Reduction in Chest CT Severity and Improved Hospital Outcomes in SARS-CoV-2 Omicron Compared with Delta Variant Infection.

Background The SARS-Cov-2 Omicron variant demonstrates rapid spread but reduced disease severity. Studies evaluating lung imaging findings of Omicron infection versus non-Omicron infection remain lacking. Purpose To compare the Omicron variant with the SARS-CoV-2 Delta variant according to their chest CT radiologic pattern, biochemical parameters, clinical severity, and hospital outcomes after adjusting for vaccination status. Materials and Methods This retrospective study included hospitalized adult patients with reverse transcriptase-polymerase chain reaction test results positive for SARS-CoV-2, with CT pulmonary angiography performed within 7 days of admission between December 1, 2021, and January 14, 2022. Multiple readers performed blinded radiologic analyses that included RSNA CT classification, chest CT severity score (CTSS) (range, 0 [least severe] to 25 [most severe]), and CT imaging features, including bronchial wall thickening. Results A total of 106 patients (Delta group, n = 66; Omicron group, n = 40) were evaluated (overall mean age, 58 years ± 18 [SD]; 58 men). In the Omicron group, 37% of CT pulmonary angiograms (15 of 40 patients) were categorized as normal compared with 15% (10 of 66 patients) of angiograms in the Delta group (P = .016). A generalized linear model was used to control for confounding variables, including vaccination status, and Omicron infection was associated with a CTSS that was 7.2 points lower than that associated with Delta infection (ß = -7.2; 95% CI: -9.9, -4.5; P < .001). Bronchial wall thickening was more common with Omicron infection than with Delta infection (odds ratio [OR], 2.4; 95% CI: 1.01, 5.92; P = .04). A booster shot was associated with a protective effect for chest infection (median CTSS, 5; IQR, 0-11) when compared with unvaccinated individuals (median CTSS, 11; IQR, 7.5-14.0) (P = .03). The Delta variant was associated with a higher OR of severe disease (OR, 4.6; 95% CI: 1.2, 26; P = .01) and admission to a critical care unit (OR, 7.0; 95% CI: 1.5, 66; P = .004) when compared with the Omicron variant. Conclusion The SARS-CoV-2 Omicron variant was associated with fewer and less severe changes on chest CT images compared with the Delta variant. Patients with Omicron infection had greater frequency of bronchial wall thickening but less severe disease and improved hospital outcomes when compared with patients with Delta infection. © RSNA, 2022 Online supplemental material is available for this article.

Achieving Molecular Profiling in Pleural Biopsies: A Multicenter, Retrospective Cohort Study.

BACKGROUND: Pleural biopsy findings offer greater diagnostic sensitivity in malignant pleural effusions compared with pleural fluid. The adequacy of pleural biopsy techniques in achieving molecular marker status has not been studied, and such information (termed "actionable" histology) is critical in providing a rational, efficient, and evidence-based approach to diagnostic investigation. RESEARCH QUESTION: What is the adequacy of various pleural biopsy techniques at providing adequate molecular diagnostic information to guide treatment in malignant pleural effusions? STUDY DESIGN AND METHODS: This study analyzed anonymized data on 183 patients from four sites across three countries in whom pleural biopsy results had confirmed a malignant diagnosis and molecular profiling was relevant for the diagnosed cancer type. The primary outcome measure was adequacy of pleural biopsy for achieving molecular marker status. Secondary outcomes included clinical factors predictive of achieving a molecular diagnosis. RESULTS: The median age of patients was 71 years (interquartile range, 63-78 years), with 92 of 183 (50%) male. Of the 183 procedures, 105 (57%) were local anesthetic thoracoscopies (LAT), 12 (7%) were CT scan guided, and 66 (36%) were ultrasound guided. Successful molecular marker analysis was associated with mode of biopsy, with LAT having the highest yield and ultrasound-guided biopsy the lowest (LAT vs CT scan guided vs ultrasound guided: LAT yield, 95%; CT scan guided, 86%; and ultrasound guided, 77% [P = .004]). Biopsy technique and size of biopsy sample were independently associated with successful molecular marker analysis. LAT had an adjusted OR for successful diagnosis of 30.16 (95% CI, 3.15-288.56; P = .003) and biopsy sample size an OR of 1.18 (95% CI, 1.02-1.37) per millimeter increase in tissue sample size (P < .03). INTERPRETATION: Although previous studies have shown comparable overall diagnostic yields, in the modern era of targeted therapies, this study found that LAT offers far superior results to image-guided techniques at achieving molecular profiling and remains the optimal diagnostic tool.

Lung cancer prediction by Deep Learning to identify benign lung nodules.

INTRODUCTION: Deep Learning has been proposed as promising tool to classify malignant nodules. Our aim was to retrospectively validate our Lung Cancer Prediction Convolutional Neural Network (LCP-CNN), which was trained on US screening data, on an independent dataset of indeterminate nodules in an European multicentre trial, to rule out benign nodules maintaining a high lung cancer sensitivity. METHODS: The LCP-CNN has been trained to generate a malignancy score for each nodule using CT data from the U.S. National Lung Screening Trial (NLST), and validated on CT scans containing 2106 nodules (205 lung cancers) detected in patients from from the Early Lung Cancer Diagnosis Using Artificial Intelligence and Big Data (LUCINDA) study, recruited from three tertiary referral centers in the UK, Germany and Netherlands. We pre-defined a benign nodule rule-out test, to identify benign nodules whilst maintaining a high sensitivity, by calculating thresholds on the malignancy score that achieve at least 99 % sensitivity on the NLST data. Overall performance per validation site was evaluated using Area-Under-the-ROC-Curve analysis (AUC). RESULTS: The overall AUC across the European centers was 94.5 % (95 %CI 92.6-96.1). With a high sensitivity of 99.0 %, malignancy could be ruled out in 22.1 % of the nodules, enabling 18.5 % of the patients to avoid follow-up scans. The two false-negative results both represented small typical carcinoids. CONCLUSION: The LCP-CNN, trained on participants with lung nodules from the US NLST dataset, showed excellent performance on identification of benign lung nodules in a multi-center external dataset, ruling out malignancy with high accuracy in about one fifth of the patients with 5-15 mm nodules.

The utility of a convolutional neural network (CNN) model score for cancer risk in indeterminate small solid pulmonary nodules, compared to clinical practice according to British Thoracic Society guidelines.

PURPOSE: To determine how implementation of an artificial intelligence nodule algorithm, the Lung Cancer Prediction Convolutional Neural Network (LCP-CNN), at the point of incidental nodule detection would have influenced further investigation and management using a series of threshold scores at both the benign and malignant end of the spectrum. METHOD: An observational retrospective study was performed in the assessment of nodules between 5-15 mm (158 benign, 32 malignant) detected on CT scans, which were performed as part of routine practice. The LCP-CNN was applied to the baseline CT scan producing a percentage score, and subsequent imaging and management determined for each threshold group. We hypothesized that the 5% low risk threshold group requires only one follow-up, the 0.56% very low risk threshold group requires no follow-up and the 80% high risk threshold group warrants expedited intervention. RESULTS: The 158 benign nodules had an LCP-CNN score between 0.1 and 70.8%, median 5.5% (IQR 1.4-18.0), whilst the 32 cancer nodules had an LCP-CNN score between 10.1 and 98.7%, median 59.0% (IQR 37.1-83.9). 24/61 CT scans in the 0.56-5% group (n = 37) and 21/21 CT scans <0.56% group (n = 13) could be obviated resulting in an overall reduction of 18.6% (45/242) CT scans in the benign cohort. In the 80% group (n = 10), expedited intervention of malignant nodules could result in a 3.6-month reduction in time delay in 5 cancer patients. CONCLUSION: We show the potential of artificial intelligence to reduce the need for follow-up scans and intervention in low-scoring benign nodules, whilst potentially accelerating the investigation and treatment of high-scoring cancer nodules.

Is microwave ablation an alternative to stereotactic ablative body radiotherapy in patients with inoperable early-stage primary lung cancer?

A best evidence topic was written according to a structured protocol. The question addressed was: in patients with inoperable early-stage primary lung cancer does microwave ablation (MWA) or stereotactic ablative body radiotherapy (SBRT) achieve improved outcomes in terms of local control, recurrence, survival and complications? Altogether, more than 550 papers were found using the reported search, of which 12 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. No single study directly compared the effects of MWA with SBRT. However, the best available evidence for MWA (7 studies) was compared to that for SBRT (5 studies). The range of 3-year survival reported for MWA was 29.2-84.7%, compared with 42.7-63.5% for SBRT. The range of median survival was 35-60 months for MWA and 32.6-48 months for SBRT. This suggests similar outcomes between these two 2 techniques. Different side-effect profiles were observed between techniques with MWA associated with pneumothorax and fever and SBRT most commonly causing radiation pneumonitis and rib fractures. The evidence base for MWA is less than that for SBRT and is heterogenous in terms of participants and technical design. However, within these limitations, we conclude that MWA appears comparable with SBRT in terms of local control and survival rates.

Development of a best-practice clinical guideline for the use of bleomycin in the treatment of germ cell tumours in the UK.

Bleomycin, a cytotoxic chemotherapy agent, forms a key component of curative regimens for lymphoma and germ cell tumours. It can be associated with severe toxicity, long-term complications and even death in extreme cases. There is a lack of evidence or consensus on how to prevent and monitor bleomycin toxicity. We surveyed 63 germ cell cancer physicians from 32 cancer centres across the UK to understand their approach to using bleomycin. Subsequent guideline development was based upon current practice, best available published evidence and expert consensus. We observed heterogeneity in practice in the following areas: monitoring; route of administration; contraindications to use; baseline and follow-up investigations performed, and advice given to patients. A best-practice clinical guideline for the use of bleomycin in the treatment of germ cell tumours has been developed and includes recommendations regarding baseline investigations, the use of pulmonary function tests, route of administration, monitoring and patient advice. It is likely that existing heterogeneity in clinical practice of bleomycin prescribing has significant economic, safety and patient experience implications. The development of an evidence-based consensus guideline was supported by 93% of survey participants and aims to address these issues and homogenise practice across the UK.

Bayesian penalised likelihood reconstruction (Q.Clear) of 18F-fluciclovine PET for imaging of recurrent prostate cancer: semi-quantitative and clinical evaluation.

OBJECTIVE: 18F-Fluciclovine (FACBC) is an amino acid PET radiotracer approved for recurrent prostate cancer imaging. We investigate the use of Bayesian penalised likelihood (BPL) reconstruction for 18F-fluciclovine PET. METHODS: 15 18F-fluciclovine scans were reconstructed using ordered subset expectation maximisation (OSEM), OSEM + point spread function (PSF) modelling and BPL using ß-values 100-600. Lesion maximum standardised uptake value (SUVmax), organ SUVmean and standard deviation were measured. Deidentified reconstructions (OSEM, PSF, BPL using ß200-600) from 10 cases were visually analysed by two readers who indicated their most and least preferred reconstructions, and scored overall image quality, noise level, background marrow image quality and lesion conspicuity. RESULTS: Comparing BPL to OSEM, there were significant increments in lesion SUVmax and signal-to-background up to ß400, with highest gain in ß100 reconstructions (mean ΔSUVmax 3.9, p < 0.0001). Organ noise levels increased on PSF, ß100 and ß200 reconstructions. Across BPL reconstructions, there was incremental reduction in organ noise with increasing ß, statistically significant beyond ß300-500 (organ-dependent). Comparing with OSEM and PSF, lesion signal-to-noise was significantly increased in BPL reconstructions where ß ≥ 300 and  ≥ 200 respectively. On visual analysis, ß 300 had the first and second highest scores for image quality, ß500 and ß600 equal highest scores for marrow image quality and least noise, PSF and ß 200 had first and second highest scores for lesion conspicuity. For overall preference, one reader preferred ß 300 in 9/10 cases and the other preferred ß 200 in all cases. CONCLUSION: BPL reconstruction of 18F-fluciclovine PET images improves signal-to-noise ratio, affirmed by overall reader preferences. On balance, ß300 is suggested for 18F-fluciclovine whole body PET image reconstruction using BPL. Advances in knowledge: The optimum ß is different to that previously published for 18F-fluorodeoxyglucose, and has practical implications for a relatively new tracer in an environment with modern reconstruction technologies.

Recurrent Malignant Melanoma Detected on 18F-Fluciclovine PET/CT Imaging for Prostate Cancer.

A 66-year-old man presented with biochemical recurrence of prostate cancer and underwent F-fluciclovine PET/CT to detect sites of recurrence. He had a history of resected truncal stage IIIC malignant melanoma, with bilateral axillary node involvement on sentinel node biopsy, in complete remission for 3 years. F-fluciclovine PET/CT demonstrated an incidental fluciclovine-avid right axillary node (SUVmax = 4.3). Diagnostic sampling confirmed recurrent malignant melanoma.

Radial artery for coronary artery bypass grafting: does proximal anastomosis to the aorta or left internal mammary artery achieve better patency?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was 'in coronary artery bypass grafting using radial artery grafts, does proximal anastomosis to the aorta or left internal mammary artery achieve better patency'. Altogether >183 papers were found using the reported search, of which 9 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Radial artery grafts typically have a narrower lumen than vein grafts, and as such there is some concern that anastomosing them directly to the aorta during coronary artery bypass grafting (CABG) may impair graft patency. As such, some surgeons prefer to anastomose radial artery grafts to a second-order vessel such as the left internal mammary artery (LIMA). We sought to assess the evidence for this. A handful of papers directly addressing the issue of the effect of the site of proximal anastomosis on graft patency were found, with three showing no significant difference. One such study reported an insignificant difference in angiographic patency at 32 months postoperatively, with 94.1% of off-aorta grafts remaining patent vs 87.2% of off-LIMA grafts (p = 0.123). However, a large-scale well-designed study was able to demonstrate a statistically significant difference at five years postoperatively, with 74.3% of off-aorta grafts patent, compared with 65.2% of off-LIMA (p = 0.004). Nonetheless, a number of papers that report patency for either off-aorta or off-LIMA grafts give comparable figures for each technique. Additionally, different centres and investigators report very different patency results for grafts that have the same site of proximal anastomosis. One centre was able to achieve patency rates for off-LIMA grafts of 88% up to a mean of 7.7 years postoperatively while another centre reported a patency rate of only 78.6% at three years. Given this, and the plethora of other factors influencing graft patency, we conclude that the best evidence suggests that the site of proximal anastomosis has little or no effect on radial artery graft patency following CABG.