Kidney cortex shear wave motion simulations based on segmented biopsy histology

BACKGROUND AND OBJECTIVE

Biopsy stands as the gold standard for kidney transplant assessment, yet its invasive nature restricts frequent use. Shear wave elastography (SWE) is emerging as a promising alternative for kidney transplant monitoring. A parametric study involving 12 biopsy data sets categorized by standard biopsy scores (3 with normal histology, 3 with interstitial inflammation (i), 3 with interstitial fibrosis (ci), and 3 with tubular atrophy (ct)), was conducted to evaluate the interdependence between microstructural variations triggered by chronic allograft rejection and corresponding alterations in SWE measurements.

METHODS

Heterogeneous shear wave motion simulations from segmented kidney cortex sections were performed employing the staggered-grid finite difference (SGFD) method. The SGFD method allows the mechanical properties to be defined on a pixel-basis for shear wave motion simulation. Segmentation techniques enabled the isolation of four histological constituents: glomeruli, tubules, interstitium, and fluid. Baseline ex vivo Kelvin-Voigt mechanical properties for each constituent were drawn from established literature. The parametric evaluation was then performed by altering the baseline values individually. Shear wave velocity dispersion curves were measured with the generalized Stockwell transform in conjunction with slant frequency-wavenumber analysis (GST-SFK) algorithm. By fitting the curve within the 100-400 Hz range to the Kelvin-Voigt model, the rheological parameters, shear elasticity (µ1) and viscosity (µ2), were estimated. A time-to-peak algorithm was used to estimate the group velocity. The resultant in silico models emulated the heterogeneity of kidney cortex within the shear wave speed (SWS) reconstructions.

RESULTS

The presence of inflammation showed considerable spatial composition disparities compared to normal cases, featuring a 23 % increase in interstitial area and a 19 % increase in glomerular area. Concomitantly, there was a reduction of 12 % and 47 % in tubular and fluid areas, respectively. Consequently, mechanical changes induced by inflammation predominate in terms of rheological differentiation, evidenced by increased elasticity and viscosity. Mild tubular atrophy showed significant elevation in group velocity and µ1. Conversely, mild and moderate fibrosis exhibited negligible alterations across all parameters, compatible with relatively limited morphological impact.

CONCLUSIONS

This proposed model holds promise in enabling patient-specific simulations of the kidney cortex, thus facilitating exploration into how pathologies altering cortical morphology correlates to modifications in SWE-derived rheological measurements. We demonstrated that inflammation caused substantial changes in measured mechanical properties.

Percutaneous Image Guided Cryoablation of Adrenal Metastases From Renal Cell Carcinoma: A Single Institution Review

OBJECTIVES

To assess the safety, technical success, disease progression, and survival associated with percutaneous image-guided cryoablation of renal cell carcinoma metastasis (mRCC) in the adrenal gland.

METHODS

Retrospective, single-institution review of adult patients undergoing percutaneous cryoablation for adrenal mRCC between the years of 2007-2021. Technical parameters, technical success, safety, and survival were analyzed according to standard criteria.

RESULTS

Forty-six patients (39 male; mean age 66 ± 8.8 years) with 57 tumors ablated over 51 sessions with a median hospital length of stay of 1 day (range 0-3 days). Forty-four (96%) had primary of clear cell histology. Aim of ablation was curative intent in 39 of 57 tumors (72%) with local tumor control in the remainder. There were 2 (4%) technical failures and technique efficacy was achieved in 52 out of the remaining 55 (95%). There were no Common Terminology Criteria for Adverse Events' immediate complications and 4 of 51 (8%) delayed complications. Twenty-five of 57 (44%) had disease progression anywhere, away from ablation site. One-, 3-, and 5-year recurrence free survival rates were 100%, 89%, and 89% and overall survival was 98%, 85%, and 71%. Fifty-one of 57 (89%) underwent preprocedural alpha blockade with hypertensive crisis in 27 of 56 (54%) available records, of which there were no adverse outcomes.

CONCLUSION

Percutaneous cryoablation of mRCC to the adrenal glands is safe with robust local control, leading to advocacy for its ongoing use in this patient population. Multi-disciplinary management is recommended for successful treatment.

Hemodynamic course during ablation and selective hepatic artery embolization for metastatic liver carcinoid: a retrospective observational study

BACKGROUND

Manipulation of carcinoid tumors during ablation or selective hepatic artery embolization (transarterial embolization, TAE) can release vasoactive mediators inducing hemodynamic instability. The main aim of our study was to review hemodynamics and complications related to minimally invasive treatments of liver carcinoids with TAE or ablation.

METHODS

Electronic medical records of all patients with metastatic liver carcinoid undergoing ablation or TAE from 2003 to 2019 were abstracted. Noted were severe hypotension (mean arterial pressure [MAP] ..± 55.ßmmHg), severe hypertension (systolic blood pressure ... 180.ßmmHg), and perioperative complications. Associations of procedure type and pre-procedure octreotide use with intraprocedural hemodynamics were assessed using linear regression. A robust covariance approach using generalized estimating equation method was used to account for multiple observations.

RESULTS

A total of 161 patients underwent 98 ablations and 207 TAEs. Severe hypertension was observed in 24 (24.5%) vs. 15 (7.3%), severe hypotension in 56 (57.1%) vs. 6 (2.9%), and cutaneous flushing observed in 2 (2.0%) vs. 48 (23.2%) ablations and TAEs, respectively. After adjusting for preprocedural MAP, ablation was associated with lower intraprocedural MAP compared to TAE (estimate -27.ßmmHg, 95%CI -30 to -24.ßmmHg, p.ß<.ß0.001). Intraprocedural declines in MAP were not affected by preprocedural use of octreotide (p.ß=.ß0.7 for TAE and p.ß=.ß0.4 for ablation).

CONCLUSIONS

Ablation of liver carcinoids was associated with substantial hemodynamic instability, especially hypotension. In contrast, a higher number of TAE patients had cutaneous flushing. Preprocedural use of octreotide was not associated with attenuation of intraprocedural hypotension.

Morphometric analysis of tumor microvessels for detection of hepatocellular carcinoma using contrast-free ultrasound imaging: A feasibility study

Introduction

A contrast-free ultrasound microvasculature imaging technique was evaluated in this study to determine whether extracting morphological features of the vascular networks in hepatic lesions can be beneficial in differentiating benign and malignant tumors (hepatocellular carcinoma (HCC) in particular).

Methods

A total of 29 lesions from 22 patients were included in this work. A post-processing algorithm consisting of clutter filtering, denoising, and vessel enhancement steps was implemented on ultrasound data to visualize microvessel structures. These structures were then further characterized and quantified through additional image processing. A total of nine morphological metrics were examined to compare different groups of lesions. A two-sided Wilcoxon rank sum test was used for statistical analysis.

Results

In the malignant versus benign comparison, six of the metrics manifested statistical significance. Comparing only HCC cases with the benign, only three of the metrics were significantly different. No statistically significant distinction was observed between different malignancies (HCC versus cholangiocarcinoma and metastatic adenocarcinoma) for any of the metrics.

Discussion

Obtained results suggest that designing predictive models based on such morphological characteristics on a larger sample size may prove helpful in differentiating benign from malignant liver masses.

Feasibility and safety of percutaneous image-guided cryoablation of abdominal wall endometriosis

PURPOSE

To evaluate the feasibility and safety of percutaneous image-guided cryoablation of abdominal wall endometriosis (AWE).

MATERIALS AND METHODS

A retrospective review of percutaneous cryoablation (CT or MR) of AWE was performed from January 2018 to December 2020. Eighteen patients were identified from an internal percutaneous ablation database. Technical success, complications, and outcomes were analyzed according to standard nomenclature.

RESULTS

Patients comprised 18 females (mean age 36.9 years) who underwent 18 cryoablation procedures to treat 23 AWE deposits. Three of the 18 cases were performed under MR guidance, while the remaining 15 employed CT guidance. Technical success was achieved in all 18 cases (100%). Fifteen of 18 patients (83%) had biopsy proven AWE deposits prior to treatment. Hydrodisplacement was used to displace adjacent bowel, bladder, or neurovascular structures in 13/18 cases (72%). The mean number of probes used per case was 3. Sixteen of 23 (70%) of AWE deposits had imaging follow-up (median 85 days). Of the 16 lesions with imaging follow-up, 15 (94%) demonstrated no residual enhancement or T1 hyperintensity at the treatment site and 1 lesion (6%) demonstrated residual/progressive disease. At clinical follow-up, 13 of 14 (93%) patients reported improvement in AWE-related symptoms. Eleven patients had clinically documented pain scores before and after ablation and all demonstrated substantial symptomatic improvement. No society of interventional radiology (SIR) major complications were observed.

CONCLUSIONS

Percutaneous cryoablation of AWE is feasible with a favorable safety profile. Further longitudinal studies are needed to document durable response over time.

Safety and Efficacy of Percutaneous Image-Guided Mediastinal Mass Core-Needle Biopsy

Objective

To retrospectively evaluate the safety and efficacy of percutaneous image-guided mediastinal mass core-needle biopsy.

Patients and Methods

Retrospective review of an institutionally maintained biopsy registry identified 337 computed tomography- or ultrasound-guided percutaneous mediastinal mass core needle biopsies between October 2002 and August 2017 in a single quaternary referral center. Mean patient age was 51 (range, 18 to 93) years. Procedural techniques, anticoagulation/antiplatelet therapy, and tumor anatomical characteristics were reviewed. Classification and gradation of complications was based on the Clavien-Dindo system. Diagnostic yield was defined as the ratio of diagnostic biopsy to all biopsies performed.

Results

Mean tumor size was 59.2 (range, 10 to 180) mm with 89.9% (n=303) of lesions located in the prevascular (anterior) mediastinum. There was a single major complication (0.3%) of a symptomatic pneumothorax requiring intervention. There were seven (2.1%) minor complications, including three bleeding complications. A transpleural approach was the only variable associated with an increased complication rate (P<.01). Forty-one (12.2%) patients had a biopsy performed while taking an antiplatelet/anticoagulant agent within the therapeutic window, with a single case (0.3%) associated with a minor bleeding complication. Of 18 (5.3%) procedures performed without cessation of anticoagulant/antiplatelet therapy, there were no bleeding complications. Of all 337 biopsies, 322 (95.5%) were diagnostic. None of the analyzed variables were significantly associated with a nondiagnostic biopsy.

Conclusion

Image-guided percutaneous core-needle biopsy of mediastinal masses is a safe procedure with high diagnostic yield. Further prospective studies are required to assess the complication profile in higher risk patients.

A Clinical Decision Aid to Support Personalized Treatment Selection for Patients with Clinical T1 Renal Masses: Results from a Multi-institutional Competing-risks Analysis

BACKGROUND

Personalized treatment for clinical T1 renal cortical masses (RCMs) should take into account competing risks related to tumor and patient characteristics.

OBJECTIVE

To develop treatment-specific prediction models for cancer-specific mortality (CSM), other-cause mortality (OCM), and 90-d Clavien grade ≥3 complications across radical nephrectomy (RN), partial nephrectomy (PN), thermal ablation (TA), and active surveillance (AS).

DESIGN, SETTING, AND PARTICIPANTS

Pretreatment clinical and radiological features were collected for consecutive adult patients treated with initial RN, PN, TA, or AS for RCMs at four high-volume referral centers (2000-2019).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Prediction models used competing-risks regression for CSM and OCM and logistic regression for 90-d Clavien grade ≥3 complications. Performance was assessed using bootstrap validation.

RESULTS AND LIMITATIONS

The cohort comprised 5300 patients treated with RN (n = 1277), PN (n = 2967), TA (n = 476), or AS (n = 580). Over median follow-up of 5.2 yr (interquartile range 2.5-8.7), there were 117 CSM, 607 OCM, and 198 complication events. The C index for the predictive models was 0.80 for CSM, 0.77 for OCM, and 0.64 for complications. Predictions from the fitted models are provided in an online calculator (https://small-renal-mass-risk-calculator.fredhutch.org). To illustrate, a hypothetical 74-yr-old male with a 4.5-cm RCM, body mass index of 32 kg/m², estimated glomerular filtration rate of 50 ml/min, Eastern Cooperative Oncology Group performance status of 3, and Charlson comorbidity index of 3 has predicted 5-yr CSM of 2.9-5.6% across treatments, but 5-yr OCM of 29% and risk of 90-d Clavien grade 3-5 complications of 1.9% for RN, 5.8% for PN, and 3.6% for TA. Limitations include selection bias, heterogeneity in practice across treatment sites and the study time period, and lack of control for surgeon/hospital volume.

CONCLUSIONS

We present a risk calculator incorporating pretreatment features to estimate treatment-specific competing risks of mortality and complications for use during shared decision-making and personalized treatment selection for RCMs.

PATIENT SUMMARY

We present a risk calculator that generates personalized estimates of the risks of death from cancer or other causes and of complications for surgical, ablation, and surveillance treatment options for patients with stage 1 kidney tumors.

Long-term renal function outcomes after renal cryoablation complicated by major hemorrhage requiring selective transarterial embolization

PURPOSE

To determine long-term renal function outcomes after renal cryoablation complicated by major hemorrhage requiring transarterial embolization compared to patients who underwent uncomplicated renal cryoablation without major hemorrhage.

METHODS

Utilizing a matched cohort study design, retrospective review identified 23 patients who underwent percutaneous image-guided renal cryoablation complicated by major hemorrhage requiring ipsilateral transarterial embolization (TAE group) and a control group of 23 patients who underwent uncomplicated renal cryoablation matched 1:1 by age, gender and RENAL Nephrometry score at a single institution from 1/1/2005 to 12/31/2019. Primary outcome parameters included change in creatinine (mg/dl) and estimated glomerular filtration rate (ml/min/1.73 m²; eGFR) from baseline and were compared between TAE and control group using a paired t-test.

RESULTS

There was a significantly higher proportion of patients on pre-ablation anticoagulation in the TAE v. control group (30% v. 4%; p = 0.047), but all patients were off anticoagulation and with normal coagulation parameters at the time of cryoablation. Otherwise there were no significant differences in clinical, renal tumor, Charlson co-morbidity index, baseline renal function or cryoablation parameters between the TAE and control group. In the post-ablation period, there was trend toward greater increase in creatinine from baseline to worst post-ablation creatinine in the TAE v. the control group (+ 0.5 ± 0.7 mg/dl v. 0.2 ± 0.1 mg/dl; p = 0.056). However, at a mean follow-up of 42.7 ± 35.7 months, there was no significant difference between the TAE and control group in creatinine (p = 0.68), eGFR (p = 0.60) or change from baseline in creatinine (p = 0.28), eGFR (p = 0.80) or CKD stage (p = 0.74). No patient required initiation of hemodialysis.

CONCLUSION

Selective transarterial embolization for post-renal cryoablation hemorrhage does not significantly affect long-term renal function compared to cryoablation alone. Pre-ablation anticoagulation despite normal coagulation at time of ablation may be a risk factor for post-ablation hemorrhage, and warrants further evaluation when considering pre-ablation embolization.

Novel Uses of Ultrasound to Assess Kidney Mechanical Properties

Ultrasound is a key imaging tool for evaluating the kidney. Over the last two decades, methods to measure the mechanical properties of soft tissues have been developed and used in clinical practice, although use in the kidney has not been as widespread as for other applications. The mechanical properties of the kidney are determined by the structure and composition of the renal parenchyma and perfusion characteristics. Because pathologic processes change these factors, the mechanical properties change and can be used for diagnostic purposes and for monitoring treatment or disease progression. Ultrasound-based elastography methods for evaluating the mechanical properties of the kidney use focused ultrasound beams to perturb the kidney and then high frame-rate ultrasound methods are used to measure the resulting motion. The motion is analyzed to estimate the mechanical properties. This review will describe the principles of these methods and discuss several seminal studies related to characterizing the kidney. Additionally, an overview of the clinical use of elastography methods in native and kidney allografts will be provided. Perspectives on future developments and uses of elastography technology along with other complementary ultrasound imaging modalities will be provided.

Percutaneous Image-Guided Thermal Ablation of Adrenal Metastasis from Melanoma: A Single-Institution Experience

The outcomes of technically successful image-guided percutaneous thermal ablation of melanoma adrenal metastases involving 11 tumors in 9 consecutive patients over 12 years (2009-2020) were evaluated. All patients had multiple treated metastatic sites, and 44.4% (4/9) had greater than 5 metastatic sites. The mean maximal tumor diameter was 3.6 ± 1.6 cm. The local recurrence-free survival at 1 year was 85.7%. With a median survival of 19.4 months, 66.6% (6/9) of patients died from tumor progression. The 1- and 3-year overall survival rate was 60.0% and 30.0%, respectively. All patients were pretreated with alpha-adrenergic blockade, and 36% (4/11) developed a hypertensive crisis. The median hospital length of stay was 1 day (range, 1-2 days), without any major complications. Thermal ablation of adrenal metastasis from a melanoma provides acceptable local control and a good safety profile.

The Role of Sonography in a Rare Case of Hepatic Artery Pseudoaneurysm: A Case Study Report

Hepatic artery pseudoaneurysms (HAPs) are rare, life-threatening complications that arise in response to liver trauma or underlying inflammatory processes. The risk of rupture necessitates prompt diagnosis and treatment. Sonography is an important imaging modality used to evaluate and characterize suspected HAPs. In the case described below, sonography played an important role in the diagnosis and successful treatment of a patient with a large, high-risk HAP.

The Effectiveness of Identifying Primary Gallbladder Adenocarcinoma Utilizing Contrast-Enhanced Ultrasound: A Case Report

Gallbladder carcinoma is rare and difficult to detect in the early stages of the disease process, due to lack of symptoms. Sonography is typically the first modality of choice for assessing gallbladder pathology due to its high sensitivity, portability, real-time imaging capability, and non-ionizing technique. Conventional gray-scale and color Doppler sonographic imaging may be ambiguous for diagnosing solid tumors, such as gallbladder carcinoma. In this case, gallbladder carcinoma was definitively diagnosed utilizing contrast-enhanced ultrasound, allowing for quick patient treatment options and an optimal surgical outcome.

Percutaneous Image-Guided Core Needle Biopsy of Neuroendocrine Tumors: How Common Is Intraprocedural Carcinoid Crisis?

PURPOSE

To retrospectively evaluate the incidence of carcinoid crisis, other complications, and physiologic disturbances during percutaneous image-guided core needle biopsy of neuroendocrine tumors (NETs) in the lung and the liver.

MATERIALS AND METHODS

Between January 2010 and January 2020, 106 computed tomography (CT) or ultrasound (US)-guided core needle biopsies of lung and liver NETs were performed in 95 consecutive adult patients. The mean age was 64 ± 13 years, and 48% were female. The small bowel was the most common primary site (33%, 31/95), and 32 (34%) patients had pre-existing symptoms of carcinoid syndrome. The mean tumor size was 3.2 ± 2.6 cm, and mean number of passes was 3.4 ± 1.6. A 17/18-gauge needle was used in 91% (96/106) of the biopsies. Thirteen (12%) patients received either outpatient or prophylactic octreotide.

RESULTS

No patients experienced carcinoid crisis or needed octreotide, inotropes, vasopressors, or resuscitation. A single biopsy procedure (0.9%, 1/106) was complicated by bleeding that required angiographic hepatic artery embolization. Changes in pre-biopsy- versus post-biopsy systolic blood pressure and heart rate were -1.6 mm Hg (P = .390) and 0.6 beat/min (P = .431), respectively. Tumor functional status, overall tumor burden, and the elevation of neuroendocrine markers were not associated with intraprocedural physiologic disturbances. There were 4 minor complications (0.4%, 4/106) associated with the biopsy procedure that were not attributed to hormone excretion from tumor manipulation.

CONCLUSIONS

Percutaneous image-guided core biopsy of NETs is safe, with low complication rate and no definite carcinoid crisis in the current cohort.

Safety and Efficacy of Retrograde Pyeloperfusion for Ureteral Protection during Renal Tumor Cryoablation

PURPOSE

To determine safety and efficacy of retrograde pyeloperfusion for ureteral protection during cryoablation of adjacent renal tumors.

MATERIALS AND METHODS

Retrospective review of 155 patients treated with renal cryoablation, including adjunctive retrograde pyeloperfusion, from 2005 to 2019 was performed. Ice contacted the ureter in 67 of the 155 patients who represented the study cohort. Median patient age was 68 years old (interquartile range [61, 74]), 52 patients (78%) were male, and 37 tumors (55%) were clear cell histology. Mean tumor size was 3.4 ± 1.3 cm, and 42 tumors (63%) were located at the lower pole. Treatment-related complication and oncologic outcomes were recorded based on a review of post-procedural images and chart review.

RESULTS

Technical success of cryoablation was attained in 67 cases (100%), and technical success of pyeloperfusion was attained in 66 cases (99%). A total of 13 patients (19.4%) experienced SIR major C or D complications related to the procedure, including hemorrhage (n = 4), urine leak (n = 3), transient urinary obstruction (n = 2), pulmonary embolism (n = 1), hypertensive urgency (n = 1), acute respiratory failure (n = 1), and ureteropelvic junction (UPJ) stricture (n = 1). No complications were attributable to pyeloperfusion. Three of 45 patients with biopsy-proven renal cell carcinoma experienced local recurrence resulting in local recurrence-free survival of 92% (95% confidence interval, 81.5%-100%) 3 years after ablation.

CONCLUSIONS

Retrograde pyeloperfusion of the renal collecting system is a relatively safe and efficacious option for ureteral protection during renal tumor cryoablation. This adjunctive procedure should be considered for patients in whom cryoablation of a renal mass could potentially involve the ureter.

A novel clinical decision aid to support personalized treatment selection for patients with CT1 renal cortical masses: Results from a multi-institutional competing risks analysis including performance status and comorbidity

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Background: Personalized treatment for clinical T1 renal cortical masses (RCMs) should account for competing risks related to tumor and patient characteristics. Using a contemporary multi-institutional cohort, we developed treatment-specific prediction models for cancer-specific mortality (CSM), other-cause mortality (OCM), and 90-day complication rates for patients managed with surgery, thermal ablation (TA), and active surveillance (AS). Methods: Preoperative clinical and radiological features were collected for eligible patients aged 18-91 years treated at four academic centers from 2000-2016. Prediction models used competing risks regressions for CSM and OCM and logistic regressions for 90-day Clavien >3 complications, adjusting for tumor size as well as patient age, sex, ECOG performance status (PS), and Charlson comorbidity index (CCI). Predictions accounted for missing data using multiple imputation. Results: After excluding 25 patients with no follow-up, the cohort included 4995 patients treated with radical nephrectomy (RN, n=1270), partial nephrectomy (PN, n=2842), thermal ablation (n=479), or active surveillance (n=404). Median follow-up was 5.1 years (IQR 2.5-8.5). Predictions from the fitted model are shown in an online calculator ( https://rgulati.shinyapps.io/rcc-risk-calculator ). To illustrate the use of this calculator for a specific patient, a 70-year-old female with a 5.5 cm RCM, PS of 2, and CCI of 3 has a predicted 5-year CSM of 4-7% across treatments, 5-year OCM of 34-49%, and 90-day risk of Clavien ≥3 complications of 4%, 10%, and 6% for RN, PN, and TA respectively. Conclusions: Personalized treatment selection for cT1 RCM is challenging. We present a competing risk calculator that incorporates pretreatment features to quantify competing causes of mortality and treatment-associated complications. Pending validation, this tool may be used in clinical practice to provide patients with estimated individualized treatment-specific probabilities of competing causes of death and complication risks to facilitate shared decision-making.

Percutaneous Image-guided Core Needle Biopsy for Upper Tract Urothelial Carcinoma

OBJECTIVE

To better understand the safety and diagnostic yield of percutaneous core-needle biopsy (PCNB) for upper tract urothelial carcinoma (UTUC).

METHODS

Of 444 patients undergoing radical nephroureterectomy (RNU) for UTUC between 2009 and 2017 at our institution, 42 who had PCNB prior to RNU were identified for analysis. Endpoints included safety, diagnostic yield, and concordance with RNU pathology. PCNB specimens were deemed histologically concordant with RNU specimens for cases when cytologic evaluation of biopsy specimen and corresponding pathologic evaluation of RNU specimen both made a histologic diagnosis of urothelial carcinoma.

RESULTS

Median tumor size was 3.8 cm (1.2-10.2 cm). All lesions arose from the pelvicalyceal system. CT-guidance was utilized in 52% (n = 22), and ultrasound-guidance in 48% (n = 20). Relative to RNU pathology, 95% of PCNBs demonstrated histologic concordance. Histologic grade was provided in 69% (n = 29) of PCNBs, with a 90% (n = 26) concordance with surgical pathology. Grades 1-2 and 3 complications occurred in 14.3% (n = 6) and 2.4% (n = 1), respectively. At a median follow-up of 28.2 months (range, 1.2-97.1 months) after biopsy, no cases of radiographic tract seeding were identified.

CONCLUSION

In our cohort of 42 patients undergoing RNU for UTUC, PCNB appeared a safe diagnostic tool with high histologic yield and grade concordance. With greater than 2 years of follow-up, no cases of tract seeding were identified.

The Safety of Ultrasound-Guided Thoracentesis in Patients on Novel Oral Anticoagulants and Clopidogrel: A Single-Center Experience

OBJECTIVE

To assess the risk of hemorrhagic complications in patients taking novel oral anticoagulants (NOACs) and/or clopidogrel who underwent an ultrasound-guided thoracentesis.

PATIENTS AND METHODS

A retrospective analysis was performed of ultrasound-guided thoracenteses completed at an academic institution between January 1, 2016, and November 14, 2017. All patients who underwent a thoracentesis while actively receiving treatment with an NOAC and/or clopidogrel were included in the study. Primary endpoints are any significant post-procedure bleeding complication; defined as a hemoglobin decrease of greater than 2 g/dL in 48 hours, hemothorax, chest wall hematoma, and bleeding requiring transfusion, surgery, or chest tube placement.

RESULTS

A total of 115 thoracenteses were performed in 103 patients actively taking an NOAC (n=43) and/or clopidogrel (n=69). All patients used either the NOAC or clopidogrel within 24 hours before the procedure and continued using it daily thereafter. There were no bleeding complications.

CONCLUSION

The overall risk of significant hemorrhage in patients taking an NOAC and/or clopidogrel while undergoing ultrasound-guided thoracentesis is very low. Albeit the total number of procedures reviewed may be insufficient to prove definitive safety, it is sufficient to provide a measure of relative risk when assessing benefits of thoracentesis in these patients.

A prospective genome-wide study of prostate cancer metastases reveals association of wnt pathway activation and increased cell cycle proliferation with primary resistance to abiraterone acetate-prednisone

Background

Genomic aberrations have been identified in metastatic castration-resistant prostate cancer (mCRPC), but molecular predictors of resistance to abiraterone acetate/prednisone (AA/P) treatment are not known.

Patients and methods

In a prospective clinical trial, mCRPC patients underwent whole-exome sequencing (n = 82) and RNA sequencing (n = 75) of metastatic biopsies before initiating AA/P with the objective of identifying genomic alterations associated with resistance to AA/P. Primary resistance was determined at 12 weeks of treatment using criteria for progression that included serum prostate-specific antigen measurement, bone and computerized tomography imaging and symptom assessments. Acquired resistance was determined using the end point of time to treatment change (TTTC), defined as time from enrollment until change in treatment from progressive disease. Associations of genomic and transcriptomic alterations with primary resistance were determined using logistic regression, Fisher's exact test, single and multivariate analyses. Cox regression models were utilized for determining association of genomic and transcriptomic alterations with TTTC.

Results

At 12 weeks, 32 patients in the cohort had progressed (nonresponders). Median study follow-up was 32.1 months by which time 58 patients had switched treatments due to progression. Median TTTC was 10.1 months (interquartile range: 4.4-24.1). Genes in the Wnt/β-catenin pathway were more frequently mutated and negative regulators of Wnt/β-catenin signaling were more frequently deleted or displayed reduced mRNA expression in nonresponders. Additionally, mRNA expression of cell cycle regulatory genes was increased in nonresponders. In multivariate models, increased cell cycle proliferation scores (≥ 50) were associated with shorter TTTC (hazard ratio = 2.11, 95% confidence interval: 1.17-3.80; P = 0.01).

Conclusions

Wnt/β-catenin pathway activation and increased cell cycle progression scores can serve as molecular markers for predicting resistance to AA/P therapy.

Percutaneous Image-Guided Nodal Biopsy After 11C-Choline PET/CT for Biochemically Recurrent Prostate Cancer: Imaging Predictors of Disease and Clinical Implications

Purpose

Management of recurrent prostate cancer necessitates timely diagnosis and accurate localization of the sites of recurrent disease. The purpose of this study was to assess predictors of histologic outcomes after 11C-choline positron emission tomography/computed tomography (CholPET) to increase the positive predictive value and specificity of CholPET in identifying imaging predictors of malignant and benign nodal disease to better inform clinical decision making regarding local therapy planning.

Materials and Methods

Retrospective review of patients undergoing CholPET followed by percutaneous core needle biopsy between January 1, 2010 and January 1, 2016. A total of 153 patients were identified who underwent 166 biopsy procedures. Patient, CholPET, procedural, and pathologic characteristics were recorded.

Results

A total of 157 biopsies were technically successful, and 110 (70.1%; 95% confidence interval, 62.2-77.1) yielded histologic results abnormal for metastatic prostate cancer. Lesion location, lesion maximum standardized uptake value (SUVmax), SUV ratio (calculated as the ratio of SUVmax to SUV mean in the right atrium), prostate-specific antigen, lesion short axis length, total Gleason score, and castration resistance were all associated with abnormal biopsy results (P values <.001, <.001, <.001, .02, .02, .02, and .015, respectively). External iliac, common iliac, and inguinal sites were associated with much lower rates of histologic positivity (mean [95% confidence interval], 51.2% [35.1-67.1], 46.2% [19.2-74.9], and 33.3% [7.5-70.1]), respectively.

Conclusions

In a cohort of patients in whom core needle biopsy was performed after CholPET, characteristics of choline localization including node location, SUVmax, lesion–to–blood pool SUV ratio, prostate-specific antigen, total Gleason score, and castration resistance were significantly associated with abnormal biopsy results for metastatic disease on CholPET. Relatively high false positive rates were found in common iliac, external iliac, and inguinal lymph node locations. Histologic confirmation of these sites should be strongly considered in the appropriate clinical scenario before designing additional local therapy plans.

Thermal ablation of intrahepatic cholangiocarcinoma: Safety, efficacy, and factors affecting local tumor progression

PURPOSE

To evaluate the safety and oncologic efficacy of percutaneous thermal ablation of intrahepatic cholangiocarcinoma (ICC) and identify risk factors for local tumor progression (LTP).

MATERIALS AND METHODS

Retrospective review of an institutional tumor ablation registry demonstrated that 20 patients (9 males, 11 females; mean age 62.5 ± 15.8 years) with 50 ICCs (mean size 1.8 ± 1.3 cm) were treated with percutaneous radiofrequency ablation (RFA) or microwave ablation (MWA) between 2006 and 2015. Thirty-eight of the treated ICCs (76%) were metastases that developed after surgical resection of the primary tumor. Patient demographics, procedure technical parameters, and clinical outcomes were reviewed. A Cox proportional hazards model was used to examine the risk of LTP by ablation modality. Survival analyses were performed using the Kaplan-Meier method.

RESULTS

Mean imaging follow-up time was 41.5 ± 42.7 months. Forty-four (88%) ICCs were treated with RFA, and 6 (12%) with MWA. Eleven (22%) cases of LTP developed in 5 (25%) patients. The median time to LTP among these 11 tumors was 7.1 months (range, 2.3-22.9 months). Risk of LTP was not significantly different for ICCs treated with MWA compared to RFA (HR 2.72; 95% CI 0.58-12.84; p = 03.21). Median disease-free survival was 8.2 months (1.1-70.4 months), and median overall survival was 23.6 months (7.4-122.5 months). No major complication occurred.

CONCLUSIONS

Percutaneous thermal ablation is a safe and effective treatment for patients with ICCs and may be particularly valuable in unresectable patients, or those who have already undergone hepatic surgery. Tumor size and ablation modality were not associated with LTP, whereas primary tumors and superficially located tumors were more likely to subsequently recur.

Imaging following renal ablation: what can we learn from recurrent tumors?

PURPOSE

The purpose of the study was to evaluate the post-contrast appearance of local tumor progression (LTP) following renal ablation to better understand patterns of tumor recurrence and to optimize follow-up imaging protocols.

METHODS

From 2002 to 2015, 913 patients underwent 988 renal ablation procedures for treatment of 1064 tumors. LTP was identified in 24 (2.6%) patients during median imaging follow-up of 30 months (range 0-139). One patient with LTP was followed with non-contrast MRI only and was excluded from evaluation. Three body radiologists reviewed the contrast-enhanced CT and/or MRI follow-up imaging in the remaining 23 patients to determine the timing and imaging appearance of the recurrent tumor.

RESULTS

Local tumor progression was identified on contrast-enhanced CT or MRI at median 11 months (range 1 and 68) after renal ablation. Corticomedullary phase imaging was performed in 16/23 (70%) patients. LTP was identified on the corticomedullary phase in all cases, and was most conspicuous on the corticomedullary phase compared to any other phase of imaging in 15/16 (94%) patients. No cases of LTP were best visualized on non-contrast or excretory phase images.

CONCLUSIONS

Delayed recurrence following renal ablation is possible; therefore, extended follow-up is indicated in ablation patients. Almost all cases of LTP were best visualized on the corticomedullary phase of imaging, which should be included in any post-ablation imaging protocol. Excretory phase images were not required to diagnose LTP in any case and could be excluded from routine post-ablation follow-up.

Palliative Percutaneous Cryoablation and Cementoplasty of Acetabular Metastases: Factors Affecting Pain Control and Fracture Risk

PURPOSE

To characterize the response of patients with acetabular metastases following combined cryoablation and cementoplasty (CCC) for pain palliation and fracture risk reduction, based on completeness of ablation and the presence of pre-existing pathologic fracture.

MATERIALS AND METHODS

Thirty-nine consecutive acetabular CCC procedures were performed in 37 patients (24 M:13F, age 66 ± 8 years). Pain was assessed using a 0-10 numeric rating scale. Development of new or progression of pre-existing fractures and local tumor progression (LTP) were determined on follow-up imaging. Pain score reduction and fracture development rates were compared by ablation completeness and the presence of pre-existing fractures.

RESULTS

Twenty-three of 27 (85%) patients with evaluable pain scores had reduced pain, decreasing from 7.5 ± 2.1 to 3.6 ± 2.6 (p < 0.0001). Of 39 tumors, 28 (72%) were completely ablated with no significant difference in pain reduction after complete versus incomplete ablations (p = 0.9387). Six of 30 (20%) patients with follow-up imaging demonstrated new/progressive acetabular fractures. Four of 5 (80%) patients with LTP developed new/progressive fractures compared to 2 of 25 (8%) without tumor progression (p = 0.0003). Pre-existing fracture was not associated with subsequent fracture/fracture progression (p = 0.2986). However, patients with prior acetabular radiation therapy or surgery had increased fractures following treatment (p = 0.0380).

CONCLUSION

Complete acetabular tumor ablation during CCC was not associated with superior pain relief compared to subtotal ablation but did result in improved fracture stabilization. Pre-treatment pathologic fractures were not associated with fracture progression, but new/progressive fractures were more frequent in patients with prior radiation therapy or surgery.

Development and Validation of a Patient-Reported Outcome Measurement for Symptom Assessment in Cirrhotic Ascites

OBJECTIVES

As current treatments of cirrhotic ascites are not associated with survival benefit, symptom relief is the major therapeutic end point. We developed a questionnaire (Ascites-Q; modified polycystic liver disease questionnaire) and assessed validity and responsiveness for symptom assessment in cirrhotic ascites.

METHODS

Ascites-Q was compared with Functional Assessment of Chronic Illness Therapy-Ascites Index (FACIT-AI; developed for malignant ascites) and Japanese Ascites Symptom Inventory-7 (ASI-7) in cirrhotics undergoing large-volume paracentesis. Convergent validity was defined as correlation >0.4 between ascites questionnaires and quality of life (QoL) visual analog scale. Responsiveness was assessed by comparing scores at baseline and 7 days after large-volume paracentesis. To test discriminative ability, we compared scores of patients with cirrhotic controls without ascites (n=24) and diuretic-sensitive ascites (n=46).

RESULTS

We included 90 patients with refractory cirrhotic ascites (61% male, mean age 59 years, Model of End-Stage Liver Disease (MELD) score 16, median paracentesis volume 4,100 ml). Higher symptoms scores were correlated with lower QoL (Ascites-Q: r=0.479, P<0.001, FACIT-AI: r=0.313, P=0.007; ASI-7: r=0.340, P=0.004), but only Ascites-Q showed convergent validity (r>0.4). Symptoms decreased after paracentesis (Ascites-Q: 57 to 34, FACIT-AI: 44 to 33, and ASI-7: 57 to 25, all P<0.001). Ascites-Q and ASI-7 discriminated between controls without ascites, diuretic-sensitive, and refractory ascites (Ascites-Q: 16 vs. 35 vs. 56 points, ASI-7: 2 vs. 25 vs. 61 points, all P<0.05), whereas FACIT-AI (39 vs. 40 vs. 52 points) could not (P=0.314). Ascites-Q was validated at 3 months in an independent cohort with ascites controlled with a pump.

CONCLUSIONS

The Ascites-Q is the best ascites-specific outcome to evaluate symptom relief in cirrhotic ascites.

Diagnostic performance of unenhanced computed tomography and 18 F-fluorodeoxyglucose positron emission tomography in indeterminate adrenal tumours

OBJECTIVE

Evidence on the diagnostic performance of adrenal imaging is limited. We aimed to assess the diagnostic performance of unenhanced computed tomography (CT) and ¹⁸ F-fluorodeoxyglucose (¹⁸ FDG) positron emission tomography (PET)/CT imaging in a high-risk population for adrenal malignancy using an optimal reference standard.

DESIGN

Retrospective cohort study.

METHODS

Imaging studies of patients with adrenal nodules who underwent adrenal biopsy and/or adrenalectomy between 1994 and 2014 were reviewed and compared to the reference standard of histology. Eighty % of patients presented with known or suspected extra-adrenal malignancy.

RESULTS

Unenhanced abdominal CT was performed in 353 patients with adrenal lesions; median size was 3 (0.7-15) cm and median radiodensity was 33 (-21-78) Hounsfield units (HU). Radiodensity of >10 HU diagnosed malignancy with a sensitivity of 100%, specificity of 33%, positive predictive value (PPV) of 72% and negative predictive value (NPV) of 100%. ¹⁸ FDG-PET/CT was performed in 89 patients; median tumour size was 2.1 (0.7-9.2) cm. Maximum standardized uptake (SUV max) was higher in malignant lesions when compared to benign lesions (median=10 [2.3-29.4] vs 3.7 [1.4-24.5], respectively, P<.0001). Similarly, median SUV max lesion to SUV max liver ratio (ALR) in malignant lesions was higher than in benign lesions (median=3 [0.74-13.4] vs 1.2 [0.5-6.6], respectively, P<.0001). ¹⁸ FDG-PET/CT ALR >1.8 diagnosed malignancy with a sensitivity of 87%, specificity of 84%, PPV of 85% and NPV of 86%.

CONCLUSION

Noncontract CT radiodensity of ≤10 HU excludes malignancy even in a high-risk population. For indeterminate adrenal lesions, given a superior specificity, ¹⁸ FDG-PET/CT could be considered as a second stage imaging study.

Outcomes After Cryoablation Versus Partial Nephrectomy for Sporadic Renal Tumors in a Solitary Kidney: A Propensity Score Analysis

BACKGROUND

While partial nephrectomy (PN) is considered the standard approach for a tumor in a solitary kidney, percutaneous cryoablation (PCA) is emerging as an alternative nephron-sparing option.

OBJECTIVE

To compare outcomes between PCA and PN for tumors in a solitary kidney.

DESIGN, SETTING, AND PARTICIPANTS

Patients who underwent PCA or PN between 2005 and 2015 for a single primary renal tumor in a solitary kidney were identified using Mayo Clinic Registries. Exclusion criteria were inherited tumor syndromes and salvage procedures.

INTERVENTION

PCA and PN.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

To achieve balance in baseline characteristics, we used inverse probability of treatment weighting (IPTW) based on propensity to receive treatment. The risk of having a post-treatment complication and percent drop in estimated glomerular filtration rate (eGFR), as well as the risks of local/ipsilateral recurrence, distant metastasis, and cancer-specific mortality, were compared between groups using logistic, linear, and Fine-and-Gray competing risk regression models.

RESULTS AND LIMITATIONS

The cohort included 118 patients (PCA: 54; PN: 64) with a median follow-up of 47 mo (interquartile range 18, 74). In unadjusted analyses, PCA was associated with a lower risk of complications (15% vs 31%; odds ratio [OR]=0.38; 95% confidence interval [CI] 0.15, 0.96; p=0.04). However, upon accounting for baseline differences with IPTW adjustment, there was no longer a significant difference in the risk of complications (28% vs 29%; OR=0.95; 95% CI 0.53, 1.69; p=0.9). There were no significant differences between PCA and PN in percentage drop in eGFR at discharge (mean: 11% vs 16%; β=-5%; 95% CI -13, 3; p=0.2) or at 3 mo (12% vs 9%; β=3%; 95% CI -3, 10; p=0.3). Likewise, no significant differences were noted in local recurrence (HR=0.87; 95% CI 0.38, 1.98; p=0.7), distant metastases (HR=0.60; 95% CI 0.30, 1.20; p=0.2), or cancer-specific mortality (HR=1.13; 95% CI 0.32, 3.98; p=0.8). Limitations include the sample size, given the relative rarity of renal masses in solitary kidneys.

CONCLUSIONS

Our study found no significant difference in complications, renal function outcomes, and oncologic outcomes between PN and PCA for patients with a tumor in a solitary kidney. Validation in a larger multi-institutional analysis may be warranted.

PATIENT SUMMARY

Partial nephrectomy (surgery) and percutaneous cryoablation are both options for treating a kidney tumor while preserving the normal portion of the kidney. In patients with a tumor in their only kidney, we found no difference in the risk of complications, kidney function outcomes, or cancer control outcomes between these two approaches.

Renal functional outcomes in patients undergoing percutaneous cryoablation or partial nephrectomy for a solitary renal mass

OBJECTIVES

To compare renal functional changes after percutaneous cryoablation (PCA) or partial nephrectomy (PN).

PATIENTS AND METHODS

Patients who underwent PCA or PN for a solitary renal mass at a single institution were identified (2003-2013). Estimated glomerular filtration rates (eGFRs) were calculated at baseline, discharge, and at the 3-month follow-up using the Chronic Kidney Disease Epidemiology Collaboration equation. Changes in renal function were compared between groups using 1:1 propensity score (PS) matching, adjustment for PS quintile, and inverse probability weighting (IPW).

RESULTS

There were 2 040 procedures available for the PS analyses, including 448 PCA and 1 592 PN. After PS adjustments, there were no significant differences in baseline clinical features between PCA and PN patients. In the PS-matched analysis, the change in eGFR from baseline to discharge for PCA and PN patients was -3.1 and -1.1 mL/min/1.73 m² , respectively (P = 0.038), with percentage changes of -4.5% and 0% respectively (P = 0.006). From baseline to the 3-month follow-up, the absolute change in eGFR for PCA and PN patients was -4.3 and -2.1 mL/min/1.73 m² , respectively (P = 0.008), and the percentage change was -6.1% and -2.4% respectively (P = 0.005). Similar results were obtained after adjusting for PS quintiles and in the IPW analysis. Importantly, the rate of chronic kidney disease stage progression at the 3-month follow-up was similar between the groups (21% vs 18%).

CONCLUSIONS

Our results confirm that both PCA and PN have a minor impact on renal function. While we observed a statistically greater decline in eGFR after PCA compared with PN, both approaches result in excellent preservation of renal function.

Outcomes of Ultrasound-Guided Thrombin Injection of Nongroin Arterial Pseudoaneurysms

PURPOSE

To evaluate success and complication rates of percutaneous ultrasound-guided thrombin injection of nongroin pseudoaneurysms (PSAs).

MATERIALS AND METHODS

Retrospective review of a prospectively maintained institutional database yielded 39 cases of arterial PSAs occurring at nongroin sites that were treated with percutaneous ultrasound-guided thrombin injection between 2000 and 2016 (average patient age 69.2 y ± 14.0). Of PSAs, 74.4% (29/39) arose in the upper extremities, and 92.3% (36/39) were iatrogenic. The brachial artery was the most commonly affected vessel (51.3% [20/39]), and arterial access was the most common cause (56.4% [22/39]). Average overall PSA size was 2.4 cm (range, 0.5-7.2 cm); average amount of thrombin injected was 320 IU (range, 50-2,000 IU). Technical success was defined as absence of flow within the PSA immediately after thrombin injection. Treatment success was defined as sustained thrombosis on follow-up imaging obtained at 1-3 days after treatment.

RESULTS

Technical and treatment success rates of thrombin injections were 100% (39/39) and 84.8% (28/33), respectively. Longer term follow-up imaging (average 71 d; range, 12-201 d) was available for 7 of the treatment successes with 100% (7/7) showing sustained thrombosis. Comparing treatment successes and failures, there was no significant difference in average PSA size (2.3 cm vs 2.0 cm, P = .51) or average amount of thrombin injected (360 IU vs 180 IU, P = .14). There were no complications.

CONCLUSIONS

Ultrasound-guided thrombin injection is a safe, efficacious treatment option for PSAs arising in nongroin locations.

Evaluation of infectious complications following percutaneous liver ablation in patients with bilioenteric anastomoses

PURPOSE

Prior bilioenteric anastomosis (BEA) has been associated with elevated risk of abscess formation after thermal ablation of hepatic tumors. We assessed the incidence of hepatic abscess after thermal ablation in a BEA cohort treated with extended antibiotic regimens following ablation.

MATERIALS AND METHODS

Retrospective review was performed to identify patients with BEA who underwent percutaneous hepatic thermal ablation between January 1, 2003-September 1, 2016. Fifteen patients with BEA underwent 18 percutaneous thermal ablation procedures. Patient and procedural characteristics were reviewed, as well as the antibiotic regiment utilized post ablation. Complications were characterized via standardized nomenclature [Common Terminology for Clinically Adverse Events (CTCAE) v4.03].

RESULTS

Fifteen patients with BEA underwent treatment of 49 liver lesions during 18 ablation sessions. Mean follow-up in these patients was 39 months (range 3-138 months). Two patients (11%) developed hepatic abscesses, both of which occurred within 45 days of the ablation procedure while the patients were still on extended prophylactic antibiotic therapy. No additional CTCAE clinically significant complications were observed.

CONCLUSION

Thermal ablation of hepatic tumors can be accomplished safely in patients with BEA. Long-term post-procedural antibiotics may mitigate the risk of hepatic abscess formation. Due to the high number of patients who are deemed surgically unresectable, patients with BEA may have limited alternate treatment modalities and percutaneous hepatic thermal ablative treatments warrant consideration.

Peri-procedural use of anticoagulants in radiology: an evidence-based review

Peri-procedural anticoagulant management hinges on the balance of hemorrhagic and thrombotic complications. The radiologist is tasked with accurately assessing the hemorrhagic risk for patients undergoing procedures, taking into account procedural bleeding rates, underlying coagulopathy based on lab tests, and use of anticoagulants. The purpose of this article is to provide a contemporary review of commonly used anticoagulants and, incorporating published evidence, review their management related to image-guided procedures.

Retrospective Review of Percutaneous Image-Guided Ablation of Oligometastatic Prostate Cancer: A Single-Institution Experience

PURPOSE

To retrospectively review and report the efficacy and safety of percutaneous image-guided ablation (cryoablation or radiofrequency ablation) in the treatment of oligometastatic prostate cancer.

MATERIALS AND METHODS

An institutional registry was retrospectively reviewed and revealed 16 patients with oligometastatic prostate cancer (median age, 67 y; range, 50-86 y) who underwent percutaneous image-guided ablation to treat 18 metastatic sites. A subgroup of 7 patients with 8 metastases were androgen-deprivation therapy (ADT)-naïve and underwent ablation to delay initiation of ADT. Local tumor control, progression-free survival (PFS), ADT-free survival, and procedural complications were analyzed.

RESULTS

Local tumor control was achieved in 15 of 18 metastases (83%) at a median follow-up of 27 months (range, 5-56 mo). Local tumor recurrence was found in 3 of 18 metastases (17%), with a median time to local recurrence of 3.5 months (range, 3-38 mo). Estimated PFS rates at 12 and 24 months were 56% (95% confidence interval [CI], 30%-76%) and 43% (95% CI, 19%-65%), respectively. In the 7 ADT-naïve patients, local tumor control was achieved in all metastases, and the median ADT-free survival period was 29 months. There were no major procedural complications.

CONCLUSIONS

In this cohort of patients with oligometastatic prostate cancer, percutaneous image-guided ablation was feasible and well tolerated and achieved acceptable local tumor control rates. Percutaneous ablation may be of particular utility in patients who wish to delay initiation of ADT.

Cryoablation of cT1 renal masses in the “healthy” patient: Early outcomes from Mayo Clinic

433

Background: Current guidelines suggest that percutaneous thermal ablation (PTA) can be utilized in those with significant comorbidity who are unable to tolerate surgery (radical or partial nephrectomy). However, the use of PTA in healthy patients, who are otherwise candidates for surgery, has been limited. Here, we reviewed our institutional experience in healthy patients electing to undergo PTA, specifically cryoablation. Methods: We identified patients ≤65 years undergoing percutaneous cryoablation for solitary, non-metastatic renal masses <7cm (cT1). We further limited our cohort to patients with an ASA score of 1 or 2, and in whom pre-operative eGFR was >60. Clincopathologic characteristics and recurrence patterns (local recurrence within the kidney versus metastatic disease) were evaluated. Results: Between March 2003 and December 2015, 705 patients underwent cryoablation, of whom 43 (6.1%) were deemed to be “healthy”. Median age of this cohort was 57 years (IQR 52−62), with pre-ablation eGFR of 75.6 (IQR 69.0-86.3). Seven patients (16.3%) had a prior partial nephrectomy, and 5 (11.6%) had a solitary kidney. The majority (40, 93.0%) of ablated masses were cT1a, with 3 (7.0%) being cT1b. Median tumor size was 2.0 cm. 27 masses (63.7%) were biopsy-proven renal cell carcinoma (RCC) and 6 (13.6%) were benign; histology was unknown in 10 (22.7%). Follow-up imaging was available for 37 patients. Median radiological follow-up was 22 months (IQR 9-42), during which time 2 patients developed metastatic disease and 1 developed local recurrence; all events were in patients with biopsy-proven RCC. No patients died from RCC during this time period. Conclusions: In this single institution cohort of “healthier” patients with cT1 solitary renal masses, cryoablation offered reasonable short term oncologic control. While longer follow-up data are needed to evaluate for durability, cryoablation in healthy patients, particularly those with challenging surgical anatomy, warrants further study.

Effects of Aspirin Therapy on Ultrasound-Guided Renal Allograft Biopsy Bleeding Complications

PURPOSE

To determine if patient aspirin exposure and timing affect bleeding risk after renal allograft biopsy.

MATERIALS AND METHODS

Review of 6,700 renal allograft biopsies (in 2,362 unique patients) was performed. Median patient age was 53.0 years [interquartile range 43.0, 62.0]; 56.2% of patients were male. Of biopsies, 4,706 (70.2%) were performed in patients with no aspirin exposure within 10 days of biopsy; 664 (9.9%), were performed within 8-10 days of aspirin exposure; 855 (12.8%), within 4-7 days; and 475 (7.1%), within 0-3 days. Follow-up to 3 months after the procedure was completed in all patients. Biopsies were categorized as protocol or indication; 19.7% were indication biopsies. Bleeding complications were graded based on SIR criteria. Logistic regression models examined the association between aspirin use and bleeding events.

RESULTS

Rate [95% confidence interval] of major bleeding complications was 0.24% [0.14, 0.39], and rate of any bleeding complication was 0.66% [0.46, 0.90]. Bleeding events were significantly associated with patients undergoing indication biopsies compared with protocol biopsies (odds ratio [OR] 2.27, P = .012). Patient factors associated with major bleeding complications in multivariate models included estimated glomerular filtration rate (OR 0.61, P = .016) and platelet count (OR 0.64, P = .033). Aspirin use was not significantly associated with increased risk of bleeding complication except for use of 325 mg of aspirin within 3 days of biopsy (any complication OR 3.87 [1.12, 13.4], P = .032; major complication OR 6.30 [1.27, 31.3], P = .024).

CONCLUSIONS

Renal allograft biopsy bleeding complications are very rare, particularly for protocol biopsies. Use of 325 mg of aspirin within 3 days of renal allograft biopsy was associated with increased bleeding complications.

IMAGE-GUIDED THERMAL ABLATION OF ADRENAL METASTASES: HEMODYNAMIC AND ENDOCRINE OUTCOMES

OBJECTIVE

Image-guided thermal ablation of adrenal metastases has been increasingly used for local tumor control. This procedure has been associated with hypertensive urgency; however, endocrine complications have not been clearly described. Our objective was to assess the hemodynamic behavior and risk for adrenal insufficiency related to adrenal ablation. Additionally, we sought to understand the utility of preprocedural α-blockade to prevent periprocedural hemodynamic complications.

METHODS

This was a retrospective study of patients undergoing image-guided ablation of adrenal metastases between 2003 and 2015 at our institution. We reviewed electronic medical records to obtain clinical information, including α-blockade preparation, periprocedural hemodynamic parameters, interventions, and postablation adrenal function.

RESULTS

Thermal ablation was performed in 58 patients (46 men [79%]; median age, 66 years) with 60 adrenal metastases ablated in 62 sessions. Alpha-blockade was used pre-ablation in 49 (79%) sessions; it was associated with less hypertensive urgency (23 [47%] for α-blockade vs. 10 [77%] for no α-blockade; P = .048) but higher need for vasopressors (22 [45%] for α-blockade vs. 1 [8%] for no α-blockade; P = .02) during ablation. Adrenal insufficiency occurred in 13 (22%) patients, of whom 10 had history of contralateral adrenalectomy or metastases, and only 3 of 13 had a normal-appearing contralateral adrenal gland.

CONCLUSION

Hemodynamic changes during ablation of adrenal metastases are common. Pre-ablation α-blockade decreases the severity of the hypertensive episode, at the expense of higher need for vasopressors periprocedurally. Adrenal function should be assessed after adrenal metastasis ablation, as adrenal insufficiency may occur after such treatment.

ABBREVIATIONS

ACTH = adrenocorticotropic hormone BP = blood pressure CT = computed tomography DBP = diastolic blood pressure HR = heart rate IQR = interquartile range IV = intravenous MAP = mean arterial pressure MWA = microwave ablation RFA = radiofrequency ablation SBP = systolic blood pressure.

Procedural and clinical outcomes of percutaneous adrenal biopsy in a high-risk population for adrenal malignancy

OBJECTIVE

The role of percutaneous adrenal biopsy in a high-risk population for adrenal malignancy has not been fully investigated. Our aim was to describe the clinical presentation leading to the adrenal biopsy and evaluate the diagnostic performance, complications and non diagnostic rate of adrenal biopsy.

DESIGN

Single-centre, retrospective cohort study.

PATIENTS AND MEASUREMENTS

Medical records of patients who underwent adrenal biopsy between 1994 and 2014 were reviewed. Adrenal biopsy outcome was compared to a predefined reference standard.

RESULTS

Biopsy was performed in 418 patients [62% men, median age 69 years (range, 15-91)] on 419 adrenal lesions, median size 3·1 cm (range, 0·6-24). The main indication for adrenal mass biopsy was (349/419, 83%) suspected adrenal metastasis from a known or suspected extra-adrenal primary source. Only 116 of 419, 28% of cases had prebiopsy biochemical testing for pheochromocytoma. Biopsy-related complications occurred in 4% of the patients. Histology revealed a metastasis in 231 of 419 (55%), benign adrenal tissue in 137 of 419 (33%), adrenocortical carcinoma in eight of 419 (2%), other lesions in 23 of 419 (5%) including seven cases of pheochromocytoma and six cases of infectious process. Biopsy was nondiagnostic in 20 of 419 (5%). All adrenal masses with unenhanced radiodensity ≤10 HU (42/137, 31%) proved to be benign adrenal adenomas. Adrenal biopsy diagnosed malignancy with a sensitivity of 88·5%, specificity of 91·5%, positive predictive value of 93·4% and negative predictive value of 85·5%.

CONCLUSION

When used in the appropriate clinical setting, adrenal biopsy is a powerful tool in the diagnostic algorithm of the evaluation of adrenal masses with features suspicious for malignancy. Efforts to increase awareness to perform biochemical testing for pheochromocytoma prior to adrenal biopsy are needed.

Incidence of bleeding complications after percutaneous core needle biopsy in hypertensive patients and comparison to normotensive patients

PURPOSE

To retrospectively determine the rate of major bleeding complications after solid organ or lung biopsy in patients with hypertension and compare to the rates of bleeding in normotensive patients.

MATERIALS AND METHODS

Following IRB approval, retrospective review of all solid organ and lung biopsies performed at our institution between June 1st, 2013 and October 31st, 2015 was performed. Hypertension was defined as a maximum observed systolic blood pressure of 160 mmHg or greater and/or diastolic blood pressure of 90 mmHg or greater at the time of the biopsy procedure. Bleeding complications were defined using the Common Terminology Criteria for Adverse Events (CTCAE, version 4.0) established by the National Cancer Institute.

RESULTS

4756 total biopsies in 3876 unique patients (median age 60, 57% male) were included. 1488 (31.3%) of these biopsies were performed in hypertensive patients. Fifteen major hemorrhages (CTCAE grade 3 or higher) occurred (0.32%). There were no deaths. There was no significant association between hypertension and major bleeding. The incidence of bleeding in hypertensive patients was 0.40% (6/1488), which was not statistically different than the incidence in normotensive patients (9/3268, 0.28%, p = 0.496). For the subgroup of native renal parenchymal biopsies, the rate of bleeding was slightly higher in hypertensive patients (3/213, 1.4% vs. 1/355, 0.28% in normotensive patients) but remained low, and the difference was not statistically significant (p = 0.188).

CONCLUSION

The overall incidence of major bleeding after percutaneous biopsy is very low. Hypertension does not appear to significantly increase the risk of major bleeding complications.

Recurrence and Survival Outcomes After Percutaneous Thermal Ablation of Oligometastatic Melanoma

OBJECTIVES

To evaluate focal treatment of melanoma metastases and to explore whether any potential extended survival benefit exists in a select patient population.

PATIENTS AND METHODS

All patients who underwent image-guided local thermal ablation of metastatic melanoma over an 11-year period (January 1, 2002, to December 31, 2013) were retrospectively identified using an internally maintained clinical registry. Only patients with oligometastatic stage IV disease amenable to complete ablation of all clinical disease at the time of ablation were included in the analysis. Overall survival and median progression-free survival periods were calculated.

RESULTS

Thirty-three patients with primary ocular or nonocular melanoma had 66 metastases treated in the lungs, liver, bones, or soft tissues. Eleven (33%) patients were on systemic medical therapy at the time of the procedure. The median survival time was 3.8 years (range, 0.5-10.5 years), with a 4-year estimated survival of 44.1% (95% CI, 28%-68%). Local recurrence at the ablation site developed in 15.1% (5 of 33) of the patients and 13.6% of the tumors (9 of 66). The median progression-free survival time was 4.4 months (95% CI, 1.4 months to 10.5 years), with an estimated 1-year progression-free survival of 30.3% (95% CI, 18%-51%). A subgroup analysis identified 11 patients with primary ocular melanoma and 22 with nonocular melanoma, with a median survival time of 3.9 years (range, 0.9-4.7 years) and 3.8 years (range, 0.5-10.5 years), respectively (P=.58). There were no major complications and no deaths within 30 days of the procedure.

CONCLUSION

Selective use of image-guided thermal ablation of oligometastatic melanoma may provide results similar to surgical resection in terms of technical effectiveness and oncologic outcomes with minimal risk.