Liposomal doxorubicin supercharge-containing front-line treatment in patients with advanced-stage diffuse large B-cell lymphoma or classical Hodgkin lymphoma: Preliminary results of a single-centre phase II study.

We evaluated the impact of liposomal doxorubicin (NPLD) supercharge-containing therapy on interim fluorodeoxyglucose positron emission tomography (interim-FDG-PET) responses in high-risk diffuse large B-cell lymphoma (DLBCL) or classical Hodgkin lymphoma (c-HL). In this phase II study (2016-2021), 81 adult patients with advanced-stage DLBCL (n = 53) and c-HL (n = 28) received front-line treatment with R-COMP-dose-intensified (DI) and MBVD-DI. R-COMP-DI consisted of 70 mg/m2 of NPLD plus standard rituximab, cyclophosphamide, vincristine and prednisone for three cycles (followed by three cycles with NPLD de-escalated at 50 mg/m2 ); MBVD-DI consisted of 35 mg/m2 of NPLD plus standard bleomycin, vinblastine and dacarbazine for two cycles (followed by four cycles with NPLD de-escalated at 25 mg/m2 ). Patients underwent R-COMP-DI and MBVD-DI with a median dose intensity of 91% and 94% respectively. At interim-FDG-PET, 72/81 patients (one failed to undergo interim-FDG-PET due to early death) had a Deauville score of ≤3. At end of treatment, 90% of patients reached complete responses. In all, 20 patients had Grade ≥3 adverse events, and four of them required hospitalisation. At a median 21-months of follow-up, the progression-free survival of the entire population was 77.3% (95% confidence interval 68%-88%). Our data suggest that the NPLD supercharge-driven strategy in high-risk DLBCL/c-HL may be a promising option to test in phase III trials, for improving negative interim-FDG-PET cases incidence.

FDG-PET/CT imaging during the Covid-19 emergency: a southern Italian perspective.

PURPOSE: To assess the impact of the Covid-19 pandemic on FDG-PET/CT work volume and to evaluate the occurrence of abnormal imaging findings suspicious or potentially diagnostic for interstitial pneumonia by Covid-19 infection in south Italy. METHODS: We retrospectively reviewed the number and the findings of FDG-PET/CT studies acquired between February and April 2020 during the Covid-19 pandemic at the University of Napoli Federico II. The number and the findings of FDG-PET/CT studies acquired in the corresponding period of 2019 were also assessed for direct comparison. RESULTS: The number of FDG-PET/CT studies performed during the pandemic (n = 299) and in the corresponding period of 2019 (n = 335) were comparable. The percentage of abnormal FDG-PET/CT findings, suspicious for interstitial pneumonia by Covid-19 infection, was significantly higher during the pandemic (9%) compared with that found in the corresponding period of 2019 (4%) (χ2 5.45, P = 0.02). No significant differences were observed in the distribution of Covid-19 reporting and data system (CO-RADS) classification and in the maximum standardized uptake value between the pandemic (2.6 ± 2.2) and the corresponding period of 2019 (3.2 ± 1.4). Of note, patients with abnormal imaging findings during the pandemic time had clinical data and/or laboratory tests negative for Covid-19 infection. CONCLUSION: Despite the restrictive medical measures for the emergency, the number of FDG-PET/CT studies was unchanged during the pandemic compared with the previous year. Our findings also indicate that Covid-19 infection was contained in our series of patients from southern Italy.

Visual and volumetric parameters by 18F-FDG-PET/CT: a head to head comparison for the prediction of outcome in patients with multiple myeloma.

In multiple myeloma (MM) patients, 18F-FDG-PET/CT allows either the detection of disease spread by using visual parameters based on the Italian Myeloma criteria for PET Use (IMPeTUs) or the direct measurement of metabolic tumor burden by volume-based parameters such as metabolic tumor volume (MTV). The purpose is to evaluate the contribution of visual and volumetric parameters in the prediction of progression-free survival (PFS) and overall survival (OS) in MM patients. Forty-seven patients in stage IIIA who had undergone whole-body 18F-FDG-PET/CT were retrospectively evaluated. In each patient, visual parameters were determined and compared with volumetric parameters for PFS and OS prediction after a mean follow-up period of 53 months. Among the visual and volumetric parameters tested, a statistically significant difference was found between maximum standardized uptake value, MTV, total lesion glycolysis, and number of lytic lesions of patients with (n = 26) or without (n = 21) progression (p = 0.0400, p = 0.0065, p = 0.015, and p = 0.0220, respectively) and of dead (n = 24) vs survivors (n = 23) (p = 0.0171, p = 0.0037, p = 0.0060, and p = 0.0270, respectively). At univariate and multivariate analysis, MTV and hemoglobin were predictive of both PFS (p = 0.008) and OS (p = 0.0026). The best MTV discriminative value assessed by receiver operating characteristic curve analysis for predicting both PFS and OS was 39.4 ml. By Kaplan-Meier analysis and log-rank test, PFS and OS were significantly better in patients with MTV ≤ 39.4 ml (p = 0.0004 and p = 0.0001, respectively) as compared with those having an MTV higher than the cutoff. The volume-based parameter MTV determined by 18F-FDG-PET/CT may be used in the prediction of PFS and OS in myeloma patients.

Preclinical imaging for targeting cancer immune evasion.

Novel anticancer immunotherapy strategies such as immune checkpoint blockade have been successfully employed in patients with a variety of cancers and became a therapeutic option in the treatment of several malignancies. However, long-term durable responses to immune checkpoint inhibitors are currently limited to a fraction of patients raising the need of an accurate selection of potentially responding patients. Although several biomarkers have been proposed for patient selection and prediction of response to immune checkpoint blockade, none can be considered as an absolute selection criterion. Whole-body imaging with tracers recognizing targets for immunotherapy by allowing visualization of target expression in all tumor and extratumoral sites at baseline and during disease evolution may provide reliable predictive imaging biomarkers. Here we will provide an overview of preclinical imaging studies aiming at the development and validation of tracers recognizing targets for immunotherapy that can be used for selection and monitoring of patients undergoing immunotherapy and for testing novel immunotherapeutic agents or strategies. Furthermore, we will focus on the selection of animal models based on the main purpose of the study and implications for clinical transfer of the results.

2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography in primary extranodal lymphomas: treatment response evaluation and prognosis.

BACKGROUND: We evaluated the role of [18F]FDG PET/CT in tumor response assessment and prognosis of primary extranodal lymphoma (PEL) patients. METHODS: We examined retrospectively, 56 PEL patients: 31 with aggressive diffuse large B cell lymphoma (DLBCL) and 25 with indolent lymphoma (20 mucosa-associated lymphoid tissue lymphoma and five follicular lymphoma). All patients had undergone [18F]FDG PET/CT at diagnosis (PET-I) and 50 of them also after therapy (PET-II). Moreover, 52 patients were subjected to a mean follow-up period of 76 months. RESULTS: PET-I was positive in 50 (89%) patients (mean SUVmax 10.3±6.7). In the assessment of tumor response, according to Lugano classification, 45 patients showed complete metabolic response (CMR), four patients had partial metabolic response (PMR) and one had progressive metabolic disease (PMD). Based on 66% ΔSUVmax cut-off, among CMR patients, 41 showed a ΔSUVmax>66% whereas among non-responders, four patients showed a ΔSUVmax<66%. At follow-up, univariate analysis showed that age, performance status, prognostic index, ΔSUVmax and Lugano classification predicted progression-free survival (PFS) (P<0.05), while, performance status, prognostic index, ΔSUVmax and Lugano classification predicted overall survival (OS) (P<0.05). At multivariate analysis only Lugano classification was retained in the model for prediction of both PFS (P<0.05) and OS (P<0.05). By Kaplan-Meier analysis and log-rank testing both PFS and OS were significantly better in patients in CMR as compared to patients in PMR or PMD according to Lugano classification (P<0.01). CONCLUSIONS: [18F]FDG PET/CT represents a useful tool in the detection of disease response and in the evaluation of outcome in PEL patients.

Coordinate Modulation of Glycolytic Enzymes and OXPHOS by Imatinib in BCR-ABL Driven Chronic Myelogenous Leukemia Cells.

Since many oncogenes, including BCR-ABL, may promote the acquisition and maintenance of the glycolytic phenotype, we tested whether treatment of BCR-ABL-driven human leukemia cells with imatinib, a selective BCR-ABL inhibitor, can modulate the expression of key glycolytic enzymes and mitochondrial complex subunits thus causing alterations of glucose metabolism. BCR-ABL-driven K562 and KCL-22 cells were incubated with increasing concentrations of imatinib to preliminarily test drug sensitivity. Then untreated and treated cells were analyzed for levels of BCR-ABL signaling mediators and key proteins of glycolytic cascade and oxidative phosphorylation. Effective inhibition of BCR-ABL caused a concomitant reduction of p-ERK1/2, p-AKT, phosphorylated form of STAT3 (at Tyr705 and Ser727), c-Myc and cyclin D1 along with an increase of cleaved PARP and caspase 3 at 48 h after treatment. Furthermore, a strong reduction of the hexokinase II (HKII), phosphorylated form of PKM2 (at Tyr105 and Ser37) and lactate dehydrogenase A (LDH-A) was observed in response to imatinib along with a strong upregulation of mitochondrial complexes (OXPHOS). According to these findings, a significant reduction of glucose consumption and lactate secretion along with an increase of intracellular ATP levels was observed in response to imatinib. Our findings indicate that imatinib treatment of BCR-ABL-driven human leukemia cells reactivates mitochondrial oxidative phosphorylation thus allowing potential co-targeting of BCR-ABL and OXPHOS.

Translational molecular imaging in exocrine pancreatic cancer.

Effective treatment for pancreatic cancer remains challenging, particularly the treatment of pancreatic ductal adenocarcinoma (PDAC), which makes up more than 95% of all pancreatic cancers. Late diagnosis and failure of chemotherapy and radiotherapy are all too common, and many patients die soon after diagnosis. Here, we make the case for the increased use of molecular imaging in PDAC preclinical research and in patient management.

Performance of FDG-PET/CT in solitary pulmonary nodule based on pre-test likelihood of malignancy: results from the ITALIAN retrospective multicenter trial.

PURPOSE: The aim of this study was to determine the performance of 18F-FDG-PET/CT in patients with solitary pulmonary nodule (SPN), stratifying the risk according to the likelihood of pulmonary malignancy. METHODS: FDG-PET/CT of 502 patients, stratified for pre-test cancer risk, were retrospectively analyzed. FDG uptake in SPN was assessed by a 4-point scoring system and semiquantitative analysis using the ratio between SUVmax in SPN and SUVmean in mediastinal blood pool (BP) and between SUVmax in SPN and SUVmean in liver (L). Histopathology and/or follow-up data were used as standard of reference. RESULTS: SPN was malignant in 180 (36%) patients, benign in 175 (35%), and indeterminate in 147 (29%). The 355 patients with a definitive SPN nature (malignant or benign) were considered for the analysis. Considering FDG uptake ≥ 2, sensitivity, specificity, positive (PPV) and negative (NPV) predictive values, and accuracy were 85.6%, 85.7%, 86%, 85.2%, and 85.6% respectively. Sensitivity and PPV were higher (P < 0.05) in intermediate and high-risk patients, while specificity and NPV were higher (P < 0.05) in low-risk patients. On receiver operating characteristic curve analysis, the cut-offs for better discrimination between benign and malignant SPN were 1.56 (sensitivity 81% and specificity 87%) and 1.12 (sensitivity 81% and specificity 86%) for SUVmax/SUVmeanBP and SUVmax/SUVmeanL respectively. In intermediate and high-risk patients, including the SUVmax/SUVmeanBP, the specificity shifted from 85% and 50% to 100%. CONCLUSION: Visual FDG-PET/CT has an acceptable performance in patients with SPN, but accuracy improves when SUVratios are considered, particularly in patients with intermediate and high risk of malignancy.

Risk-related 18F-FDG PET/CT and new diagnostic strategies in patients with solitary pulmonary nodule: the ITALIAN multicenter trial.

PURPOSE: Diagnosis of solitary pulmonary nodule (SPN) is an important public health issue and 18F-FDG PET/CT has proven to be more effective than CT alone. Pre-test risk stratification and clinical presentation of SPN could affect the diagnostic strategy. A relevant issue is whether thoracic segmental (s)-PET/CT could be implemented in patients with SPN. This retrospective multicenter study compared the results of FDG whole-body (wb)-PET/CT to those of s-PET/CT. METHODS: 18F-FDG PET/CT of 502 patients, stratified for pre-test cancer risk, were retrospectively analyzed. The thoracic part of wb-PET/CT, considered s-PET/CT, was compared to wb-PET/CT. Clinical and PET/CT variables were investigated for SPN characterization as well as for identification of patients in whom s-PET/CT could be performed. Histopathology or follow-up data were used as a reference. RESULTS: In the study population, 36% had malignant, 35% benign, and 29% indeterminate SPN. 18F-FDG uptake indicative of thoracic and extra-thoracic lesions was detectable in 13% and 3% of the patients. All patients with extra-thoracic metastases (n = 13) had thoracic lymph node involvement and highest 18F-FDG uptake at level of SPN (negative predictive value 100%). Compared to wb-PET/CT, s-PET/CT could save about 2/3 of 18F-FDG dose, radiation exposure or scan-time, without affecting the clinical impact of PET/CT. CONCLUSION: Pre-test probability of malignancy can guide the diagnostic strategy of 18FDG-PET/CT in patients with SPN. In subjects with low-intermediate pretest probability s-PET/CT imaging might be planned in advance, while in those at high risk and with thoracic lymph node involvement a wb-PET/CT is necessary.

Neutrophil Extracellular Traps as an Adhesion Substrate for Different Tumor Cells Expressing RGD-Binding Integrins.

Neutrophil extracellular traps (NETs), in addition to their function as a host defense mechanism, play a relevant role in thrombus formation and metastatic dissemination of cancer cells. Here we screened different cancer cell lines endogenously expressing a variety of integrins for their ability to bind to NETs. To this end, we used NETs isolated from neutrophil-like cells as a substrate for adhesion assays of HT1080, U-87 MG, H1975, DU 145, PC-3 and A-431 cells. Levels of α5, αIIb, αv, ß1, ß3 and ß5 chains were determined by western blot analysis in all cell lines and levels of whole integrins on the plasma membrane were assessed by fluorescence-activated cell sorting (FACS) analysis. We found that high levels of α5ß1, αvß3 and αvß5 enhance cell adhesion to NETs, whereas low expression of α5ß1 prevents cell attachment to NETs. Excess of cyclic RGD peptide inhibited cell adhesion to NETs by competing with fibronectin within NETs. The maximal reduction of such adhesion was similar to that obtained by DNase 1 treatment causing DNA degradation. Our findings indicate that NETs from neutrophil-like cells may be used as a substrate for large screening of the adhesion properties of cancer cells expressing a variety of RGD-binding integrins.

Preclinical imaging in oncology: advances and perspectives.

Preclinical imaging with radiolabeled probes became an integral part of the complex translational process that moves a newly developed compound from laboratory to clinical application. Imaging studies in animal tumor models may be undertaken to test a newly synthesized tracer, a newly developed drug or to interrogate, in the living organism, specific molecular and biological processes underlying tumor growth and progression. The aim of the present review is to outline the current knowledge and future perspectives of preclinical imaging in oncology by providing examples from recent literature. Among the biological processes and molecular targets that can be visualized with radiolabeled probes in animal tumor models, we focused on proliferation, expression of targets suitable for therapy, glycolytic phenotype, metastatic dissemination, tumor angiogenesis and survival. The major contribution of preclinical imaging emerging from these studies is the development and validation of imaging biomarkers that can be translated into the clinical context for patient selection and evaluation of tumor response to molecularly targeted agents.

Machine Learning and Texture Analysis of [18F]FDG PET/CT Images for the Prediction of Distant Metastases in Non-Small-Cell Lung Cancer Patients.

The aim of our study was to predict the occurrence of distant metastases in non-small-cell lung cancer (NSCLC) patients using machine learning methods and texture analysis of 18F-labeled 2-deoxy-d-glucose Positron Emission Tomography/Computed Tomography {[18F]FDG PET/CT} images. In this retrospective and single-center study, we evaluated 79 patients with advanced NSCLC who had undergone [18F]FDG PET/CT scan at diagnosis before any therapy. Patients were divided into two independent training (n = 44) and final testing (n = 35) cohorts. Texture features of primary tumors and lymph node metastases were extracted from [18F]FDG PET/CT images using the LIFEx program. Six machine learning methods were applied to the training dataset using the entire panel of features. Dedicated selection methods were used to generate different combinations of five features. The performance of selected machine learning methods applied to the different combinations of features was determined using accuracy, the confusion matrix, receiver operating characteristic (ROC) curves, and area under the curve (AUC). A total of 104 and 78 lesions were analyzed in the training and final testing cohorts, respectively. The support vector machine (SVM) and decision tree methods showed the highest accuracy in the training cohort. Seven combinations of five features were obtained and introduced in the models and subsequently applied to the training and final testing cohorts using the SVM and decision tree. The accuracy and the AUC of the decision tree method were higher than those obtained with the SVM in the final testing cohort. The best combination of features included shape sphericity, gray level run length matrix_run length non-uniformity (GLRLM_RLNU), Total Lesion Glycolysis (TLG), Metabolic Tumor Volume (MTV), and shape compacity. The combination of these features with the decision tree method could predict the occurrence of distant metastases with an accuracy of 74.4% and an AUC of 0.63 in NSCLC patients.

Coefficient of Variation in Metastatic Lymph Nodes Determined by 18F-FDG PET/CT in Patients with Advanced NSCLC: Combination with Coefficient of Variation in Primary Tumors.

Purpose The aim of the present study was to test whether the coefficient of variation (CoV) of 18F-FDG PET/CT images of metastatic lymph nodes and primary tumors may predict clinical outcome in patients with advanced non-small cell lung cancer (NSCLC). Materials and Methods Fifty-eight NSCLC patients who had undergone 18F-FDG PET/CT at diagnosis were evaluated. SUVmax, SUVmean, CoV, MTV and TLG were determined in targeted lymph nodes and corresponding primary tumors along with Total MTV (MTVTOT) and Whole-Body TLG (TLGWB) of all malignant lesions. Univariate analysis was performed using Cox proportional hazards regression whereas the Kaplan-Meier method and log-rank tests were used for survival analysis. Results Fifty-eight metastatic lymph nodes were analyzed and average values of SUVmax, SUVmean, CoV, MTV and TLG were 11.89 ± 8.54, 4.85 ± 1.90, 0.37 ± 0.16, 46.16 ± 99.59 mL and 256.84 ± 548.27 g, respectively, whereas in primary tumors they were 11.92 ± 6.21, 5.47 ± 2.34, 0.36 ± 0.14, 48.03 ± 64.45 mL and 285.21 ± 397.95 g, respectively. At univariate analysis, overall survival (OS) was predicted by SUVmax (p = 0.0363), SUVmean (p = 0.0200) and CoV (p = 0.0139) of targeted lymph nodes as well as by CoV of primary tumors (p = 0.0173), MTVTOT (p = 0.0007), TLGWB (p = 0.0129) and stage (p = 0.0122). Using Kaplan-Meier analysis, OS was significantly better in patients with CoV of targeted lymph nodes ≤ 0.29 than those with CoV > 0.29 (p = 0.0147), meanwhile patients with CoV of primary tumors > 0.38 had a better prognosis compared to those with CoV ≤ 0.38 (p = 0.0137). Finally, we combined the CoV values of targeted lymph nodes and primary tumors in all possible arrangements and a statistically significant difference was found among the four survival curves (p = 0.0133). In particular, patients with CoV of targeted lymph nodes ≤ 0.29 and CoV of primary tumors > 0.38 had the best prognosis. Conclusions The CoV of targeted lymph nodes combined with the CoV of primary tumors can predict prognosis of NSCLC patients.

Heterogeneity of Glycolytic Phenotype Determined by 18F-FDG PET/CT Using Coefficient of Variation in Patients with Advanced Non-Small Cell Lung Cancer.

We investigated the role of Coefficient of Variation (CoV), a first-order texture parameter derived from 18F-FDG PET/CT, in the prognosis of Non-Small Cell Lung Cancer (NSCLC) patients. Eighty-four patients with advanced NSCLC who underwent 18F-FDG PET/CT before therapy were retrospectively studied. SUVmax, SUVmean, CoV, total Metabolic Tumor Volume (MTVTOT) and whole-body Total Lesion Glycolysis (TLGWB) were determined by an automated contouring program (SUV threshold at 2.5). We analyzed 194 lesions: primary tumors (n = 84), regional (n = 48) and non-regional (n = 17) lymph nodes and metastases in liver (n = 9), bone (n = 23) and other sites (n = 13); average CoVs were 0.36 ± 0.13, 0.36 ± 0.14, 0.42 ± 0.18, 0.30 ± 0.14, 0.37 ± 0.17, 0.34 ± 0.13, respectively. No significant differences were found between the CoV values among the different lesion categories. Survival analysis included age, gender, histology, stage, MTVTOT, TLGWB and imaging parameters derived from primary tumors. At univariate analysis, CoV (p = 0.0184), MTVTOT (p = 0.0050), TLGWB (p = 0.0108) and stage (p = 0.0041) predicted Overall Survival (OS). At multivariate analysis, age, CoV, MTVTOT and stage were retained in the model (p = 0.0001). Patients with CoV > 0.38 had significantly better OS than those with CoV ≤ 0.38 (p = 0.0143). Patients with MTVTOT ≤ 89.5 mL had higher OS than those with MTVTOT > 89.5 mL (p = 0.0063). Combining CoV and MTVTOT, patients with CoV ≤ 0.38 and MTVTOT > 89.5 mL had the worst prognosis. CoV, by reflecting the heterogeneity of glycolytic phenotype, can predict clinical outcomes in NSCLC patients.

Prediction of 2-[18F]FDG PET-CT SUVmax for Adrenal Mass Characterization: A CT Radiomics Feasibility Study.

BACKGROUND: Indeterminate adrenal masses (AM) pose a diagnostic challenge, and 2-[18F]FDG PET-CT serves as a problem-solving tool. Aim of this study was to investigate whether CT radiomics features could be used to predict the 2-[18F]FDG SUVmax of AM. METHODS: Patients with AM on 2-[18F]FDG PET-CT scan were grouped based on iodine contrast injection as CT contrast-enhanced (CE) or CT unenhanced (NCE). Two-dimensional segmentations of AM were manually obtained by multiple operators on CT images. Image resampling and discretization (bin number = 16) were performed. 919 features were calculated using PyRadiomics. After scaling, unstable, redundant, and low variance features were discarded. Using linear regression and the Uniform Manifold Approximation and Projection technique, a CT radiomics synthetic value (RadSV) was obtained. The correlation between CT RadSV and 2-[18F]FDG SUVmax was assessed with Pearson test. RESULTS: A total of 725 patients underwent PET-CT from April 2020 to April 2021. In 150 (21%) patients, a total of 179 AM (29 bilateral) were detected. Group CE consisted of 84 patients with 108 AM (size = 18.1 ± 4.9 mm) and Group NCE of 66 patients with 71 AM (size = 18.5 ± 3.8 mm). In both groups, 39 features were selected. No statisticallyf significant correlation between CT RadSV and 2-[18F]FDG SUVmax was found (Group CE, r = 0.18 and p = 0.058; Group NCE, r = 0.13 and p = 0.27). CONCLUSIONS: It might not be feasible to predict 2-[18F]FDG SUVmax of AM using CT RadSV. Its role as a problem-solving tool for indeterminate AM remains fundamental.

ATM inhibition blocks glucose metabolism and amplifies the sensitivity of resistant lung cancer cell lines to oncogene driver inhibitors.

BACKGROUND: ATM is a multifunctional serine/threonine kinase that in addition to its well-established role in DNA repair mechanisms is involved in a number of signaling pathways including regulation of oxidative stress response and metabolic diversion of glucose through the pentose phosphate pathway. Oncogene-driven tumorigenesis often implies the metabolic switch from oxidative phosphorylation to glycolysis which provides metabolic intermediates to sustain cell proliferation. The aim of our study is to elucidate the role of ATM in the regulation of glucose metabolism in oncogene-driven cancer cells and to test whether ATM may be a suitable target for anticancer therapy. METHODS: Two oncogene-driven NSCLC cell lines, namely H1975 and H1993 cells, were treated with ATM inhibitor, KU55933, alone or in combination with oncogene driver inhibitors, WZ4002 or crizotinib. Key glycolytic enzymes, mitochondrial complex subunits (OXPHOS), cyclin D1, and apoptotic markers were analyzed by Western blotting. Drug-induced toxicity was assessed by MTS assay using stand-alone or combined treatment with KU55933 and driver inhibitors. Glucose consumption, pyruvate, citrate, and succinate levels were also analyzed in response to KU55933 treatment. Both cell lines were transfected with ATM-targeted siRNA or non-targeting siRNA and then exposed to treatment with driver inhibitors. RESULTS: ATM inhibition deregulates and inhibits glucose metabolism by reducing HKII, p-PKM2Tyr105, p-PKM2Ser37, E1α subunit of pyruvate dehydrogenase complex, and all subunits of mitochondrial complexes except ATP synthase. Accordingly, glucose uptake and pyruvate concentrations were reduced in response to ATM inhibition, whereas citrate and succinate levels were increased in both cell lines indicating the supply of alternative metabolic substrates. Silencing of ATM resulted in similar changes in glycolytic cascade and OXPHOS levels. Furthermore, the driver inhibitors amplified the effects of ATM downregulation on glucose metabolism, and the combined treatment with ATM inhibitors enhanced the cytotoxic effect of driver inhibitors alone by increasing the apoptotic response. CONCLUSIONS: Inhibition of ATM reduced both glycolytic enzymes and OXPHOS levels in oncogene-driven cancer cells and enhanced apoptosis induced by driver inhibitors thus highlighting the possibility to use ATM and the driver inhibitors in combined regimens of anticancer therapy in vivo.

What molecular imaging of cancer patients can teach us about COVID-19.

COVID-19 pandemic had a great impact on health systems and cancer care worldwide. Patients with cancer who develop COVID-19 are at high risk of severe outcomes and clarifying the determinants of such vulnerability of cancer patients would be of great clinical benefit. While the mechanisms of SARS-CoV-2 infection have been elucidated, the pathogenetic pathways leading to severe manifestations of the disease are largely unknown. Critical manifestations of COVID-19 mainly occur in elderly patients and in patients with serious comorbidities including cancer. Efforts to understand the intersection of pathways between severe manifestations of COVID-19 and cancer may shed light on the pathogenesis of critical illness in COVID-19 patients. Here, we will focus our attention on two major fields of potential intersection between COVID-19 and cancer, namely the dysfunction of immune system and the prothrombotic state that can occur in both COVID-19 and cancer patients, testing whether cancer imaging can provide clues to better understand such interactions.

Tumor-induced Osteomalacia: A Systematic Review and Individual Patient's Data Analysis.

CONTEXT: Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome, usually caused by small, benign, and slow-growing phosphaturic mesenchymal tumors. Clinically, TIO is characterized by renal phosphate leak, causing hypophosphatemia and osteomalacia. This review was performed to assess the clinical characteristics of TIO patients described worldwide so far. EVIDENCE ACQUISITION: On June 26, 2021, a systematic search was performed in Medline, Google Scholar, Google book, and Cochrane Library using the terms: "tumor induced osteomalacia," "oncogenic osteomalacia," "hypophosphatemia." There were no language restrictions. This review was performed according to Preferred Reporting Items for Systematic reviews and Meta-Analyses criteria. EVIDENCE RESULTS: Overall, 1725 TIO cases were collected. TIO was more frequent in adult men, who showed a higher incidence of fractures compared with TIO women. The TIO-causing neoplasms were identified in 1493 patients. The somatostatin receptor-based imaging modalities have the highest sensitivity for the identification of TIO-causing neoplasms. TIO-causing neoplasms were equally located in bone and soft tissues; the latter showed a higher prevalence of fractures and deformities. The surgery is the preferred TIO definitive treatment (successful in > 90% of patients). Promising nonsurgical therapies are treatments with burosumab in TIO patients with elevated fibroblast growth factor-23 levels, and with radiolabeled somatostatin analogs in patients with TIO-causing neoplasm identified by somatostatin receptor-based imaging techniques. CONCLUSION: TIO occurs preferentially in adult men. The TIO clinical expressiveness is more severe in men as well as in patients with TIO-causing neoplasms located in soft tissues. Treatments with burosumab and with radiolabeled somatostatin analogs are the most promising nonsurgical therapies.

Heterogeneity of SSTR2 Expression Assessed by 68Ga-DOTATOC PET/CT Using Coefficient of Variation in Patients with Neuroendocrine Tumors.

High levels of somatostatin receptor subtype 2 (SSTR2) are a prerequisite for therapy with unlabeled or labeled somatostatin analogs. However, it is still unclear how the heterogeneity of SSTR2 expression may affect tumor response to therapy. The aim of our study was to test the ability of an imaging parameter such as coefficient of variation (CoV) derived from PET/CT with 68Ga-peptides in the evaluation and quantification of the heterogeneity of SSTR2 expression within primary and metastatic lesions of patients with neuroendocrine tumors. Methods: Thirty-eight patients with pathologically proven neuroendocrine tumors who underwent 68Ga-DOTATOC PET/CT were studied. Primary tumors were localized in the gastroenteropancreatic, bronchopulmonary, and other anatomic districts in 25, 7, and 6 patients, respectively. Malignant lesions were segmented using an automated contouring program and an SUV threshold of more than 2.5 or, in the case of liver lesions, a threshold of 30% of the SUVmax The imaging parameters SUVmean, CoV, SUVmax, receptor-expressing tumor volume, and total lesion receptor expression were obtained for each lesion. SUVmean, CoV, and SUVmax were also obtained for representative volumes of normal liver and spleen, as well as for the whole pituitary gland. Results: In total, 107 lesions were analyzed, including 35 primary tumors, 32 metastatic lymph nodes, and 40 distant metastases. Average CoVs were 0.49 ± 0.20 for primary tumors, 0.57 ± 0.26 for lymph node metastases, and 0.44 ± 0.20 for distant metastases. The CoVs of malignant lesions were up to 4-fold higher than those of normal tissues (P ≤ 0.0001). Among malignant lesions, the highest CoV was found for bone metastases (0.68 ± 0.20), and it was significantly greater than that of primary lesions (P = 0.01) and liver metastases (P < 0.0001). On the other hand, the lowest CoV was found for liver lesions (0.32 ± 0.07), probably because of the high background uptake. Conclusion: Our findings indicate that the heterogeneity of uptake, reflecting that of SSTR2, varies with the type and site of malignant lesions as assessed by CoVs obtained from 68Ga-DOTATOC PET/CT scans. These observations may be related to different biologic characteristics of tumor lesions in the same patient-differences that may affect their response to treatment with both labeled and unlabeled somatostatin analogs.

Impact of COVID-19 pandemic on 2-[18F]FDG PET/CT imaging work-flow in a single medical institution: comparison among the three Italian waves.

PURPOSE: To compare the impact of COVID-19 pandemic on 2-[18F]FDG PET/CT imaging work-flow during the three waves in a medical institution of southern of Italy. METHODS: We retrospectively reviewed the numbers and results of 2-[18F]FDG PET/CT studies acquired during the following three periods of the COVID-19 waves: 1) February 3-April 30, 2020; 2) October 15, 2020-January 15, 2021; and 3) January 18-April 16, 2021. RESULTS: A total of 861 PET/CT studies in 725 patients (388 men, mean age 64 ± 4 years) was acquired during the three waves of COVID-19 pandemic. The majority (94%) was performed for diagnosis/staging (n = 300) or follow-up (n = 512) of neoplastic diseases. The remaining 49 studies (6%) were acquired for non-oncological patients. The distribution of number and type of clinical indications for PET/CT studies in the three waves were comparable (p = 0.06). Conversely, the occurrence of patients positive for COVID-19 infection progressively increased (p < 0.0001) from the first to third wave; in particular, patients with COVID-19 had active infection before PET/CT study as confirmed by molecular oro/nasopharyngeal swab. CONCLUSION: Despite the restrictive medical measures for the emergency, the number of 2-[18F]FDG PET/CT studies was unchanged during the three waves guaranteeing the diagnostic performance of PET/CT imaging for oncological patients.