Improved outcome of percutaneous radiofrequency ablation in renal cell carcinoma: a retrospective study of intraoperative contrast-enhanced ultrasonography in 73 patients

Ultrasonography of Hepatocellular Carcinoma: From Diagnosis to Prognosis

Hepatocellular carcinoma (HCC) is a prominent contributor to cancer-related mortality worldwide. Early detection and diagnosis of liver cancer can significantly improve its prognosis and patient survival. Ultrasound technology, serving has undergone substantial advances as the primary method of HCC surveillance and has broadened its scope in recent years for effective management of HCC. This article is a comprehensive overview of ultrasound technology in the treatment of HCC, encompassing early detection, diagnosis, staging, treatment evaluation, and prognostic assessment. In addition, the authors summarized the application of contrast-enhanced ultrasound in the diagnosis of HCC and assessment of prognosis. Finally, the authors discussed further directions in this field by emphasizing overcoming existing obstacles and integrating cutting-edge technologies.

Contrast-Enhanced Ultrasound for Image-Guided Procedures

Contrast-enhanced ultrasound (CEUS) uses intravenously injected gas microbubbles as a pure blood pool contrast agent to demonstrate blood flow and tissue perfusion at a much higher sensitivity than color Doppler and power Doppler ultrasound. CEUS has gained traction in abdominal diagnostic imaging for improved lesion detection and characterization and a complementary problem-solving tool to CT and MRI. In addition to its diagnostic applications, CEUS has also proven useful for pre-procedure planning, procedure guidance, and post-procedure evaluation. This review provides a practical overview and guides to the application of CEUS in percutaneous, ultrasound-guided, needle-driven procedures, focusing on 2 common procedures, which illustrate the many benefits of CEUS- core needle biopsy (CNB) and percutaneous hepatic lesion ablation.

CT renal arteriography as a novel imaging guidance for the percutaneous ablation of small renal tumors

PURPOSE

To report procedural data and outcomes of a novel image guidance technique, CT renal arteriography (CTRA), performed to target and ablate small intraparenchymal renal tumors.

MATERIALS AND METHODS

We retrospectively analyzed data of 2 patients undergoing CTRA-guided ablation for 3 renal intraparenchymal tumors, from February to March 2023. We previously evaluated tumor visibility with US/CEUS, and in all cases conspicuity was poor, whereas contrast-enhanced CT (CECT) clearly depicted all hypervascular nodules. Our primary endpoint was CTRA-guidance feasibility for renal ablation, defined as the precise probe deployment inside the target tumor. The secondary endpoint was CTRA-guided ablation technical success, intended as the inclusion of the whole tumor inside the necrotic volume, with 5 mm safety margins. RENAL scores, complications, procedural time, dose length product (DLP), serum creatinine variation and hospital stay length were also recorded.

RESULTS

A confident deployment of the probe tip inside the nodule was accomplished in all 3 cases, with a 100% of correct targeting. We observed immediate technical success after all 3 ablations. The 3 nodules had a RENAL score <7 points, and we encountered no complications due to line placement or ablation. The average time from preablative to postablative CTRA was 54 min (50-58min), with a DLP of 3632mGy*cm (2807-4458mGy*cm). Serum creatinine didn't show a significant variation after the procedures; both patients were hospitalized for 2 days.

CONCLUSION

Preliminary data showed that CTRA-guidance might provide unique advantages over conventional CECT-guidance to assist the ablation of small renal intraparenchymal tumor not visualized on US/CEUS.

Contemporary Clinical Definitions, Differential Diagnosis, and Novel Predictive Tools for Renal Cell Carcinoma

Despite significant progress regarding clinical detection/imaging evaluation modalities and genetic/molecular characterization of pathogenesis, advanced renal cell carcinoma (RCC) remains an incurable disease and overall RCC mortality has been steadily rising for decades. Concomitantly, clinical definitions have been greatly nuanced and refined. RCCs are currently viewed as a heterogeneous series of cancers, with the same anatomical origin, but fundamentally different metabolisms and clinical behaviors. Thus, RCC pathological diagnosis/subtyping guidelines have become increasingly intricate and cumbersome, routinely requiring ancillary studies, mainly immunohistochemistry. Meanwhile, RCC-associated-antigen targeted systemic therapy has been greatly diversified and emerging, novel clinical applications for RCC immunotherapy have already reported significant survival benefits, at least in the adjuvant setting. Even so, systemically disseminated RCCs still associate very poor clinical outcomes, with currently available therapeutic modalities only being able to prolong survival. In lack of a definitive cure for advanced RCCs, integration of the amounting scientific knowledge regarding RCC pathogenesis into RCC clinical management has been paramount for improving patient outcomes. The current review aims to offer an integrative perspective regarding contemporary RCC clinical definitions, proper RCC clinical work-up at initial diagnosis (semiology and multimodal imaging), RCC pathological evaluation, differential diagnosis/subtyping protocols, and novel clinical tools for RCC screening, risk stratification and therapeutic response prediction.

Contrast-enhanced ultrasonography to guide diagnostic and therapeutic interventional procedures

Although not necessary for the vast majority of ultrasound-guided procedures, intravenous contrast agents can be useful for procedures aimed at lesions that require contrast enhancement to be seen on ultrasonography. Using contrast-enhanced ultrasonography to guide procedures has two drawbacks: first, because enhancement from ultrasound contrast agents is short lived, it is often necessary to plan several injections; second, because the needle is poorly seen on contrast-enhanced ultrasonography, a dual image display format is necessary. Contrast-enhanced ultrasonography can be used for planning and monitoring diagnostic and therapeutic procedures, for guiding the procedures, and for follow-up. Using contrast-enhanced ultrasonography enables better results in both types of procedures; moreover, it can be used within cavities.

Radiofrequency ablation using real-time ultrasonography–computed tomography fusion imaging improves treatment outcomes for T1a renal cell carcinoma: Comparison with laparoscopic partial nephrectomy

Purpose

To determine whether real-time ultrasonography–computed tomography (US-CT) fusion imaging can improve technical feasibility versus B-mode US and provide comparable outcomes of radiofrequency ablation (RFA) for T1a renal cell carcinoma (RCC) compared with laparoscopic partial nephrectomy (LPN).

Materials and Methods

Between June 2013 and August 2016, biopsy- or pathologically confirmed stage T1a RCCs were retrospectively reviewed. Of these, 39 cases were included in the RFA group, and 46 cases were included in the LPN group. In the RFA group, we evaluated tumor visibility and technical feasibility before RFA on a four-point scale on B-mode US and US-CT fusion images. After RFA, hospital days, creatinine value, complications, and disease-free survival rate were compared between the two groups. All results were analyzed by use of the Mann–Whitney U-test and Kaplan–Meier method.

Results

Compared with B-mode US alone, real-time US-CT fusion significantly improved the tumor visibility score and overall mean technical feasibility grade (p<0.001). The 5-year disease-free survival rate was 97.4% and 97.8% in the RFA and LPN groups, respectively, and there was no statistically significant difference between groups (p=0.1). Mean periprocedural creatinine levels were significantly lower in the RFA group than in the LPN group. The number of hospital days was shorter in the RFA group. Minor complications were present in 5.1% of the RFA group and 13.0% of the LPN group, with no major complications.

Conclusions

US-CT fusion-image-guided RFA improved tumor visibility scores and overall mean technical validity and resulted in a comparable disease-free survival rate to LPN.

Contrast-enhanced ultrasound (CEUS) in HCC diagnosis and assessment of tumor response to locoregional therapies

Hepatocellular carcinoma (HCC) is a global problem constituting the second leading cause of cancer deaths worldwide, thereby necessitating an accurate and cost-effective solution for managing care. Ultrasound is well poised to address this need due to its low cost, portability, safety, and excellent temporal resolution. The role of ultrasound for HCC screening has been well established and supported by multiple international guidelines. Similarly, contrast-enhanced ultrasound (CEUS) can be used for the characterization of focal liver lesions in high-risk populations, and standardized criteria for CEUS have been established by the American College of Radiology Liver Imaging Reporting & Data System (LI-RADS). Following HCC identification, CEUS can also be highly beneficial in treatment planning, delivery, and monitoring HCC response to locoregional therapies. Specific advantages of CEUS include providing real-time treatment guidance and improved diagnostic performance for the detection of residual tumor viability or recurrence, thereby identifying patients in need of retreatment substantially earlier than contrast-enhanced CT and MRI. This review provides a primer on ultrasound and CEUS for the screening and characterization of HCC, with an emphasis on assessing tumor response to locoregional therapies.

Contrast-enhanced US for the Interventional Radiologist: Current and Emerging Applications

US is a powerful and nearly ubiquitous tool in the practice of interventional radiology. Use of contrast-enhanced US (CEUS) has gained traction in diagnostic imaging given the recent approval by the U.S. Food and Drug Administration (FDA) of microbubble contrast agents for use in the liver, such as sulfur hexafluoride lipid-type A microspheres. Adoption of CEUS by interventional radiologists can enhance not only procedure guidance but also preprocedure patient evaluation and assessment of treatment response across a wide spectrum of oncologic, vascular, and nonvascular procedures. In addition, the unique physical properties of microbubble contrast agents make them amenable as therapeutic vehicles in themselves, which can lay a foundation for future therapeutic innovations in the field in drug delivery, thrombolysis, and vascular flow augmentation. The purpose of this article is to provide an introduction to and overview of CEUS aimed at the interventional radiologist, highlighting its role before, during, and after frequently practiced oncologic and vascular interventions such as biopsy, ablation, transarterial chemoembolization, detection and control of hemorrhage, evaluation of transjugular intrahepatic portosystemic shunts (TIPS), detection of aortic endograft endoleak, thrombus detection and evaluation, evaluation of vascular malformations, lymphangiography, and percutaneous drain placement. Basic physical principles of CEUS, injection and scanning protocols, and logistics for practice implementation are also discussed. Early adoption of CEUS by the interventional radiology community will ensure rapid innovation of the field and development of future novel procedures. Online supplemental material is available for this article. ^©RSNA, 2020.

Contrast-enhanced ultrasonography to guide diagnostic and therapeutic interventional procedures

Although not necessary for the vast majority of ultrasound-guided procedures, intravenous contrast agents can be useful for procedures aimed at lesions that require contrast enhancement to be seen on ultrasonography. Using contrast-enhanced ultrasonography to guide procedures has two drawbacks: first, because enhancement from ultrasound contrast agents is short lived, it is often necessary to plan several injections; second, because the needle is poorly seen on contrast-enhanced ultrasonography, a dual image display format is necessary. Contrast-enhanced ultrasonography can be used for planning and monitoring diagnostic and therapeutic procedures, for guiding the procedures, and for follow-up. Using contrast-enhanced ultrasonography enables better results in both types of procedures; moreover, it can be used within cavities.

Anesthesia for Percutaneous Radiofrequency Tumor Ablation (PRFA): A Review of Current Practice and Techniques

Percutaneous radiofrequency ablation (PRFA) of solid tumors is a minimally invasive procedure used to treat primary or metastatic cancer lesions via needle targeted thermal energy transfer. Some of the most common tumor lesions treated using PRFA include those within the liver, lungs and kidneys. Additionally, bone, thyroid, and breast lesions can also be treated. In most cases, this procedure is performed outside of the operating room in a specialized radiology suite. As a result, the clinician must adapt in many cases to the specific environmental issues attendant to providing anesthesia outside the operating room, including the lack of availability of an anesthesia machine in some cases, and frequently a lack of adequate scavenging and other specialized monitoring and equipment. At this time, routine practice and anesthetic prescriptions for PRFA can vary widely, ranging from patients receiving local anesthesia alone, to monitored anesthesia care, to regional anesthesia, to combined regional and general anesthesia. The choice of anesthetic technique will depend on tumor location and practitioner experience. This review aims to summarize the current state of the art in terms of anesthetic techniques for patients undergoing PRFA of solid tumors.

Renal Cell Carcinoma Ablation: Preprocedural, Intraprocedural, and Postprocedural Imaging

The rising incidence of renal cell carcinoma (RCC) in recent decades necessitates careful consideration of additional treatment options, especially for patients who may be poor surgical candidates. An emerging body of evidence suggests that ablation may be performed effectively and safely even in patients with multiple comorbidities. Accordingly, clinical guidelines now include thermal ablation as an alternative for such patients with localized tumors that are 4.0 cm or smaller. Recent experience with these minimally invasive techniques has led to a greater understanding of the imaging findings that merit close attention when ablation is anticipated, or after it is performed. These imaging findings may guide the interventionalist's perception of the risks, technical challenges, and likelihood of treatment success associated with RCC ablation. The present review provides an overview of clinically relevant radiologic findings during the preprocedural, intraprocedural, and postprocedural period in the context of image-guided renal ablation. Keywords: Interventional-Body, Kidney, Percutaneous, Urinary © RSNA, 2019.

Contrast-Enhanced Ultrasound Guidance for Interventional Procedures

Since its introduction, contrast-enhanced ultrasound (CEUS) has gained an important role in the diagnosis and management of abdominal and pelvic diseases. Contrast-enhanced ultrasound can improve lesion detection rates as well as success rates of interventional procedures when compared to conventional ultrasound alone. Additionally, CEUS enables the interventionalist to assess the dynamic enhancement of different tissues and lesions, without the adverse effects of contrast-enhanced computed tomography, such as exposure to ionizing radiation and nephrotoxicity from iodinated contrast material. This review article describes the various applications and advantages of the use of CEUS to enhance performance of ultrasound-guided interventions in the abdomen and pelvis.

Imaging after radiofrequency ablation of renal tumors

The number of percutaneous radiofrequency ablation procedures performed for renal tumors is progressively increasing worldwide. Periodic imaging follow-up has the double role to guarantee the treatment efficacy over time and to early detect any possible complication. Tumor size reductions, as well as the appearance of the characteristic ‘halo sign’, are normal findings that represent good ablative outcomes. However the most reliable factor of ablation efficacy remains the total absence of contrast enhancing zones within the ablated area. The aim of this article is to illustrate the typical aspect of an effective radiofrequency ablation treatment, which are the imaging findings that may suggest the presence of residual tumoral tissue and which are the main early and late procedural complications.

Contrast-enhanced ultrasonography in interventional oncology

Contrast-enhanced ultrasound (CEUS) has evolved from the use of agitated saline to second generation bioengineered microbubbles designed to withstand insonation with limited destruction. While only one of these newer agents is approved by the Food and Drug Administration for use outside echocardiography, interventional radiologists are increasingly finding off-label uses for ultrasound contrast agents. Notably, these agents have an extremely benign safety profile with no hepatic or renal toxicities and no radiation exposure. Alongside diagnostic applications, CEUS has begun to develop its own niche within the realm of interventional oncology. Certainly, the characterization of focal solid organ lesions (such as hepatic and renal lesions) by CEUS has been an important development. However, interventional oncologists are finding that the dynamic and real-time information afforded by CEUS can improve biopsy guidance, ablation therapy, and provide early evidence of tumor viability after locoregional therapy. Even more novel uses of CEUS include lymph node mapping and sentinel lymph node localization. Critical areas of research still exist. The purpose of this article is to provide a narrative review of the emerging roles of CEUS in interventional oncology.

Contrast-enhanced ultrasound (CEUS) in abdominal intervention

The introduction of ultrasound contrast agents has rendered contrast-enhanced ultrasound (CEUS) a valuable complementary technique to address clinically significant problems. This pictorial review describes the use of CEUS guidance in abdominal intervention and illustrates such application for a range of clinical indications. Clinical application of CEUS discussed include commonly performed abdominal interventional procedures, such as biopsy, drainage, nephrostomy, biliary intervention, abdominal tumor ablation and its subsequent monitoring, and imaging of vascular complications following abdominal intervention. The purpose of this article is to further familiarize readers with the application of CEUS, particularly its specific strength over alternative imaging modalities, in abdominal intervention.

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.

Percutaneous radiofrequency ablation for renal cell carcinoma vs. partial nephrectomy: Comparison of long-term oncologic outcomes in both clear cell and non-clear cell of the most common subtype

OBJECTIVES

To compare the clinical outcomes of percutaneous radiofrequency ablation (PRFA) and partial nephrectomy (PN) in patients with clear cell renal cell carcinoma (ccRCC) and non-clear cell RCC (nccRCC) of the most common subtypes.

MATERIALS AND METHODS

A retrospective study was conducted to review the records of all the patients who underwent PRFA or PN between February 2005 and April 2014 at our institution. Patients with histologic confirmation of ccRCC, papillary RCC, and chromophobe RCC were included. The Mann-Whitney U test was applied to compare PRFA to PN in the ccRCC and nccRCC groups. The Kaplan-Meier method was used to generate the survival curves that were compared to the log-rank test.

RESULTS

A total of 264 patients meeting the selection criteria were included in this study. The tumor size ranged from 0.9 to 7.0cm. The median follow-up period was 78 months (range: 8-132 mo). Although PRFA provided comparable 10-year overall survival rates and 10-year disease-free survival (DFS) rates to PN both in ccRCC ≤4cm and nccRCC, the 10-year DFS for patients treated with PRFA was lower than that of PN in ccRCC >4cm. The DFS survival curve between the 2 operations and 2 subtypes was statistically significant in patients with tumor size >4cm. Limitations include retrospective review and selection bias.

CONCLUSIONS

Patients with T1b ccRCC treated with PRFA have less favorable outcomes than those with PN whereas PRFA provides comparable oncologic outcomes to PN in patients with T1b nccRCC. It is necessary to take RCC subtypes into consideration when choosing a surgical approach to treat T1b RCC between PFRA and PN.

Neutrophil-to-lymphocyte ratio as an independent predictor for survival in patients with localized clear cell renal cell carcinoma after radiofrequency ablation: a propensity score matching analysis

OBJECTIVE

To investigate the role of neutrophil-to-lymphocyte ratio as a prognostic indicator in patients with localized clear cell renal cell carcinoma treated with radiofrequency ablation.

PATIENTS AND METHODS

We retrospectively analyzed data from patients with renal cell carcinoma who underwent radiofrequency ablation from 2006 to 2013. The Kaplan-Meier method was used to generate the survival curves according to different categories of neutrophil-to-lymphocyte ratio. Relationships between preoperative neutrophil-to-lymphocyte ratio or the change of neutrophil-to-lymphocyte ratio and survival were evaluated with multivariable Cox proportional hazards regression analysis. A propensity score matching analysis was carried out to avoid confounding bias.

RESULTS

A total of 185 patients were included in present study. When stratified by preoperative neutrophil-to-lymphocyte ratio cutoff value of 2.79, 5-year recurrence-free survival, 5-year disease-free survival, and 5-year overall survival rates of neutrophil-to-lymphocyte ratio <2.79 versus ≥2.79 were 100, 98.5, and 99.2% versus 80.5, 72.6, and 90.6%, respectively (P < 0.001, P < 0.001, P = 0.003). In terms of propensity score matching analysis, 5-year recurrence-free survival, 5-year disease-free survival, and 5-year overall survival rates of neutrophil-to-lymphocyte ratio <2.79 versus ≥2.79 were 100, 97.9, and 100% versus 82.3, 73.4, and 89.4%, respectively (P = 0.003, P = 0.001, P = 0.022). When combining preoperative neutrophil-to-lymphocyte ratio with the change of neutrophil-to-lymphocyte ratio, patients with both preoperative neutrophil-to-lymphocyte ratio ≥2.79 and the change of neutrophil-to-lymphocyte ratio ≥0.40 had the worst disease-free survival. Results of multivariable analysis showed that preoperative neutrophil-to-lymphocyte ratio and the change of neutrophil-to-lymphocyte ratio correlated with cancer relapse remarkably.

CONCLUSIONS

High preoperative neutrophil-to-lymphocyte ratio and elevated postoperative neutrophil-to-lymphocyte ratio are associated with significant increase in risk of local recurrence as well as distant metastasis. The combination of neutrophil-to-lymphocyte ratio with the other prognostic indicators can be applied in the evaluation of relapse risk in patients with clear cell renal cell carcinoma after radiofrequency ablation.

Percutaneous radiofrequency ablation with contrast-enhanced ultrasonography for solitary and sporadic renal cell carcinoma in patients with autosomal dominant polycystic kidney disease

Background

The aim of this study was to assess the functional and oncologic outcomes of percutaneous radiofrequency ablation (RFA) with contrast-enhanced ultrasonography (CEUS) for renal cell carcinoma in patient with autosomal dominant polycystic kidney.

Methods

We performed a retrospective review of five patients with renal cell carcinoma (RCC) in autosomal dominant polycystic kidney disease (ADPKD) from January 2009 to December 2014 with a media follow-up of 33 months. The tumors were ablated with Cool-tip RFA system under the guidance of CEUS. Routine follow-up included contrast-enhanced computed tomography/magnetic resonance imaging (CT/MRI) and renal function tests.

Results

Media diameter of the treated renal tumors was 3.1 cm (range 1.7–5.2 cm). Initial ablation success rate was 4/5. After over 6 months contrast-enhanced CT/MRI follow-up after RFA, no patients experienced local tumor recurrence. No patients required dialysis in the periprocedural period. Minor complications only developed in two cases. There was no significant difference in estimated glomerular filtration rate (eGFR) between pre- and post-RFA.

Conclusions

Our initial experience of this technique for RCC in ADPKD was favorable with good renal function preservation and oncologic outcomes. It may be a good choice for RCC in ADPKD.

Imaging of renal cell carcinoma

Renal cell carcinoma (RCC) is the most common kidney cancer in adults. Early and accurate imaging plays an important role in the detection, staging, and follow-up of RCC. Patient care and case management revolves heavily around diagnostic imaging so it is imperative that appropriate and adequate imaging is acquired. There are well-established standard imaging protocols available to patients and their providers, although at the same time, there is also extensive ongoing research on improving the various modalities. Ultrasound has been the most commonly used imaging technique for renal imaging in general. However, computed tomography (CT) is the first choice for imaging of renal masses, and has been the mainstay for several decades. High resolution, reproducibility, reasonable preparation and acquisition time, and acceptable cost allow CT to remain as the primary choice for radiologic imaging. Magnetic resonance imaging (MRI) is considered as an important alternative in patients requiring further imaging or in cases of allergies, pregnancy, or surveillance. With increasing concern over radiation exposure, there has been a trend toward the higher use of MRI. It is important to understand the various imaging options available, as well as the current status of and results from recent RCC imaging studies. In this review we discuss these modalities, including the current state of ultrasound, CT, and MRI in RCC.

Contrast enhanced ultrasound in the evaluation and percutaneous treatment of hepatic and renal tumors

Image-guided percutaneous ablation techniques are increasingly being used for the treatment of malignant tumors of the liver and kidney. Contrast enhanced ultrasound (CEUS) is a real-time dynamic imaging technique that plays an important role in the pre-, intra-, and post-procedural management of these patients. This review will focus on the role of CEUS in the evaluation of patients undergoing treatment with percutaneous ablation for hepatic or renal tumors.

The Comparison of R.E.N.A.L., PADUA and Centrality Index Score in Predicting Perioperative Outcomes and Complications after Laparoscopic Radio Frequency Ablation of Renal Tumors

PURPOSE

We assessed the association between the R.E.N.A.L., PADUA and centrality index scores and perioperative outcomes, and determined the efficacy of each scoring system over the simple parameter of tumor size.

MATERIALS AND METHODS

We conducted a retrospective review of the records of patients who underwent laparoscopic radio frequency ablation of renal tumors from February 2006 to April 2014 at our institution. Tumors were categorized using the R.E.N.A.L., PADUA and centrality index score, which were determined by analyzing preoperative imaging. The relationships between each variable and change in glomerular filtration rate, estimated blood loss, operative time and postoperative complications were examined.

RESULTS

Laparoscopic radio frequency ablation was performed in 215 selected patients with preoperative imaging available. The interclass correlations coefficient of the 3 observers was 0.87, 0.84 and 0.82 for the C-Index, the R.E.N.A.L. and the PADUA scoring system, respectively. R.E.N.A.L. score, PADUA score and PADUA complexity were significantly associated with postoperative complications (p=0.040, 0.015 and 0.006, respectively). However, major complications were only associated with high PADUA complexity (chi-square 23.851, p <0.05). Each scoring system had a significant association with operative time and estimated blood loss (p <0.05), except that the C-index score had no relationship with estimated blood loss (p=0.083). The accuracy of each scoring system in predicting perioperative outcomes and postoperative complications was superior to that of tumor size.

CONCLUSIONS

Each scoring system has an advantage over tumor size in describing tumor complexity and may help with surgical decision making. Further studies are required to validate their efficacy in evaluating the intraoperative and postoperative results after renal laparoscopic radio frequency ablation.

Radio frequency ablation versus partial nephrectomy for clinical T1b renal cell carcinoma: long-term clinical and oncologic outcomes

PURPOSE

We compared outcomes in patients treated with radio frequency ablation or partial nephrectomy for clinical cT1b renal cell carcinoma.

MATERIALS AND METHODS

We retrospectively reviewed the records of all patients who underwent radio frequency ablation or nephrectomy between February 2006 and December 2010. Radiographic followup with contrast imaging was performed 7 days, 3 and 6 months, and every 6 months thereafter after radio frequency ablation sequentially. The followup protocol for partial nephrectomy was every 6 months in the initial 3 years and annually thereafter. The Kaplan-Meier method was used to generate survival curves, which were compared with the log rank test. Multivariable regression analysis was done to determine predictors of survival.

RESULTS

A total of 56 patients who met selection criteria were included in study. Patients in the radio frequency ablation group had relatively higher mean age and a higher mean ASA® score than those in the partial nephrectomy group. Mean tumor diameter was significantly larger in the partial nephrectomy cohort. For radio frequency ablation vs partial nephrectomy 5-year overall, cancer specific and disease-free survival was 85.5% (95% CI 72.2-98.8) vs 96.6% (95% CI 95.9-97.3), 92.6% (95% CI 82.4-98.1) vs 96.6% (95% CI 95.9-97.3) and 81.0% (95% CI 66.2-95.8) vs 89.7% (95% CI 78.5-97.9), respectively. The percent decrease in the glomerular filtration rate was significantly lower in the radio frequency ablation group at early and last followup.

CONCLUSIONS

In appropriately selected patients with stage cT1b renal cell carcinoma radio frequency ablation is an effective treatment option that provides 5-year overall, cancer specific and disease-free survival comparable to that of partial nephrectomy as well as better renal function preservation than partial nephrectomy.

[Interventional sonography of the liver and kidneys]

CLINICAL/METHODICAL ISSUE

Optimization of ultrasound guided interventional procedures of the liver and kidneys using new imaging methods.

STANDARD RADIOLOGICAL METHODS

Punctures, biopsies, drainage, intraoperative ultrasound, fusion, embolization in correlation with ultrasound and other imaging methods.

METHODICAL INNOVATIONS

Real-time-sonography, contrast-enhanced ultrasound (CEUS) and fusion for planning, monitoring and postinterventional control.

PERFORMANCE

The use of CEUS enables better detection, characterization and execution of interventional procedures. Fusion facilitates detection.

ACHIEVEMENTS

The CEUS procedure is superior for detection and characterization of smaller lesions in comparison to the B scan. Fusion enables the performance of difficult interventional procedures.

PRACTICAL RECOMMENDATIONS

The B scan is the standard imaging method but CEUS and fusion could be helpful for smaller lesions.

Evaluation of renal masses with contrast-enhanced ultrasound

The clinical need for characterising small renal masses (SRMs) is increasing due to their rising incidental detection. This increase is especially seen in younger and older generations and concerns mainly SRMs. Diagnostics is mainly made by contrast-enhanced CT or MRI. However, these imaging methods fail to accurately distinguishing benign from malignant SRMs. Other disadvantages of CT or MRI are high costs, the use of ionizing radiation, nephrotoxicity induced by iodine contrast agents or nephrogenic systemic fibrosis (NSF) induced by gadolinium contrast agents. Contrast-enhanced ultrasound (CEUS) is based on ultrasonography and microbubbles to real-time visualize the renal blood flow without the use of nephrotoxic agents or ionizing radiation. This comprehensive review evaluates the capabilities of CEUS in the diagnostics of benign (angiomyolipomas, cysts, oncocytomas, pseudotumors) and malignant masses (renal cell carcinomas), and focuses on possible future treatment.

Percutaneous radiofrequency ablation of renal cell carcinomas in patients with von Hippel Lindau disease: indications, techniques, complications, and outcomes

Renal cell carcinoma (RCC) in patients with von Hippel Lindau (VHL) disease tends to be multifocal, bilateral, and recur or develop new tumors after removal. These characteristics make treating hereditary RCCs difficult for urologists or radiologists compared to treating a sporadic RCC. Radiofrequency ablation (RFA) is a minimally-invasive treatment for small hereditary RCCs associated with a low complication rate and a minimal decrease in renal function. No RFA guidelines have been established about what to treat and when and how to ablate RCCs in patients with VHL disease. Besides, reports on complications and treatment outcomes in this patient group are rare. The purpose of this review is to discuss the indications, techniques, complications, and outcomes of RFA in treating RCC in patients with VHL disease.