Long-Term Clinical Outcomes Following Radiofrequency and Microwave Ablation of Renal Cell Carcinoma at a Single VA Medical Center
Introduction
Open or laparoscopic partial nephrectomy, with a 97% 5-year recurrence-free survival, is considered the gold-standard treatment for renal cell carcinoma (RCC).1 Percutaneous treatments such as cryoablation (CRA) and radiofrequency ablation (RFA), however, have demonstrated 5-year survival rates (87%-89%) nearly approaching partial nephrectomy for stage T1a tumors.1, 2, 3, 4 Although each modality may have relative advantages and drawbacks, there are no data definitively favoring CRA or RFA for treatment of RCC.1
The relatively recent introduction of microwave ablation (MWA) adds yet another minimally invasive treatment option with specific potential treatment advantages. Potential advantages of MWA over RFA include reduced sensitivity to heat-sink effects and the ability to create larger, more uniform ablation zones compared to RFA.5 These same attributes, however, may also introduce increased theoretical risk to adjacent vascular structures, organs, and the renal collecting sytem.6 Importantly, the intermediate and long-term outcomes of MWA for RCC have not been extensively investigated.5 This retrospective study examines the short- and long-term treatment success and effectivness rates of RFA and MWA for RCC at a single Veterans Affairs (VA) medical center.
Section snippets
Study Cohort
We performed a retrospective analysis of each patient receiving RFA and MWA for biopsy-proven or presumed RCC by imaging at a single large VA medical center. Institutional review board approval was received for conducting this study. The study cohort included patients treated with percutaneous thermal ablation for RCC between January 2007 and December 2014. Inclusion criteria included (1) patients with biopsy-proven RCC or imaging findings and clinical presentation typical of RCC, (2) dedicated
Results
A total of 71 patients with 78 renal lesions underwent ablation (Fig. 1, Fig. 2, Fig. 3, Fig. 4). Further, 61 and 17 lesions were treated with RFA and MWA, respectively; 53.8% of lesions were biopsied before ablation; and 51% of all lesions were biopsy-proven RCC. MWA and RFA groups were not statistically different in R.E.N.A.L. parameters, patient demographics, tumor size, or tumor histopathology. Mean follow-up time for RFA (41 months) was significantly longer than MWA (12 months) (P <
Discussion
The R.E.N.A.L. nephrometry score is a reproducible scoring system of renal lesion complexity that has been validated in the surgical literature as a useful guide for surgical approach for renal lesion resection and predictor of treatment success and complications following surgery.3, 8 More recently, it has been shown that the R.E.N.A.L. nephrometry score, or at least specific components of the nephrometry score including tumor diameter and distance from the hilum, may be useful for predicting
Main Points
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RFA and MWA both represent effective treatment modalities for T1a RCC.
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Correlation of outcomes following ablation of renal tumors using a nephrometry score in future large studies with long-term follow-up may yield additional insight into tumor parameters associated with treatment failure or recurrence risk.
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Larger tumor size may be associated with the lower treatment effectiveness.
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Cited by (17)
Efficacy and safety of MWA versus RFA and CA for renal tumors: A systematic review and meta-analysis of comparison studies
2023, European Journal of RadiologyThe Role of Stereotactic Ablative Body Radiotherapy in Renal Cell Carcinoma
2022, European UrologyCitation Excerpt :The treatment options are limited for patients with ≥T1b disease who are not surgical candidates. TA is not suitable for patients with ≥T1b RCC due to an increased risk of local recurrence and complications [11]. In this subset of patients, SABR can be an attractive approach.
Long-Term Survival after Percutaneous Radiofrequency Ablation of Pathologically Proven Renal Cell Carcinoma in 100 Patients
2020, Journal of Vascular and Interventional RadiologyThe Role of Ablation and Minimally Invasive Techniques in the Management of Small Renal Masses
2018, European Urology OncologyCitation Excerpt :Modern MW generators can result in tissue temperatures as high as 170 °C [34]. As such, MW ablation can overcome the heat sink related to blood flow and urine pool more effectively than RFA [35–40]. On the contrary, care must be taken to avoid excessive heating of the urine in the collecting system, which may cause ureteral stricture [41].
Safety and efficacy of RFA versus MWA for T1a renal cell carcinoma: a propensity score analysis
2023, European Radiology
Prior presentation/publications: These data were presented as an oral presentation in the same name at 2015 RSNA.