Plasma DNA as a "liquid biopsy" incompletely complements tumor biopsy for identification of mutations in a case series of four patients with oligometastatic breast cancer.

PURPOSE: Circulating tumor DNA in plasma may present a minimally invasive opportunity to identify tumor-derived mutations to inform selection of targeted therapies for individual patients, particularly in cases of oligometastatic disease where biopsy of multiple tumors is impractical. To assess the utility of plasma DNA as a "liquid biopsy" for precision oncology, we tested whether sequencing of plasma DNA is a reliable surrogate for sequencing of tumor DNA to identify targetable genetic alterations. METHODS: Blood and biopsies of 1-3 tumors were obtained from 4 evaluable patients with advanced breast cancer. One patient provided samples from an additional 7 tumors post-mortem. DNA extracted from plasma, tumor tissues, and buffy coat of blood were used for probe-directed capture of all exons in 149 cancer-related genes and massively parallel sequencing. Somatic mutations in DNA from plasma and tumors were identified by comparison to buffy coat DNA. RESULTS: Sequencing of plasma DNA identified 27.94 ± 11.81% (mean ± SD) of mutations detected in a tumor(s) from the same patient; such mutations tended to be present at high allelic frequency. The majority of mutations found in plasma DNA were not found in tumor samples. Mutations were also found in plasma that matched clinically undetectable tumors found post-mortem. CONCLUSIONS: The incomplete overlap of genetic alteration profiles of plasma and tumors warrants caution in the sole reliance of plasma DNA to identify therapeutically targetable alterations in patients and indicates that analysis of plasma DNA complements, but does not replace, tumor DNA profiling. TRIAL REGISTRATION: Subjects were prospectively enrolled in trial NCT01836640 (registered April 22, 2013).

Liver Abscesses: Factors That Influence Outcome of Percutaneous Drainage.

OBJECTIVE: The purpose of this study was to identify the details of percutaneous catheter drainage (PCD) of pyogenic liver abscesses, the etiologic factors, and the management techniques that contribute to successful treatment. MATERIALS AND METHODS: The records of 75 consecutively registered patients who underwent PCD of 96 abscesses at a single institution between May 2009 and May 2014 were retrospectively reviewed. Thirty-nine patients (52%) were oncology patients, and 36 (48%) had recently undergone abdominal surgery. Primary success was defined as abscess healing with the primary PCD intervention and 30-day postdrainage survival. Salvage success was defined as abscess healing with follow-up secondary PCD placement for symptomatic hepatic satellite collections or for clinical recurrence. Catheter adjustments were performed during follow-up to optimize existing drains. Univariate, multivariate, and general linear mixed model analyses were performed. The median follow-up time after catheter removal was 6 months (range, 2-62 months). RESULTS: Drains were primarily successful in 54 patients (72%), and 17 patients (23%) needed salvage PCD; thus, overall success was achieved in 71 patients (95%). The other four patients (5%) died of sepsis. The primary success rate was reduced in patients with unresectable malignancies (p = 0.01), multiple abscesses (p = 0.01), and output ≥ 15 mL/d at catheter endpoint (n = 7, p = 0.001). Only unresectable malignancies had slightly lower overall success. Large abscesses (> 150 cm3) required more catheter adjustments and longer drainage duration to reach abscess cavity closure. Successfully drained abscesses reached cavity closure a mean of 23 days (95% CI, 20-27 days) after treatment. CONCLUSION: PCD was effective first-line treatment of complicated pyogenic liver abscesses, which often require catheter adjustment and salvage drainage procedures to reliably achieve success.

Changing the paradigm for diagnostic MRI in pediatrics: Don't hold your breath.

Increasingly complex pediatric patients and improvements in technology warrant reevaluation of the risk associated with anesthesia for diagnostic imaging. Although magnetic resonance imaging is the imaging modality of choice for children given the potentially harmful effects of computerized tomography-associated ionizing radiation, we dare to suggest that certain patients would benefit from the liberalization of our current standard. Incorporating the use of newer computerized tomography technology may improve safety for those that are already at higher risk for adverse events. Furthermore, magnetic resonance imaging is not risk-free-what is often overlooked is the need for controlled ventilation and breath-holding to minimize motion artifact. As physicians at the forefront of the development and sustainability of the perioperative surgical home, anesthesiologists must work to not only optimize patients preoperatively but should also act as gatekeepers for procedural safety.

Sequential Imaging of a Rapidly Progressive Rheumatoid Vasculitis: A Unique Depiction.

Rheumatoid vasculitis is a clinically heterogenous complication of rheumatoid arthritis (RA), primarily affecting small- and medium-sized vessels.1 A 63-year-old man with long-standing seropositive erosive RA presented to our emergency department with abdominal pain and diarrhea.

Tunneled hemodialysis catheter outcomes in elderly patients.

PURPOSE: This retrospective study evaluated tunneled catheter outcomes in patients aged 75 years and older undergoing hemodialysis. MATERIALS AND METHODS: Patients aged 75 years or older receiving hemodialysis comprised the study group. A control group of patients 40-60 years of age was randomly selected from the same dialysis quality assurance database. Demographic data, medical comorbidities, and catheter-specific data regarding indwelling time, function, interventions, and complications were recorded. RESULTS: Sixty-nine tunneled catheters were identified in 23 patients who comprised the study group (13 men and 10 women; mean age, 81.3 years; range, 75-88 y). The mean number of catheters per patient was three (range, 1-8). The mean indwelling time was 137.4 days (range, 2-622 d). Seventy-eight catheters were identified in the control group (n = 29; 14 men and 15 women; mean age, 50.6 years; range, 41-59 y). The mean number of catheters per patient was 2.7 (range, 1-9). The mean indwelling time was 139.7 days (range, 1-994 d). There was no statistically significant difference in the mean number of catheters per patient (P = .83) or the mean indwelling time (P = .93) between the two groups. There was no significant difference between the two groups in the indications for catheter removal or exchange: infection (P = 1.0), catheter no longer needed (P = 1.0), and physical catheter malfunction (P = .48). The calculated infection rates in the elderly patient and younger control groups were 0.30 per 100 catheter-days and 0.26 per 100 catheter-days, respectively. CONCLUSIONS: Tunneled catheter outcomes in patients aged 75 years and older undergoing hemodialysis do not vary significantly compared with those in a younger cohort.

Medical Student Performance After a Vertically Integrated Radiology Clerkship.

PURPOSE: Proper selection of imaging examinations and basic image interpretation skills are essential for all physicians, yet only approximately 25% of US medical schools require clerkships in radiology. Although there is limited time in most medical school curricula to allow the addition of a required radiology clerkship, the authors developed one that is vertically integrated over a two-year period. This clerkship includes one week of contact with radiologists distributed over the M2 and M3 years, podcasts, online modules, required readings, and presentations. A standard national examination is administered at the end of the clerkship period. This clerkship was designed to address the educational needs of students while occupying minimal time in the curriculum. The purpose of this study was to determine if students completing this clerkship perform as well on a national radiology examination as students from other medical schools, regardless of their curricula. METHODS: At the end of the M3 year, these students take a computer-based radiology examination developed by the Alliance of Medical Student Educators in Radiology and used by students at multiple medical schools nationally. The mean and median scores of these students were compared with those of students at these other institutions. RESULTS: The mean and median scores of the students were 74% and 74% (standard deviation, 7.5%) compared with 74% and 50% (standard deviation, 8.4%) at other institutions. CONCLUSIONS: Students completing this vertically integrated radiology clerkship had test scores comparable with those of students at other medical schools.

Needs Assessment for Standardized Medical Student Imaging Education: Review of the Literature and a Survey of Deans and Chairs.

RATIONALE AND OBJECTIVES: Medical imaging education often has limited representation in formal medical student curricula. Although the need for greater inclusion of radiology material is generally agreed on, the exact skillset that should be taught is less clear. The purpose of our study was to perform a needs assessment for a national radiology curriculum for medical students. MATERIALS AND METHODS: We analyzed data from previous unpublished portions of the American College of Radiology/Alliance of Medical Student Educators in Radiology survey of Deans and Radiology Chairs regarding prevalence of radiology curricular revisions, assessment tools, use of the American College of Radiology Appropriateness Criteria, and resources used in curriculum revision. We also performed a literature search through both PubMED and a general search engine (Google) to identify available resources for designing and implementing imaging curricula and curricular revisions. RESULTS: Medical school deans and chairs reported a need for more overall radiology content; one of every six programs (15%) reported they had no recognized imaging curriculum. Of schools currently with imaging curricula, 82% have undergone revision in the last 10 years using a variety of different resources, but there is no universally agreed on guide or standard curriculum. The PubMED and Google searches identified only 23 and eight resources, respectively, suggesting a sizable deficit in available guidance; however, a single published medical student radiology curriculum is available through the Alliance of Medical Student Educators in Radiology. CONCLUSIONS: There is a need, but few available resources, to guide educators in adding imaging content to medical school curricula. We postulate that a standardized national curriculum directed by a focused skillset may be useful to educators and could result in greater uniformity of imaging skills among graduating US medical students. A proposed skillset to guide a national curriculum in radiology is described.

Development of the AMSER standardized examinations in radiology for medical students.

RATIONALE AND OBJECTIVES: The variability in medical imaging evaluation across US medical schools inspired leading radiology student educators to develop the Alliance of Medical Student Educators in Radiology (AMSER) Standardized Exam (SE). This examination tests the understanding of essential material and concepts which are endorsed by the AMSER National Medical Student Curriculum in Radiology. MATERIALS AND METHODS: The AMSER Electronics Committee developed and deployed the AMSER SE using Radiology ExamWeb (REW), a previously-developed databank of imaging questions. The Committee created an examination blueprint that placed emphasis on effective use of medical imaging and less emphasis on image interpretation. Question items correlating to the blueprint were used from the REW databank to draft AMSER SE version 1, which was piloted in early 2012. Item performance was then analyzed, and the exam was revised. After national deployment, a subsequent revision was performed 1 year later. AMSER SE version 2, developed in a similar manner, was released in early 2013 and will go through a similar process of revision. A 20-question Practice Exam was also developed. RESULTS: Since national deployment, more than 1400 students, in over 22 institutions, have taken the AMSER SEs. CONCLUSIONS: The collaborative project of the AMSER Electronics Committee has resulted in the successful national deployment of two examinations using questions that have been validated and based on the AMSER peer-reviewed national curriculum. We hope that this assessment tool will help drive a more uniform approach to curriculum development, promoting more effective and safe use of medical imaging. This step should also help promote the value radiologists bring to the patient care arena.

Improving accuracy in reporting CT scans of oncology patients: assessing the effect of education and feedback interventions on the application of the Response Evaluation Criteria in Solid Tumors (RECIST) criteria.

RATIONALE AND OBJECTIVES: In February 2010, our radiology department adopted the use of the Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 criteria for newly diagnosed oncology patients. Prior to staff used RECIST 1.1, we hypothesized that education and feedback interventions could help clarify differences between RECIST 1.0 and the newly adopted RECIST 1.1 guidelines and result in appropriate and accurate utilization of both reporting systems. This study evaluates the effect of education and feedback interventions on the accuracy of computed tomography (CT) reporting using RECIST criteria. MATERIALS AND METHODS: Consecutive CT scan reports and images were retrospectively reviewed during three different periods to assess for compliance and adherence to RECIST guidelines. Data collected included interpreting faculty, resident, type, and total number of errors per report. Significance testing of differences between cohorts was performed using an unequal variance t-test. Group 1 (baseline): RECIST 1.0 used; prior to adoption of RECIST 1.1 criteria. Group 2 (post distributed educational materials): Following adoption of RECIST 1.1 criteria and distribution of educational materials. Group 3 (post audit and feedback): Following the audit and feedback intervention. RESULTS: The percentage of reports with errors decreased from 30% (baseline) to 28% (group 2) to 22% (group 3). Only the difference in error rate between the baseline and group 3 was significant (P = .03). CONCLUSION: The combination of distributed educational materials and audit and feedback interventions improved the quality of radiology reports requiring RECIST criteria by reducing the number of studies with errors.

Radiology ExamWeb: development and implementation of a national web-based examination system for medical students in radiology.

RATIONALE AND OBJECTIVES: Faculty are often limited in time, knowledge, and resources to develop efficient, effective, and valid computer-based examinations to evaluate students. Our purpose was to develop a web-based pool of standardized National Board of Medical Examiners (NBME)-format, peer-reviewed, and peer-tested questions based on the Alliance of Medical Student Educators in Radiology (AMSER) National Medical Student Curriculum to evaluate the radiologic knowledge of medical students. MATERIALS AND METHODS: Members of the AMSER Electronics Committee submitted questions they had written for their institutions and later developed a 113-question standardized examination. Questions were edited by 24 subspeciality editors and then further edited by the authors to NBME recommendations. Software was developed using commercially available software (www.ExamWeb.com) with extensive modifications and additions following initial deployment. Students take examinations online and receive their scores immediately. Items were validated by identifying those answered >30 times and analyzing the following: number of times deployed, number of times correctly answered, distractor-specific breakdown, difficulty level (P), and point biserial coefficient (rbi). RESULTS: Radiology ExamWeb (REW) is available online with 3500 registered students from 65 institutions and 1800 active questions. Instructors can create examinations or use "shared examinations" made by another instructor but enabled for other institutions to administer or modify. More than 300 shared examinations have been developed. The AMSER curriculum was converted into database format and crosschecked with question items to ensure that the question pool adequately covered the spectrum of the curriculum. An AMSER standardized examination has been developed and deployed within REW. CONCLUSIONS: REW has provided medical student educators with the means to evaluate students in a systematic way, using a nationally edited and regularly reviewed web-based process.

Cytomorphologic features of advanced lung adenocarcinomas tested for EGFR and KRAS mutations: a retrospective review of 50 cases.

Associations between bronchioloalveolar carcinoma (BAC), mucinous differentiation, and epidermal growth factor receptor (EGFR) and KRAS mutations have been previously reported in studies of surgical specimens. We present the cytomorphology of lung adenocarcinomas, including metastases that were diagnosed by cytologic methods and the relationship to both EGFR and KRAS mutational status. We retrospectively reviewed the clinical and cytomorphologic features of 50 lung adenocarcinomas that were tested for both EGFR and KRAS mutations. Cytomorphologic features evaluated included cell size, architectural pattern, nucleoli, intranuclear cytoplasmic inclusions (INCI), mucin, necrosis, squamoid features, lymphocytic response, and histologic features of BAC differentiation. DNA was extracted from a paraffin-embedded cell block or frozen needle core fragments. Exon 19 deletions and the L858R mutation in exon 21 of EGFR were detected using PCR followed by capillary electrophoresis for fragment sizing. KRAS mutational analysis was performed by real-time PCR using a set of seven different Taqman(r) allelic discrimination assays to detect six mutations in codon 12 and one mutation in codon 13. Six cases (12%) showed EGFR mutations, 12 (24%) showed KRAS mutations, and 38 (62%) contained neither EGFR nor KRAS mutations. The majority of patients had stage IV disease (78%); 20 samples (40%) were from metastatic sites. The presence of prominent INCI (P = 0.036), papillary fragments (P = 0.041), and histologic features of BAC on paraffin block (P = 0.039) correlated with the presence of EGFR mutations. The presence of necrosis (P = 0.030), squamoid features (P = 0.048), and poorly differentiated tumors (P = 0.025) were more likely to be identified in the KRAS positive group.

Complication rates and outcomes of 536 implanted subcutaneous chest ports: do rates differ based on the primary operator's level of training?

RATIONALE AND OBJECTIVES: Totally implanted subcutaneous central venous access devices (chest ports) are an attractive option for patients in need of intermittent, recurrent venous access. In our department, these are placed by different operator types including interventional radiology (IR) attending physicians, dedicated IR nurse practitioners (NP), and IR fellows/radiology residents. The purpose of our study is to assess the rate of complications of subcutaneous chest port placement among the different operator types. MATERIALS AND METHODS: A retrospective review of all subcutaneous central venous access devices implanted in our department between October 8, 2004, and October 19, 2007, was undertaken. Total numbers of port days, overall complication rates for all operators, as well as complication rates for the various operator types were calculated and were compared using the chi square test. RESULTS: A total of 558 patients had totally implanted subcutaneous central venous access devices placed during the period of study. Of these, 536 had documented follow-up and comprise the study population. A total of 89 were placed by attending physician alone, 133 by an NP, and 314 by an IR fellow or resident, with supervision by an attending physician. Mean duration of port usage was 341 days with 182,522 total port days. A total of 39 complications occurred (7.28%), including 27 infections (5%). There was no statistically significant difference in overall complication rates, including infection rates, among operator groups (P = .925). CONCLUSIONS: Our results confirm that well-trained physician extenders and trainees can safely perform chest port placement and that these providers, under appropriate supervision, can help provide improved access to chest port placement for patients and referring clinicians.

Implantable subcutaneous venous access devices: is port fixation necessary? A review of 534 cases.

Conventional surgical technique of subcutaneous venous port placement describes dissection of the port pocket to the pectoralis fascia and suture fixation of the port to the fascia to prevent inversion of the device within the pocket. This investigation addresses the necessity of that step. Between October 8, 2004 and October 19, 2007, 558 subcutaneous chest ports were placed at our institution; 24 cases were excluded from this study. We performed a retrospective review of the remaining 534 ports, which were placed using standard surgical technique with the exception that none were sutured into the pocket. Mean duration of port use, total number of port days, indications for removal, and complications were recorded and compared with the literature. Mean duration of port use was 341 days (182,235 total port days, range 1-1279). One port inversion/flip occurred, which resulted in malfunction and necessitated port revision (0.2%). Other complications necessitating port removal included infection 26 (5%), thrombosis n = 2 (<1%), catheter fracture/pinch n = 1 (<1%), pain n = 2 (<1%), and skin erosion n = 3 (1%). There were two arrhythmias at the time of placement; neither required port removal. The overall complication rate was 7%. The 0.2% incidence of port inversion we report is concordant with that previously published, although many previous reports do not specify if suture fixation of the port was performed. Suture fixation of the port, in our experience, is not routinely necessary and may negatively impact port removal.

Reactivation Mycobacterium Tuberculosis Presenting as Empyema Necessitans 55 Years Following Thoracoplasty.

We describe the case of a 79-year-old man who presented with an enlarging mass on his chest wall. He had a history of thoracoplasty performed 55 years ago for treatment of pulmonary tuberculosis. The mass was subsequently proven to be the result of empyema neccesitans caused by reactivation tuberculosis. Empyema neccesitans is a well described entity in which an empyema spontaneously decompresses by dissecting into the chest wall and extrathoracic soft tissues. This can occur following necrotizing pneumonia, including pyogenic or tuberculus, or pulmonary abscess. Complications from collapse therapy for tuberculosis can be encountered decades following the surgery, however, empyema necessitans due to reactivation tuberculosis is rare. This case affords the opportunity to review the goals, techniques, and radiologic appearance of thoracoplasty.

Multidetector CT of the liver and hepatic neoplasms: effect of multiphasic imaging on tumor conspicuity and vascular enhancement.

OBJECTIVE: Our aim was to determine which of three contrast-enhanced phases (early arterial, late arterial, or portal venous) was optimal for achieving maximal enhancement of the celiac artery, portal vein, and hepatic parenchyma. We also wanted to learn which phase provided the maximal tumor-to-parenchyma difference when using multidetector CT (MDCT) with fixed timing delays. MATERIALS AND METHODS: Fifty-two patients with suspected or known hepatic tumors underwent multiphasic contrast-enhanced MDCT using double arterial (early and late arterial) and venous phase acquisitions with fixed timing delays. All patients were administered 150 mL of IV contrast material at an injection rate of 4 mL/sec. Images were acquired at 20 sec for the early arterial phase, 35 sec for the late arterial phase, and 60 sec for the portal venous phase. Attenuation measurements of the celiac artery, portal vein, normal hepatic parenchyma, and the hepatic tumor were compared. Three reviewers independently and subjectively rated tumor conspicuity for each of the three phases. Ratings were compared using kappa statistics. RESULTS: Late arterial phase images showed maximal celiac axis attenuation, whereas portal venous phase images revealed the highest portal vein and normal hepatic parenchymal attenuation. Maximal tumor-to-parenchyma differences for hypovascular tumors was superior in the portal venous phase, but we found no significant differences in maximal tumor-to-parenchyma differences for hypervascular tumors among the evaluated phases. On subjective analysis, interobserver agreement was moderate to very good for the three phases. All three reviewers graded both hypovascular and hypervascular tumor conspicuity as superior in either the late arterial phase or the portal venous phase in most patients. In only one patient was the early arterial phase graded as superior to the late arterial and portal venous phases (by two of the three reviewers). CONCLUSION: When MDCT of the liver is performed using fixed timing delays, maximal vascular and hepatic parenchymal enhancement is achieved on either late arterial phase or portal venous phase imaging. In most patients, early arterial phase imaging does not improve tumor conspicuity by either quantitative or subjective analysis.