?Skipping? is still a problem with radiofrequency ablation of small renal tumours

Small renal carcinoma: the "when" and "how" of operation, active surveillance, and ablation

Small, locally restricted renal cell carcinoma less than 4 cm in size should ideally be removed operatively by nephron-sparing tumour enucleation (partial kidney resection). In an increasingly elderly population, there is a growing trend toward parallel incidence of renal cell carcinoma and chronic renal insufficiency, with the latter's associated general comorbidities. Thus, for some patients, the risks of the anaesthesia and operation increase, while the advantage in terms of survival decreases. Transcutaneous radio-frequency ablation under local anaesthesia, transcutaneous afterloading high-dose-rate brachytherapy under local anaesthesia, and percutaneous stereotactic ablative radiotherapy may offer a less invasive alternative therapy. Active surveillance is to be regarded as no more than a controlled bridging up to definitive treatment (operation or ablation), while watchful waiting, on account of the lack of prognostic relevance and the symptomatology of renal cell carcinoma, with its comorbidity-related, clearly reduced life expectancy, does not involve any further diagnostic or therapeutic measures.

Surveillance versus ablation for incidentally diagnosed small renal tumours: the SURAB feasibility RCT

BACKGROUND

There is uncertainty around the appropriate management of small renal tumours. Treatments include partial nephrectomy, ablation and active surveillance.

OBJECTIVES

To explore the feasibility of a randomised trial of ablation versus active surveillance.

DESIGN

Two-stage feasibility study: stage 1 - clinician survey and co-design work; and stage 2 - randomised feasibility study with qualitative and economic components.

METHODS

Stage 1 - survey of radiologists and urologists, and development of patient information materials. Stage 2 - patients identified across eight UK centres with small renal tumours (< 4 cm) were randomised (1 : 1 ratio) to ablation or active surveillance in an unblinded manner. Randomisation was carried out by a central computer system. The primary objective was to determine willingness to participate and to randomise a target of 60 patients. The qualitative and economic data were collected separately.

RESULTS

The trial was conducted across eight centres, with a site-specific period of recruitment ranging from 3 to 11 months. Of the 154 patients screened, 36 were eligible and were provided with study details. Seven agreed to be randomised and one patient was found ineligible following biopsy results. Six patients (17% of those eligible) were randomised: three patients received ablation and no serious adverse events were recorded. The 3- and 6-month data were collected for four (67%) and three (50%) out of the six patients, respectively. The qualitative substudy identified factors directly impacting on the recruitment of this trial. These included patient and clinician preferences, organisational factors (variation in clinical pathway) and standard treatment not included. The health economic questionnaire was designed and piloted; however, the sample size of recruited patients was insufficient to draw a conclusion on the feasibility of the health economics.

CONCLUSIONS

The trial did not meet the criteria for progression and the recruitment rate was lower than hypothesised, demonstrating that a full trial is presently not possible. The qualitative study identified factors that led to variation in recruitment across the sites. Implementation of organisational and operational measures can increase recruitment in any future trial. There was insufficient information to conduct a full economic analysis.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN31161700.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 81. See the NIHR Journals Library website for further project information.

[Small renal cell carcinoma-active surveillance and ablation]

The incidence of renal cell carcinoma has been rising for years. At the same time there is an increasing prevalence of chronic renal failure with subsequent higher morbidity and shorter life expectancy in those affected. In the last decades the gold standard has thus shifted from radical to partial nephrectomy or tumor enucleation. A treatment alternative can be advantageous for selected patients with high morbidity and an increased risk of complications in anesthesia or surgery. Active surveillance represents a controlled delay in the initiation of treatment with a curative intention. Percutaneous radiofrequency ablation and laparoscopic cryoablation are currently the most commonly used treatment alternatives. Newer ablation procedures, such as high-intensity focused ultrasound, irreversible electroporation, microwave ablation, stereotactic ablative radiotherapy and high-dose brachytherapy have a high potential in some cases but are still considered experimental for the treatment.

[Focal therapy for small renal masses : Observation, ablation or surgery]

BACKGROUND

The rising incidence of renal cell carcinoma, its more frequent early detection (stage T1a) and the increasing prevalence of chronic renal failure with higher morbidity and shorter life expectancy underscore the need for multimodal focal nephron-sparing therapy.

DISCUSSION

During the past decade, the gold standard shifted from radical to partial nephrectomy. Depending on the surgeon's experience, the patient's constitution and the tumor's location, the intervention can be performed laparoscopically with the corresponding advantages of lower invasiveness. A treatment alternative can be advantageous for selected patients with high morbidity and/or an increased risk of complications associated with anesthesia or surgery. Corresponding risk stratification necessitates previous confirmation of the small renal mass (cT1a) by histological examination of biopsy samples. Active surveillance represents a controlled delay in the initiation of treatment.

RESULTS

Percutaneous radiofrequency ablation (RFA) and laparoscopic cryoablation are currently the most common treatment alternatives, although there are limitations particularly for renal tumors located centrally near the hilum. More recent ablation procedures such as high intensity focused ultrasound (HIFU), irreversible electroporation, microwave ablation, percutaneous stereotactic ablative radiotherapy and high-dose brachytherapy have high potential in some cases but are currently regarded as experimental for the treatment of renal cell carcinoma.

First Delayed Resection Findings After Irreversible Electroporation (IRE) of Human Localised Renal Cell Carcinoma (RCC) in the IRENE Pilot Phase 2a Trial

INTRODUCTION

It is postulated that focal IRE affords complete ablation of soft-tissue tumours while protecting the healthy peritumoral tissue. Therefore, IRE may be an interesting option for minimally invasive, kidney-tissue-sparing, non-thermal ablation of renal tumours.

AIM

With this current pilot study ("IRENE trial"), we present the first detailed histopathological data of IRE of human RCC followed by delayed tumour resection. The aim of this interim analysis of the first three patients was to investigate the ablation efficiency of percutaneous image-guided focal IRE in RCC, to assess whether a complete ablation of T1a RCC and tissue preservation with the NanoKnife system is possible and to decide whether the ablation parameters need to be altered.

METHODS

Following resection 4 weeks after percutaneous IRE, the success of ablation and detailed histopathological description were used to check the ablation parameters.

RESULTS

The IRE led to a high degree of damage to the renal tumours (1 central, 2 peripheral; size range 15-17 mm). The postulated homogeneous, isomorphic damage was only partly confirmed. We found a zonal structuring of the ablation zone, negative margins and, enclosed within the ablation zone, very small tumour residues of unclear malignancy.

CONCLUSION

According to these initial, preliminary study results of the first three renal cases, a new zonal distribution of IRE damage was described and the curative intended, renal saving focal ablation of localised RCC below <3 cm by percutaneous IRE by the NanoKnife system appears to be possible, but needs further, systematic evaluation for this treatment method and treatment protocol.

The management of small renal masses: what is likely to change?

The diffusion of imaging has determined an increased discovery of small renal masses (SRMs). Recent publications have been reviewed to present the state of the art in the management of SRMs and to try to foresee the next steps in this challenging condition. The role of percutaneous biopsies is expanding, since management algorithms include also active surveillance and ablative therapies. However up to 30% of biopsies fail to provide histological diagnosis and there is the risk of under-evaluating high-grade tumors. Active surveillance has been proposed in patients with reduced life expectancy and numerous comorbidities. The average growth of SRMs is slow, and metastatic progression has been observed in about 1%. Ablative therapies (cryotherapy and radiofrequency ablation) are used in patients with relevant comorbidities or advanced age and unfit for surgery, but who desire active treatment. Compared to conservative surgical treatment both techniques have increased local progression rates, while metastatic progression is relatively low.Partial nephrectomy (PN) is the recommended curative treatment for SRMs and can be performed open, laparoscopically or robotically. Open PN represents the benchmark, with similar cancer specific survival and better preservation of renal function compared to nephrectomy. Laparoscopy is comparable to open surgery in terms of oncologic results, but a long learning curve is necessary. Perioperative outcomes of robot-assisted PN appear superior to laparoscopy and the learning curve is shorter, but data for oncological results are still immature. With the increasing diffusion of robotic technology it is likely more SRMs will be managed with this approach.

Radiofrequency ablation of renal tumours with clinical, radiographical and pathological results

WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: Radiological imaging is heavily relied on for follow up after renal ablative therapy. We show that while this is largely reliable, there are quantifiable false negative and false positive findings. A non-involuting zone of ablation should be considered for multisite-directed core biopsies even in the absence of detectable enhancement.

OBJECTIVE

To evaluate our experience with radiofrequency ablation (RFA) for renal masses and to report on clinical, radiological and post-RFA biopsy results.

PATIENTS AND METHODS

The study collected clinical, radiological and pathological data from 150 consecutive patients who were treated with RFA of a renal mass between 2002 and 2008 at a tertiary referral centre. Post-ablation biopsies were performed in patients with non-involuting lesions or suspicion of recurrence on imaging. Comparisons were performed using the Mann-Whitney U-test. Survival was estimated using the Kaplan-Meier method.

RESULTS

Renal malignancy was found in 72.1% of patients based on the initial diagnostic biopsy. Median tumour size was 2.6 cm, 22.7% of patients had a solitary kidney, and most were central tumours. The mean follow-up period was 40.1 month. There was no recurrence in 96.7% of the entire cohort. Cancer-specific survival for 106 patients with sporadic, localized, biopsy proven renal malignancy was 100% at 38.5 months. Biopsies were obtained in 43 patients for a median of 21 months after RFA. Among 38 patients who had biopsy for non-involuting, non-enhancing zones of ablation, three (7.9%) were positive.

CONCLUSIONS

Short-term cancer-specific survival after RFA remains excellent and most cases are successful based on a combination of imaging and post-ablation biopsies performed almost 2 years after treatment. There were four out of 150 (2.7%) patients who had recurrences with tissue confirmation; one of these patients was detected on imaging and three (2%) were radiologically occult. The absence of enhancement in the setting of non-involuting lesions is not always a guarantee of a successful ablation.

Cryoablation vs radiofrequency ablation for the treatment of renal cell carcinoma: a meta-analysis of case series studies

Study Type - Therapy (systematic review). Level of Evidence 2b What's known on the subject? and What does the study add? The oncological success of partial nephrectomy in the treatment of small renal masses is well established. However, partial nephrectomy has largely supplanted the radical approach. In the last decade, laparoscopy has been adopted as the new surgical approach for the treatment of renal cell carcinoma. Laparoscopy offers the advantage of lower analgesic use, shorter hospital stay, and quicker recovery time. More recently, ablative technologies have been investigated as an alternative to laparoscopic partial nephrectomy. These techniques can often be performed percutaneously in the radiology suite, or laparoscopically without the need for hilar clamping. However, only the cryoablation and radiofrequency ablation modalities have had widespread use with several series reporting short to intermediate results. This review shows that both cryoablation and radiofrequency ablation are promising therapies in patients with small renal tumours (<4 cm), who are considered poor candidates for more involved surgery.

OBJECTIVE

• To determine the current status of the literature regarding the clinical efficacy and complication rates of cryoablation vs radiofrequency ablation in the treatment of small renal tumours.

METHODS

• A review of the literature was conducted. There was no language restriction. Studies were obtained from the following sources: MEDLINE, EMBASE and LILACS. • Inclusion criteria were (i) case series design with more than one case reported, (ii) use of cryoablation or radiofrequency ablation, (iii) patients with renal cell carcinoma and, (iv) outcome reported as clinical efficacy. • When available, we also quantified the complication rates from each included study. • Proportional meta-analysis was performed on both outcomes with a random-effects model. The 95% confidential intervals were also calculated.

RESULTS

• Thirty-one case series (20 cryoablation, 11 radiofrequency ablation) met all inclusion criteria. • The pooled proportion of clinical efficacy was 89% in cryoablation therapy from a total of 457 cases. There was a statistically significant heterogeneity between these studies showing the inconsistency of clinical and methodological aspects. • The pooled proportion of clinical efficacy was 90% in radiofrequency ablation therapy from a total of 426 cases. There was no statistically significant heterogeneity between these studies. • There was no statistically significant difference regarding complications rate between cryoablation and radiofrequency ablation.

CONCLUSIONS

• This review shows that both ablation therapies have similar efficacy and complication rates. • There is urgency for performing clinical trials with long-term data to establish which intervention is most suitable for the treatment of small renal masses.

Ablative therapies for renal tumors

Owing to an increased use of diagnostic imaging for evaluating patients with other abdominal conditions, incidentally discovered kidney masses now account for a majority of renal tumors. Renal ablative therapy is assuming a more important role in patients with borderline renal impairment. Renal ablation uses heat or cold to bring about cell death. Radiofrequency ablation and cryoablation are two such procedures, and 5-year results are now emerging from both modalities. Renal biopsy at the time of ablation is extremely important in order to establish tissue diagnosis. Real-time temperature monitoring at the time of radiofrequency ablation is very useful to ensure adequacy of ablation.

Current and future technology for minimally invasive ablation of renal cell carcinoma

Purpose of Review:

To provide an overview of the technologic advancements in the field of ablative therapy, focusing on the treatment of renal neoplasms.

Materials and Methods:

A MEDLINE search was performed using each specific ablative technique name as the search term. Articles written in the English language were selected for review. In cases of multiple reports by a single institution, the most recent report was utilized. Pertinent articles specific to the technologic advancement in ablative therapy were selected for review.

Recent Findings:

Intermediate-term oncologic outcomes of radiofrequency ablation (RFA) and cryoablation (CA) for the treatment of small renal masses are encouraging. For thermal therapies, molecular adjuvants to enhance cellular kill and local control have been developed. Improvements in microwave technology have allowed for reductions in antenna size and increases in ablation size. Laparoscopic high-intensity focused ultrasound (HIFU) probes have been developed to overcome the limitations of transcutaneous energy delivery, but HIFU remains experimental for the treatment of renal lesions. Irreversible electroporation (IRE), a novel nonthermal ablative technique, is currently undergoing clinical investigation in human subjects. Histotripsy causes mechanical destruction of targeted tissue and shows promise in treating renal and prostate pathology.

Summary:

Ablative techniques are commonly utilized in the primary treatment of urologic malignancies. The purpose of this review is to discuss technologic advances in ablative therapies with emphasis on the treatment of renal masses. RFA and CA show acceptable intermediate-term efficacy and technical refinement continues. Emerging technologies, including microwave thermotherapy, IRE, HIFU and histotripsy, are described with emphasis on the mechanism of cellular kill, energy delivery, and stage in clinical development.

Initial experience using microwave ablation therapy for renal tumor treatment: 18-month follow-up

OBJECTIVES

To assess efficacy and morbidity of microwave ablation (MWA) for small renal tumors in an initial cohort of patients. MWA is a recently introduced thermal needle ablation treatment modality with theoretical advantages compared with radiofrequency ablation, such as greater intratumoral temperatures, lack of a grounding pad, and superior convection profile. However, experience has been limited in the human kidney.

METHODS

Ten patients with a single, solid-enhancing renal tumor from June 2008 to November 2008 received laparoscopic or computed tomography-guided percutaneous MWA at a tertiary referral center with ≥14 months of follow-up. MWA was performed using the Valleylab Evident, 915-MHz MWA system at 45 W with intraoperative biopsy before ablation, and peripheral fiberoptic thermometry to determine the treatment endpoints. The patients were followed up with contrast-enhanced computed tomography at 1 month, 6 months to 1 year, and annually to monitor for tumor recurrence.

RESULTS

The follow-up duration for the 6 male and 4 female patients (mean tumor size 3.65 cm, range 2.0-5.5; mean age 69.8 years) was 17.9 months. The recurrence rate, defined by persistent enhancement, was 38% (3 of 8). The intraoperative and postoperative complication rate was 20% and 40%, respectively.

CONCLUSIONS

MWA resulted in poor oncologic outcomes with a significant complication rate at an intermediate level of follow-up. However, MWA has promising theoretical advantages and should not be discarded. Additional studies should be considered to better understand the microwave-tissue interaction and treatment endpoints for different size renal masses before widespread use.

Radiofrequency ablation: a minimally invasive approach in kidney tumor management

The management and diagnosis of renal tumors have changed significantly over the last decade. Due to advances in imaging techniques, more than 50% of kidney tumors are discovered incidentally and many of them represent an early stage lesion. This has stimulated the development of nephron-sparing surgery and of the minimally invasive treatment options including ablative techniques, i.e., radiofrequency ablation (RFA) and cryoablation. The objective of the minimally invasive approach is to preserve the renal function and to lower the perioperative morbidity. RFA involves inducing the coagulative necrosis of tumor tissue. Being probably one of the least invasive procedures in kidney tumor management, RFA may be performed percutaneously under ultrasound (US), computed tomography (CT) or magnetic resonance (MR) guidance. Most of the studies show that the RFA procedure is efficient, safe and has a low complication rate. Due to the still limited data on the oncological outcome of RFA, the indication for this intervention remains limited to selected patients with small organ-confined renal tumors and contraindication to surgery or who have a solitary kidney. The aim of our study is to review the literature on RFA of kidney tumors.

Partial nephrectomy and enbloc liver resection using a bipolar radiofrequency device for renal cell carcinoma invading the liver

A 66-year-old man presented with right- sided abdominal pain. Ultrasound, CT and MRI scans showed a right renal mass arising from the upper pole with direct involvement of the right lobe of the liver. Biopsy confirmed renal cell carcinoma. After Multi Disciplinary Team (MDT) discussion, right partial nephrectomy with enbloc resection of segments VI and VII of the liver was performed with the help of intraoperative ultrasound scan and the Habib 4X bipolar radiofrequency device. Apart from symptomatic collection, which was drained radiologically, the patient made a good recovery. The patient developed recurrence at the resection margin but is in remission following chemotherapy at 12 months.

Focal therapy and imaging in prostate and kidney cancer: high-intensity focused ultrasound ablation of small renal tumors

The rising incidence of small, incidentally detected renal masses in elderly, infirm patients has raised interest in minimally invasive, energy ablative techniques. High-intensity focused ultrasound (HIFU) delivers ultrasonic energy, resulting in heat and tissue destruction in the targeted tissue at a selected depth. In contrast to radiofrequency ablation and cryoablation, HIFU does not require puncturing the tumor, avoiding the high risk of hemorrhage or tumor spillage. While the extracorporeal approach shows unsatisfactory results, laparoscopic HIFU appears to be a promising alternative treatment option. Problems with respiratory movement and interphases, as seen in extracorporeal HIFU, are avoided when the transducer is brought directly to the target by laparoscopic HIFU. Potential benefits of laparoscopic HIFU are decreased morbidity, shorter hospitalization and convalescence, and preservation of renal function. Nevertheless, further prospective studies have to be performed to define the oncological success of HIFU as an alternative to open and laparoscopic surgery in small renal masses.

Low dose, alternating electric current inhibits growth of prostate cancer

BACKGROUND

A number of minimally invasive technologies exist for the treatment of prostate cancer (CaP), each with their associated morbidities. We sought to test the efficacy of low dose alternating electric current (LDAEC) to inhibit CaP growth in a preclinical setting and determine its effect on normal tissue.

METHODS

In the first study, two power settings, 15 or 25 mA of current, and two treatment times, 15 or 60 min, were evaluated in C4-2B CaP xenografts. In the second study, power was regulated to maintain an intra-tumoral temperature of <or=45 degrees C in C4-2B and LuCaP 35 tumors. In both studies, tumor volume, serum PSA levels, survival and histology were analyzed. In a third study, LDAEC was applied to mice hamstrings with evaluation of gait and histology.

RESULTS

The most effective tumor volume reduction in the first study was seen with tumors treated with 25 mA for 15 min (62 +/- 9.4% decrease, P = 0.001). Longer treatment time did not enhance treatment effect. Using 45 degrees C to govern delivery of LDAEC resulted in a near 100% reduction in tumor volume in 8/10 mice with C4-2B tumors (P < 0.001) with similar inhibition of LuCaP 35 tumors (P = 0.01). This treatment, although resulting in skeletal muscle necrosis, did not affect nerves, smooth muscle and blood vessels.

CONCLUSION

LDAEC demonstrates efficacy against C4-2B and LuCaP 35 CaP xenografts while causing no harm to nerves and blood vessels. These results warrant further investigations into the use of LDAEC as a treatment for CaP.

Management of small renal masses: a review

INTRODUCTION

Recently, small renal masses (SRMs) (< or =4 cm) are found more frequently, especially in the elderly and co-morbid patients. Standard treatment for SRMs is nephron-sparing surgery (NSS). New techniques like energy ablation and surveillance have been introduced.

MATERIALS AND METHODS

Overview of treatment options for SRMs, based mainly on the meta-analyses available for NSS, cryoablation, radio-frequency ablation (RFA), and surveillance.

RESULTS

NSS for SRMs is the standard therapy with excellent cancer-specific survival rates up to 97%. Cryoablation was mainly performed laparoscopically, and RFA mainly percutaneously. Pretreatment biopsies were used frequently for cryoablation (80%) and less frequently for RFA (50%). Primary failure rate for cryoablation was 4.8% and for RFA 13%. Major complication rates for both procedures are around 5%. Based on 6-month post-ablative biopsies, non-contrast enhancement seems to be an effective surrogate marker after cryoablation, but not after RFA. Follow-up after energy ablation is too short to draw final conclusion. Data on surveillance are based on small, retrospective data with insufficient follow-up. Growth patterns during follow-up do not correlate with the underlying tumour entity.

CONCLUSION

Standard therapy for SRMs is still NSS. Energy ablation should be reserved for the elderly patients with co-morbidities and surveillance for the elderly and infirm patients.

A critical analysis of the actual role of minimally invasive surgery and active surveillance for kidney cancer

CONTEXT

The incidence of renal cell carcinomas (RCCs) has increased steadily-most rapidly for small renal masses (SRMs). Paralleling the changing face of RCC in the past 2 decades, new, less invasive surgical options have been developed. Laparoscopic radical nephrectomy (LRN) is an established procedure for the treatment of RCC. Treatment of SRMs includes open partial nephrectomy (OPN), laparoscopic partial nephrectomy (LPN), thermal ablation, and active surveillance.

OBJECTIVE

To present an overview of minimally invasive treatment options and data on surveillance for kidney cancer.

EVIDENCE ACQUISITION

Literature and meeting abstracts were searched using the terms renal cell carcinoma, minimally invasive surgery, laparoscopic surgery, thermal ablation, surveillance, and robotic surgery. The articles with the highest level of evidence were identified with the consensus of all the collaborative authors and reviewed.

EVIDENCE SYNTHESIS

Renal insufficiency, as measured by the glomerular filtration rate, occurs more often after radical nephrectomy than partial nephrectomy (PN). OPN and LPN show comparable results in long-term oncologic outcomes. The treatment modality for SRMs should therefore be nephron-sparing surgery (NSS). In select patients, thermal ablation or active surveillance of SRMs is an alternative.

CONCLUSIONS

LRN has become the standard of care for most organ-confined tumours not amenable to NSS. Amongst NSS options, PN is the treatment of choice, yet remains underutilised in the community. Initial data during its learning curve revealed that LPN had higher urologic morbidity. However, current emerging data indicate that in experienced hands, LPN has shorter ischaemia times, a lower complication rate, and equivalent long-term oncologic and renal functional outcomes, yet with decreased patient morbidity compared to OPN. Robotic partial nephrectomy is being explored at select centres, and cryotherapy and radiofrequency ablation are options for carefully selected tumours. Active surveillance is an option for selected high-risk patients. Percutaneous needle biopsy is likely to gain increasing relevance in the management of small renal tumours.

Minimally invasive nephron sparing management for renal tumors in solitary kidneys

PURPOSE

We present a large series of minimally invasive nephron sparing surgery outcomes in solitary kidneys with a focus on treatment selection criteria, and oncological and functional outcomes.

MATERIALS AND METHODS

Of 1,019 patients who underwent minimally invasive nephron sparing surgery since September 1997 at our institution 36, 36 and 29 underwent laparoscopic partial nephrectomy, cryoablation and radio frequency ablation, respectively, for tumors in a solitary kidney. Data, including patient and tumor characteristics, surgery details, complications, and postoperative renal function and intermediate term oncological outcomes in each patient, were obtained by telephone contact or from charts. The 3 groups were compared for perioperative, functional and oncological outcomes.

RESULTS

On multivariate analysis tumor size, aspect and remnant kidney status were independent predictors of treatment selection. Cancer specific and overall survival at 2 years was 100% and 91.2% for laparoscopic partial nephrectomy, 88.5% and 88.5% for cryoablation, and 83.9% and 83.9% for radio frequency ablation, respectively. Disease-free survival was significantly better for laparoscopic partial nephrectomy than for cryoablation and radio frequency ablation (100% vs 69.6% and 33.2%, respectively, p <0.0001). The mean estimated glomerular filtration rate change for laparoscopic partial nephrectomy, cryoablation and radio frequency ablation of 17, 3 and 7 ml per minute per 1.73 m(2) reflected a 26%, 6% and 13% decrease from baseline, respectively, which was statistically significant (p = 0.0016).

CONCLUSIONS

Laparoscopic partial nephrectomy and probe ablative procedures can be safely and efficiently done for renal tumor in patients with a solitary kidney. Intermediate term oncological outcomes are superior for laparoscopic partial nephrectomy despite somewhat poorer renal function outcomes than those of cryoablation and radio frequency ablation.

Partial nephrectomy after previous radio frequency ablation: the National Cancer Institute experience

PURPOSE

Development of new renal tumors or recurrence after radio frequency ablation not amendable for repeat ablation presents a difficult therapeutic dilemma. We report on the outcomes of partial nephrectomy on kidneys previously treated with radio frequency ablation.

MATERIALS AND METHODS

We performed a chart review of 13 patients who underwent 16 attempted partial nephrectomies following radio frequency ablation. Hospital records and operative reports were reviewed for demographic data, perioperative data and outcomes. The outcomes of the present series were compared to historical controls of published studies in similar patient populations.

RESULTS

No cases were converted to radical nephrectomy. Median time from radio frequency ablation to surgery was 2.75 years (range 1 to 7.1). A median of 7 tumors (range 2 to 40) were removed with a median estimated blood loss of 1,500 ml (range 500 to 3,500) and a median operative time of 7.8 hours (range 5 to 10.7). Operative notes commented on the presence of severe fibrosis in the operative field in 12 of 16 cases (75%). There was a modest but statistically significant decrease in renal function. Partial nephrectomy after radio frequency ablation had a higher reoperation rate compared to other series of primary or repeat partial nephrectomies but had the lowest rate of vascular or visceral injuries.

CONCLUSIONS

Partial nephrectomy on kidneys previously treated with radio frequency ablation is a technically challenging but feasible procedure. Residual or metachronous disease after radio frequency ablation may be salvaged with partial nephrectomy with a modest decrease in renal function. A trend toward a higher chance of reoperation and urine leak after partial nephrectomy after radio frequency ablation may be useful information for the planning and discussion of treatment decisions.

Management of renal masses with laparoscopic-guided radiofrequency ablation versus laparoscopic partial nephrectomy

BACKGROUND AND PURPOSE

Laparoscopic-guided radiofrequency ablation (LRFA) has been introduced as a minimally invasive nephron-sparing management option for renal tumors. Many patients who desire treatment present with multiple comorbidities, which poses a therapeutic challenge. Our purpose is to determine if multipass LRFA is comparable, in terms of surgical risk and immediate postoperative outcomes, to laparoscopic partial nephrectomy (LPN).

PATIENTS AND METHODS

A retrospective study identified 36 and 33 patients who underwent LRFA and LPN, respectively. Perioperative demographic data, tumor characteristics, and follow-up data were evaluated. Statistical analysis was performed using the Student t test and chi-square analysis.

RESULTS

Age, American Society of Anesthesiology score, and Charlson Comorbidity Index were significantly higher in the LRFA group than the LPN group (P < 0.001). Average tumor size was 2.8 cm and 3.1 cm for the LRFA and LPN groups, respectively. There were no significant differences in change between the preoperative and postoperative creatinine/glomerular filtration rate values or perioperative complication rates for the groups. Estimated blood loss and length of stay were significantly lower for the LRFA group than the LPN group (P < 0.05). Follow-up ranged 6 to 23 months and 6 to 58 months for the LRFA and the LPN groups, respectively. There has been no evidence of tumor recurrence in the follow-up period.

CONCLUSIONS

We present our initial report comparing patients undergoing LRFA v LPN for the management of renal tumors. Our preliminary results with our experience with multipass laparoscopic-guided RFA demonstrate that this technique can be safely used in an elderly, higher risk population. Long-term follow-up is needed to determine oncologic efficacy.

Current status of renal radiofrequency ablation

PURPOSE OF REVIEW

To provide an overview of the current literature addressing the role of radiofrequency ablation (RFA) for the management of renal cortical tumors.

RECENT FINDINGS

As the renal RFA experience continues to mature, longer-term data addressing the oncologic efficacy of this ablative modality are now available. Furthermore, the impact of RFA on secondary clinical endpoints, such as renal function outcomes, has now been addressed in several series.

SUMMARY

With the stage migration toward diagnosis of smaller renal masses, energy ablative techniques are being increasingly utilized as primary surgical modalities. Here, we review the role of RFA for the management of such masses and comment on technical considerations for this particular ablative technique. In addition, we provide a summary of contemporary longer-term oncologic outcomes and review the impact of RFA on renal function. As more renal masses are diagnosed in the elderly or comorbid patients, it is likely that ablative approaches will assume an increasingly central role in management strategies. In this regard, continued studies are necessary, particularly in regards to oncologic outcomes.

Thermal ablation: update and technique at a high-volume institution

In the era of nephron-sparing surgery for small renal tumors, thermal ablation is gaining popularity. Both cryoablation and radiofrequency ablation have well-demonstrated short-term oncologic efficacy and safety. This article shares the current literature and the radiofrequency ablation technique at a high-volume institution. Cases are presented that illustrate solutions to obstacles frequently encountered during percutaneous ablation of renal masses.

Surveillance for the management of small renal masses

Surveillance is a new management option for small renal masses (SRMs) in aged and infirm patients with short-life expectancy. The current literature on surveillance of SRM contains mostly small, retrospective studies with limited data. Imaging alone is inadequate for suggesting the aggressive potential of SRM for both diagnosis and followup. Current data suggest that a computed tomography (CT) or magnetic resonance imaging (MRI) every 3 months in the 1st year, every 6 months in the next 2 years, and every year thereafter, is appropriate for observation. The authors rather believe in active surveillance with mandatory initial and followup renal tumor biopsies than classical observation. Since not all SRMs are harmless, selection criteria for active surveillance need to be improved. In addition, there is need for larger studies in order to better outline oncological outcome and followup protocols.