MRI- Versus CT-Guided Renal Tumor Cryoablation: Is There a Difference?

To compare procedure-related variables, safety, renal function, and oncologic outcomes in patients undergoing percutaneous cryoablation (CA) of renal tumors with MRI- or CT-guidance.

Patient, tumour, procedure, and follow-up data were collected and analysed. MRI and CT groups were matched using a coarsened exact approach according to patient's gender and age, tumour grade, size and location. P < 0.05 was considered statistically significant.

Two-hundred fifty-three patients (266 tumors) were retrospectively selected. Following the coarsened exact matching 46 patients (46 tumors) in the MRI group and 42 patients (42 tumors) in the CT group were matched. There were no significant baseline differences between the two populations except for the duration of follow-up (P = 0.002) and renal function (P = 0.002). On average MRI-guided CA lasted 21 min longer than CT-guided ones (P = 0.005). Following CA, complication rates (6.5% for MRI vs 14.3% for CT; P = 0.30) and GFR decline (mean - 13.1 ± 15.8%; range - 64.5-15.0 for MRI; mean - 8.1 ± 14.8%; range - 52.5-20.4; for CT; P = 0.13) were similar in both groups. The 5-year local progression-free, cancer-specific and overall survivals in the MRI and CT groups were 94.0% (95% CI 86.3%-100.0%) and 90.8% (95% CI 81.3%-100.0%; P = 0.55), 100.0% (95% CI 100.0%-100.0%) and 100.0% (95% CI 100.0%-100.0%; P = 1), and 83.7% (95% CI 64.0%-100.0%) and 76.2% (95% CI 62.0%-93.6%; P = 0.41), respectively.

Apart from increased procedural times associated with MRI-guided CA of renal tumors compared to CT-guidance, both modalities demonstrate similar safety, GFR decline and oncologic outcomes.