Image-Guided Precision Medicine in the Diagnosis and Treatment of Pheochromocytomas and Paragangliomas.

In this comprehensive review, we aimed to discuss the current state-of-the-art medical imaging for pheochromocytomas and paragangliomas (PPGLs) diagnosis and treatment. Despite major medical improvements, PPGLs, as with other neuroendocrine tumors (NETs), leave clinicians facing several challenges; their inherent particularities and their diagnosis and treatment pose several challenges for clinicians due to their inherent complexity, and they require management by multidisciplinary teams. The conventional concepts of medical imaging are currently undergoing a paradigm shift, thanks to developments in radiomic and metabolic imaging. However, despite active research, clinical relevance of these new parameters remains unclear, and further multicentric studies are needed in order to validate and increase widespread use and integration in clinical routine. Use of AI in PPGLs may detect changes in tumor phenotype that precede classical medical imaging biomarkers, such as shape, texture, and size. Since PPGLs are rare, slow-growing, and heterogeneous, multicentric collaboration will be necessary to have enough data in order to develop new PPGL biomarkers. In this nonsystematic review, our aim is to present an exhaustive pedagogical tool based on real-world cases, dedicated to physicians dealing with PPGLs, augmented by perspectives of artificial intelligence and big data.

Left gastric vein embolization during TIPS placement for acute variceal bleeding has no effect on bleeding recurrence: Results of a multicenter study.

PURPOSE: The purpose of this study was to evaluate whether concomitant left gastric vein embolization (LGVE) during transjugular intrahepatic portosystemic shunt (TIPS) for acute variceal hemorrhage could reduce the risk of bleeding recurrence. MATERIAL AND METHOD: A national multicenter observational study was conducted in 14 centers between January 2019 and December 2020. All cirrhotic patients who underwent TIPS placement for acute variceal bleeding were included. During TIPS procedure, size of left gastric vein (LGV), performance of LGVE, material used for LGVE and portosystemic pressure gradient (PPG) before and after TIPS placement were collected. A propensity score for the occurrence of LGVE was calculated to assess effect of LGVE on rebleeding recurrence at six weeks and one year. RESULTS: A total of 356 patients were included (mean age 57.3 ± 10.8 [standard deviation] years; 283/356 [79%] men). Median follow-up was 11.2 months [interquartile range: 1.2, 13.3]. The main indication for TIPS was pre-emptive TIPS (162/356; 46%), rebleeding despite secondary prophylaxis (105/356; 29%), and salvage TIPS (89/356; 25%). Overall, 128/356 (36%) patients underwent LGVE during TIPS procedure. At six weeks and one year, rebleeding-free survival did not differ significantly between patients who underwent LGVE and those who did not (6/128 [5%] vs. 15/228 [7%] at six weeks, and 11/128 [5%] vs. 22/228 [7%] at one year, P = 0.622 and P = 0.889 respectively). A total of 55 pairs of patients were retained after propensity score matching. In patients without LGVE, the rebleeding rate was not different from those with LGVE (3/55 [5%] vs. 4/55 [7%], P > 0.99, and 5/55 [9%] vs. 6/55[11%], P > 0.99, at six weeks and one year respectively). Multivariable analysis identified PPG after TIPS placement as the only predictor of bleeding recurrence (hazard ratio = 1.09; 95% confidence interval: 1.02-1.18; P = 0.012). CONCLUSION: In this multicenter national real-life study, we did not observe any benefit of concomitant LGVE during TIPS placement for acute variceal bleeding on bleeding recurrence rate.

Emerging and Evolving Concepts in Cancer Immunotherapy Imaging.

Criteria based on measurements of lesion diameter at CT have guided treatment with historical therapies due to the strong association between tumor size and survival. Clinical experience with immune checkpoint modulators shows that editing immune system function can be effective in various solid tumors. Equally, novel immune-related phenomena accompany this novel therapeutic paradigm. These effects of immunotherapy challenge the association of tumor size with response or progression and include risks and adverse events that present new demands for imaging to guide treatment decisions. Emerging and evolving approaches to immunotherapy highlight further key issues for imaging evaluation, such as dissociated response following local administration of immune checkpoint modulators, pseudoprogression due to immune infiltration in the tumor environment, and premature death due to hyperprogression. Research that may offer tools for radiologists to meet these challenges is reviewed. Different modalities are discussed, including immuno-PET, as well as new applications of CT, MRI, and fluorodeoxyglucose PET, such as radiomics and imaging of hematopoietic tissues or anthropometric characteristics. Multilevel integration of imaging and other biomarkers may improve clinical guidance for immunotherapies and provide theranostic opportunities.

Body weight changes and duration of estrogen exposure modulate the evolution of hepatocellular adenomas after contraception discontinuation.

BACKGROUND AND AIMS: The natural history of hepatocellular adenomas (HCAs) remains to be better described, especially in nonresected patients. We aim to identify the predictive factors of HCA evolution after estrogen-based contraception discontinuation. APPROACH AND RESULTS: We retrospectively included patients with a histological diagnosis of HCA from three centers. Clinical, radiological, and pathological data were collected to identify predictive factors of radiological evolution per Response Evaluation Criteria in Solid Tumors, version 1.1, and occurrence of complications (bleeding, malignant transformation). We built a score using variables that modulate estrogen levels: body mass index and duration of estrogen-based contraception. An external cohort was used to validate this score. 183 patients were included in the cohort, including 161 women (89%) using estrogen-based contraception for a median of 12 years. Thirty percent of patients had at least one HNF1A -inactivated HCA, 45.5% at least one inflammatory HCA, and 11% at least one HCA with activation of ß-catenin (bHCA). Twenty-one symptomatic bleedings (11%) and eleven malignant transformations (6%) occurred. Ages < 37 years old ( p = 0.004) and HCA > 5 cm at imaging were independently associated with symptomatic bleeding ( p = 0.003), whereas a bHCA was associated with malignant transformation ( p < 0.001). After a median follow-up of 5 years, radiological regression was observed in 31%, stabilization in 47%, and progression in 22% of patients. Weight loss was associated with regression ( p < 0.0001) and weight gain with progression ( p = 0.02). The estrogen exposure score predicted radiological regression (odds ratio, 2.33; confidence interval 95%, 1.29-4.19; p = 0.005) with a linear relationship between the rate of estrogen exposure and the probability of regression. This result was confirmed in an external cohort of 72 female patients ( p = 0.003). CONCLUSION: Weight variation is strongly associated with radiological evolution after oral contraception discontinuation. A score of estrogen exposure, easily assessable in clinical practice at diagnosis, predicts regression of HCA.

Artificial intelligence and radiomics: fundamentals, applications, and challenges in immunotherapy.

Immunotherapy offers the potential for durable clinical benefit but calls into question the association between tumor size and outcome that currently forms the basis for imaging-guided treatment. Artificial intelligence (AI) and radiomics allow for discovery of novel patterns in medical images that can increase radiology's role in management of patients with cancer, although methodological issues in the literature limit its clinical application. Using keywords related to immunotherapy and radiomics, we performed a literature review of MEDLINE, CENTRAL, and Embase from database inception through February 2022. We removed all duplicates, non-English language reports, abstracts, reviews, editorials, perspectives, case reports, book chapters, and non-relevant studies. From the remaining articles, the following information was extracted: publication information, sample size, primary tumor site, imaging modality, primary and secondary study objectives, data collection strategy (retrospective vs prospective, single center vs multicenter), radiomic signature validation strategy, signature performance, and metrics for calculation of a Radiomics Quality Score (RQS). We identified 351 studies, of which 87 were unique reports relevant to our research question. The median (IQR) of cohort sizes was 101 (57-180). Primary stated goals for radiomics model development were prognostication (n=29, 33.3%), treatment response prediction (n=24, 27.6%), and characterization of tumor phenotype (n=14, 16.1%) or immune environment (n=13, 14.9%). Most studies were retrospective (n=75, 86.2%) and recruited patients from a single center (n=57, 65.5%). For studies with available information on model testing, most (n=54, 65.9%) used a validation set or better. Performance metrics were generally highest for radiomics signatures predicting treatment response or tumor phenotype, as opposed to immune environment and overall prognosis. Out of a possible maximum of 36 points, the median (IQR) of RQS was 12 (10-16). While a rapidly increasing number of promising results offer proof of concept that AI and radiomics could drive precision medicine approaches for a wide range of indications, standardizing the data collection as well as optimizing the methodological quality and rigor are necessary before these results can be translated into clinical practice.

A Dynamic Anatomic Study of Parasacral Perforators: Mapping, Perforasome, and Applications for Buttock Enhancement.

BACKGROUND: Due to the lack of knowledge about parasacral artery perforators, flaps from this region cannot be used with complete confidence in their security and effectiveness. Knowledge of the clusters and perforasome of these perforators could help in the design of more reliable flaps and extend the range of applications. OBJECTIVES: This study aimed to identify the location, number, and density of perforators, and to subsequently analyze the perfusion flow and linking vessel distribution. METHODS: Five fresh cadavers were harvested and dissected. For the mapping, after injecting lateral sacral arteries with colored latex, perforators with a diameter of >0.5 cm were examined in 5 sacral regions. All data were collected on the suprafascial plane, with an orthonormal coordinate system placed on iliac crests and median lines. For perforasome analysis, 5 perforators and 3 three sacral flaps were injected with radiopaque dye. A dynamic (4-dimensional) computed tomographic angiography completed the analysis. RESULTS: A mean [standard deviation] of 8.4 [1.36] perforators per corpse, with a mean diameter of 0.72 [0.14] mm, were identified. There was a higher density of parasacral perforators close to the median line and 7.6 cm above the iliac crests. This pattern was not a random distribution (P < 0.05). The perfusion area was preferentially in the superior gluteal region. Perfusion flow was permitted by the dominant direct-linking vessels towards adjacent lumbar perforators, oriented diagonally upward and outward to the midline. CONCLUSIONS: Parasacral perforator flaps appear to be a useful procedure in reconstruction and in aesthetic surgery, especially in gluteal augmentation. Their reliability depends on sound anatomic knowledge, with accurate preoperative perforator mapping.

Interpretation of 2-[18F]FDG PET/CT in Hodgkin lymphoma patients treated with immune checkpoint inhibitors.

The development of immunotherapy has revolutionized cancer treatment, improving the outcome and survival of many patients. Immune checkpoint inhibitors (ICIs), the most common form of immunotherapy, use antibodies to restore T-cells' anti-tumor activity. Immune checkpoint inhibitors are gaining ground in the therapeutic strategy across various cancers. Although widely used in solid tumors, ICIs have shown remarkable efficacy in patients with Hodgkin lymphoma. 2-[18F]Fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography (PET)/CT is the gold standard to stage and monitor responses in Hodgkin lymphoma. This article reviewed the use of 2-[18F]FDG-PET/CT in patients with Hodgkin lymphoma treated with ICI, focusing on image interpretation for response monitoring and detecting adverse events. Key Points • Immune checkpoint inhibitors have dramatically improved the outcome of patients with cancer. Their mechanisms of action induce inflammatory processes that might translate into a high 2-[18F]FDG uptake visible on 2-[18F]FDG-PET/CT, requiring an adaptation of the evaluation criteria. • PET readers should be aware of new patterns of response observed with immunotherapy in assessing treatment response in HL patients. • -[18F]FDG-PET/CT has an unparalleled ability of assessing tumor response, visualizing signs of immune activation as well as immune-related adverse events in a one-stop-shop examination.

Predicting death or recurrence of portal hypertension symptoms after TIPS procedures.

BACKGROUND: Accurate prediction of portal hypertension recurrence after transjugular intrahepatic portosystemic shunt (TIPS) placement will improve clinical decision-making. PURPOSE: To evaluate if perioperative variables could predict disease-free survival (DFS) in cirrhotic patients with portal hypertension (PHT) treated with TIPS. MATERIALS AND METHODS: We recruited 206 cirrhotic patients with PHT treated with TIPS, randomly assigned to training (n = 138) and validation (n = 68) sets. We recorded 7 epidemiological, 4 clinical, and 9 radiological variables. TIPS-distal end positioning (TIPS-DEP) measured the distance between the distal end of the stent and the hepatocaval junction on contrast-enhanced CT scans. In the training set, the signature was defined as the random forest for survival algorithm achieving the lowest error rate for the prediction of DFS which was landmarked 4 weeks after the TIPS procedure. In the training set, a simple to use scoring system was derived from variables selected by the signature. The primary endpoint was to assess if TIPS-DEP was associated with DFS. The secondary endpoint was to validate the scoring system in the validation set. RESULTS: Overall, patients with TIPS-DEP ≥ 6 mm (n = 49) had a median DFS of 24.5 months vs. 72.8 months otherwise (n = 157, p = 0.004). In the training set, the scoring system was calculated by adding age ≥ 60 years old, Child-Pugh B or C, and TIPS-DEP ≥ 6 mm (1 point each) since the signature showed high DFS probability at 6.5 months post-landmark in patients that did not meet these criteria: 86%, 80%, and 78%, respectively. The hazard ratio [95 CI] between patients determined to be low-risk (< 2 points) and high-risk (≥ 2 points) was 2.30 [1.35-3.93] (p = 0.002) in the training set and 2.01 [0.94-4.32] (p = 0.072) in the validation set. CONCLUSION: TIPS-DEP is an actionable radiological biomarker which can be combined with age and Child-Pugh score to predict death or PHT symptom recurrence after TIPS procedure. KEY POINTS: • TIPS-DEP measurement was the third most important but only actionable variable for predicting DFS. • TIPS-DEP < 6 mm was associated with a DFS probability of 78% at 6.5 months post-landmark. • A simple scoring system calculated using age, Child-Pugh score, and TIPS-DEP predicted DFS after TIPS.

Investigating of the role of CT scan for cancer patients during the first wave of COVID-19 pandemic.

Introduction: Amidst this current COVID-19 pandemic, we undertook this systematic review to determine the role of medical imaging, with a special emphasis on computed tomography (CT), on guiding the care and management of oncologic patients. Material and Methods: Study selection focused on articles from 01/02/2020 to 04/23/2020. After removal of irrelevant articles, all systematic or non-systematic reviews, comments, correspondence, editorials, guidelines and meta-analysis and case reports with less than 5 patients were also excluded. Full-text articles of eligible publications were reviewed to select all imaging-based publications, and the existence or not of an oncologic population was reported for each publication. Two independent reviewers collected the following information: ( 1) General publication data; (2) Study design characteristics; (3) Demographic, clinical and pathological variables with percentage of cancer patients if available; (4) Imaging performances. The sensitivity and specificity of chest CT (C-CT) were pooled separately using a random-effects model. The positive predictive value (PPV) and negative predictive value (NPV) of C-CT as a test was estimated for a wide range of disease prevalence rates. Results: A total of 106 publications were fully reviewed. Among them, 96 were identified to have extractable data for a two-by-two contingency table for CT performance. At the end, 53 studies (including 6 that used two different populations) were included in diagnosis accuracy analysis (N = 59). We identified 53 studies totaling 11,352 patients for whom the sensitivity (95CI) was 0.886 (0.880; 0.894), while specificity remained low: in 93% of cases (55/59), specificity was ≤ 0.5. Among all the 106 reviewed studies, only 7 studies included oncologic patients and were included in the final analysis for C-CT performances. The percentage of patients with cancer in these studies was 0.3% (34/11352 patients), lower than the global prevalence of cancer. Among all these studies, only 1 (0.9%, 1/106) reported performance specifically in a cohort of cancer patients, but it however only reported true positives. Discussion: There is a concerning lack of COVID-19 studies involving oncologic patients, showing there is a real need for further investigation and evaluation of the performance of the different medical imaging modalities in this specific patient population.

Toward Generalizability in the Deployment of Artificial Intelligence in Radiology: Role of Computation Stress Testing to Overcome Underspecification.

The clinical deployment of artificial intelligence (AI) applications in medical imaging is perhaps the greatest challenge facing radiology in the next decade. One of the main obstacles to the incorporation of automated AI-based decision-making tools in medicine is the failure of models to generalize when deployed across institutions with heterogeneous populations and imaging protocols. The most well-understood pitfall in developing these AI models is overfitting, which has, in part, been overcome by optimizing training protocols. However, overfitting is not the only obstacle to the success and generalizability of AI. Underspecification is also a serious impediment that requires conceptual understanding and correction. It is well known that a single AI pipeline, with prescribed training and testing sets, can produce several models with various levels of generalizability. Underspecification defines the inability of the pipeline to identify whether these models have embedded the structure of the underlying system by using a test set independent of, but distributed identically, to the training set. An underspecified pipeline is unable to assess the degree to which the models will be generalizable. Stress testing is a known tool in AI that can limit underspecification and, importantly, assure broad generalizability of AI models. However, the application of stress tests is new in radiologic applications. This report describes the concept of underspecification from a radiologist perspective, discusses stress testing as a specific strategy to overcome underspecification, and explains how stress tests could be designed in radiology-by modifying medical images or stratifying testing datasets. In the upcoming years, stress tests should become in radiology the standard that crash tests have become in the automotive industry. Keywords: Computer Applications-General, Informatics, Computer-aided Diagnosis © RSNA, 2021.

Updated Trends in Imaging Practices for Pancreatic Neuroendocrine Tumors (PNETs): A Systematic Review and Meta-Analysis to Pave the Way for Standardization in the New Era of Big Data and Artificial Intelligence.

PURPOSE: Medical imaging plays a central and decisive role in guiding the management of patients with pancreatic neuroendocrine tumors (PNETs). Our aim was to synthesize all recent literature of PNETs, enabling a comparison of all imaging practices. METHODS: based on a systematic review and meta-analysis approach, we collected; using MEDLINE, EMBASE, and Cochrane Library databases; all recent imaging-based studies, published from December 2014 to December 2019. Study quality assessment was performed by QUADAS-2 and MINORS tools. RESULTS: 161 studies consisting of 19852 patients were included. There were 63 'imaging' studies evaluating the accuracy of medical imaging, and 98 'clinical' studies using medical imaging as a tool for response assessment. A wide heterogeneity of practices was demonstrated: imaging modalities were: CT (57.1%, n=92), MR (42.9%, n=69), PET/CT (13.3%, n=31), and SPECT/CT (9.3%, n=15). International imaging guidelines were mentioned in 2.5% (n=4/161) of studies. In clinical studies, imaging protocol was not mentioned in 30.6% (n=30/98) of cases and only mentioned imaging modality without further information in 63.3% (n=62/98), as compared to imaging studies (1.6% (n=1/63) of (p<0.001)). QUADAS-2 and MINORS tools deciphered existing biases in the current literature. CONCLUSION: We provide an overview of the updated current trends in use of medical imaging for diagnosis and response assessment in PNETs. The most commonly used imaging modalities are anatomical (CT and MRI), followed by PET/CT and SPECT/CT. Therefore, standardization and homogenization of PNETs imaging practices is needed to aggregate data and leverage a big data approach for Artificial Intelligence purposes.

Results of endovascular aortic arch repair using the Relay Branch system.

OBJECTIVES: Our goal was to evaluate results of endovascular aortic arch repair using the Relay Branch system. METHODS: Forty-three patients with thoracic aortic pathology involving the aortic arch have been treated with the Relay Branch system (Terumo Aortic, Sunrise, FL, USA) in 10 centres. We assessed in-hospital mortality, neurological injury, treatment success according to current reporting standards and the need for secondary interventions. In addition, outcome was analysed according to the underlying pathology: non-dissective disease versus residual aortic dissection (RAD) (defined as remaining dissection after previous type A repair, chronic type B aortic dissections). RESULTS: In-hospital mortality was 9% (0% in patients with RAD). Disabling stroke occurred in 7% (0% in patients with RAD); non-disabling stroke occurred in 19% (7% in patients with RAD). Early type IA and B endoleak formation occurred in 4%. Median follow-up was 16 ± 18 months. During the follow-up period, 23% of the patients died. Aortic-related deaths were low (3% in patients with RAD). CONCLUSIONS: The results of endovascular aortic arch repair using the Relay Branch system in a selected patient population with regard to technical success are good. In-hospital mortality is acceptable, the number of disabling strokes is low and technical success is high. Non-disabling stroke is a major concern, and every effort has to be taken to reduce this to a minimum. The best outcome is seen in patients with underlying RAD. Finally, more data are needed.

Are gastric metastases of renal cell carcinoma really rare? A case report and systematic review of the literature.

INTRODUCTION: Renal cell carcinoma (RCC) represents above 3 % of all cancers. At diagnosis, above 25 % of patients with RCC present an advanced disease. Gastric metastasis of RCC is associated with poor outcome. We report the case of a patient treated for a gastric metastasis of RCC and we conducted a systematic review of the literature to report all published cases of RCC patients with gastric metastasis. CASE PRESENTATION: In December 2010, a 61-year-old man was treated by open partial nephrectomy for a localized right clear cell RCC. In September 2018, a metachronous gastric metastasis was found on CT scan. The lesion was located on the lesser curvature of the stomach, measuring 4.5 cm long axis. No other secondary lesions were identified. A laparoscopic wedge resection, converted to laparotomy was performed. Two years later, in September 2020, a CT scan was performed, revealing a 17 mm adenopathy behind the hepatic hilum and a surgical management was performed, including a lymph node dissection of the hepatic hilum and the hepatic artery. Actually, he remains healthy. CLINICAL DISCUSSION AND CONCLUSION: Our systematic review suggests that solitary gastric metastasis of RCC are scarce. In comparison of patients with multiple metastatic sites, the median survival of patients with solitary gastric metastasis is longer.

Management of anastomotic biliary stricture after liver transplantation and impact on survival.

BACKGROUND: Anastomotic biliary strictures (AS) is the main surgical complication after liver transplantation. The aims of this study are to investigate the risk factors of AS, its management and its impact on overall survival and survival of the graft. METHODS: All patients who had received a liver transplantation with duct-to-duct anastomosis at Toulouse University Hospital between 2010 and 2016 were included. RESULTS: Of 225 included patients, 56 (24.9%) presented with AS. The median time to discovery of AS was 83 days and 69.6% of the AS appeared within 6 months. Transplantation in critically ill patients, with a liver score >800 points, was an independent predictive factor of survival (P = 0.003). The first-line treatment was endoscopic (87.5%), with a success rate of 79.6% and a median of 4 procedures per patient in 12 months. In cases of failure of endoscopic therapy, percutaneous treatment had a high failure rate (50%). AS had no impact in terms of overall survival or in terms of graft survival. CONCLUSION: AS do not have any repercussions on patient or graft survival, requiring long endoscopic treatment with multiple procedures. In the event of failure of this first-line endoscopic treatment, it seems preferable to turn directly towards surgical repair.

Blended learning of radiology improves medical students' performance, satisfaction, and engagement.

PURPOSE: To evaluate the impact of blended learning using a combination of educational resources (flipped classroom and short videos) on medical students' (MSs) for radiology learning. MATERIAL AND METHODS: A cohort of 353 MSs from 2015 to 2018 was prospectively evaluated. MSs were assigned to four groups (high, high-intermediate, low-intermediate, and low achievers) based on their results to a 20-MCQs performance evaluation referred to as the pretest. MSs had then free access to a self-paced course totalizing 61 videos based on abdominal imaging over a period of 3 months. Performance was evaluated using the change between posttest (the same 20 MCQs as pretest) and pretest results. Satisfaction was measured using a satisfaction survey with directed and spontaneous feedbacks. Engagement was graded according to audience retention and attendance on a web content management system. RESULTS: Performance change between pre and posttest was significantly different between the four categories (ANOVA, P = 10-9): low pretest achievers demonstrated the highest improvement (mean ± SD, + 11.3 ± 22.8 points) while high pretest achievers showed a decrease in their posttest score (mean ± SD, - 3.6 ± 19 points). Directed feedback collected from 73.3% of participants showed a 99% of overall satisfaction. Spontaneous feedback showed that the concept of "pleasure in learning" was the most cited advantage, followed by "flexibility." Engagement increased over years and the number of views increased of 2.47-fold in 2 years. CONCLUSION: Learning formats including new pedagogical concepts as blended learning, and current technologies allow improvement in medical student's performance, satisfaction, and engagement.

Performance of CT Compared with 18F-FDG PET in Predicting the Efficacy of Nivolumab in Relapsed or Refractory Hodgkin Lymphoma.

Background CT and fluorine 18 (18F) fluorodeoxyglucose (FDG) PET/CT performances following immune therapy are not well known in patients with relapsed or refractory Hodgkin lymphoma (RRHL). Purpose To compare CT and PET/CT for prognostic value of early response evaluation following nivolumab therapy. Materials and Methods This retrospective study included patients from 34 institutions who underwent early imaging response evaluation from July 2013 to April 2017. Three experienced readers classified imaging response by using Cheson et al and 2016 Lymphoma Response to Immunomodulatory Therapy Criteria as follows: complete (metabolic) response, partial (metabolic) response, stable disease or no metabolic response, or progressive (metabolic) disease. Primary CT and PET assessments were performed at a median of 2.0 months (interquartile range, 1.7-3.7 months) after nivolumab initiation. Kaplan-Meier analysis was used to determine the relationship of primary CT and PET assessment response categories to overall survival (OS). Agreements between primary and secondary imaging assessments were assessed by using κ analysis. Results A total of 45 patients (median age, 37 years; range, 18-77 years; 25 men) underwent a primary assessment using CT and PET/CT; 36 patients also underwent a subsequent assessment. Eleven patients (24%) died after a median follow-up of 21.2 months. CT and PET response categories were associated with OS (P = .03 for primary CT assessment; P = .02 for primary PET assessment). There was no pseudoprogression at primary CT and PET assessments. At the primary assessment, response categories by using CT were reclassified by using PET in 44% (20 of 45) of patients. Among these, 55% (11 of 20) were reclassified to complete metabolic response (complete metabolic response rate: 29% [13 of 45 patients] vs complete response rate: 4% [two of 45 patients]), with a 2-year OS probability of 100%. At the secondary assessment, complete response rate using CT increased to 17% (six of 36 patients), hence a better agreement with PET (κ = 0.78; P < .001). Conclusion Early CT and PET/CT at a median of 2 months after initiation of nivolumab predicted overall survival in relapsed or refractory Hodgkin lymphoma. Early PET detected additional patients with complete metabolic response. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Scott and Wang in this issue.

Using a single abdominal computed tomography image to differentiate five contrast-enhancement phases: A machine-learning algorithm for radiomics-based precision medicine.

PURPOSE: The clinical adoption of quantitative imaging biomarkers (radiomics) has established the need for high quality contrast-enhancement in medical images. We aimed to develop a machine-learning algorithm for Quality Control of Contrast-Enhancement on CT-scan (CECT-QC). METHOD: Multicenter data from four independent cohorts [A, B, C, D] of patients with measurable liver lesions were analyzed retrospectively (patients:time-points; 503:3397): [A] dynamic CTs from primary liver cancer (60:2359); [B] triphasic CTs from primary liver cancer (31:93); [C] triphasic CTs from hepatocellular carcinoma (121:363); [D] portal venous phase CTs of liver metastasis from colorectal cancer (291:582). Patients from cohort A were randomized to training-set (48:1884) and test-set (12:475). A random forest classifier was trained and tested to identify five contrast-enhancement phases. The input was the mean intensity of the abdominal aorta and the portal vein measured on a single abdominal CT scan image at a single time-point. The output to be predicted was: non-contrast [NCP], early-arterial [E-AP], optimal-arterial [O-AP], optimal-portal [O-PVP], and late-portal [L-PVP]. Clinical utility was assessed in cohorts B, C, and D. RESULTS: The CECT-QC algorithm showed performances of 98 %, 90 %, and 84 % for predicting NCP, O-AP, and O-PVP, respectively. O-PVP was reached in half of patients and was associated with a peak in liver malignancy density. Contrast-enhancement quality significantly influenced radiomics features deciphering the phenotype of liver neoplasms. CONCLUSIONS: A single CT-image can be used to differentiate five contrast-enhancement phases for radiomics-based precision medicine in the most common liver neoplasms occurring in patients with or without liver cirrhosis.

Impact of cone beam - CT on adrenal vein sampling in primary aldosteronism.

PURPOSE: The aim of this study in a group of patients with primary aldosteronism was to evaluate the contribution of CB-CT (cone beam CT) to the overall success rate of adrenal vein sampling (AVS), and in particular to the selective cannulation of the right adrenal vein (RAV). METHOD: This was a retrospective single-center study including 91 AVS procedures performed by our consultant radiologist between March 2011 and January 2017. Fifty cases were performed with CB-CT and 50 were performed without. Angiography with CB-CT was carried out after RAV cannulation to check the accurate catheter position. For each patient, we collected technical and biochemical success rates, as well as irradiation data. RESULTS: The overall success rate of AVS with CB-CT was 80 %, vs. 44 % without (p = 0.00046), with right-sided selectivity of 88 % vs. 49 % (p < 0.0001). There was no significant increase in radiation exposure with CB-CT (p = 0.8206). Fluoroscopy time and quantity of iodine injected were significantly lower with CB-CT than without (p = 0.0039 and p < 0.0001). CONCLUSION: CB-CT allows a better evaluation of the selectivity of right-sided adrenal catheterization and greatly increases the overall success rate of AVS.