Minimally Invasive Nephron-Sparing Surgery (MINSS) for Renal Tumours

The evolving management of small renal masses

Small renal masses (SRMs) are a heterogeneous group of tumours with varying metastatic potential. The increasing use and improving quality of abdominal imaging have led to increasingly early diagnosis of incidental SRMs that are asymptomatic and organ confined. Despite improvements in imaging and the growing use of renal mass biopsy, diagnosis of malignancy before treatment remains challenging. Management of SRMs has shifted away from radical nephrectomy, with active surveillance and nephron-sparing surgery taking over as the primary modalities of treatment. The optimal treatment strategy for SRMs continues to evolve as factors affecting short-term and long-term outcomes in this patient cohort are elucidated through studies from prospective data registries. Evidence from rapidly evolving research in biomarkers, imaging modalities, and machine learning shows promise in improving understanding of the biology and management of this patient cohort.

"Could Patient Age and Gender, along with Mass Size, Be Predictive Factors for Benign Kidney Tumors?": A Retrospective Analysis of 307 Consecutive Single Renal Masses Treated with Partial or Radical Nephrectomy

Due to the increased use of common and non-invasive abdominal imaging techniques over the last few decades, the diagnosis of about 60% of renal tumors is incidental. Contrast-enhancing renal nodules on computed tomography are diagnosed as malignant tumors, which are often removed surgically without first performing a biopsy. Most kidney nodules are renal cell carcinoma (RCC) after surgical treatment, but a non-negligible rate of these nodules may be benign on final pathology; as a result, patients undergo unnecessary surgery with an associated significant morbidity. Our study aimed to identify a subgroup of patients with higher odds of harboring benign tumors, who would hence benefit from further diagnostic examinations (such as renal biopsy) or active surveillance. We performed a retrospective review of the medical data, including pathology results, of patients undergoing surgery for solid renal masses that were suspected to be RCCs (for a total sample of 307 patients). Owing to the widespread use of common and non-invasive imaging techniques, the incidental diagnosis of kidney tumors has become increasingly common. Considering that a non-negligible rate of these tumors is found to be benign after surgery at pathological examination, it is crucial to identify features that can correctly diagnose a mass as benign or not. According to our study results, female sex and tumor size ≤ 3 cm were independent predictors of benign disease. Contrary to that demonstrated by other authors, increasing patient age was also positively linked to a greater risk of malign pathology.

"To Be or Not to Be Benign" at Partial Nephrectomy for Presumed RCC Renal Masses: Single-Center Experience with 195 Consecutive Patients

In daily medical practice, an increasing number of kidney masses are being incidentally detected using common imaging techniques, owing to the improved diagnostic accuracy and increasingly frequent use of these techniques. As a consequence, the rate of detection of smaller lesions is increasing considerably. According to certain studies, following surgical treatment, up to 27% of small enhancing renal masses are identified as benign tumors at the final pathological examination. This high rate of benign tumors challenges the appropriateness of surgery for all suspicious lesions, given the morbidity associated with such an intervention. The objective of the present study was, therefore, to determine the incidence of benign tumors at partial nephrectomy (PN) for a solitary renal mass. To meet this end, a total of 195 patients who each underwent one PN for a solitary renal lesion with the intent to cure RCC were included in the final retrospective analysis. A benign neoplasm was identified in 30 of these patients. The age of the patients ranged from 29.9-79 years (average: 60.9 years). The tumor size range was 1.5-7 cm (average: 3 cm). All the operations were successful using the laparoscopic approach. The pathological results were renal oncocytoma in 26 cases, angiomyolipomas in two cases, and cysts in the remaining two cases. In conclusion, we have shown in our present series the incidence rate of benign tumors in patients who have been subjected to laparoscopic PN due to a suspected solitary renal mass. Based on these results, we advise that the patient should be counseled not only about the intra- and post-operative risks of nephron-sparing surgery but also about its dual therapeutic and diagnostic role. Therefore, the patients should be informed of the considerably high probability of a benign histological result.

Comprehensive Management of Renal Masses in Solitary Kidneys

BACKGROUND

A renal mass in a solitary kidney (RMSK) has traditionally been managed with partial nephrectomy (PN), although radical nephrectomy (RN) is occasionally required. Most RMSK studies have focused on patients for whom PN was achieved.

OBJECTIVE

To provide a comprehensive analysis of the management strategies/outcomes for an RMSK and address knowledge deficits regarding this challenging disorder.

DESIGN, SETTING, AND PARTICIPANTS

A total of 1024 patients diagnosed with an RMSK (1975-2022) were retrospectively evaluated. Baseline characteristics and pathologic/functional/survival outcomes were analyzed.

INTERVENTION

PN/RN/cryoablation (CA)/active surveillance (AS).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Functional outcomes, perioperative morbidity/mortality, and 5-yr recurrence-free survival (RFS) were evaluated. Kruskal-Wallis and chi-square tests were used to compare cohorts, and log-rank test and Cox proportional hazard model were used for survival analysis.

RESULTS AND LIMITATIONS

Of 1024 patients, 842 underwent PN (82%), 102 CA (10%), 54 RN (5%), and 26 AS (3%). The median tumor size and RENAL([R]adius [tumor size as maximal diameter], [E]xophytic/endophytic properties of tumor, [N]earness of tumor deepest portion to collecting system or sinus, [A]nterior [a]/posterior [p] descriptor, and [L]ocation relative to polar lines) score were 3.7 cm and 8, respectively. The median follow-up was 53 mo. For PN, 95% were clamped, and the median warm and cold ischemia times were 22 and 45 min, respectively. For PN, the median preoperative glomerular filtration rate (GFR) was 57 ml/min/1.73 m², and the median new baseline and 5-yr GFRs were 47 and 48 ml/min/1.73 m², respectively. Dialysis-free survival for PN was 97% at 5 yr. Twenty-two (2.1%) patients with clear-cell renal cell carcinoma and RENAL score ≥10 (median = 11) received tyrosine kinase inhibitors (TKIs) to facilitate PN, leading to 57% median decrease of tumor volume; PN was accomplished in 20 (91%). Forty-one patients had planned RN (4.0%), most often due to severe pre-existing chronic kidney disease (CKD), and 13 were converted from PN to RN (1.5%). Clavien III-V perioperative complications were observed in 80 (8%) patients and 90-d mortality was 0.6%. Five-year RFS for PN, CA, and RN were 83%, 80%, and 72%, respectively (p = 0.03 for PN vs RN).

CONCLUSIONS

Nephron-sparing approaches are feasible and successful in most RMSK patients. PN for an RMSK is often challenging but can be facilitated by selective use of TKIs. RN is occasionally required due to severe CKD, over-riding oncologic concerns, or conversion from PN. This is the first large RMSK study to provide a comprehensive analysis of all management strategies/outcomes.

PATIENT SUMMARY

Kidney cancer in a solitary kidney is a major challenge for achieving cancer-free status and avoiding dialysis. Although partial nephrectomy is the principal treatment for a renal mass in a solitary kidney, other options are occasionally required to optimize outcomes.

A systematic review and meta-analysis comparing tumor progression and complications between radiofrequency ablation and thyroidectomy for papillary thyroid carcinoma

BACKGROUND

Papillary thyroid cancer (PTC) is the most frequent thyroid cancers worldwide. The efficacy and acceptability of radiofrequency ablation (RFA) in the treatment of PTC have been intensively studied. The aim of this study is to focus on extra detailed that may influent for PTC or papillary thyroid microcarcinoma (PTMC).

MATERIALS AND METHODS

We identified a total of 1,987 records of a primary literature searched in PubMed, Embase, Cochrane Library, and Google Scholar by key words, from 2000 to 2022. The outcome of studies included complication, costs, and local tumor progression. After scrutiny screening and full-text assessment, six studies were included in the systematic review. Heterogeneity was estimated using I2, and the quality of evidence was assessed for each outcome using the GRADE guidelines.

RESULTS

Our review enrolled 1,708 patients reported in six articles in the final analysis. There were 397 men and 1,311 women in the analysis. Two of these studies involved PTC and four focused on PTMC. There were 859 patients in the RFA group and 849 patients in the thyroidectomy group. By contrast, the tumor progression of RFA group was as same as that surgical groups [odds ratio, 1.31; 95% CI, 0.52-3.29; heterogeneity (I2 statistic), 0%, p = 0.85]. The risk of complication rates was significantly lower in the RFA group than that in the surgical group [odds ratio, 0.18; 95% CI, 0.09-0.35; heterogeneity (I2 statistic), 40%, p = 0.14].

CONCLUSIONS

RFA is a safe procedure with a certain outcome for PTC. RFA can achieve a good efficacy and has a lower risk of major complications.

Computed tomography-guided biopsy for small renal masses before or immediately after tumor ablation: factors affecting diagnostic yield

PURPOSE

To evaluate the diagnostic yield of percutaneous renal mass biopsy (RMB) before and after ablation.

MATERIALS AND METHODS

In total, 333 renal masses in 332 consecutive patients underwent computed tomography (CT)-guided biopsies and were included in this study. All biopsies were performed with 18-gauge core needles with CT fluoroscopic guidance before ablation (n  =  234) or immediately after radiofrequency ablation (RFA) (n  =  40) or cryoablation (CA) (n  =  59). The safety and diagnostic yield of RMB were evaluated. Both univariate and multivariate analyses were used to identify factors affecting diagnostic yield.

RESULTS

No major complication occurred. The 281 specimens (84%) were diagnostic. There were 257 renal cell carcinomas (77%), 21 benign masses (6%), and 3 metastases (1%). The remaining 52 specimens (16%) were nondiagnostic. The diagnostic yields before ablation, after RFA, and CA were 91% (212/234), 80% (32/40), and 63% (37/59), respectively. Small masses (P  =  0.050 and 0.006), cystic masses (P < 0.001 and < 0.001), and post-CA (P < 0.001 and < 0.001) were independent and significant factors affecting the nondiagnostic results in both univariate and multivariate analyses.

CONCLUSION

CT-guided RMB can be nondiagnostic when the tumor is small, cystic, or biopsied immediately after CA.

Comparison among cryoablation, radiofrequency ablation, and partial nephrectomy for renal cell carcinomas sized smaller than 2 cm or sized 2-4 cm: A population-based study

This study aimed to compare radiofrequency ablation (RFA), cryoablation (CRA), and partial nephrectomy (PN) for renal cell carcinoma (RCC) sized ≤2 cm or 2 to 4 cm.The Surveillance, Epidemiology, and End Results (SEER) database was used to identify 17,234 patients diagnosed with T1aN0M0 RCC from 2004 to 2015. Overall survival (OS) and cancer-specific survival (CSS) were compared among patients who were treated using PN, CRA, or RFA. The Cox proportional hazards model was used to determine prognostic factors for survival.In patients with RCCs sized 2 to 4 cm, better OS and CSS were observed with PN than with CRA or RFA. On multivariable analysis, compared to PN, CRA and RFA were independently associated with poor OS and CSS in patients with RCCs sized 2 to 4 cm. In patients with RCCs sized ≤2 cm, better OS was observed with PN than with CRA or RFA; however, CSS was similar. On multivariable analysis, compared to PN, RFA was independently associated with poor OS in patients with RCCs sized ≤2 cm.CRA or RFA should not be recommended for patients with RCCs sized 2 to 4 cm; PN is an effective treatment modality in these patients. For patients with RCCs sized ≤2 cm, CRA can be an equally effective alternative to PN.

Reninoma: a rare cause of curable hypertension

The most common type of refractory hypertension found in children is secondary hypertension, which is a potentially curable disease. Reninoma, a renin-secreting juxtaglomerular cell tumor, is a rare cause of severe hypertension that is usually diagnosed in adolescents and young adults. Surgical resection of the tumor completely cures the hypertension of patients with reninoma. The typical clinical presentation of reninoma includes hypokalemia, metabolic alkalosis, and features secondary to the increased activation of the renin-angiotensin system without renal artery stenosis. We report a case of reninoma in a female adolescent with a typical clinical presentation, in which surgical removal of the tumor completely cured hypertension. We discuss here the clinical features, imaging studies, and immunohistochemical examination of the tumor used to establish the diagnosis of reninoma and for the management of the condition.

Partial Nephrectomy versus Thermal Ablation for Clinical Stage T1 Renal Masses: Systematic Review and Meta-Analysis of More than 3,900 Patients

PURPOSE

A systematic review and meta-analysis of clinical trials was undertaken to compare percutaneous thermal ablation versus partial nephrectomy (PN) for stage T1 renal tumors.

MATERIALS AND METHODS

A comprehensive search of major databases was conducted from October 2000 to July 2016. Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed. Incidences of all-cause mortality (ACM), cancer-specific mortality (CSM), local recurrence (LR), and metastases, as well as complication rates and changes in estimated glomerular filtration rate (eGFR), were evaluated.

RESULTS

Inclusion criteria were met by 15 of 961 papers. These studies represented 3,974 patients who had undergone an ablative procedure (cryoablation or radiofrequency ablation; n = 1,455; 37%) or PN (n = 2,519; 63%). ACM and CSM rates were higher for ablation than for PN (hazard ratio [HR], 2.11; 95% confidence interval [CI], 1.54-2.87 [P < .05]; HR, 3.84; 95% CI, 1.66-8.88 [P < .05], respectively). No statistically significant difference in LR rate or risk of metastasis was seen between ablation and PN (HR, 1.32; 95% CI, 0.79-2.22 [P = .22]; HR, 1.83; 95% CI, 0.67-5.01 [P = 0.23], respectively). Complication rates were lower for ablation than for PN (13% vs 17.6%; odds ratio, 0.49; 95% CI, 0.25-0.94; P < .05). A significantly greater decrease in eGFR was observed after PN (13.09 mL/min/1.73 m²) vs ablation therapy (4.47 mL/min/1.73 m²).

CONCLUSIONS

Thermal ablation showed no significant difference in LR or metastases compared with PN. Thermal ablation was associated with a lower morbidity rate and a lesser reduction in eGFR compared with PN, but with higher ACM and CSM rates.

Thermal ablative therapies for treatment of localised renal cell carcinoma: a systematic review of the literature

BACKGROUND AND AIMS

Small renal masses are commonly diagnosed incidentally. The majority are malignant and require intervention. The gold standard treatment is partial nephrectomy unless the patient has significant co-morbidities when surveillance or ablative therapies are utilised. The latter are relatively novel and their long-term efficacy and safety remain generally poorly understood. We performed a literature review to establish the current evidence on the oncological outcome of thermal ablative techniques in small renal masses treatment.

METHODS AND RESULTS

A systematic literature search was performed using PubMed, supplemented with additional references. Articles were reviewed for data on indications, tumour characteristics, ablative techniques, oncological outcome, impact on renal function and complications. The vast majority of articles identified were observational studies. There has not been any direct comparison against partial nephrectomy. Radiofrequency ablation and cryoablation are the techniques that are more commonly used. They have favourable oncological results on intermediate follow-up and indications that successful outcome is sustained long term. The morbidity and impact on renal function appear to be minimal.

CONCLUSION

Thermal ablative therapies are valid alternatives to partial nephrectomy for the treatment of small renal masses in patients unfit for surgery. Prospective long-term data will be needed before the indications for their use expand further.

Emerging surgical treatments for renal cell carcinoma

Treatment of renal cell carcinoma has evolved considerably over the last few years. While total nephrectomy is necessary at times, nephron-sparing surgery, with a goal of renal function preservation, should always be considered. Although open partial nephrectomy is considered the gold standard approach for nephron-sparing surgery, laparoscopic- or robotic-assisted techniques allow urologists to perform renal surgery less invasively, with excellent long-term oncological outcomes. Cryotherapy and radiofrequency ablation are less invasive management approaches for carefully selected patients with small renal masses. Active surveillance should be considered in elderly or patients who are unfit for surgery. Ultimately, the method chosen for management of a renal mass is an informed decision made by the physician and patient.

Contrast-enhanced ultrasound (CEUS): an excellent tool in the follow-up of small renal masses treated with cryoablation

Strict imaging follow-up is mandatory after cryoablation of small renal masses (SRMs). Although it uses ionizing radiation and nephrotoxic iodinated contrast, computed tomography (CT) is still the gold standard test. Contrast-enhanced ultrasound (CEUS) is a novel technique that informs in real time about renal perfusion avoiding radiation and nephrotoxicity. The objective of this study is to compare outcomes between CEUS and CT in the follow-up of SRMs treated with cryoablation, as well as to assess degree of agreement between them. This is a prospective observational study (May 2012 to December 2013) comparing CEUS and CT in 16 patients with SRMs cryoablated. The on-going protocol of the study includes a CT and CEUS 3 months after treatment and then every 6 months during 5 years. Local relapse was defined as the presence of contrast enhancement in the mass. All the CEUS were performed by a single experienced observer (E.S.). Degree of agreement was measured with kappa index. CEUS detected contrast enhancement in three patients (3/16, 18.8%) and CT in two patients (2/16, 12.5%). Degree of agreement between CEUS and CT, according to Landis-Koch classification, was 0.76 (CI 0.33-1.19; p = 0.0165), which is excellent and higher than expected by random. Sensitivity of the test is 93.75% (15/16). Median time of follow-up after cryoablation is 22 months (15.5-36.5). CEUS has an excellent agreement with CT and a high sensitivity in the follow-up of SRMs treated with cryosurgery, demonstrating its usefulness. Due to these encouraging results, it could become a reference test in the near future for monitoring SRMs after ablative treatment.

Anesthetic management for percutaneous computed tomography-guided radiofrequency ablation of reninoma: a case report

A reninoma is an uncommon, benign, renin-secreting juxtaglomerular cell tumor that causes secondary hypertension in young patients. This hypertension is treated by tumor resection. Except for increased levels of plasma renin and angiotensin I and II, the other physical and laboratory examinations and electrocardiographs were within normal limits upon admission of a 19-year-old woman with a reninoma. For percutaneous computed tomography-guided radiofrequency ablation, general anesthesia was induced by thiopental sodium and rocuronium bromide and maintained with servoflurane (2-4 vol%) and oxygen. The operation ended uneventfully in hemodynamic stability. However, the patient complained of dizziness while sitting 5 hours after the operation, and hypotension was diagnosed. After aggressive normal saline (1 L) infusion over 30 min, the hypotension was corrected and the patient recovered without any other surgical complications. Here, we report the anesthetic management of a patient who underwent percutaneous computed tomography-guided radiofrequency ablation for reninoma destruction, particularly focusing on postoperative hypotension.

Tumor-specific immunity induced by cryoablation in a murine renal cell carcinoma model

Purpose

To evaluate tumor-specific immunity and define the mechanisms involved in the cryoimmunologic response, we compared the tumor control efficacy and immunologic responses of cryoablation with those of surgical excision in a tumor rechallenge model.

Materials and Methods

Sixty BALB/c mice with RENCA tumors that were generated in the left flank area underwent cryoablation or radical excision. The mice successfully treated were rechallenged with RENCA or an undifferentiated colon carcinoma cell line, CT26, in the contralateral right flank area. The recurrence rate after tumor rechallenge in each group was then observed. To assess the immunologic response of each treatment modality, fluorescent-activated cell sorting (FACS) analysis and a cytotoxicity assay using ⁵¹Cr release were performed.

Results

After reinoculation of the RENCA cells, the rate of tumor growth was significantly higher in the surgical excision group than in the cryoablation group (94.4% vs. 11.1%, p=0.001). In the cryoablation group, the tumor growth rate was significantly increased after rechallenge of CT26 cells compared with RENCA (94.1% vs. 11.1%, p=0.001). The cryoablation group showed an elevated CD3, CD4, CD8 T, and natural killer cell count in the FACS analysis and also showed significantly increased cytotoxicity in the ⁵¹Cr release assay compared with the excision group.

Conclusions

These results showed that cryoablation, compared to surgical resection, was more effective in preventing tumor growth after rechallenge with RENCA cells and that this response was tumor-specific, because the CT26 cells did not have the same effect.

[Laparoscopic partial nephrectomy for renal tumors. Time for a new standard?]

PURPOSE

Our aim was to evaluate the laparoscopic partial nephrectomies (LPN) performed at our hospital and compare the results with those from other current studies on partial nephrectomy.

PATIENTS AND METHODS

Between March 2006 and January 2014, 280 patients were treated with LPN in our hospital. We evaluated age, sex, and surgical parameters like operating time, warm ischemia time (WIT), hospital stay, complications, tumor staging, grading, and size

RESULTS

The patients were 61.6±12.4 years old. The median operating time for LPN was 134±51 min. A total of 30% of the operations were treated using the zero ischemia technique. The WIT was 19.9±9.8 min. The WIT of the last 50 LPN performed was 13±7 min. Complications were documented in 15% of the LPNs.

CONCLUSION

LPN is a curative treatment option for the renal cell carcinoma similar to open partial nephrectomy; however, laparoscopy is associated with lower morbidity.

Landmarks in the diagnosis and treatment of renal cell carcinoma

The most common renal cancer is renal cell carcinoma (RCC), which arises from the renal parenchyma. The global incidence of RCC has increased over the past two decades by 2% per year. RCC is the most lethal of the common urological cancers: despite diagnostic advances, 20-30% of patients present with metastatic disease. A clearer understanding of the genetic basis of RCC has led to immune-based and targeted treatments for this chemoresistant cancer. Despite promising results in advanced disease, overall response rates and durable complete responses are rare. Surgery remains the main treatment modality, especially for organ-confined disease, with a selective role in advanced and metastatic disease. Smaller tumours are increasingly managed with biopsy, minimally invasive interventions and surveillance. The future promises multimodal, integrated and personalized care, with further understanding of the disease leading to new treatment options.

[Renal cell carcinoma: A 12-year retrospective study of epidemiologic, therapeutic and follow-up data]

OBJECTIVE

To describe the evolution of epidemiology and management of renal cell carcinoma and their impact on overall and progression-free survivals.

PATIENTS AND METHODS

We reviewed the files of consecutive patients with renal cell carcinoma in our center between January 2000 and December 2011. Patients with confirmed diagnosis on histology who underwent radical nephrectomy, partial nephrectomy or thermoablation were included. Benign tumors were excluded. Epidemiologic and therapeutic data during the period of study were compared. Overall and progression-free survivals divided in three periods were compared by Kaplan-Meier curves.

RESULTS

Four hundred and forty-nine patients were included with a median age of 60 years old [21; 89], and median follow-up of 39 months. Tumor histology was clear cell carcinoma in 75.9% of cases. During the period of study, patients with ASA score upper than 3 increased from 20.4% to 47.8%, tumor size decreased from 58.4mm to 49.5mm and incidental tumor discovery increased from 59.1% to 71.6%. Nephron-sparing surgery increased from 19.7% to 44%. Overall survival and progression-free survival was not different during this period (P=0.071 and P=0.582).

CONCLUSION

The increase in early incidental discovery of renal cell carcinoma allowed nephron-sparing surgery in spite of patients with more comorbidities, with stable overall and progression-free survivals in our series.

Thermal ablation in renal cell carcinoma: what affects renal function?

Because of its minimally invasive nature, thermal ablation is increasingly performed in patients with renal cell carcinoma (RCC) who are poor surgical candidates. Thermal ablation has been associated with excellent outcomes, and thus has been regarded as a viable alternative to nephron-sparing surgery. Many papers report minimal to no reduction in renal function after ablation therapies. However, in order to achieve good local control, normal renal tissue must be sacrificed, subsequently leading to reduced renal function. The amount of normal renal tissue to be ablated depends on the size, location, and number of RCCs, as well as the type of thermal ablation applied. However, there are few reports about what reduces renal function following thermal ablation therapies. The purpose of this review was to discuss factors that affect reduction in renal function and to assess the relationship between local tumour control and renal function.

Three-dimensional tumour volume and cancer-specific survival for patients undergoing nephrectomy to treat pT1 clear-cell renal cell carcinoma

Study Type - Prognosis (case series) Level of Evidence 4. What's known on the subject? and What does the study add? The positive association of tumour size (largest tumour dimension on pathology review) and risk of RCC progression and survival following nephrectomy is well documented. Moreover, several clinicopathological scoring systems (i.e. nomograms and algorithms) have been developed to predict outcomes for surgically treated RCC patients and each of these includes tumour size as an independent predictor of RCC outcome. There is still the question of whether information on three-dimensional tumour volume (cm(3) ) can provide additional prognostic information, particularly among patients with small pT1 tumours where the range of tumour size is more limited. Our study demonstrates that increasing tumour volume is associated with a greater risk of RCC-specific death in patients with pT1 ccRCC, with a more pronounced association in pT1a tumours specifically. In addition, we observed evidence that tumour volume may provide more accurate prognostic information than tumour size alone in pT1a patients. Tumour volume may add prognostic information specifically in pT1a RCC.

OBJECTIVE

To address whether information on three-dimensional tumour volume can provide additional prognostic information for patients with small, localized renal cell carcinoma (RCC) superior to tumour size alone.

PATIENTS AND METHODS

We identified 955 patients treated with radical nephrectomy or nephron-sparing surgery for unilateral, sporadic, pT1, pN0/NX, M0, non-cystic clear-cell RCC (ccRCC) between 1980 and 2004, including 515 pT1a patients and 440 pT1b patients. • We estimated tumour volume using three tumour dimensions recorded on pathological analysis and the equation for the volume of an ellipsoid [π/6 (length × width × height)]. For tumour size alone, we used the maximum tumour diameter recorded on pathological analysis. • Univariate and multivariable associations with RCC-specific death were evaluated using Cox proportional hazards regression models summarized with hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Among pT1a patients, the risk of RCC death associated with having a tumour volume above the median (HR = 4.55; 95% CI, 1.30-15.83; P= 0.018) was markedly higher than having a tumour size above the median (HR = 2.55; 95% CI 0.83-7.85; P= 0.10). Comparison of concordance (c) index values further supported the idea that additional prognostic information was provided by tumour volume (c= 0.659) compared with tumour size (c= 0.600) for pT1a patients. • Among pT1b patients, we noted that associations of tumour volume and tumour size with RCC-specific death were similar. • Multivariable adjustment did not alter our findings.

CONCLUSIONS

Tumour volume could provide valuable prognostic information for patients with pT1a ccRCC but not pT1b ccRCC. • Future investigations are needed to confirm this finding, explore other RCC subtypes and evaluate accuracy of tumour volume determination on radiographic imaging for potential patient management before surgery.

Integrated optical coherence tomography and optical coherence microscopy imaging of ex vivo human renal tissues

PURPOSE

We evaluated the feasibility of using optical coherence tomography and optical coherence microscopy technology to assess human kidney morphology.

MATERIALS AND METHODS

A total of 35 renal specimens from 19 patients, consisting of 12 normal tissues and 23 tumors (16 clear cell renal cell carcinomas, 5 papillary renal cell carcinomas and 2 oncocytomas) were imaged ex vivo after surgical resection. Optical coherence tomography and optical coherence microscopy images were compared to corresponding hematoxylin and eosin histology to identify characteristic features of normal and pathological renal tissues. Three pathologists blinded to histology evaluated the sensitivity and specificity of optical coherence microscopy images to differentiate normal from neoplastic renal tissues.

RESULTS

Optical coherence tomography and optical coherence microscopy images of normal kidney revealed architectural features, including glomeruli, convoluted tubules, collecting tubules and loops of Henle. Each method of imaging renal tumors clearly demonstrated morphological changes and decreased imaging depth. Optical coherence tomography and microscopy features matched well with the corresponding histology. Three observers achieved 88%, 100% and 100% sensitivity, and 100%, 88% and 100% specificity, respectively, when evaluating normal vs neoplastic specimens using optical coherence microscopy images with substantial interobserver agreement (κ = 0.82, p <0.01).

CONCLUSIONS

Integrated optical coherence tomography and optical coherence microscopy imaging provides coregistered, multiscale images of renal pathology in real time without exogenous contrast medium or histological processing. High sensitivity and specificity were achieved using optical coherence microscopy to differentiate normal from neoplastic renal tissues, suggesting possible applications for guiding renal mass biopsy or evaluating surgical margins.

CT-guided percutaneous cryoablation of renal masses in selected patients

PURPOSE

We analysed our experience with computed tomography (CT)-guided percutaneous cryoablation (PCA) in patients who were not surgical candidates or refused surgery for small to medium-sized renal masses.

MATERIALS AND METHODS

Two freezing cycles were applied and separated by a passive warming cycle using 1.7- and 2.4-mm cryoprobes under either general anaesthesia or sedation based on patient positioning and respiratory status. Postoperative monitoring included haematological and biochemistry evaluation and CT scan 24 h after PCA. Follow-up consisted of a multislice CT scan at 1 month and every 3 months in the first year then every 6 months thereafter.

RESULTS

Thirty-seven patients (38 lesions) underwent 40 PCA procedures; 5/37 (13.5%) had a solitary kidney. Median mass size was 35 (range 12-70) mm. No complications occurred during the procedure. Clavien grade ≥2 anaemia occurred in two patients (5.4 %): one patient required 1 U of packed red blood cells; the other required an arterial embolisation. Serum creatinine did not increase in any case. Two patients showed persisting or recurrent disease at 1 and 9 months, respectively, and both could be re-treated with PCA. All other patients showed a hypodense mass 3 months after PCA, with no contrast enhancement. Subsequent examinations showed that lesion sizes decreased and CT densitometry remained stable or increased minimally, also with no contrast enhancement.

CONCLUSIONS

PCA proved relatively easy and safe and could be considered an effective alternative for patients who are not surgical candidates or refuse surgery, as well as in patients with medium-sized lesions.

Treatment of localised renal cell carcinoma

CONTEXT

The increasing incidence of localised renal cell carcinoma (RCC) over the last 3 decades and controversy over mortality rates have prompted reassessment of current treatment.

OBJECTIVE

To critically review the recent data on the management of localised RCC to arrive at a general consensus.

EVIDENCE ACQUISITION

A Medline search was performed from January 1, 2004, to May 3, 2011, using renal cell carcinoma, nephrectomy (Medical Subject Heading [MeSH] major topic), surgical procedures, minimally invasive (MeSH major topic), nephron-sparing surgery, cryoablation, radiofrequency ablation, surveillance, and watchful waiting.

EVIDENCE SYNTHESIS

Initial active surveillance (AS) should be a first treatment option for small renal masses (SRMs) <4 cm in unfit patients or those with limited life expectancy. SRMs that show fast growth or reach 4 cm in diameter while on AS should be considered for treatment. Partial nephrectomy (PN) is the established treatment for T1a tumours (<4 cm) and an emerging standard treatment for T1b tumours (4-7 cm) provided that the operation is technically feasible and the tumour can be completely removed. Radical nephrectomy (RN) should be limited to those cases where the tumour is not amenable to nephron-sparing surgery (NSS). Laparoscopic radical nephrectomy (LRN) has benefits over open RN in terms of morbidity and should be the standard of care for T1 and T2 tumours, provided that it is performed in an advanced laparoscopic centre and NSS is not applicable. Open PN, not LRN, should be performed if minimally invasive expertise is not available. At this time, there is insufficient long-term data available to adequately compare ablative techniques with surgical options. Therefore ablative therapies should be reserved for carefully selected high surgical risk patients with SRMs <4 cm.

CONCLUSIONS

The choice of treatment for the patient with localised RCC needs to be individualised. Preservation of renal function without compromising the oncologic outcome should be the most important goal in the decision-making process.

Current status of partial nephrectomy for renal mass

The standard treatment for a small mass has shifted from radical nephrectomy to partial nephrectomy. The benefits of partial nephrectomy, including preserving renal function, prolonging overall survival, preventing postoperative chronic kidney disease, and reducing cardiovascular events, have been discussed in many studies. With the accumulation of surgeons' experience and simplification of the operative procedures, the warm ischemic time has become shorter despite the indication of tumor size becoming larger. With the help of intraoperative ultrasound, partial nephrectomy can be performed for an endophytic renal mass. Recently, laparoscopic partial nephrectomy has become well indicated for most renal tumors in many centers with advanced laparoscopic expertise. Open partial nephrectomy remains indicated for complex tumors. With technical innovation, robotic partial nephrectomy shows at least comparable perioperative outcomes with a benefit for challenging cases. Laparoendoscopic single-site partial nephrectomy has recently been tried in limited indications and seems to be feasible.

In vivo microwave-induced porcine kidney thermoablation: results and perspectives from a pilot study of a new probe

OBJECTIVE

To test the in vivo effects (toxicity, completeness of necrosis, dimensions of the lesion) of microwave thermoablation on porcine kidneys, using the Amica Probe v3 (Hospital Service SpA, Aprilia, Italy), in a refrigerated 17-G microwave applicator, that can be used to induce a spherical necrotic area.

PATIENTS AND METHODS

Six pigs were used; each kidney was treated, with no kidney pedicle clamping, by microwave thermoablation at least in three different zones with different exposure times and power, during open surgery. Twelve kidneys had 32 microwave thermoablations overall. The kidneys were then surgically removed, and necrotic lesions measured and evaluated microscopically. The sphericity index (SI) was also calculated to evaluate lesion reproducibility. Areas of renal tissue that were missed were then microscopically evaluated by NADH in vivo staining.

RESULTS

In all, 32 thermoablations were applied; the mean (sd) lesion diameter ranged from 1.2 (0.3) to 4.2 (0.1) cm and changed in relation to both power and time of exposure. The 50-W power particularly induced necrotic renal lesions ranging from 1.9 (0.2) to 4.2 (0.1) cm as a function of the time of exposure and the optimal SI (1.04). Pathological evaluation showed no skipped areas in the context of the lesion, or healthy kidney tissue damage close to necrotic lesions.

CONCLUSIONS

Thermoablation with the Amica probe is safe and showed excellent in vivo effects in this porcine model. Increasing the exposure time at 50 W power could be a useful percutaneous minimally invasive treatment for small solid masses (<4.2 cm), avoiding the risk of missing tumour areas or kidney parenchymal damage from microwave treatment.

Cryoablation vs. radiofrequency ablation for small renal masses

RATIONALE AND OBJECTIVES

Cancer of the kidney is the third most common cancer of the urinary tract, and renal cell carcinoma is the most lethal of all genitourinary tumors. The incidental discovery of renal cell carcinoma has increased with increased use of cross-sectional imaging. Concomitantly, minimally invasive ablative technologies, including image-guided cryoablation, radiofrequency ablation, and others, have evolved as therapeutic options for small renal masses.

MATERIALS AND METHODS

Between 2006 and 2009, 111 patients (age range, 31-91 years; mean age, 70 years) underwent percutaneous computed tomography-guided thermal ablation for suspected renal cell carcinoma at two major academic centers. Outcomes data were retrospectively collected and analyzed to compare recurrence rates for patients undergoing radiofrequency ablation (n = 41) versus cryoablation (n = 70).

RESULTS

There were four cases of suspicious enhancement on follow-up computed tomography or magnetic resonance imaging in each group, with cumulative imaging recurrence rates of 11% and 7% for radiofrequency ablation and cryoablation, respectively. Log rank test analysis revealed no significant difference between rates of imaging recurrence between the two groups (P = .6044).

CONCLUSIONS

These results suggest that the use of cryoablative technology will result in similar outcomes compared with radiofrequency ablation.

Thermal ablation of renal cell carcinoma: triage, treatment, and follow-up

The incidence of renal cell carcinoma (RCC) is increasing. With the increasing emphasis on minimally invasive nephron-sparing surgery, thermal ablation is playing a larger role in the management of patients with this disease. This review outlines imaging management, intraoperative and percutaneous ablation, and postprocedural follow-up of RCC.

Efficacy of laparoscopic renal cryoablation as an alternative treatment for small renal mass in patients with poor operability: experience from the Korean single center

OBJECTIVE

The aim of this work was to evaluate the efficacy and safety of laparoscopic renal cryoablation (LRC) for the treatment of incidentally found small renal masses in patients with poor operability, from our initial experience in Korea.

MATERIALS AND METHODS

From June 2005 to April 2009, surgical and oncologic outcomes were evaluated from a database of 45 renal tumors in 39 patients who underwent LRC due to a high American Society of Anesthesiology (ASA) physical status score (i.e., over 3) or old age (i.e., over 70 years old).

RESULTS

Mean (range) age was 63.3 years (range, 43-81), and mean tumor size was 2.5 cm (range 0.7-3.9). Mean of ASA physical status score of whole patients was 2.8 (range, 1-4), and 79.4% (31/39) of patients had an ASA physical status score over 3. Eleven patients (28.2%) were over 70 years old. Among 45 treated lesions, 23 (51.1%) were exophytic tumors, 17 (37.8%) were endophytic tumors, and the other 5 (11.1%) were mesophytic tumors. Mean operating time was 173.7 minutes (range, 110-220), and mean blood loss was 106.3 mL (range, 40-150). None of the patients developed major complications, including adjacent organ injury, collecting system injury, open surgical conversion, or conversion to nephrectomy. Pathologic examination revealed that 60% (27/45) of lesions were renal-cell carcinoma (RCC). During a mean follow-up duration of 23.5 months (range, 6-53), radiologic evidence of tumor recurrence was found in 1 patient (3.7% for RCC). With the exception of this patient, all other patients have remained free of recurrence or metastasis, as determined by a periodic radiologic work-up. Serum creatinine remains stable, with no statistical difference, compared to preoperative levels, in both whole patients and patients with solitary kidney.

CONCLUSIONS

In this series, LRC for small renal tumors showed favorable oncologic and surgical outcomes, including maintenance of renal function, without adverse effects in selected patients with poor operability.

Midterm results of radiofrequency ablation versus nephrectomy for T1a renal cell carcinoma

PURPOSE

The aim of this study was to retrospectively evaluate midterm results of renal radiofrequency (RF) ablation compared to the results after nephrectomy in patients with T1a renal cell carcinoma (RCC).

MATERIALS AND METHODS

A total of 115 patients with a single RCC measuring </=4 cm (T1a) were included; 51 patients underwent RF ablation, 54 patients radical nephrectomy, and 10 patients partial nephrectomy. The survival and the percent decreases in glomerular filtration rate (GFR) were compared among the three treatments.

RESULTS

Although overall survival after RF ablation (75.0% at 5 years) was lower than those after radical and partial nephrectomy, the RCC-related survival (100% at 5 years) was comparable to those following radical nephrectomy (100% at 5 years) and partial nephrectomy (100% at 3 years). The disease-free survival (DFS) after RF ablation (98.0% at 5 years) was also comparable to those after radical nephrectomy (95.0% at 5 years) (P = 0.72) and partial nephrectomy (75.0% at 3 years) (P = 0.13). The percent decrease in the GFR at last follow-up in the RF ablation group (median 7.9%) was significantly lower than that in the radical nephrectomy group (median 29.0%) (P < 0.001) and comparable to that in the partial nephrectomy group (median 11.5%) (P = 0.73).

CONCLUSION

RF ablation provides RCC-related and DFS comparable to that found after nephrectomy with little loss of renal function.

Prospective analysis of the safety and efficacy of percutaneous cryoablation for pT1NxMx biopsy-proven renal cell carcinoma

PURPOSE

Our objective was to determine the efficacy and safety of image-guided, percutaneous cryoablation for American Joint Committee on Cancer pT1ANxMx and pT1BNxMx biopsy-proven renal cell carcinoma (RCC).

MATERIALS AND METHODS

Computed tomography (CT)-guided, percutaneous cryoablation was used to treat 117 renal lesions in 113 consecutive patients with pT1NxMx RCC. All 117 ablations were included in the safety analysis, and complications were categorized according to Common Terminology Criteria for Adverse Events version 3.0 (CTCAE v3.0). Eighty-one lesions were biopsy-proven RCC and were included in the efficacy analysis. Technical success was defined as the "ice-ball" covering the entire lesion plus a minimum 5-mm margin. Efficacy was defined as complete lack of enhancement and continuous decrease in size on subsequent follow-up imaging studies.

RESULTS

Technical success was 100%, with 15% of ablations requiring air or saline injection to prevent nontarget ablation. We recorded a 7% rate of clinically significant complications (CTCAE category≥2) and 0% mortality. Renal function was not adversely affected. Seventy percent of patients were discharged to home on the same day. Efficacy was 98.7% for a median follow-up of 67 weeks (range 7-172). For the subgroup of patients that reached a median follow-up of 2 (n=59) and 3 years (n=13), efficacy was 98.3 and 92.3%, respectively. Cancer specific survival was 100%.

CONCLUSIONS

CT-guided, percutaneous cryoablation has an excellent safety and efficacy profile for stage T1A and T1B RCC; however, longer follow-up is needed to compare it with other nephron-sparing surgical treatments. It is a great option for nonsurgical patients, those in whom renal function cannot be further sacrificed, and those at risk for metachronous lesions.

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.

Laparoscopic Partial Nephrectomy Using FloSeal for Hemostasis: Technique and Experiences in 102 Patients

Objectives. The authors report their techniques, perioperative data, and oncological outcome for laparoscopic partial nephrectomy in a single-center experience with 3 different surgeons. Patients and methods. A total of 102 consecutive patients underwent laparoscopic transperitoneal partial nephrectomy for exophytic tumors using FloSeal for hemostasis. Mean age was 58 years (range = 26-79 years), and median tumor size was 2.6 cm (range = 0.5-8.5 cm). In 84 cases, the renal artery was clamped using endoscopic bulldog clamps, and tumor resection was performed using scissors or the harmonic scalpel. Hemostasis was achieved by application of FloSeal; lesions of the collecting system were closed with Lahodny sutures in 33 cases (31%). Frozen sections were obtained for margin status. Results . All 102 procedures were successful with no intraoperative complications. Mean surgical time was 201 minutes (range = 60-355 minutes); clamping time was 25.8 minutes (range = 6-75 minutes) in 64 cases. Margins were negative in 92 cases; in 8 cases secondary resection was necessary to achieve negative margin status, and in 2 cases radical nephrectomy was performed. Histological findings were clear-cell carcinoma in 51 (50.0%), papillary carcinoma in 26 (25.5%), and others in 25 (24.5%) cases. At a mean follow-up of 32 months (12-62 months), no recurrence was observed. Conclusions. Laparoscopic partial nephrectomy with the use of FloSeal is a feasible and safe method for treatment of small renal masses. The technique is reproducible by surgeons who are used to complex laparoscopic procedures. Patient outcome during follow-up was comparable with data published for open standard procedures.

The evolving management of small renal masses

The incidence of small renal masses (SRMs) continues to rise, largely because of the widespread use of cross-sectional imaging for abdominal symptomatology. Clinical management must balance the risk of disease progression from renal cell carcinoma in these tumors against the potential morbidity of treatment, particularly in elderly patients or those with multiple comorbidities. Moreover, a significant minority of SRMs represent benign lesions. This article reviews the current data for surgical excision, cryoablation, radiofrequency ablation, and active surveillance of SRMs. Surgical excision, predominantly in the form of nephron-sparing surgery, remains the standard of care because of its durable oncologic and favorable functional outcomes. Active surveillance and ablative technologies have emerged as alternatives to surgery in select patients based on short-term oncologic data. Nevertheless, the extent to which treatment alters the natural history of SRMs has yet to be established.