Percutaneous Thermal Ablation for Treatment of T1a Renal Cell Carcinomas

Percutaneous treatment of renal tumours

Image-guided ablation is an accepted treatment option in the management of renal cell carcinoma. Percutaneous renal ablation offers the possibility of minimally invasive treatment while attempting to preserve renal function. Over the past several years there have been advances in tools and techniques that have improved procedure safety and patient outcomes. This article provides an updated comprehensive review of percutaneous ablation in the management of renal cell carcinoma.

Percutaneous ablation of renal tumors: Long-term outcomes

OBJECTIVE

To evaluate the long-term outcomes of renal tumor ablation, analyzing efficacy, long-term survival, and factors associated with complications and therapeutic success.

MATERIAL AND METHODS

We retrospectively reviewed 305 ablations (generally done with expandable electrodes) of 273 renal tumors between May 2005 and April 2019. We analyzed survival, primary and secondary efficacy, and complications according to various patient factors and tumor characteristics.

RESULTS

Mean blood creatinine was 1.14 mg/dL before treatment and 1.30 mg/dL after treatment (p < 0.0001). Complications were observed in 13.25% of the ablations, including major complications in in 4.97%. Complications were associated with age (p = 0.013) and tumor diameter (p < 0.0001). Primary efficacy was 96.28%. Incomplete ablation was more common in lesions measuring > 4 cm in diameter (p = 0.002). Secondary efficacy was 95.28%. The only factor associated with the risk of recurrence was the size of the tumor (p = 0.02). Overall survival was 95.26% at 1 year, 77.01% at 5 years, and 51.78% at 10 years, with no differences between patients with malignant and benign lesions. Mortality was higher in patients with creatinine >1 (p = 0.05) or ASA > 2 (p = 0.0001).

CONCLUSIONS

Percutaneous ablation is extremely efficacious for renal tumors; it improves the prognosis of renal carcinoma to the point where it does not differ from that of benign lesions. Complications are rare. Like survival, complications are associated with age and overall health status.

Long-term comparative outcomes of partial nephrectomy and cryoablation in patients with solitary kidneys: a single-center analysis

BACKGROUND

Patients with solitary kidneys are amenable to postoperative acute kidney injury (AKI) after PN. We compared the functional and oncological outcomes of cryoablation (CA) and PN in patients with a solitary kidney and a cT1a renal mass.

METHODS

From a single-institution series, we analyzed 74 patients (31 PN, 43 CA) with a solitary kidney who underwent treatment for a cT1a renal mass. The functional outcomes were AKI and estimated glomerular filtration rate (eGFR) preservation. Oncological outcomes were recurrence and death. Linear mixed-effects and logistic regression models were used for functional outcomes analysis, whereas oncological outcomes were analyzed using the Kaplan-Meier method.

RESULTS

Median follow-up was 63.9 months. PN group had lower median age (59 years vs. 68, P<0.001) and larger median tumor size (2.80 cm vs. 2.0, p =0.003). AKI was more common in the PN group on postoperative day 1 (58% vs. 2.8%, P<0.001). However, only one patient in the PN group required temporary dialysis in the perioperative period. eGFR preservation was similar at postoperative 3 months (89% vs. 90%, P=0.083), or 12 months (85% vs. 94%, P=0.2) follow-up. CA group had higher recurrence rate (29% vs. 3.2%, P=0.005), and worse recurrence-free survival (P=0.027). Overall survival (OS) was comparable (P=0.31).

CONCLUSIONS

In a solitary kidney setting, CA is associated with a lower risk of AKI at postoperative day 1 compared to PN. Functional outcome is comparable upon longer follow-up. The local recurrence rates are significantly higher in the CA group with no significant difference in OS.

An Exploratory Analysis of Changes in Circulating Plasma Protein Profiles Following Image-Guided Ablation of Renal Tumours Provides Evidence for Effects on Multiple Biological Processes

Simple Summary

Ablation techniques use extremely hot or cold temperatures to kill small cancers. It is now known that in addition to killing the cancer cells, the ablation treatment may stimulate an immune response in patients against the cancer cells, acting like a vaccine. As a result, there is now interest in combining ablation together with drugs that target the immune system of patients with cancer to enhance the effects of both treatments. In order to develop such combined treatments and test them in clinical trials, we need to understand more about their effects so trials can be optimally designed to be most effective. We have analysed 164 circulating proteins in the blood from patients with small renal tumours undergoing ablation treatment to understand more about the effects of ablation on the patient, both at the level of the effects on the cancer cells and the response of the patients.

Abstract

Further biological understanding of the immune and inflammatory responses following ablation is critical to the rational development of combination ablation-immunotherapies. Our pilot exploratory study evaluated the circulating plasma protein profiles after image-guided ablation (IGA) of small renal masses to determine the resultant systemic effects and provide insight into impact both on the tumour and immune system. Patients undergoing cryotherapy (CRYO), radiofrequency ablation (RFA) or microwave ablation (MWA) for small renal tumours were recruited. Blood samples were obtained at four timepoints; two baselines prior to IGA and at 24 h and 1–3 months post-IGA, and a panel of 164 proteins measured. Of 55 patients recruited, 35 underwent ablation (25 CRYO, 8 RFA, 2 MWA) and biomarker measurements. The most marked changes were 24 h post-CRYO, with 29 proteins increasing and 18 decreasing significantly, principally cytokines and proteins involved in regulating inflammation, danger-associated molecular patterns (DAMPs), cell proliferation, hypoxic response, apoptosis and migration. Intra-individual variation was low but inter-individual variation was apparent, for example all patients showed increases in IL-6 (1.7 to 29-fold) but only 50% in CD27. Functional annotation analysis highlighted immune/inflammation and cell proliferation/angiogenesis-related clusters, with interaction networks around IL-6, IL-10, VEGF-A and several chemokines. Increases in IL-8, IL-6, and CCL23 correlated with cryoprobe number (p = 0.01, r_s = 0.546; p = 0.009, r_s = 0.5515; p = 0.005, r_s = 0.5873, respectively). This initial data provide further insights into ablation-induced biological changes of relevance in informing trial design of immunotherapies combined with ablation.

Percutaneous Cryoablation versus Robot-Assisted Partial Nephrectomy of Renal T1A Tumors: a Single-Center Retrospective Cost-Effectiveness Analysis

PURPOSE

To evaluate the cost-effectiveness of percutaneous cryoablation (PCA) versus robot-assisted partial nephrectomy (RPN) in patients with small renal tumors (T1a stage), considering perioperative complications.

MATERIALS AND METHODS

Retrospective study from November 2008 to April 2017 of 122 patients with a T1a renal mass who after being analyzed by a multidisciplinary board underwent to PCA (59 patients) or RPN (63 patients). Hospital costs in US dollars, and clinical and tumor data were compared. Non-complicated intervention was considered as an effective outcome. A hypothetical model of possible complications based on Clavien-Dindo classification (CDC) was built, grouping them into mild (CDC I and II) and severe (CDC III and IV). A decision tree model was structured from complications of published data.

RESULTS

Patients who underwent PCA were older (62.5 vs. 52.8 years old, p < 0.001), presented with more coronary disease and previous renal cancer (25.4% vs. 10.1%, p = 0.023 and 38% vs. 7.2%,  p < 0.001, respectively). Patients treated with PCA had a higher preoperative risk (American Society of Anesthesiologists-ASA ≥ 3) than those in the RPN group (25.4% vs. 0%, p < 0.001). Average operative time was significantly lower with PCA than RPN (99.92 ± 29.05 min vs. 129.28 ± 54.85 min, p < 0.001). Average hospitalization time for PCA was 2.2 ± 2.95 days, significantly lower than RPN (mean 3.03 ± 1.49 days, p = 0.04). The average total cost of PCA was significantly lower than RPN (US$12,435 ± 6,176 vs. US$19,399 ± 6,047, p < 0.001). The incremental effectiveness was 5% higher comparing PCA with RPN, resulting a cost-saving result in favor of PCA.

CONCLUSION

PCA was the dominant strategy (less costly and more effective) compared to RPN, considering occurrence of perioperative complications.