SBRT for HCC: Overview of technique and treatment response assessment.

Stereotactic body radiation therapy (SBRT) is an emerging locoregional treatment (LRT) modality used in the management of patients with hepatocellular carcinoma (HCC). The decision to treat HCC with LRT is evaluated in a multidisciplinary setting, and the specific LRT chosen depends on the treatment intent, such as bridge-to-transplant, down-staging to transplant, definitive/curative treatment, and/or palliation, as well as underlying patient clinical factors. Accurate assessment of treatment response is necessary in order to guide clinical management in these patients. Patients who undergo LRT need continuous imaging evaluation to assess treatment response and to evaluate for recurrence. Thus, an accurate understanding of expected post-SBRT imaging findings is critical to avoid misinterpreting normal post-treatment changes as local progression or viable tumor. SBRT-treated HCC demonstrates unique imaging findings that differ from HCC treated with other forms of LRT. In particular, SBRT-treated HCC can demonstrate persistent APHE and washout on short-term follow-up imaging. This brief review summarizes current evidence for the use of SBRT for HCC, including patient population, SBRT technique and procedure, tumor response assessment on contrast-enhanced cross-sectional imaging with expected findings, and pitfalls in treatment response evaluation.

Association of obesity with illness severity in hospitalized patients with COVID-19: A retrospective cohort study.

BACKGROUND: Although recent studies have shown an association between obesity and adverse coronavirus disease 2019 (COVID-19) patient outcomes, there is a paucity in large studies focusing on hospitalized patients. We aimed to analyze outcomes associated with obesity in a large cohort of hospitalized COVID-19 patients. METHODS: We performed a retrospective study at a tertiary care health system of adult patients with COVID-19 who were admitted between March 1 and April 30, 2020. Patients were stratified by body mass index (BMI) into obese (BMI ≥ 30 kg/m 2) and non-obese (BMI < 30 kg/m 2) cohorts. Primary outcomes were mortality, intensive care unit (ICU) admission, intubation, and 30-day readmission. RESULTS: A total of 1983 patients were included of whom 1031 (51.9%) had obesity and 952 (48.9%) did not have obesity. Patients with obesity were younger (P < 0.001), more likely to be female (P < 0.001) and African American (P < 0.001) compared to patients without obesity. Multivariable logistic models adjusting for differences in age, sex, race, medical comorbidities, and treatment modalities revealed no difference in 60-day mortality and 30-day readmission between obese and non-obese groups. In these models, patients with obesity had increased odds of ICU admission (adjusted OR, 1.37; 95% CI, 1.07-1.76; P = 0.012) and intubation (adjusted OR, 1.37; 95% CI, 1.04-1.80; P = 0.026). CONCLUSIONS: Obesity in patients with COVID-19 is independently associated with increased risk for ICU admission and intubation. Recognizing that obesity impacts morbidity in this manner is crucial for appropriate management of COVID-19 patients.

Small intrahepatic peripheral cholangiocarcinomas as mimics of hepatocellular carcinoma in multiphasic CT.

PURPOSE: Liver transplant guidelines for diagnosing hepatocellular carcinoma (HCC) do not mandate pathologic confirmation; instead, 'classic' imaging features alone are deemed satisfactory. Intrahepatic peripheral mass forming cholangiocarcinoma (IHPMCC) is a relative contraindication for transplantation due to high rate of recurrence and poor prognosis. This study examines the imaging findings of IHPMCC, to aid in the identification and differentiation from potentially confounding cases of HCC. METHODS: After IRB approval, 43 tissue-proven cases of IHPMCC on multiphase CT were retrospectively reviewed by 2 fellowship-trained radiologists. Tumor size, presence of cirrhosis, tumor capsule, vascular invasion, tumor markers, and enhancement pattern were assessed. A grading system was assigned as determined by enhancement pattern to background liver on arterial, portal venous, and equilibrium phases, ranging from typical HCC to typical IHPMCC enhancement pattern. RESULTS: Analysis based on our grading system shows 5 (11.6%) tumors demonstrating grade 1-2 enhancement, 9 (21%) grade 3-4 enhancement, and 29 (67.4%) grade 5 enhancement. Kruskal-Wallis test comparing CA19-9 between the five groups, Wilcoxin rank-sum test comparing tumor markers with presence or absence of tumor capsule, vascular invasion and cirrhosis, and nonparametric Pearson's correlation coefficient comparing tumor markers to tumor size were not statistically significant (p > 0.05). CONCLUSION: Typical enhancement pattern of IHPMCC consisting of arterial phase hypoenhancement with progressive, centripetal-delayed enhancement is present in the majority of cases (68%). Five cases (11.7%) showed enhancement features potentially mimicking HCC, all of which are under 3.5 cm in size. Thus, small hyperenhancing lesions in a cirrhotic liver should be carefully scrutinized in light of differing therapy options from HCC, particularly in transplant situations.

Simulation center training as a means to improve resident performance in percutaneous noncontinuous CT-guided fluoroscopic procedures with dose reduction.

OBJECTIVE: The purpose of this study was to evaluate the effectiveness of a multifaceted simulation-based resident training for CT-guided fluoroscopic procedures by measuring procedural and technical skills, radiation dose, and procedure times before and after simulation training. SUBJECTS AND METHODS: A prospective analysis included 40 radiology residents and eight staff radiologists. Residents took an online pretest to assess baseline procedural knowledge. Second-through fourth-year residents' baseline technical skills with a procedural phantom were evaluated. First-through third-year residents then underwent formal didactic and simulation-based procedural and technical training with one of two interventional radiologists and followed the training with 1 month of supervised phantom-based practice. Thereafter, residents underwent final written and practical examinations. The practical examination included essential items from a 20-point checklist, including site and side marking, consent, time-out, and sterile technique along with a technical skills portion assessing pedal steps, radiation dose, needle redirects, and procedure time. RESULTS: The results indicated statistically significant improvement in procedural and technical skills after simulation training. For residents, the median number of pedal steps decreased by three (p=0.001), median dose decreased by 15.4 mGy (p<0.001), median procedure time decreased by 4.0 minutes (p<0.001), median number of needle redirects decreased by 1.0 (p=0.005), and median number of 20-point checklist items successfully completed increased by three (p<0.001). The results suggest that procedural skills can be acquired and improved by simulation-based training of residents, regardless of experience. CONCLUSION: CT simulation training decreases procedural time, decreases radiation dose, and improves resident efficiency and confidence, which may transfer to clinical practice with improved patient care and safety.

The use of a simulation center to improve resident proficiency in performing ultrasound-guided procedures.

RATIONALE AND OBJECTIVES: With advancements in technology and push for health care reform and reduced costs, minimally invasive procedures, such as those that are ultrasound-guided, have become an essential part of radiology, and are used in many divisions of radiology. By incorporating standardized training methodologies in a risk free environment through utilization of a simulation center with phantom training, we hope to improve proficiency and confidence in procedural performance. MATERIALS AND METHODS: Twenty-nine radiology residents from four levels of training were enrolled in this prospective study. The residents were given written, video, and live interactive training on the basics of ultrasound-guided procedures in our simulation center on a phantom mannequin. All of the teaching materials were created by residents and staff radiologists at the institution. RESULTS: Residents demonstrated statistically significant improvement (P < .05) between their pre- and posttest scores on both the written and practical examinations. They also showed a trend toward improved dexterity in the technical aspects of ultrasound-guided procedures (P = .07) after training. On the survey questionnaire, residents confirm improved knowledge level, technical ability, and confidence levels pertaining to ultrasound-guided procedures. CONCLUSIONS: The use of controlled simulation based training can be an invaluable tool to improve the knowledge level, dexterity, and confidence of residents performing ultrasound-guided procedures. Additionally, a simulation model allows standardization of education.