Long-term outcomes of image-guided ablation and laparoscopic partial nephrectomy for T1 renal cell carcinoma

Objective: To compare long-term outcomes and peri-operative outcomes of image-guided ablation (IGA) and laparoscopic partial nephrectomy (LPN).

Material and methods: This is a retrospective cohort study of localised RCC (T1a/bN0M0) patients undergoing cryoablation (CRYO), radio-frequency ablation (RFA), or LPN at our institution from 2003 to 2016. Oncological outcomes were compared using Cox regression and log-rank analysis. eGFR changes were compared using Kruskal-Wallis and Wilcoxon-rank tests.

Results: A total of 296 (238 T1a, 58 T1b) consecutive patients were identified; 103, 100, and 93 patients underwent CRYO, RFA, and LPN, respectively. Median follow-up time was 75, 98, and 71 months, respectively. On univariate analysis, all oncological outcomes were comparable amongst CRYO, RFA, and LPN (p > 0.05). On multivariate analysis, T1a patients undergoing RFA had improved local recurrence-free survival (LRFS) (HR 0.002, 95% CI 0.00-0.11, p = 0.003) and metastasis-free survival (HR 0.002, 95% CI 0.00-0.52, p = 0.029) compared to LPN. In T1a and T1b patients combined, both CRYO (HR 0.07, 95% CI 0.01-0.73, p = 0.026) and RFA (HR 0.04, 95% CI 0.03-0.48, p = 0.011) had improved LRFS rates. Patients undergoing CRYO and RFA had a significantly smaller median decrease in eGFR post-operatively compared to LPN (T1a: p < 0.001; T1b: p = 0.047). Limitations include retrospective design and limited statistical power.

Conclusions: IGA is potentially as good as LPN in oncological durability. IGA preserves kidney function significantly better than LPN. More studies with larger sample size should be performed to establish IGA as a first-line treatment alongside LPN.

Key points: • Ablative therapies are alternatives to partial nephrectomy for managing small renal cell carcinomas. • This study reports long-term outcomes of image-guided ablation versus partial nephrectomy. • Ablative therapies have comparable oncological durability and better renal function preservation compared to partial nephrectomy.