Radiofrequency ablation of renal tumors: four-year follow-up results in 47 patients

Renal cell carcinoma

The landscape of the management of renal cell carcinoma has evolved substantially in the last decade, leading to improved survival in localised and advanced disease. We review the epidemiology, pathology, and diagnosis of renal cell carcinoma and discuss the evidence for current management strategies from localised to metastatic disease. Developments in adjuvant therapies are discussed, including use of pembrolizumab-the first therapy to achieve overall survival benefit in the adjuvant setting. The treatment of advanced disease, including landmark trials that have established immune checkpoint inhibition as a standard of care, are also reviewed. We also discuss the current controversies that exist surrounding the management of metastatic renal cell carcinoma, including the use of risk assessment models for disease stratification and treatment selection for frontline therapy. Management of non-clear cell renal cell carcinoma subtypes is also reviewed. Future directions of research, including a discussion of ongoing clinical trials and the need for reliable biomarkers to guide treatment in kidney cancer, are also highlighted.

Radiofrequency ablation for renal tumours: A retrospective study from a tertiary centre

Objective

This study aimed to evaluate the safety and efficacy outcomes of percutaneous radiofrequency ablation (RFA) for localised renal cell carcinoma (RCC) in a tertiary hospital patient who remained unfit for surgical intervention.

Methods

We retrospectively analysed survival outcomes for patients with biopsy proven RCC treated by RFA at Royal Perth Hospital between September 2009 and May 2018. Complication data were gathered for all patients that underwent renal RFA along with 2- and 5-year recurrence-free survival (RFS) rate and compared the outcomes with data from previous studies.

Results

A total of 69 patients (73 procedures) were eligible for the study, and those patients had biopsy-proven RCC with a minimum of 2-year follow-up. The complication rate was 8.2% (6/73) and local recurrence rate 9.6% (7/73). Two-year RFS is 95.7% and 5-year RFS is 78.8% on a median 3.82-year follow-up (interquartile range 1.90-5.75 years).

Conclusion

RFA performed at our centre was found to be safe and effective with low complication rates and durable RFS in line with expectations from existing research. Our study demonstrated that RFA is an alternative modality of treatment for small renal tumours in patients unfit for surgical approach.

Risk Factors for Renal Function Impairment Following Radiofrequency Ablation of Renal Tumors

Purpose

Materials and Methods

Results

Conclusion

Comparison of Chronologic Change in the Size and Contrast-Enhancement of Ablation Zones on CT Images after Irreversible Electroporation and Radiofrequency Ablation

Objective

To compare short-, mid-, and long-term follow-up ablation zone volume alterations as well as imaging features on contrast-enhanced computed tomography (CT) after irreversible electroporation (IRE) of primary and secondary liver tumors with findings subsequent to radiofrequency ablation (RFA).

Materials and Methods

Volume assessment of 39 ablation zones (19 RFA, 20 IRE) after intervention was performed at four time intervals (day 0 [t1; n = 39], day 1-7 [t2; n = 25], day 8-55 [t3; n = 28], after day 55 [t4; n = 23]) on dual-phase CT. Analysis of peripheral rim enhancement was conducted. Lesion's volume decrease relative to the volume at t1 was calculated and statistically analyzed with respect to patient's sex, age, ablation modality (IRE/RFA), and history of platinum-based chemotherapy (PCT).

Results

No influence of patient's sex or age on ablation volume was detected. The decrease in ablation zones' volume was significantly larger (p < 0.05 for all time intervals) after IRE (arterial phase, 7.5%; venous phase, 9.7% of initial volume) compared to RFA (arterial phase, 39.6%; venous phase, 45.3% of initial volume). After RFA, significantly smaller decreases in the ablation volumes, in general, were detected in patients treated with PCT in their history (p = 0.004), which was not detected after IRE (p = 0.288). In the arterial phase, peripheral rim enhancement was frequently detected after both IRE and RFA. In the venous phase, rim-enhancement was depicted significantly more often following IRE at t1 and t2 (pt1 = 0.003, pt2 < 0.001).

Conclusion

As per our analysis, ablation zone volume decreased significantly in a more rapid and more profound manner after IRE. Lesion's remodeling after RFA but not IRE seems to be influenced by PCT, possibly due to the type of cell death induced by the different ablation modalities.

Endovascular Embolization of Renal Cell Carcinoma in a Patient with Solitary Kidney

Background

Kidney tumors account for about 3% of tumors in adults. The primary therapy of renal cancer is the surgical removal. Traditionally, and also modern procedures are performed to remove the kidneys, especially when the tumor involves the entire kidney. In the cases of unresectable tumors embolization is used as a palliative procedure.

Case Report

The aim of this study is to present the case of endovascular treatment of renal cell carcinoma in patient with solitary kidney. 77-years old patient had an ultrasound examination because of the pain in left lumbar region. MRI confirmed the presence of tumor size 29×45 mm in the left kidney. The right kidney had been removed eight years earlier because of clear cell carcinoma. Histopathological diagnosis was renal clear cell carinoma. The patient did not consent to surgical treatment. Tumor embolization was proceeded as a minimally invasive procedure. Pathological tumor vessels were closed using particles filling the entire vascular tumor. Next, the blood vessels supplying the tumor were closed using a mixture of lipiodolu and glubranu. Control angiographiy of the left renal artery confirmed the effective closure of all vascular pathology. In a recent ultrasound examination which was done 15 months after surgery no evidence of vascular pathology was found.

Conclusions

Embolization of kidney cancer in particular cases may be an alternative way of treatment and give a good result in the form of stopping the growth of the tumor with simultaneous retaining the remaining parenchyma and renal function.

Renal Cell Carcinoma: Alternative Nephron-Sparing Treatment Options for Small Renal Masses, a Systematic Review

BACKGROUND

The standard treatment of T1 renal cell carcinoma (RCC) is (partial) nephrectomy. For patients where surgery is not the treatment of choice, for example in the elderly, in case of severe comorbidity, inoperability, or refusal of surgery, alternative treatment options are available. These treatment options include active surveillance (AS), radiofrequency ablation (RFA), cryoablation (CA), microwave ablation (MWA), or stereotactic body radiotherapy (SBRT). In the present overview, the efficacy, safety, and outcome of these different options are summarized, particularly focusing on recent developments.

MATERIALS AND METHODS

Databases of MEDLINE (through PubMed), EMBASE, and the Cochrane Library were systematically searched according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. The search was performed in December 2016, and included a search period from 2010 to 2016. The terms and synonyms used were renal cell carcinoma, active surveillance, radiofrequency ablation, microwave ablation, cryoablation and stereotactic body radiotherapy.

RESULTS

The database search identified 2806 records, in total 73 articles were included to assess the rationale and clinical evidence of alternative treatment modalities for small renal masses. The methodological quality of the included articles varied between level 2b and level 4.

CONCLUSION

Alternative treatment modalities, such as AS, RFA, CA, MWA, and SBRT, are treatment options especially for those patients who are unfit to undergo an invasive treatment. There are no randomized controlled trials available comparing surgery and less invasive modalities, leading to a low quality on the reported articles. A case-controlled registry might be an alternative to compare outcomes of noninvasive treatment modalities in the future.

Safety and feasibility of radiofrequency ablation for treatment of Bosniak IV renal cysts

Purpose

To describe our initial experience with radiofrequency ablation (RFA) of Bosniak IV renal cysts.

Materials and Methods

From 2010 to 2014, 154 renal tumor cases were treated with percutaneous thermal ablation, of which 10 cases (6.4%) from nine patients were complex renal cysts and were treated with radiofrequency ablation.

Results

All complex cysts were classified as Bosniak IV (four women and five men; mean age: 63.6 yrs, range: 33–83 years). One patient had a single kidney. Lesion size ranged from 1.5 to 4.1cm (mean: 2.5cm) and biopsy was performed on four cysts immediately before the procedure, all of which were malignant (two clear cell and two papillary carcinoma). Mean volume reduction of complex cysts was 25% (range: 10–40%). No patients required retreatment with RFA and no immediate or late complications were observed. The follow-up of Bosniak IV cysts had a median of 27 months (interquartile range [IQR], 23 to 38) and no recurrence or significant loss of renal function were observed.

Conclusions

Mid-term follow-up of the cases in our database suggests that image-guided percutaneous RFA can treat Bosniak IV cysts with very low complication rates and satisfactorily maintain renal function.

Complications of ultrasound-guided percutaneous microwave ablation of renal cell carcinoma

Purpose

To retrospectively review the complications of ultrasound (US)-guided percutaneous microwave ablation (MWA) of renal cell carcinoma.

Patients and methods

In this study, 101 patients with 105 tumors seen from April 2006 to Feb 2014 were enrolled retrospectively. The patients were treated with US-guided percutaneous MWA and were followed up with contrast-enhanced US and computed tomography or magnetic resonance imaging at 1, 3, and 6 months and every 6 months thereafter.

Results

Technical success was achieved in 99 of 105 tumors (94.3%). The median follow-up time was 25 (range 1.13–93.23) months. Among the 105 tumors, 26 complications in 24.8% of patients and 23 minor complications (Clavien–Dindo Grades I and II) in 21.9% of patients were noted, accounting for 88.5% of all complications. All the minor complications were cured. Three major complications (Clavien–Dindo Grade ≥III) occurred in 2.9% of the patients, accounting for 11.5% of all complications: hydrothorax in two patients and bowel injury in one. The two patients who had hydrothorax post-MWA had a history of cirrhosis and were treated with catheter drainage. The bowel injury was treated surgically. In all patients, the changes in serum creatinine and urea nitrogen levels from before to after the procedure were small.

Conclusion

US-guided percutaneous MWA is a beneficial treatment for renal cell carcinoma in selected patients; however, if the renal tumor is close to the bowel, or the patient has serious comorbidities or has undergone abdominal surgery, the procedure must be performed more carefully.

Laparoscopic Radiofrequency Ablation versus Partial Nephrectomy for cT1a Renal Tumors: Long-Term Outcome of 179 Patients

OBJECTIVES

To compare the long-term functional and oncological results between laparoscopic radiofrequency ablation (LRFA) and laparoscopic partial nephrectomy (LPN) in selected clinical T1a (cT1a) renal tumor patients.

METHODS

We retrospectively analyzed the medical records of patients with cT1a renal tumors who had LRFA or LPN at our institution between February 2006 and February 2015. Student's t test was used to compare the perioperative data between the two groups. Survival analyses were calculated using the Kaplan-Meier method.

RESULTS

A total of 179 patients were included in the study. Patients in the LRFA cohort were significantly older and had higher American Society of Anesthesiologists sore than in the LPN cohort. The LRFA group had a significantly lower mean blood loss than the LPN group (p = 0.03). The percent decrease of GFR in the LRFA group was significantly lower than in the LPN group (p = 0.021). The 5-year overall, cancer-specific and disease-free survival were 93.3 vs. 94.6%, 98.0 vs. 98.5% and 97.1 vs. 97.3%, for LRFA and LPN, respectively (all p value >0.05).

CONCLUSIONS

The excellent perioperative results, long-term functional and oncological outcomes of LRFA confirm that this technique is safe, nephron sparing and oncologically effective for the treatment of cT1a renal tumors.

[Percutaneous radiofrequency ablation of renal tumors: update 2015]

BACKGROUND

Stage I renal cell carcinoma is a malignancy with a relatively good prognosis. The incidence of all renal cell carcinomas is approximately 9/100,000 persons. There are nearly 15,000 newly diagnosed patients every year (men twice as often as women).

TREND

In the last decade, a trend away from radical open resection towards nephron-sparing approaches has been observed. Currently, partial nephrectomy is the surgical gold standard for the treatment of small renal tumors. However, excellent clinical results are obtained using percutaneous radiofrequency ablation (RFA): low complication rates and preservation of the renal function.

RESULTS

Primary and secondary technical success rates are 69-100% and 90-100%, respectively. In large series, major complication rates of RFA of 0-14% are reported. A relevant deterioration of renal function after RFA is very rare. The 5-year local recurrence-free survival rates, metastasis-free survival rates, cancer-specific survival rates, and overall survival rates are 88-93, 95-100, 98-100, and 58.3-85%, respectively. In this context, the lack of appropriate long-term data is often cited as a limitation.

CONCLUSION

Different meta-analyses come to the conclusion that in case of adequate tumor and patient selection RFA shows oncologic results comparable with surgical resection. Accepted indications for RFA are T1 renal tumors in patients with advanced age, significant comorbidities, reduced renal function, single kidney, and/or no wish for operation. Predictors for the success include tumor size and location as well as operator experience. To define the real efficacy of RFA in the treatment of renal tumors, randomized controlled clinical long-term studies are indicated.

Comparative Outcome of Computed Tomography-guided Percutaneous Radiofrequency Ablation, Partial Nephrectomy or Radical Nephrectomy in the Treatment of Stage T1 Renal Cell Carcinoma

Renal cell carcinoma (RCC) accounts for 3% of all cancers in adults. The indications for Radiofrequency Ablation (RFA) for renal carcinomas include T1a (tumor 4 cm or less, limited to the kidney), elderly patients, renal impairment, comorbidities, poor surgical candidate, and multiple bilateral renal masses. We retrospectively reviewed medical records, specifically investigating the indications, complications and outcomes of RFA and nephrectomy for treatment of RCC in a tertiary medical center with a predominantly Hispanic patient population. Forty-nine patients with RCC were evaluated. Nine patients had RFA, 9 had partial nephrectomy and 31 had radical nephrectomy. All patients among the 3 groups had stage T1N0M0 RCC at diagnosis. Tumor recurrence was observed in 2 (22%) patients that had RFA, one (11%) patient that had partial nephrectomy and no patients that had radical nephrectomy. One patient had recurrence of the tumor at the opposite kidney pole from the initial RFA site 4 years later. This particular patient did not have any tumor recurrence at the site of the initial RFA. A second RFA was performed on the recurrent tumor with no recurrence upon subsequent follow up visits. The second patient had recurrence of the RCC on 1 year follow that was discovered to be sarcomatoid RCC, which is an aggressive type with a poor prognosis. Our results support the clinical utility of RFA in patients with stage T1 RCC who are poor surgical candidates or those with reduced renal function. The clinical utility of RFA as an equally effective approach when compared to partial nephrectomy in patients with stage T1 RCC that meet strict indications for the procedure. The treatment choice should be individualized and based on the characteristics of the renal tumor such as size, location and histological type of RCC. We conclude that RFA presents a safe treatment choice for patients with RCC if long term follow up is maintained.

Analysis of radiofrequency ablation of small renal tumors in patients at high anesthetic and surgical risk: urologist experience with follow-up results in the initial six months

BACKGROUND

To evaluate the results of various types of radiofrequency ablation (RFA) treatment of renal tumors in patients with excessive anesthetic and surgical risk.

MATERIALS AND METHODS

Data for RFA performed in in high risk patients were retrospectively evaluated. Other RFA applications in patients with no anesthetic and/or surgical risk were excluded. RFA was by ultrasound or CT guided percutaneous (USG/CT-PRFA) and retroperitoneally or transperitoneally laparoscopic (R/T-LRFA) techniques under general or local anethesia. Follow-up data of enhanced CT or MRI after 1, 3 and 6 months were analysed for twelve RFA applications.

RESULTS

The RFA applications included 4 (40%) left-sided, 5 (50%) right-sided and 1 (10%) bilaterally RFA (simultaneously 1 right and 2 left). The localizations of tumors were 2 (16.6%) upper, 5 (41.6%) mid and 5 (41.6%) lower pole. The RFA applications included 9 (75%) USG-PRFA, 1 (8.3%) CT-PRFA, 1 (8.3%) T-LRFA and 1 (8.3%) R-LRFA. The mean age was 65.3 ± 8.5 (52-76) years. The mean tumor size was 29.6 ± 6.08 (15-40) mm. No complications related to the RFA were encountered in any of the cases. Failure (residual tumour) was determined in 8.3% (1/12) of USG-RFA application. The success rate was thus 91.7% (11/12). Other 1st, 3rd and 6th months follow-up data revealed no residua and recurrence.

CONCLUSIONS

RFA application appears to be safe as a less invasive and effective treatment modality in selected cases of small renal tumors in individuals with excessive anesthetic and also surgical risk.