinical Outcomes of Percutaneous Cryoablation of Central Renal Tumors without Pyeloperfusion in 94 Patients

Abstract

To assess the safety, technical success, and clinical outcomes of percutaneous cryoablation (PCA) without pyeloperfusion in 94 patients with central renal tumors. A single-center retrospective review of all adult patients with a central renal tumor treated by interventional radiology using PCA without pyeloperfusion was approved by the local IRB. Central tumors were defined as those involving the renal sinus fat on pre-procedural cross-sectional imaging. Patient demographics and baseline tumor characteristics including maximal tumor diameter, tumor stage, RENAL nephrometry score, and distance to the nearest critical structure was recorded. Details of the PCA procedure, primary and secondary technical success, rates of local recurrence, adverse events (AEs), cancer-specific survival (CSS), and overall survival (OS) were compiled. Aes were categorized according to SIR criteria. 94 patients (48 females (51%); mean age: 68.2 (range:38-87)) with 94 central renal tumors were included. The mean BMI and Charlson co-morbidity index of the cohort were 33.7 (range:20-56) and 6.9 (range:2-12), respectively. Mean maximal tumor diameter, mean RENAL nephrometry score, and mean distance to the nearest critical structure were 37 mm (range:15-67), 8 (range:4-11), and 9 mm (range:0-29), respectively. 59 tumors (63%) and 35 tumors (37%) were classified as T1a and T1b tumors, respectively. Five patients (5%) underwent embolization of the primary mass prior to PCA. The mean number of probes used during PCA was 2.9 (range:1-8). Primary technical success was achieved in 94% (n = 88) of procedures. Of those that did not achieve primary technical success, three underwent successful repeat PCA (secondary technical success: 97%; n = 91/94). The other three patients were surveilled for residual disease. 24 patients (26%) required hydrodissection during PCA. Six patients (6%) experienced major Aes after PCA including hemorrhage requiring embolization (n = 3), hemorrhage requiring transfusions with admission (n = 2), and perinephric abscess necessitating drain placement (n = 1). 22 patients (23%) experienced minor Aes. Nine patients (10%) experienced local recurrence during the follow-up period. OS was 94% (n = 88/94) while CSS was 98% (n = 92/94). PCA of central renal tumors can achieve high rates of technical and oncologic success with major AE and local recurrence rates comparable to published outcomes of PCA for non-central renal tumors, even without the use of pyeloperfusion.