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Amnon Zisman

Publications and source records attributed to Amnon Zisman.

At least 37 records · Page 2Linked to original sources

Novel concepts in the staging of renal cell carcinoma.

The incidence of renal cell carcinoma (RCC) continues to rise steadily; unfortunately, our ability to cure patients with metastatic RCC remains limited. When developing and evaluating new treatment protocols, it is important to consider the role of prognostic factors, often defined as pretreatment features, that are predictive of outcome. The complexity and variability of patients' individual clinical outcome and the recently recognized limitation of conventional staging systems have lead to the formulation of integrated prognostic staging systems. In this review, we discuss the evolution of various clinically relevant integrated staging systems for RCC.

Carcinoma, Renal Cell↗

Number of metastatic sites rather than location dictates overall survival of patients with node-negative metastatic renal cell carcinoma.

OBJECTIVES: To perform a retrospective study to determine whether survival and immunotherapy response are related to the site of metastases (lung versus bone) and to the number of organ sites involved (one versus multiple). The most common sites of metastatic renal cell carcinoma (mRCC) are the lung and bone. METHODS: The records of 434 patients with mRCC were reviewed. Patients with pathologic evidence of nodal involvement were excluded, leaving 120 patients with mRCC to lung only, 33 patients to bone only, and 144 patients with multiple organ involvement. The response rates to immunotherapy and overall survival were compared. The variables evaluated in statistical analyses included Eastern Cooperative Oncology Group score, grade, 1997 tumor stage, and multiple organ involvement. RESULTS: The median survival for patients with lung only and bone only mRCC was 27 months; patients with multiple organ involvement had a median survival of 11 months. In patients who underwent nephrectomy followed by immunotherapy, the median survival time was 31, 31, and 13 months in the lung, bone, and multiple sites groups, respectively. The response rate to immunotherapy after nephrectomy was 44%, 20%, and 14% in the lung, bone, and multiple organ groups, respectively. Multivariate analysis confirmed that metastatic disease to more than one organ site was associated with poor prognosis (2.05 risk ratio, P <0.001). CONCLUSIONS: Patients with mRCC to only one organ site fared significantly better than patients who had evidence of disease in multiple organs. Survival in patients with disease limited to the lung was similar to that of patients whose disease was limited to bone.

Bone Neoplasms↗

Current staging of renal cell carcinoma.

Most (>80%) cancers involving the kidney are renal cell carcinoma (RCC). One third of patients diagnosed with kidney cancer have evidence of metastatic disease at the time of diagnosis, and as many as half of patients treated for localized disease eventually relapse. As is true for any other malignancy, one must determine which tumor features, patient factors, and laboratory techniques will provide diagnostic and prognostic information for patients with RCC. This article focuses on the history and rationale of the current staging systems for RCC as well as the potential for improvements by the addition of other clinical, pathologic, and molecular prognostic markers.

Carcinoma, Renal Cell↗

Renal cell carcinoma with tumor thrombus extension: biology, role of nephrectomy and response to immunotherapy.

PURPOSE: We outline the biology, prognosis and role of immunotherapy for renal cell carcinoma with gross venous tumor thrombus. MATERIALS AND METHODS: A total of 207 patients with unilateral renal cell carcinoma and tumor thrombus into the renal vein (107) and inferior vena cava (100) who underwent nephrectomy and thrombectomy were compared with 607 without tumor thrombus. RESULTS: At diagnosis 77 patients (37%) had N0M0 disease and 130 (63%) had lymph node (N+) or distant (M1) metastases. Compared with nontumor thrombus cases tumor thrombus was associated with more advanced stage, N+ (26% versus 12%), M1 (54% versus 31%) disease, higher grade and Eastern Cooperative Oncology Group performance status. In N0M0 cases with inferior vena caval tumor thrombus capsular penetration, collecting system invasion and extension into the hepatic vein were more important prognostic variables then the level of inferior vena caval thrombus. In patients with confined N0M0 tumors mean 2 and 5-year survival +/- SD was 83% +/- 8.8% and 72% +/- 10.7% in those with inferior vena caval tumor thrombus, and 90% +/- 9.4% and 68% +/- 16.1% in those with renal vein tumor thrombus, similar to the 93.4% +/- 1.7% and 81 +/- 3.1% rates, respectively, in those without thrombus who had no recurrence within 6 months after nephrectomy. Of patients with M1 disease in whom cytoreductive surgery was done those with and without thrombus showed a similar response to immunotherapy. When there was inferior vena caval and renal vein thrombus, mean 2-year survival was higher after nephrectomy and immunotherapy than after nephrectomy alone (41% +/- 9% and 52% +/- 7% versus 32% +/- 13% and 45% +/- 7%), immunotherapy alone (0% and 13% +/- 12%, respectively) and no treatment (0%). CONCLUSIONS: Renal cell carcinoma with tumor thrombus is associated with worse characteristics. Local tumor extension has greater prognostic importance than the level of inferior vena caval tumor thrombus. Survival is fair in patients with truly confined N0M0 disease and thrombus. The combination of surgery and immunotherapy has a role in thrombus cases. Our data provide the rationale for a prospective study of adjuvant immunotherapy after surgery in N0M0 cases with extensive tumor thrombus.

Carcinoma, Renal Cell↗

TNM T3a renal cell carcinoma: adrenal gland involvement is not the same as renal fat invasion.

PURPOSE: Upper pole tumors with direct extension into the adrenal gland are currently staged as pT3a tumors in the 1997 TNM staging system. To determine whether the clinical behavior of pT3a adrenal tumors differs from that of tumors with perinephric fat invasion (also stage pT3a) a retrospective analysis was performed. MATERIALS AND METHODS: Of 1,087 patients who underwent nephrectomy 27 were identified with direct adrenal involvement and 187 were identified with perinephric fat or renal sinus involvement. Variables and outcomes analyzed in each group included the percent of patients with metastatic disease at presentation, lymph node involvement, Eastern Cooperative Oncology Group score, response to immunotherapy, and median and overall survival using Kaplan-Meier curves. RESULTS: Median survival for patients with pT3a disease and perinephric or renal sinus fat involvement was 36 months with a 36% 5-year cancer specific survival rate. In contrast, patients with adrenal gland invasion had significantly worse survival at a median of 12.5 months and a 0% 5-year cancer specific survival rate (p <0.001), which was similar to median survival of those with stage pT4 disease (11 months). CONCLUSIONS: Upper pole tumors with direct extension into the adrenal gland predict significantly worse survival than similarly staged tumors with fat invasion and they have a prognosis similar to that of stage pT4 disease. While these data await external validation, consideration should be given to re-categorizing tumors with direct adrenal gland involvement as stage pT4 or in a subcategory such as pT4a.

Adipose Tissue↗

Renal cell carcinoma with retroperitoneal lymph nodes: role of lymph node dissection.

PURPOSE: We better defined the benefits and morbidity of lymph node dissection in patients with localized renal cell carcinoma using the experience of patients treated at our institution. MATERIALS AND METHODS: A retrospective cohort study was performed with outcome assessment based on the chart review of demographic, clinical and pathological data in 1,087 patients with renal cell carcinoma treated at our institution. Patients with renal cell carcinoma who did not undergo nephrectomy as part of cancer treatment, those with bilateral disease and those for whom nodal status was unknown were not included in this study. A total of 900 patients meeting these criteria who underwent nephrectomy for unilateral renal cell carcinoma at our medical center form the principal study population. RESULTS: Positive lymph nodes were associated with larger, higher grade, locally advanced primary tumors that were more commonly associated with sarcomatoid features. Positive nodes were 3 to 4 times more common in patients with metastatic disease and the majority of these patients could be identified preoperatively. The survival of patients with regional lymph node involvement only was identical to that of patients with distant metastatic disease only. Patients with regional nodes and distant metastases had significantly inferior survival to those with either condition alone. In node negative cases lymph node dissection can be performed with no additional morbidity but it confers no survival advantage. In node positive cases lymph node dissection can also be performed safely but it is associated with improved survival and a trend toward an improved response to immunotherapy. CONCLUSIONS: Regional lymph node dissection is unnecessary in patients with clinically negative lymph nodes since it offers extremely limited staging information and no benefit in terms of decreasing disease recurrence or improving survival. In patients with positive lymph nodes lymph node dissection is associated with improved survival when it is performed in carefully selected patients undergoing cytoreductive nephrectomy and postoperative immunotherapy. When lymph nodes are present, they should be resected when technically feasible.

Analysis of Variance↗

Treatment of organ confined prostate cancer with third generation cryosurgery: preliminary multicenter experience.

PURPOSE: Cryosurgical ablation of the prostate is 1 approach to the treatment of localized prostate cancer. Third generation cryosurgery uses gas driven probes that allow for a decrease in probe diameter to 17 gauge (1.5 mm). The safety, morbidity and preliminary prostate specific antigen (PSA) results of 122 cases are reported. MATERIALS AND METHODS: A total of 106 patients have undergone percutaneous cryosurgery using a brachytherapy template with at least 12 months of PSA followup. Immediate and delayed morbidities were evaluated. PSA results at 3 and 12 months were recorded, and failure was defined as the inability to reach a nadir of 0.4 ng/ml or less. RESULTS: Complications in patients undergoing primary cryosurgery included tissue sloughing (5%), incontinence (pads, 3%), urge incontinence/no pads (5%), transient urinary retention (3.3%) and rectal discomfort (2.6%). There were no cases of fistulas or infections. Postoperative impotence was 87% in previously potent patients. For patients who underwent salvage cryosurgery there were no fistulas reported and 2 (11%) patients required pads after salvage cryosurgery. A total of 96 (81%) patients achieved a PSA nadir of 0.4 ng/ml or less at 3 months of followup, while 79 of 106 (75%) remained free from biochemical recurrence at 12 months. A total of 42 (78%) low risk patients (Gleason score 7 or less and PSA 10 or less) remained with a PSA of 0.4 ng/ml or less at 12 months of followup, compared to 37 (71%) high risk patients. All patients were discharged within 24 hours. CONCLUSIONS: After a followup of 1 year 3rd generation cryosurgery appears to be well tolerated and minimally invasive. The use of ultrathin needles through a brachytherapy template allows for a simple percutaneous procedure and a relatively short learning curve. A prospective multicenter trial is ongoing to determine the long-term efficacy of this technique.

Aged↗

Validation of an integrated staging system toward improved prognostication of patients with localized renal cell carcinoma in an international population.

PURPOSE: Outcome prediction for patients with renal cell carcinoma is based on a combination of factors. In this study a previously published clinical outcome algorithm based on 1997 T stage, Fuhrman grade and performance score is validated using an international database. MATERIALS AND METHODS: A total of 1,060 patients from Nijmegen, the Netherlands (NN), MD Anderson (MDA) and University of California, Los Angeles (UCLA) who had localized renal cell carcinoma were evaluated for outcome prediction using a clinical outcome algorithm previously shown to stratify patients into low, intermediate and high risk groups. Validation was performed by comparing the 3 risk groups separately within the 3 centers as well as by comparing hazard ratios and concordance indices among the 3 centers. RESULTS: Estimated disease specific survival rates at 5 years for the low risk groups were 94% (NN), 92% (MDA) and 93% (UCLA). The 5-year disease specific survival rates for the intermediate risk groups were 65% (NN), 73% (MDA) and 78% (UCLA), while the rates for the high risk groups were 40% (NN), 30% (MDA) and 48% (UCLA). The concordance indices for each of the databases were 79% (NN), 86% (MDA) and 84% (UCLA). CONCLUSIONS: A clinical algorithm that uses only 3 prognostic variables (1997 T stage, Fuhrman grade and performance status) to stratify patients with localized renal cell carcinoma into 3 risk groups has been shown to be applicable to external databases. This algorithm may be useful for patient counseling, surveillance and identification of high risk patients for enrollment in clinical trials.

Algorithms↗

Retrograde intrarenal lithotripsy outcome after failure of shock wave lithotripsy.

PURPOSE: We report our experience with retrograde intrarenal lithotripsy (RIRL) for renal stones not alleviated by shock wave lithotripsy (SWL). MATERIALS AND METHODS: A total of 28 females and 53 males with a mean age of 53 years (range 18 to 86) were studied. They had been treated with a mean of 3.2 previous SWLs. Mean stone size was 9.2 mm (range 4 to 22) and the mean number of stones per patient was 1.27 (range 1 to 5) for a total of 103 stones overall. In 70 patients there was 1 stone. Rigid and flexible ureteroscopes were used in 8 and 67 cases, respectively, while a combined approach was used in 6. A holmium:YAG laser was used for fragmentation in 52 patients. Success was defined as stone-free status or residual fragments less than 3 mm. RESULTS: The overall success rate was 67%. RIRL yielded a 46% stone-free rate. Of the 44 patients 17 (39%) had residual stones less than 3 mm, while 13 required ancillary procedures. There were no residual ureteral stones. Original stone size correlated inversely with the success rate. Most failures involved lower pole stones, in that laser fiber deflection prevented reaching them in 9 cases. The procedure was interrupted due to extravasation or bleeding in 5 patients and 6 had postoperative urinary tract infections (16% overall complication rate). CONCLUSIONS: RIRL effectively and safely alleviated upper tract stones unresponsive to earlier SWL. It can be considered salvage therapy in such cases. RIRL is well suited for treating stones less than 2 cm with better stone-free rates than SWL in the same circumstances. Residual stones were more likely in lower pole cases.

Adolescent↗

[Acute epididymitis].

Epididymitis may be acute (symptoms last less than 6 weeks) or chronic (more than 3 months). Acute epididymitis is almost always unilateral. In sexually active men under 35 years of age, acute epididymitis is frequently caused by Chlamydia trachomatis and less frequently by Neisseria gonorrhoeae and is usually associated with overt or subclinical urethritis. Acute epididymitis in older men, children or following urinary tract instrumentation is commonly caused by gram-negative bacilli. The epididymis is sometimes the site of metastatic infection, such as tuberculosis. It is important to differentiate epididymitis from other causes for acute scrotum, such as testicular torsion and tumor. The cause of acute scrotum especially in children cannot always be identified. Therefore, Doppler ultrasonography and radionuclide scans are often used. In infants and young boys, genitourinary abnormalities are causative factors, and therefore should be excluded by imaging. Supportive measures and antimicrobial agents are the mainstay of therapy.

Acute Disease↗

[Molecular markers for transitional cell carcinoma of bladder].

Superficial transitional cell carcinoma (TCC) has significant rates of recurrence and progression, therefore accurate urinary makers for early diagnosis and follow-up are essential. Urine cytology is the oldest marker, constantly used clinically and considered the "gold standard". In this review we will summarize the properties of different molecular markers for TCC and their yield compared to cytology. Briefly, the older markers--BTA stat, BTA TRAK and NMP22 are more sensitive than cytology, but their specificity is lower, especially in patients with underlying urologic pathologies. FDP (fibrinogen degradation products) analysis is rapid and the test is available clinically. It's sensitivity is higher than cytology for low grade tumors, but specificity is low. Of the newer markers, telomerase has a high sensitivity, and a specificity similar to urine cytology, but also has an increased rate of false positive results. HA-HAase (Hyaluronidase) and CK20 have promising sensitivity and specificity, but are still unavailable for clinical use. CK20 has the additional advantage of being able to detect premalignant conditions as well as predicting recurrence. The role of urinary markers in replacing cystoscopy and urine sediment cytology in the follow-up of TCC and in hematuria work up is still uncertain. It is possible that urinary markers in different panel arrays will have a role in the future for those indications and perhaps in the screening of populations at risk, such as smokers and workers exposed to occupational hazards.

Biomarkers, Tumor↗

Use of heparin and protamine sulfate during laparoscopic donor nephrectomy.

BACKGROUND: Our aim was to evaluate the necessity of heparin and protamine administration during laparoscopic donor nephrectomy. METHODS: Data from 52 consecutive living-related laparoscopic donor nephrectomies performed at University of California Los Angeles between August 1999 and August 2001 were used for this analysis. For the purpose of this analysis, the patients were divided into three cohorts: group A received both heparin and protamine; group B received heparin only; and group C received neither. Intraoperative blood loss, length of admission, recipient creatinine at follow-up, and intraoperative and postoperative complications were compared between the groups. Statistical analysis was performed using a two-tailed test. RESULTS: There were no significant differences between the groups with regard to patient age and gender. Intraoperative blood loss did not differ between group B (99+/-73 mL) and group C (82+/-54 mL) ( =0.4). None of the patients required blood transfusion. No graft loss occurred in any group. Length of hospital stay, excluding any preoperative days, was similar (2.8+/-0.7, 2.9+/-1.6, and 2.5+/-0.8 days, for groups A, B, and C, respectively, ( >0.05). No systemic thromboembolic complications were noted in any of the groups. One patient in group B was converted to an open procedure because of a difficult dissection unrelated to heparin administration. The mean recipient creatinine levels at follow-up in the recipients of kidneys from groups A, B, and C were not significantly different (1.1, 1.3, and 1.3; >0.05) through the extended follow-up period of 691, 286, and 97 days, respectively. CONCLUSIONS: According to our experience, there is no apparent benefit in the administration of heparin alone or in the administration of protamine sulfate to reverse heparin anticoagulation during laparoscopic donor nephrectomy if heparin is given. This is not only in terms of bleeding complications but is also true in regard to recipient renal function through the follow-up period. It is important to note that our warm ischemic times were less than 2 minutes, because longer warm ischemic times may make the use of heparin a more important consideration. This is the first time that these questions have been studied in the laparoscopic donor nephrectomy population.

Adult↗

Synergy is achieved by complementation with Apo2L/TRAIL and actinomycin D in Apo2L/TRAIL-mediated apoptosis of prostate cancer cells: role of XIAP in resistance.

BACKGROUND: Tumors have an inherent immunogenicity that can be exploited by immunotherapy. However, often tumors develop mechanisms that render them resistant to most immunologic cytotoxic effector mechanisms. This study examines the underlying mechanism of resistance to Apo2L/TRAIL (tumor necrosis factor-related apoptosis-inducing ligand)-mediated apoptosis. METHODS: We studied prostate tumor cell lines for their sensitivity to Apo2L/TRAIL-mediated apoptosis in the presence and absence of the sensitizing agent actinomycin D (Act D). Apoptosis was determined by flow cytometry and signaling for apoptosis by Western blot. RESULTS: Treatment with subtoxic concentrations of Act D significantly sensitizes the tumor cells (CL-1, DU-145, and PC-3 prostate tumor cells) to Apo2L/TRAIL-mediated apoptosis. The cytotoxicity of Act D-sensitized prostate tumor cells was a result of synergistic activation of caspases (caspase-3, -9, and -8), detectable after 6 hr of treatment. Treatment with Apo2L/TRAIL alone, although it was insufficient to induce apoptosis, resulted in the loss of mitochondrial membrane potential and release of cytochrome c from the mitochondria into the cytoplasm in the absence of significant caspases activation. These findings suggested that a major apoptosis resistance factor blocking the Apo2L/TRAIL apoptotic signaling events is present downstream of the mitochondrial activation. The expression of receptors and anti-apoptotic proteins were examined in Act D-sensitized CL-1 cells. The earliest and the most pronounced change induced by Act D was down-regulation of X-linked inhibitor of apoptosis (XIAP) and up-regulation of Bcl-xL/-xS proteins. The role of XIAP in resistance was demonstrated by overexpression of Smac/DIABLO, which inhibited inhibitors of apoptosis (IAPs) and sensitized the cells to Apo2L/TRAIL. Apo2L/TRAIL receptors (DR4, DR5, DcR1, and DcR2), c-FLIP, Bcl-2, and other IAP members (c-IAP1 and c-IAP2) were marginally affected at later times in the cells sensitized by Act D. CONCLUSION: This study suggests that the combination of Act D-induced down-regulation of XIAP (Signal I) and Apo2L/TRAIL-induced release of cytochrome c (Signal II) leads to the reversal of resistance to Apo2L/TRAIL-mediated apoptosis in the tumor cells. The sensitization of tumor cells to Apo2L/TRAIL by Act D is of potential clinical application in the immunotherapy of drug/Apo2L/TRAIL refractory tumors.

Apoptosis↗

Risk group assessment and clinical outcome algorithm to predict the natural history of patients with surgically resected renal cell carcinoma.

PURPOSE: To create a comprehensive algorithm that can predict postoperative renal cell carcinoma (RCC) patient outcomes and response to therapy. PATIENTS AND METHODS: A prospective cohort study was performed with outcome assessment on the basis of chart review of 814 patients who underwent nephrectomy between 1989 and 2000. At diagnosis, M1 or N1/N2M0 metastatic disease (M) was present in 346 patients (43%), whereas 468 patients had no metastatic disease (NM) (N0M0). On the basis of UCLA Integrated Staging System category and the presence of metastases, patients were divided into low-risk (LR), intermediate-risk (IR), and high-risk (HR) groups. Decision boxes integrating tumor-node-metastasis staging, tumor grade, and performance status were compiled for determining a patient's risk group. RESULTS: NM-LR patients had 91% disease-specific survival at 5 years, lower recurrence rate, and better disease-free survival compared with NM-IR and HR patients. Disease progressed in 50% of NM-HR patients. Disease-specific survival of NM-HR patients who received immunotherapy (IMT) for recurrent disease was similar to that of M-LR patients treated with cytoreductive nephrectomy and adjuvant IMT. Time from recurrence to death for NM-HR patients was inferior to that for M-LR patients. After IMT, approximately 25% of M-LR and 12% of M-IR patients had long-term progression-free survival. M-HR patients did poorly despite IMT. CONCLUSION: Stratifying RCC patients into high-, intermediate-, and low-risk subgroups provides a clinically useful system for predicting outcome and provides a unique tool for risk assignment and outcome analysis. Subclassifying RCC into well-defined risk groups should allow better patient counseling and identification of both NM-HR subgroups that need adjuvant treatment and nonresponders who need alternative therapies.

Algorithms↗

Optimizing prostate cancer suicide gene therapy using herpes simplex virus thymidine kinase active site variants.

The herpes simplex virus (HSV) thymidine kinase gene (tk) forms the basis of a widely used strategy for suicide gene therapy. A library of HSV thymidine kinase enzyme (TK) active site mutants having different affinities for guanosine analog prodrugs was developed. We sought to determine the optimal combination of tk variant and prodrug specifically for prostate cancer gene therapy, using in vitro and in vivo studies of adenovirally infected CL1, DU-145, and LNCaP tumor lines carrying wild-type tk, tk30, tk75, and sr39tk mutants expressed by a strong, constitutive cytomegalovirus promoter and treated with ganciclovir and acyclovir. In vitro experiments involving prostate cancer (CaP) cell line infection were carried out with a broad range of prodrug concentrations, and cell killing was determined by limiting dilution (colony-forming), MTT, and propidium iodide assays. In vivo studies based on CL1-GFP xenograft experiments were carried out to examine the ability of each TK variant to prevent tumor formation and to inhibit tumor growth and development of metastases in established orthotopic and subcutaneous tumors in SCID mice. Both in vitro and in vivo studies suggest improved killing with the sr39tk variant. Thus, the results suggest that the use of sr39tk in future trials of prostate cancer tk suicide gene therapy may be beneficial.

Acyclovir↗

Mathematical model to predict individual survival for patients with renal cell carcinoma.

PURPOSE: To develop a multivariate model and mathematical formula capable of calculating personalized survival for renal cell carcinoma (RCC) patients with clinically available variables. PATIENTS AND METHODS: A total of 477 patients out of 661 undergoing nephrectomy at the University of California Los Angeles between 1989 and 1999 were eligible for evaluation and formed the analyzed cohort for this retrospective study. Time to death was the primary end point assessed. Univariate analysis for 14 to 20 variables was conducted, followed by a multivariate Cox analysis. The variables that provided independent information as to the time of death for metastatic and nonmetastatic patients were coded and incorporated into a function based on the Nadas equation principle. RESULTS: For nonmetastatic patients, the significant variables in the multivariate analysis were Fuhrman's grade and Eastern Cooperative Oncology Group performance status. For the metastatic patients, Fuhrman's grade, 1997 classification T stage, number of symptoms, nodal involvement, and immunotherapy were independent predictors for survival. These variables, based on the Cox multivariate regression model, were implanted into an exponential Nadas equation. The expected survival predicted by use of the Nadas equations faithfully describes the actual survival based on Kaplan-Meier curves. CONCLUSION: We have developed mathematical equations for estimating survival after radical nephrectomy for RCC. The resulting formulas are capable of better tailoring survival estimates for a specific patient and are based on widely accepted clinical prognostic variables. On validation with external data, this type of representation can be used as a tool for the determination of personalized prognosis and may be useful for patient education and counseling.

Carcinoma, Renal Cell↗

Minimally invasive ablative approaches in the treatment of renal cell carcinoma.

Ablative techniques for the treatment of renal cell carcinoma (RCC) are an extension of nephron-sparing surgery and include cryoablation, radiofrequency ablation (RFA), and high-intensity focused ultrasound (HIFU). Although experimental, these are evolving treatment modalities. The widespread use of computed tomography scans, ultrasound, and magnetic resonance imaging caused an increase in the diagnosis rate of small renal masses amenable to nephron-sparing surgery. The same imaging modalities permit interactive monitoring both during the delivery of ablative measures and at postoperative follow-up. Cryosurgery is the most studied of the ablative approaches, and clinical studies have demonstrated promising short-term results and a remarkable safety profile. Long-term studies, however, are needed in order to determine the appropriate selection criteria and to confirm a response as durable as that for partial and radical nephrectomy. More data are needed to evaluate the efficacy of RFA. Currently, preclinical results with HIFU do not justify its use for treating RCC in humans.

Carcinoma, Renal Cell↗