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Background Lesion/tissue segmentation on digital medical images enables biomarker extraction, image-guided therapy delivery, treatment response measurement, and training/validation for developing artificial intelligence algorithms and workflows. To ensure data reproducibility, criteria for standardised segmentation are critical but currently unavailable. Methods A modified Delphi process initiated by the European Imaging Biomarker Alliance (EIBALL) of the European Society of Radiology (ESR) and the European Organisation for Research and Treatment of Cancer (EORTC) Imaging Group was undertaken. Three multidisciplinary task forces addressed modality and image acquisition, segmentation methodology itself, and standards and logistics. Devised survey questions were fed via a facilitator to expert participants. The 58 respondents to Round 1 were invited to participate in Rounds 2-4. Subsequent rounds were informed by responses of previous rounds. Results/conclusions Items with >= 75% consensus are considered a recommendation. These include system performance certification, thresholds for image signal-to-noise, contrast-to-noise and tumour-to-background ratios, spatial resolution, and artefact levels. Direct, iterative, and machine or deep learning reconstruction methods, use of a mixture of CE marked and verified research tools were agreed and use of specified reference standards and validation processes considered essential. Operator training and refreshment were considered mandatory for clinical trials and clinical research. Items with a 60-74% agreement require reporting (site-specific accreditation for clinical research, minimal pixel number within lesion segmented, use of post-reconstruction algorithms, operator training refreshment for clinical practice). Items with Funding Agencies|European Union [826494, 952159, 952172, 101057699]; NIH/NCI Cancer Center Support Grant [P30 CA008748]; National Institute for Health Research University College London Hospitals Biomedical Research Centre; French government under management of the Agence Nationale de la Recherche as part of the "Investissements davenir" program [ANR19-P3IA-0001]

The goal of this guideline/procedure standard is to assist nuclear medicine physicians, other nuclear medicine professionals, oncologists or other medical specialists for recommended use of [F]FDG PET/CT in oncological patients undergoing immunotherapy, with special focus on response assessment in solid tumors. In a cooperative effort between the EANM, the SNMMI and the ANZSNM, clinical indications, recommended imaging procedures and reporting standards have been agreed upon and summarized in this joint guideline/procedure standard. The field of immuno-oncology is rapidly evolving, and this guideline/procedure standard should not be seen as definitive, but rather as a guidance document standardizing the use and interpretation of [F]FDG PET/CT during immunotherapy. Local variations to this guideline should be taken into consideration. The European Association of Nuclear Medicine (EANM) is a professional non-profit medical association founded in 1985 to facilitate worldwide communication among individuals pursuing clinical and academic excellence in nuclear medicine. The Society of Nuclear Medicine and Molecular Imaging (SNMMI) is an international scientific and professional organization founded in 1954 to promote science, technology and practical application of nuclear medicine. The Australian and New Zealand Society of Nuclear Medicine (ANZSNM), founded in 1969, represents the major professional society fostering the technical and professional development of nuclear medicine practice across Australia and New Zealand. It promotes excellence in the nuclear medicine profession through education, research and a commitment to the highest professional standards. EANM, SNMMI and ANZSNM members are physicians, technologists, physicists and scientists specialized in the research and clinical practice of nuclear medicine. All three societies will periodically put forth new standards/guidelines for nuclear medicine practice to help advance the science of nuclear medicine and improve service to patients. Existing standards/guidelines will be reviewed for revision or renewal, as appropriate, on their fifth anniversary or sooner, if indicated. Each standard/guideline, representing a policy statement by the EANM/SNMMI/ANZSNM, has undergone a thorough consensus process, entailing extensive review. These societies recognize that the safe and effective use of diagnostic nuclear medicine imaging requires particular training and skills, as described in each document. These standards/guidelines are educational tools designed to assist practitioners in providing appropriate and effective nuclear medicine care for patients. These guidelines are consensus documents based on current knowledge. They are not intended to be inflexible rules or requirements of practice, nor should they be used to establish a legal standard of care. For these reasons and those set forth below, the EANM, SNMMI and ANZSNM caution against the use of these standards/guidelines in litigation in which the clinical decisions of a practitioner are called into question. The ultimate judgment regarding the propriety of any specific procedure or course of action must be made by medical professionals considering the unique circumstances of each case. Thus, there is no implication that an action differing from what is laid out in the guidelines/procedure standards, standing alone, is below standard of care. To the contrary, a conscientious practitioner may responsibly adopt a course of action different from that set forth in the standards/guidelines when, in the reasonable judgment of the practitioner, such course of action is indicated by the condition of the patient, limitations of available resources or advances in knowledge or technology subsequent to publication of the guidelines/procedure standards. The practice of medicine involves not only the science, but also the art of dealing with the prevention, diagnosis, alleviation and treatment of disease. The variety and complexity of human conditions make it impossible for general guidelines to consistently allow for an accurate diagnosis to be reached or a particular treatment response to be predicted. Therefore, it should be recognized that adherence to these standards/ guidelines will not ensure a successful outcome. All that should be expected is that practitioners follow a reasonable course of action, based on their level of training, current knowledge, clinical practice guidelines, available resources and the needs/context of the patient being treated. The sole purpose of these guidelines is to assist practitioners in achieving this objective. The present guideline/procedure standard was developed collaboratively by the EANM, the SNMMI and the ANZSNM, with the support of international experts in the field. They summarize also the views of the Oncology and Theranostics and the Inflammation and Infection Committees of the EANM, as well as the procedure standards committee of the SNMMI, and reflect recommendations for which the EANM and SNMMI cannot be held responsible. The recommendations should be taken into the context of good practice of nuclear medicine and do not substitute for national and international legal or regulatory provisions.

Background EBV produces miRNAs with important functions in cancer growth, tumor invasion and host immune surveillance. The discovery of EBV miR-BARTs is recent, and most of their functions are still unknown. Nonetheless, some new studies underline their key roles in EBV-associated malignancies. Main body In EBV-associated tumors, the expression profile of miR-BARTs varies according to the cell type, autophagic process and signals received from the tumor microenvironment. By the same way of interest is the interaction between tumor cells and the tumor environment by the release of selected EBV miR-BARTs in addition to the tumor proteins trough tumor exosomes. Conclusion In this review, we discuss new findings regarding EBV miR-BARTs in Hodgkin lymphoma and gastric cancer. The recent discovery that miRNAs are released by exosomes, including miR-BARTs, highlights the importance of tumor and microenvironment interplay with more specific effects on the host immune response.

Conventional magnetic resonance imaging (cMRI) has an established role as a crucial disease parameter in the multidisciplinary management of glioblastoma, guiding diagnosis, treatment planning, assessment, and follow-up. Yet, cMRI cannot provide adequate information regarding tissue heterogeneity and the infiltrative extent beyond the contrast enhancement. Advanced magnetic resonance imaging and PET and newer analytical methods are transforming images into data (radiomics) and providing noninvasive biomarkers of molecular features (radiogenomics), conveying enhanced information for improving decision making in surgery. This review analyzes the shift from image guidance to information guidance that is relevant for the surgical treatment of glioblastoma.

A Correction to this paper has been published

Existing quantitative imaging biomarkers (QIBs) are associated with known biological tissue characteristics and follow a well-understood path of technical, biological and clinical validation before incorporation into clinical trials. In radiomics, novel data-driven processes extract numerous visually imperceptible statistical features from the imaging data with no a priori assumptions on their correlation with biological processes. The selection of relevant features (radiomic signature) and incorporation into clinical trials therefore requires additional considerations to ensure meaningful imaging endpoints. Also, the number of radiomic features tested means that power calculations would result in sample sizes impossible to achieve within clinical trials. This article examines how the process of standardising and validating data-driven imaging biomarkers differs from those based on biological associations. Radiomic signatures are best developed initially on datasets that represent diversity of acquisition protocols as well as diversity of disease and of normal findings, rather than within clinical trials with standardised and optimised protocols as this would risk the selection of radiomic features being linked to the imaging process rather than the pathology. Normalisation through discretisation and feature harmonisation are essential pre-processing steps. Biological correlation may be performed after the technical and clinical validity of a radiomic signature is established, but is not mandatory. Feature selection may be part of discovery within a radiomics-specific trial or represent exploratory endpoints within an established trial; a previously validated radiomic signature may even be used as a primary/secondary endpoint, particularly if associations are demonstrated with specific biological processes and pathways being targeted within clinical trials. KEY POINTS: • Data-driven processes like radiomics risk false discoveries due to high-dimensionality of the dataset compared to sample size, making adequate diversity of the data, cross-validation and external validation essential to mitigate the risks of spurious associations and overfitting. • Use of radiomic signatures within clinical trials requires multistep standardisation of image acquisition, image analysis and data mining processes. • Biological correlation may be established after clinical validation but is not mandatory. ispartof: EUROPEAN RADIOLOGY vol:31 issue:8 pages:6001-6012 ispartof: location:Germany status: published

Background: Treatment monitoring in metastatic colorectal cancer (mCRC) relies on imaging to evaluate the tumor burden. Response Evaluation Criteria in Solid Tumors (RECIST) provide a framework on reporting and interpretation of imaging findings yet offer no guidance on a standardized imaging protocol tailored to mCRC patients. Imaging protocol heterogeneity remains a challenge for the reproducibility of conventional imaging endpoints and is an obstacle for research on novel imaging endpoints. Patients and methods: Acknowledging the recently highlighted potential of radiomics and artificial intelligence (AI) tools as decision support for patient care in mCRC, a multidisciplinary, international, and expert panel of imaging specialists was formed to find consensus on mCRC imaging protocols using the Delphi method. Results: Under the guidance of the European Organisation for Research and Treatment of Cancer (EORTC) Imaging and Gastrointestinal Tract Cancer Groups, the European Society of Oncologic Imaging (ESOI) and the European Society of Gastrointestinal and Abdominal Radiology (ESGAR), the EORTC-ESOI-ESGAR core imaging protocol was identified. Conclusion: This consensus protocol attempts to promote standardization and to diminish variations in patient preparation, scan acquisition and scan reconstruction. We anticipate that this standardization will increase reproducibility of radiomics and AI studies and serve as a catalyst for future research on imaging endpoints. For ongoing and future mCRC trials, we encourage principal investigators to support the dissemination of these imaging standards across recruiting centers., peer-reviewed

The molecular mechanisms responsible for the high immunosuppressive capacity of CD4(+) Tregs in tumors are not well known. High-dimensional single-cell profiling of T cells from chemotherapy-naive individuals with non–small-cell lung cancer identified the transcription factor IRF4 as specifically expressed by a subset of intratumoral CD4(+) effector Tregs with superior suppressive activity. In contrast to the IRF4(–) counterparts, IRF4(+) Tregs expressed a vast array of suppressive molecules, and their presence correlated with multiple exhausted subpopulations of T cells. Integration of transcriptomic and epigenomic data revealed that IRF4, either alone or in combination with its partner BATF, directly controlled a molecular program responsible for immunosuppression in tumors. Accordingly, deletion of Irf4 exclusively in Tregs resulted in delayed tumor growth in mice while the abundance of IRF4(+) Tregs correlated with poor prognosis in patients with multiple human cancers. Thus, a common mechanism underlies immunosuppression in the tumor microenvironment irrespective of the tumor type.

Objectives: In Siewert type I/II oesophageal adenocarcinoma, the sensitivity and specificity of computed tomography (CT), positron emission tomography (PET)-CT and endoscopic ultrasound (EUS) for assessment of the N descriptor in defined groups of lymph nodes were investigated. Methods: CT, PET/CT, EUS images and the pathological data of 101 oesophageal adenocarcinomas submitted to primary resection were compared. The lymph nodes were identified as (a) right paratracheal/subcarinal/pulmonary ligament; (b) paraoesophageal; (c) paracardial; (d) left gastric artery, lesser curvature; (e) coeliac trunk, hepatic/splenic artery. Results: Of the 2451 lymph nodes identified, 273 (11.1%) were histologically positive. Overall sensitivity, specificity and negative and positive predictive value for detection of lymph nodes metastatic were respectively: CT sensitivity 39%, specificity 86%, negative 58% and positive 74% predictive value; PET/CT sensitivity 30%, specificity 98%, negative 58% and positive 93% predictive value; EUS sensitivity 50%, specificity 81%, negative 72% and positive 62% predictive value. The sensitivity of CT, PET/CT and EUS in the thoracic nodal groups (a) and (b) was, respectively, 58.3%, 7.1% and 87.5% and 33.3%, 20% and 80%. Sensitivity was below 47% for all tests in the abdominal nodal groups. In contrast, specificity (88.6-100%) was super imposable in all nodal groups. The strength of agreement among the 3 imaging techniques was poor (kappa < 0.30) for the thoracic anatomical groups of interest: (a) lower paratracheal/subcarinal/pulmonary ligament and (b) paraoesophageal; it was moderate/good (kappa >0.30) for the abdominal N groups of interest: c, d and e. Conclusions: The diagnostic performance of CT, PET and EUS for assessing the N descriptor in the paracardial and abdominal stations close to the primary tumour is not satisfactory. EUS can efficiently assess the presence/absence of nodal metastases in the thoracic stations.

CD8+ T cells infiltrating tumors are largely dysfunctional. Brummelman and Mazza et al. identify partially exhausted CXCR5+ TIM-3– CD8+ T cells with enhanced stem-like properties and cytotoxicity infiltrating human solid tumors. These cells express candidate immunotherapeutic targets (PD-1, TIGIT and CD27) for their reinvigoration., CD8+ T cells infiltrating tumors are largely dysfunctional, but whether a subset maintains superior functionality remains ill defined. By high-dimensional single cell analysis of millions of CD8+ T cells from 53 individuals with lung cancer, we defined those subsets that are enriched in tumors compared with cancer-free tissues and blood. Besides exhausted and activated cells, we identified CXCR5+ TIM-3– CD8+ T cells with a partial exhausted phenotype, while retaining gene networks responsible for stem-like plasticity and cytotoxicity, as revealed by single cell sequencing of the whole transcriptome. Ex vivo, CXCR5+ TIM-3– CD8+ T cells displayed enhanced self-renewal and multipotency compared with more differentiated subsets and were largely polyfunctional. Analysis of inhibitory and costimulatory receptors revealed PD-1, TIGIT, and CD27 as possible targets of immunotherapy. We thus demonstrate a hierarchy of differentiation in the context of T cell exhaustion in human cancer similar to that of chronically infected mice, which is further shown to disappear with disease progression., Graphical Abstract

Purpose: To evaluate the clinical–pathological and prognostic significance of the circulating PD-L1 level in patients with surgically treated NSCLC, by combining data for PD-L1 expression with other immune-related markers and tumor metabolism. Methods: Overall, 40 patients with resected NSCLC (stage Ia–IIIa) who had preoperative blood storage and underwent staging PET/CT were enrolled for the study. In all cases, we determined plasma levels of PD-L1 (pg/ml), immune-reactive areas (IRA%) covered by CD3, CD68, CD20, CD8, PD-1, and PD-L1 in the tumor specimen, and metabolic parameters on PET, i.e., SUVmax, SUVpeak, metabolic tumor volume (MTV), and total lesion glycolysis (TLG). Variables were statistically analyzed to establish their association with disease-free survival (DFS). Results: The circulating levels of PD-L1 in the bloodstream could be determined in 38/40 (95%) samples. The mean and median expression levels were 34.86pg/ml and 24.83pg/ml, respectively. We did not find any statistically significant correlation between circulating PD-L1 and tissue expression of PD-L1/PD-1. Some mild degree of positive correlation was determined between tissue PD-L1 and SUVmax (ρ = 0.390; p = 0.0148). Hierarchical clustering combining circulating, tissue, and metabolic parameters identified clusters with high metabolic tumor burden or high expression of plasma PD-L1 levels (Z score ≥ 2) as having a poor DFS (p = 0.033). The multivariate analysis detected stage and metabolism (i.e., SUVmax and SUVpeak) as independent prognostic factors for DFS. Conclusion: Plasma levels of PD-L1 are independent of the expression of PD-1/PD-L1 in NSCLC tumor tissue and, when combined with other clinical–pathological parameters, allow for the identification of clusters with different outcomes.

Background: Positron emission tomography (PET) is a valuable tool for the characterization of brain tumors in vivo. However, few studies have investigated the correlation between carbon-11-methionine (11C-METH) PET metrics and the clinical, radiological, histological, and molecular features of patients affected by lower grade gliomas (LGGs). The present observational study evaluated the relationships between 11C-METH PET metrics and structural magnetic resonance imaging (MRI) findings with the histomolecular biomarkers in patients with LGGs who were candidates for surgery. Methods: We enrolled 96 patients with pathologically proven LGG (51 men, 45 women; age 44.1 ± 13.7 years; 45 with grade II, 51 with grade III), who had been referred from March 2012 to January 2015 for tumor resection and had undergone preoperative 11C-METH PET. The semiquantitative metrics for 11C-METH PET included maximum standardized uptake value (SUVmax), SUV ratio to normal brain, and metabolic tumor burden (MTB). The PET semiquantitative metrics were analyzed and compared with the MRI features, histological diagnosis, isocitrate dehydrogenase-1/2 status, and 1p/19q codeletion. Results: Histological grade was associated with SUVmax (P = 0.002), SUV ratio (P = 0.011), and MTB (P = 0.001), with grade III lesions showing higher values. Among the nonenhancing lesions on MRI, SUVmax (P = 0.001), SUV ratio (P = 0.003) and MTB (P < 0.001) were significantly different statistically for grade II versus grade III. The MRI lesion volume correlated poorly with MTB (r2 = 0.13). The SUVmax and SUV ratio were greater (P < 0.05) in isocitrate dehydrogenase-1/2 wild-type lesions, and the SUV ratio was associated with the presence of the 1p19q codeletion. Conclusions: The 11C-METH PET metrics correlated significantly with histological grade and the molecular profile. Semiquantitative PET metrics can improve the preoperative evaluation of LGGs and thus support clinical decision-making.

Objectives In-vivo characterization of malignant pleural mesothelioma (MPM) with 11C-methionine PET/computed tomography (MET PET). Methods Between September 2014 and February 2016, 30 consecutive patients with clinical suspicion of MPM were prospectively recruited. The study was approved and registered at www.clinicaltrials.gov (NCT02519049). Patients were evaluated at baseline with MET PET (experimental) and fluorine-18 fluorodeoxyglucose PET/computed tomography (FDG PET) (standard). Principal parameters analyzed were SUVmax, SUVmean, metabolic tumor volume (MTV), and metabolic tumor burden (MTB = MTV ×SUVmean). The reference standard for diagnostic performance was based on histology. Results The presence of malignancy was confirmed in 29/30 patients: 23 (76.6%) with MPM (20 epithelioid, two biphasic, and one sarcomatoid), five (16.6%) with adenocarcinoma of the lung, and one (3.3%) with an undifferentiated carcinoma. In one case, diagnosis was benign pleural inflammation. All tumors showed increased uptake of 11C-methionine: median SUVmax, SUVmean, MTV, and MTB were, respectively, 5.70 [95% confidence interval (CI): 4.51-6.79], 3.15 (95% CI: 2.71-3.40), 33.85 (95% CI: 14.08-66.64), and 105.25 (95% CI: 41.77-215.25). Pathology data revealed MTV and MTB to be significantly higher in nonepithelioid histology (P < 0.05). The other parameters showed a homogeneous distribution across the tumor types. Overall, MET PET identified 49 lymph nodes, compared with 34 nodes on FDG PET, demonstrating a sensitivity of 91% (95% CI: 80-96%), a positive predictive value of 92% (95% CI: 82- 97%), and an accuracy of 85% (P = 0.0042). Conclusions MET PET is able to characterize MPM lesions regardless of histology. This technique shows higher sensitivity than FDG PET for the identification of secondary lymph nodes.

International audience; This paper follows the immunotherapy symposium held during the European Association of Nuclear Medicine (EANM) 2017 Annual Congress. The biological basis of the immune checkpoint inhibitors and the drugs most frequently used for the treatment of solid tumours are reviewed. The issues of pseudoprogression (frequency, timeline), hyperprogression and immune-related side effects are discussed, as well as their implications for patient management. A review of the recent literature on the use of FDG PET for assessment of immunotherapy is presented, and recommendations are provided for assessing tumour response and reporting immune-related side effects with FDG PET based on published data and experts' experience. Representative clinical cases are also discussed.