We retrospectively analyzed data from seven high-volume U.S. and European centers for patients who underwent RAPN or PTA (including cryoablation, radiofrequency, or microwave ablation) for a renal mass between 2010 and 2020. Patients with previous kidney cancer surgery or multiple renal tumors were excluded. We included patients who had a renal mass score 3 points for the “E” domain of the R.E.N.A.L. nephrometry score (completely endophytic). Follow-up protocol included a CT scan in both groups and relapse was defined as detection of a new lesion after RAPN or a persisting/recurring enhancement after PTA. Trifecta for RAPN was defined as no major complication + no significant (<25%) eGFR reduction from baseline + negative surgical margins. For PTA: no major complication + no significant (<25%) eGFR reduction from baseline + no technical failure (no residual mass/enhancement at 6 months).
In our population, PTA approach was adopted in older and more comorbid patients. During follow-up, we observed a worse ∆eGFR at 1-year follow-up, whereas no difference was found at last follow-up (mean time 40.4 and 35.6 months for RAPN and PTA, respectively). However, looking at the baseline characteristics, PTA cohort showed a significantly worse eGFR than the RAPN one (69.7 vs 89.1, p<0.001) and a higher rate of CKD>III stage (31.5% vs 5%, p<0.001). This selection bias and the worse baseline characteristics of the PTA cohort might explain the worsening of renal function and the higher rate of new-onset CKD at the latest PTA follow-up. Relatively to the surgical outcomes, PTA showed advantages in terms of lower mean operation time (OT, p<0.001) and ∆Hb at discharge (p<0.001), and higher Hb at discharge (p=0.03). Additionally, minor post-operative complication rates were lower for the PTA group (p<0.001), while no difference was found for major complication rates. Trifecta was achieved in 65.3% and 58.8% for RAPN and PTA groups respectively, with no significant difference. We did not find a difference for recurrence rate. The two cohorts were similar for RFS (p=0.154), too; however, it is worth mentioning that metastases occurred in 3 patients of the PTA group.
Despite the intrinsic limitations of a retrospective study lacking central review and standardization of pre-and post-operative management among the different centers, our study confirms that PTA as an effective treatment option for completely endophytic renal masses, offering low complication rates and good mid-term and functional and oncologic outcomes. RAPN remains the preferred option for younger and less comorbid patients.
Written by: C. Cerrato1 & S.D. Pandolfo2
- University Hospital Southampton NHS Trust, Southampton, UK
- Department of Neurosciences, Science of Reproduction and Odontostomatology, University of Naples Federico II, Naples, Italy