Predicting aggressive behavior in small renal tumors prior to treatment

Percutaneous Ablation of T1 Renal Masses: Comparative Local Control and Complications after Radiofrequency and Cryoablation

The efficacy and complication rates of percutaneous radiofrequency ablation (RFA) and cryoablation (CA) in the treatment of T1 renal masses in two Northern Italy hospitals were retrospectively investigated. Eighty-two patients with 80 T1a tumors and 10 T1b tumors treated with thermal ablation from 2015 through 2020 were included. A total of 43 tumors in 38 patients were treated with RFA (2.3 ± 0.9 cm), and 47 tumors in 44 patients were treated with CA (2.1 ± 0.8 cm). The mean follow-up observation period was 26 ± 19 months. The major complications and efficacy, as measured using the technical success and local tumor recurrence rates, were recorded. There were three (6.9%) technical failures with RFA and one (2.1%) with cryoablation (p = 0.30). Among the 40 tumors that were successfully treated with RFA, 1 tumor (2.5%) developed local tumor recurrence; 5/46 tumors that were treated with cryoablation (10.8%) developed local tumor recurrence (p = 0.17). T1b lesions (4.0 ± 0.7 cm) resulted in 1/6 technically unsuccessful cases with RFA and 0/4 with CA. No recurrent disease was detected in the T1b lesions. Major complications occurred after 2.3% (1/43) of RFAs and 0/47 of cryoablation procedures. RFA and cryoablation are both effective in the treatment of renal masses. Major complications with either procedure are uncommon.

Radiofrequency Ablation, Cryoablation, and Microwave Ablation for the Treatment of Small Renal Masses: Efficacy and Complications

Over the last two decades the detection rate of small renal masses has increased, due to improving diagnostic accuracy, and nephron-sparing treatments have become the first-choice curative option for small renal masses. As a minimally invasive alternative, thermal ablation has increased in popularity, offering a good clinical outcome and low recurrence rate. Radiofrequency ablation, Cryoablation, and Microwave ablation are the main ablative techniques. All of them are mostly overlapping in term of cancer specific free survival and outcomes. These techniques require imaging study to assess lesions features and to plan the procedure: US, CT, and both of them together are the leading guidance alternatives. Imaging findings guide the interventional radiologist in assessing the risk of complication and possible residual disease after procedure. The purpose of this review is to compare different ablative modalities and different imaging guides, underlining the effectiveness, outcomes, and complications related to each of them, in order to assist the interventional radiologist in choosing the best option for the patient.

Renal tumor biopsy in patients with cT1b-T4-M0 disease susceptible to radical nephrectomy: analysis of safety, accuracy and clinical impact on definitive management

PURPOSE

Renal tumor biopsy was provided in patients candidate to radical nephrectomy for a renal mass ≥4 cm, to evaluate treatment deviation.

METHODS

Between 2008 and 2017, 102 patients with a solid renal mass ≥4 cm with no distant metastases underwent preliminary renal tumor biopsy. We investigated the proportion of patients who proceeded with radical nephrectomy, variables predicting non-renal cell carcinoma (RCC) and concordance between biopsy findings and definitive pathology.

RESULTS

Median tumor size was 70 mm (IQR 55-110). Clinical stage was cT1b in 41, cT2 in 33, cT3 in 25 and cT4 in three patients. A median of three (IQR 2-3) renal tumor biopsies were taken with 16/18 Gauge needles in 97% of cases. Clavien grade I complications occurred in five cases. Malignant tumors were documented in 84 patients: 78 RCCs and six non-RCCs. Fifteen biopsies documented oncocytoma and three were non-diagnostic. Grade was reported in 50 RCCs: 42 (84%) were low and eight (16%) high grade. Eighty-three patients proceeded with radical nephrectomy; six non-RCC malignant tumors underwent combined and/or intensified treatment; 13 of 15 patients with oncocytoma did not undergo radical nephrectomy (eight underwent observation). Definitive pathology confirmed diagnosis in all cases. Grade concordance was 84%, considering two tiers (high vs low grade). No preoperative clinical variable predicted definitive pathology.

CONCLUSIONS

Renal tumor biopsy is a safe procedure that leads to radical nephrectomy in most tumors ≥4 cm. Nonetheless, 20% of patients exhibited non-RCC histology. Renal tumor biopsy should be considered in this setting.

Update on MRI of Cystic Renal Masses Including Bosniak Version 2019

Incidental cystic renal masses are common, usually benign, and almost always indolent. Since 1986, the Bosniak classification has been used to express the risk of malignancy in a cystic renal mass detected at imaging. Historically, magnetic resonance imaging (MRI) was not included in that classification. The proposed Bosniak v.2019 update has formally incorporated MRI, included definitions of imaging terms designed to improve interobserver agreement and specificity for malignancy, and incorporated a variety of masses that were incompletely defined or not included in the original classification. For example, at unenhanced MRI, homogeneous masses markedly hyperintense at T₂ -weighted imaging (similar to cerebrospinal fluid) and homogeneous masses markedly hyperintense at fat suppressed T₁ -weighted imaging (approximately ≥2.5 times more intense than adjacent renal parenchyma) are classified as Bosniak II and may be safely ignored, even when they have not been imaged with a complete renal mass MRI protocol. MRI has specific advantages and is recommended to evaluate masses that at computed tomography (CT) 1) have abundant thick or nodular calcifications; 2) are homogeneous, hyperattenuating, ≥3 cm, and nonenhancing; or 3) are heterogeneous and nonenhancing. Although MRI is generally excellent for characterizing cystic renal masses, there are unique weaknesses of MRI that bear consideration. These details and others related to MRI of cystic renal masses are described in this review, with an emphasis on Bosniak v.2019. A website (https://bosniak-calculator.herokuapp.com/) and mobile phone apps named "Bosniak Calculator" have been developed for ease of assignment of Bosniak classes. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY STAGE: 3.

Preoperative Neutrophil-to-Lymphocyte Ratio Was a Predictor of Overall Survival in Small Renal Cell Carcinoma: An Analysis of 384 Consecutive Patients

Objective

The aim of this study was to investigate the prognostic significance of the preoperative neutrophil-to-lymphocyte ratio (NLR) in small renal cell carcinoma (sRCC, ≤4 cm).

Methods

This study was approved by the review board (NO.XYFY2019-KL032-01). Between 2007 and 2016, a total of 384 consecutive patients who underwent curative surgery for sRCC at our institution were evaluated. Patients were divided into high NLR and low NLR groups by plotting the NLR receiver operating characteristic curve. The Kaplan–Meier method was utilized to graphically display survivor functions. Univariate and multivariate Cox proportional hazards regression analysis addressed time to overall survival (OS) and cancer-specific survival (CSS).

Results

Of the 384 patients, 264 (68.8%) were males and 120 (31.2%) were females. Median follow-up time after surgical resection was 54 months. One hundred and eighty-seven (48.7%) patients had a high NLR (≥1.97), and the remaining 197 (51.3%) had a low NLR (<1.97). Patients with high NLR were more likely to be aged compared with patients with low NLR (P=0.028). High NLR was associated with decreased OS and CSS compared with low NLR (P=0.028). High NLR was associated with decreased OS and CSS compared with low NLR (P=0.028). High NLR was associated with decreased OS and CSS compared with low NLR (P=0.028). High NLR was associated with decreased OS and CSS compared with low NLR (

Conclusions

Elevated preoperative NLR is an independent adverse prognostic factor for OS after surgery with curative intent for sRCC.

A new management strategy for renal angiomyolipomas: superselective arterial embolization in combination with radiofrequency ablation

Background

The present study analyzed the safety and efficacy of superselective arterial embolization (SAE) combined with radiofrequency ablation (RFA) to treat renal angiomyolipoma (RAML).

Methods

This retrospective study included the clinical data of 6 patients with RAML treated between March 2016 and October 2017. All patients underwent RFA treatment immediately after SAE guided by angio-computed tomography (angio-CT). The tumor size, renal function and complications, and time to recurrence were compared before and after treatment.

Results

The success rate of the SAE + RFA technique was 100%, and no serious complications were found during or after surgery. After treatment, the patients' symptoms, including low back pain and hematuria, were relieved. The pre-treatment creatinine level (55.6±11.0 µmol/L) did not differ significantly from the post-treatment creatinine level (68.2±13.7 µmol/L), which was measured 1 day after surgery (t=1.75, P=0.109). The mean follow-up time was 29.5±6.1 months. By the end of the follow-up period, the maximum diameter of the tumor was 3.1±0.6 cm, which was significantly smaller than the pre-treatment diameter of 5.9±1.01 cm (t=5.83, P<0.001). At 3 months after surgery, the maximum diameter of the tumor was reduced by 22-38% in all 6 patients. At the last follow-up examination, the maximum diameter of the tumor was reduced by 36-61%. Contrast-enhanced CT or magnetic resonance imaging scans showed that the enhanced part of the original lesion had disappeared, the renal parenchyma was full of even fat signals, and only one patient had new enhanced lesions at the site of the original lesions.

Conclusions

SAE combined with RFA is a safe and effective treatment for RAML, and its strengths qualify it to become a new treatment strategy for RAML.

Association among the R.E.N.A.L. nephrometry score and clinical outcomes in patients with small renal masses treated with percutaneous contrast enhanced ultrasound radiofrequency ablation

Introduction

An association between the R.E.N.A.L. nephrometry score (RNS) and clinical outcomes in patients with a small renal mass (SRM) has been proposed. We analyzed clinical outcomes according to the RNS in patients with a SRM treated with percutaneous contrast enhanced ultrasound (CEUS) radiofrequency ablation (RFA).

Material and methods

Patients with a SRM, who underwent RFA between January 2005 and March 2015, were retrospectively identified. The association between RNS and clinical outcomes was evaluated using parametric and non-parametric analysis.

Results

We analyzed 163 SRMs in 149 consecutive patients. The mean age was 71.7 years. Mean follow-up time was 33.3 months ±20.6 (2-102). The mean RNS was 5.6 ±1.52 (4-11). A total of 121 (74.2%) cases were of low complexity and 42 (25.8%) were medium complexity. We identified 11 cases of tumor persistence (6.7%). The mean RNS was 5.58 in the cases with no persistence and 5.73 in the cases with persistence (p = 0.788). We identified 15 (9.2%) cases of recurrence. The mean RNS was 5.57 ±0.1 (4-11) in the cases without recurrence and 5.73 ±0.4 (4-9) in recurrence cases (p = 0.804). Of the 76 biopsy proven RCC cases, 8 (10.5%) cases of recurrence were observed, 5 in the low complexity group and 3 in the medium complexity group (p = 0.690). A total of 9 (5.5%) cases of complications were observed, with 5 (4.3%) in the low complexity group and 4 cases in the medium complexity group (p = 0.23). The mean length of stay was 1.5 days with a significant difference between low and medium complexity groups (1.3 vs. 2.1 days, p = 0.02). The mean difference between preoperative eGFR and estimated eGFRat 12 months was -3.08 mL / min ±13.3 (-49.4-34.1) and was significant (p = 0.008).However, this variation did not show significant differences between the low and medium complexity groups (p = 0.936). All-cause mortality was 11.7%, 14 cases (11.6%) in the low complexity group and 5 (11.9%) in the medium complexity group (p = 1.0). No cases of renal cell carcinoma (RCC) specific mortality were identified.

Conclusions

The RNS was not associated with tumor persistence, recurrence, cancer specific mortality, complications or renal function 12 months after the first treatment, showing significant difference only in length of hospital stay between low and medium complexity groups.