Brendan P. McMenomy

Percutaneous Cryoablation of Musculoskeletal Oligometastatic Disease for Complete Remission

PURPOSE To assess the safety and effectiveness of percutaneous cryoablation to treat limited metastases to the musculoskeletal system, with the goal of complete disease remission. MATERIALS AND METHODS In a single-institution retrospective study of data from December 2003 to October 2011, 43 consecutive patients underwent initial cryoablation of limited (five or fewer) musculoskeletal metastases with the goal of complete disease remission (ie, no clinical or radiographic evidence of disease). Three patients were lost to follow-up. As a result, the present report describes 40 patients who underwent 40 cryoablation procedures to treat 52 tumors. RESULTS Local control was achieved in 45 of 52 tumors (87%; 95% confidence interval [CI], 75%-93%) at a median follow-up of 21 months (range, 4-62 mo). Thirteen of 19 treated bone metastases (68%) and 32 of 33 soft-tissue metastases (97%) showed local control (P = .007). One- and 2-year overall survival rates were 91% (95% CI, 75%-97%) and 84% (95% CI, 65%-93%), respectively. Median overall survival was 47 months (95% CI, 26-62 mo). One- and 2-year disease-free survival rates were 22% (95% CI, 11%-37%) and 7% (95% CI,<1% to 26%), respectively. Median disease-free survival was 7 months (95% CI, 5-10 mo). Two of 40 procedures (5%) were associated with major complications. CONCLUSIONS Percutaneous cryoablation is a safe and effective treatment to achieve local tumor control and short-term complete disease remission in patients with limited metastatic disease to the musculoskeletal system.

Critical Care Ultrasonography Differentiates ARDS, Pulmonary Edema, and Other Causes in the Early Course of Acute Hypoxemic Respiratory Failure

BACKGROUND Pathogenic causes of acute hypoxemic respiratory failure (AHRF) can be difficult to identify at early clinical presentation. We evaluated the diagnostic utility of combined cardiac and thoracic critical care ultrasonography (CCUS). METHODS Adult patients in the ICU were prospectively enrolled from January through September 2010 with a Pao2/Fio2 ratio < 300 on arterial blood gas (ABG) analysis within 6 h of a new hypoxemic event or the ICU admission. Focused cardiac and thoracic CCUS was conducted within 6 h of ABG testing. Causes of AHRF were categorized into cardiogenic pulmonary edema (CPE), ARDS, and miscellaneous causes after reviewing the hospitalization course in electronic medical records. RESULTS One hundred thirty-four patients were enrolled (median Pao2/Fio2 ratio, 191; interquartile range, 122-253). Fifty-nine patients (44%) received a diagnosis of CPE; 42 (31%), ARDS; and 33 (25%), miscellaneous cause. Analysis of CCUS findings showed that a low B-line ratio (proportion of chest zones with positive B-lines relative to all zones examined) was predictive of miscellaneous cause vs CPE or ARDS (receiver operating characteristic area under the curve [AUC], 0.82; 95% CI, 0.75-0.88). For further differentiation of CPE from ARDS, left-sided pleural effusion (> 20 mm), moderately or severely decreased left ventricular function, and a large inferior vena cava minimal diameter (> 23 mm) were predictive of CPE (AUC, 0.79; 95% CI, 0.70-0.87). CONCLUSIONS Combined cardiac and thoracic CCUS assists in early bedside differential diagnosis of ARDS, CPE, and other causes of AHRF.

The Timing and Presentation of Major Hemorrhage After 18,947 Image-Guided Percutaneous Biopsies

OBJECTIVE The objective of our study was to characterize the temporal and clinical manifestation of major bleeding events after biopsy to guide clinicians in the institution of appropriate surveillance. MATERIALS AND METHODS We performed a retrospective review of percutaneous image-guided biopsies performed between September 1, 2005, and May 31, 2012, including 18,947 biopsy events. According to routine protocol, follow-up telephone calls were made to patients 24 hours after biopsy, and chart review was performed 3 months after biopsy. Bleeding complications were defined using the Common Terminology Criteria for Adverse Events (CTCAE, version 4.0) established by the National Cancer Institute. In patients with a grade 3 or greater bleeding complication, a retrospective chart review was performed to characterize the details of the complication including the timing of the complication and the primary clinical presentation of the event. RESULTS Grade 3 hemorrhage was associated with 64 of 18,947 (0.3%) procedures, and there were three deaths associated with the biopsy event (0.02% or ≈ 2/10,000). Hemorrhage was most commonly associated with biopsy of a native kidney (17/1407, 1.2%). Twenty patients (31%) presented with a bleeding complication within 1 hour of biopsy. Twenty-seven patients (42%) presented within 2 hours of biopsy. Fifty-two patients (81%) presented within 24 hours, and the remaining 12 patients (19%) presented more than 24 hours after biopsy. Pain was the most common presentation of patients with bleeding complications, occurring in 39 (61%) patients. CONCLUSION The incidence of major bleeding after percutaneous biopsies is very low, but delayed complications occur more frequently than anticipated. Pain is the most common clinical presentation of major bleeding complications.

Mutational landscapes of sequential prostate metastases and matched patient derived xenografts during enzalutamide therapy

Developing patient derived models from individual tumors that capture the biological heterogeneity and mutation landscape in advanced prostate cancer is challenging, but essential for understanding tumor progression and delivery of personalized therapy in metastatic castrate resistant prostate cancer stage. To demonstrate the feasibility of developing patient derived xenograft models in this stage, we present a case study wherein xenografts were derived from cancer metastases in a patient progressing on androgen deprivation therapy and prior to initiating pre-chemotherapy enzalutamide treatment. Tissue biopsies from a metastatic rib lesion were obtained for sequencing before and after initiating enzalutamide treatment over a twelve-week period and also implanted subcutaneously as well as under the renal capsule in immuno-deficient mice. The genome and transcriptome landscapes of xenografts and the original patient tumor tissues were compared by performing whole exome and transcriptome sequencing of the metastatic tumor tissues and the xenografts at both time points. After comparing the somatic mutations, copy number variations, gene fusions and gene expression we found that the patient’s genomic and transcriptomic alterations were preserved in the patient derived xenografts with high fidelity. These xenograft models provide an opportunity for predicting efficacy of existing and potentially novel drugs that is based on individual metastatic tumor expression signature and molecular pharmacology for delivery of precision medicine.

Subtraction Color Map of Contrast-Enhanced and Unenhanced CT for the Prediction of Pancreatic Necrosis in Early Stage of Acute Pancreatitis

OBJECTIVE The objective of our study was to evaluate the accuracy of subtraction color-map images created from contrast-enhanced CT (CECT) and unenhanced CT for the diagnosis of pancreatic necrosis in the early stage of acute pancreatitis. MATERIALS AND METHODS Forty-eight patients underwent unenhanced CT and CECT within 72 hours from the onset of acute pancreatitis. Subtraction color-map images were created from unenhanced CT and CECT using a 3D nonrigid registration method. Three radiologists reviewed two image sets: CECT alone and subtraction color-map images in conjunction with CECT. Readers evaluated each image set for the presence of pancreatic necrosis. The reference standard for pancreatic necrosis was CT or MRI 1 week or more after the onset of acute pancreatitis. The performance of each image set for the prediction of pancreatic necrosis was calculated and compared using the McNemar test. RESULTS Eleven of the 48 patients developed pancreatic necrosis. There were no technical failures creating the subtraction images. The sensitivity, specificity, and accuracy for predicting pancreatic necrosis with CECT were 64%, 97%, and 90%, respectively, for reader 1; 73%, 87%, and 83% for reader 2; and 73%, 87%, and 83% for reader 3. The sensitivity, specificity, and accuracy for predicting pancreatic necrosis with the subtraction color maps were 100%, 100%, and 100%, respectively, for reader 1; 100%, 95%, and 96% for reader 2; and 82%, 92%, and 90% for reader 3. Accuracy significantly improved with the addition of subtraction color maps compared with CECT alone for reader 1 (p = 0.03) and reader 2 (p = 0.02) but not for reader 3 (p = 0.37). CONCLUSION A subtraction color map is accurate in the diagnosis of pancreatic necrosis in the early stage of acute pancreatitis.

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, Fishers 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.

Bleeding Complications following Image-Guided Percutaneous Biopsies in Patients Taking Clopidogrel—A Retrospective Review

PURPOSE To report incidence of bleeding after image-guided percutaneous core needle biopsy performed in patients taking clopidogrel within 5 days. MATERIALS AND METHODS This was a retrospective review of image-guided percutaneous core needle biopsies performed in patients with clopidogrel use within 5 days of the procedure between January 2002 and November 2014. Data including biopsy site, needle size, number of samples, and serum coagulation studies were collected. Routine follow-up of patients was performed 24-72 hours after biopsy. Major bleeding complications were defined as grade 3 or greater using Common Terminology Criteria for Adverse Events. There were 63 deep biopsies performed in 63 patients with recent use of clopidogrel. Mean time of clopidogrel abstinence before biopsy was 2.9 days ± 1.9 (median 3 days). Clopidogrel had been taken within 24 hours of the biopsy by 12 patients. There were 48 patients (76%) who also took aspirin within 5 days of the procedure. The most common procedure was liver biopsy (21/63; 33%), followed by lung (12/63; 19%), abdominal/pelvic/retroperitoneal mass (12/63; 19%), and renal (11/63; 17%) biopsies. RESULTS A major bleeding complication (1/63; 1.6%) occurred after injury to an intercostal artery during lung biopsy, which was successfully treated with coil embolization. No minor bleeding complications were identified. CONCLUSIONS In this study comprising a small number of patients undergoing various biopsy procedures, recent clopidogrel use was associated with a very low incidence of major bleeding.

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.

Introducing First-Year Radiology Residents to the ACR at the AMCLC from 2009 to 2013: Summary of Experiences and Five-Year First-Cohort Follow-Up

PURPOSE The aim of this report is to provide a five-year summary of the Minnesota Radiological Societys initiative to send first-year radiology residents to the ACR at the AMCLC. The authors provide an update of the survey data for the first five years (2009-2013) and a report of the ACR membership status of the original 2009 cohort (class of 2012) five years after their conference experience. METHODS Participating residents from 2009 to 2013 completed pre- and postconference surveys assessing their knowledge of ACR-related topics, conference satisfaction, and intention to join the ACR. ACR membership status of the first cohort was determined using the ACR membership database and compared with both the previous five graduating classes and the national average for practicing radiologists. RESULTS Seventy first-year Minnesota radiology residents attended the conference from 2009 to 2013. Knowledge of the ACR significantly increased after the conference. Most residents were highly satisfied or satisfied with their conference experience and highly likely or likely to join the ACR in the future. Two years after residency, 87% of the first cohort (13 of 15) were ACR members, compared with an average membership rate of 57% (63 of 110) for the previous five graduating classes. CONCLUSIONS Exposing radiology residents early to the ACR at the AMCLC leads to a significant increase in knowledge pertaining to the professional organization. This exposure likely leads to increased ACR membership when residents enter practice. This early engagement in radiology affairs can lead to a higher rate of ACR membership and to a better informed membership.

Imaging findings of mammary and systemic silicone deposition secondary to breast implants

In patients with silicone breast implants, implant rupture can occur, which can be intra- or extracapsular. Following implant rupture, silicone can travel through the lymphatic system into regional and distant lymph nodes. The purpose of this pictorial essay is to present findings of silicone implant rupture with intramammary and systemic silicone deposition as seen on dual energy CT, ultrasound, mammogram, PET/CT and MRI. We include imaging findings of silicone deposition in the breast in cases of intra- and extracapsular rupture. We also present silicone deposition in mediastinal, axillary, and internal mammary lymph nodes, as well as in the liver and spleen. To our knowledge, deposition of silicone in the liver and spleen has not been previously demonstrated on cross-sectional imaging. While all imaging modalities were able to detect silicone in the spleen, ultrasound appeared to be more sensitive than dual energy CT or MRI for detection of silicone deposition in the liver.