Role of splenic and bone marrow uptake at 18 F-FDG PET/CT for the assessment of large vessels vasculitis and the influence of glucocorticoids therapy on their values.

INTRODUCTION: To assess the relationship between splenic and bone marrow (BM) uptake with the presence of large vessel vasculitis (LVV) at 18 F-FDG PET/CT and to evaluate the influence of glucocorticoid (GC) therapy on these uptakes. METHODS: One hundred and one subjects with LVV and 18 F-FDG PET/CT were included in the study. Clinical features, including blood samples and duration of GC therapy, were collected. Standardized uptake value body weight max (SUVmax) of the spleen, BM, liver and arterial walls were extracted; spleen/liver (SL) and BM/liver (BML) ratios were calculated. Chi-square and T-test were used to assess the relationship between PET/CT parameters and clinical features with the presence of LVV. Rank correlation was used to evaluate the correlation between PET/CT parameters and clinical parameters. Receiver operating curve (ROC) analysis was used to find the best parameter able to discriminate between positive and negative PET/CT. All analyses were performed considering the duration of GC therapy. RESULTS: Significant correlation for PET/CT results with spleen uptake (P-value = 0.001), SL (P-value < 0.001) and BML (P-value = 0.005) were reported in patients with no more than 3 days of therapy; the correlation with SL was confirmed in the total cohort of patients. A value of 0.92 for SL had an AUC of 0.959, a sensitivity of 92.6% and a specificity of 96.6% (P-value < 0.001) in predicting PET/CT results. CONCLUSION: Higher splenic and BM uptake in patients with positive PET/CT for LVV were reported. A long duration of GC therapy is able to reduce such uptakes.

Temporal Evolution and Prognostic Role of Indeterminate Response Sub-Groups in Patients with Differentiated Thyroid Cancer after Initial Therapy with Radioiodine.

The clinical outcome of patients affected by Differentiated Thyroid Carcinoma (DTC) and an indeterminate response (IR) after initial therapy is not yet clear. IR includes three different sub-groups of patients: (1) IRTg+ group: Detectable thyroglobulin (Tg), regardless of antithyroglobulin antibodies (TgAb) presence or imaging studies; (2) IRTgAb+ group: Positive TgAb, regardless of Tg levels and nonspecific imaging findings; (3) IRImaging+ group: Nonspecific findings on neck ultrasonography or faint uptake in the thyroid bed on the whole-body scan, negative TgAb, and undetectable Tg. The main aim of this retrospective study was to investigate the dynamic evolution and prognostic role of these patients. From January 2010 to December 2017, 2176 patients who received radioiodine for DTC after total thyroidectomy were included. Two-hundred-eighty-eight patients had IR one year after therapy (187 TgAb+, 76 Tg+, 25 imaging+). After two years, 110 patients (38%) were reclassified as an excellent response and 5 (2%) as an incomplete response; after five years, 221 (77%) achieved an excellent response and 11 (4%) showed an incomplete response. One-year stimulated Tg and nodal disease at diagnosis may predict the final status of the disease. Progression-free survival was significantly shorter in IRTg+ than in IRTgAb+ and IRimaging+ groups. Considering Tg+ patients, a threshold of 3.3 ng/mL is best to predict prognosis.

"Vascular inflammation and cardiovascular disease: review about the role of PET imaging".

Inflammation characterizes all stages of atherothrombosis and provides a critical pathophysiological link between plaque formation and its acute rupture, leading to coronary occlusion and heart attack. In the last 20 years the possibility of quantifying the degree of inflammation of atherosclerotic plaques and, therefore, also of vascular inflammation aroused much interest. 18Fluoro-deoxy-glucose photon-emissions-tomography (18F-FDG-PET) is widely used in oncology for staging and searching metastases; in cardiology, the absorption of 18F-FDG into the arterial wall was observed for the first time incidentally in the aorta of patients undergoing PET imaging for cancer staging. PET/CT imaging with 18F-FDG and 18F-sodium fluoride (18F-NaF) has been shown to assess atherosclerotic disease in its molecular phase, when the process may still be reversible. This approach has several limitations in the clinical practice, due to lack of prospective data to justify their use routinely, but it's desirable to develop further scientific evidence to confirm this technique to detect high-risk patients for cardiovascular events.

Prognostic role of baseline 18F-FDG pet/CT in stage I and stage ii non-small cell lung cancer.

OBJECTIVE: investigate the prognostic role of baseline 18F-FDG PET/CT in stage I-II NSCLC. MATERIAL AND METHODS: 296 patients were included. Clinicopathological features and PET/CT semiquantitative parameters [standardized uptake value (SUV) body weight max (SUVmax), SUV body weight mean (SUVmean), SUV lean body mass (SUVlbm), SUV body surface area (SUVbsa), metabolic tumor volume (MTV), total lesion glycolysis (TLG), ratio SUVmax/liver (S-L) and ratio SUVmax/blood-pool (S-BP) were extracted]. Anova and Kruskall-Wallis tests were used to assess the relationship between these parameters. Kaplan-Meier, univariate and multivariate analysis were performed to search independent prognostic factors for progression free (PFS), overall survival (OS) and disease specific survival (DSS). RESULTS: Correlation between PET/CT semiquantitative parameters and histology, stage, size, grading and presence of nodal metastasis were reported. Mean PFS was 28.1 months, relapse/progression of disease occurred in 85 patients (28.7%). Mean OS was 33.3 months, death occurred in 43 patients (14.5%); specific death by NSCLC occurred in 26 subjects (8.8%). Kaplan-Meier analyses revealed most of semiquantitative parameters as predictive for PFS, OS and DSS. For DSS, this was confirmed when dividing between patients with surgery and surgery with other therapies. SUVmax, SUVmean, SUVlbm, SUVbsa and S-L revealed to be independent prognosticators for OS and DSS. S-BP was an independent prognosticator for DSS. SUVmax, SUVmean, SUVlbm, S-L and S-BP were confirmed as independent prognosticators for DSS in the group of patients treated with surgery and subsequent adjuvant therapy. CONCLUSION: Baseline 18F-FDG PET/CT semiquantitative parameters are confirmed as prognostic tools for stage I-II NSCLC, in particular for DSS.

Relationship between Baseline [18F]FDG PET/CT Semiquantitative Parameters and BRCA Mutational Status and Their Prognostic Role in Patients with Invasive Ductal Breast Carcinoma.

AIM: To assess the relationship between [18F]FDG PET/CT, breast cancer gene (BRCA) status, and their prognostic role in patients with ductal breast cancer (DBC). METHODS: Forty-one women were included. PET/CT semiquantitative parameters such as standardized uptake value (SUV) body weight max (SUVmax), SUV body weight mean (SUVmean), SUV lean body mass (SUVlbm), SUV body surface area (SUVbsa), metabolic tumor volume (MTV), total lesion glycolysis (TLG), ratio SUVmax/blood-pool (S-BP), and ratio SUVmax/liver (S-L) were also extracted. The relationship between these parameters, BRCA, and other clinicopathological features were evaluated. Kaplan-Meier, univariate, and multivariate analyses were performed to find independent prognosticators for progression free (PFS) and overall survival (OS). RESULTS: Significant positive correlations between BRCA status and SUVmax (p-value 0.025), SUVlbm (p-value 0.016), and SUVbsa (p-value 0.018) were reported. Mean PFS was 53.90 months with relapse/progression of disease occurring in nine (22.0%) patients; mean OS was 57.48 months with death occurring in two (4.9%) patients. Survival curves revealed TLG, MTV, and BRCA status as prognosticator for PFS; BRCA was also a prognosticator for OS. Univariate and multivariate analyses did not confirm such insights. CONCLUSION: We reported a correlation between some PET/CT parameters and BRCA status; some insights on their prognostic role have been underlined.

18F-fluorodeoxyglucose PET and PET/computed tomography for the evaluation of immunoglobulin G4-related disease: a systematic review.

BACKGROUND: In the last years, 18F-fluorodeoxyglucose PET/computed tomography (18F-FDG PET/CT) has demonstrated its utility for the evaluation of immunoglobulin G4 (IgG4)-related disease (IgG4RD). The studies are, however, really heterogeneous and different. The aim of this review is, therefore, to analyze the diagnostic performance of 18F-FDG PET and PET/CT for the assessment of IgG4RD. METHODS: A wide literature search of the PubMed/MEDLINE, Scopus, Embase and Cochrane library databases was made to find relevant published articles about the diagnostic performance of 18F-FDG PET or PET/CT for the evaluation of IgG4RD. RESULTS: The comprehensive computer literature search revealed 779 articles. On reviewing the titles and abstracts, 756 articles were excluded because the reported data were not within the field of interest. Twenty-three studies were included in the review. CONCLUSION: Despite some limitations that affect our review, 18F-FDG PET or PET/CT demonstrated the ability to assess IgG4RD both at initial evaluation and after therapy. In general, no correlation between PET/CT parameters and IgG4 serum levels has been reported. A possible role for 18F-FDG PET/CT to drive differential diagnosis with other disease is starting to emerge.

Different glucose metabolism behavior relating to histotypes in synchronous breast cancers evaluated by [18F]FDG PET-CT.

Glucose metabolism is increased in most aggressive tumors and it is commonly evaluated by positron emission tomography-computed tomography (PET-CT) with 18F-fluorodeoxyglucose ([18F]FDG), measuring the Maximum Standardized Uptake Value (SUVmax) for the assessment. Particularly, it is known that breast cancer expresses different glucose metabolism inrelation to estrogen receptor (ER), progesterone receptor (PR), Ki67 score, tumor grading, tumor size, and Human Epidermal Growth Factor Receptor 2 (HER2). We present an interesting case of a woman with two different, synchronous breast cancers characterized by different glucose metabolism, according to literature knowledge.

A Rare Case of Incidental Finding of Cervical Spinal Cord Hemangioblastoma by 68Ga-DOTATOC Positron Emission Tomography/Computed Tomography Scan.

Hemangioblastomas are rare vascular tumors of the central nervous system usually related to other pathological conditions, such as Von Hippel Lindau Syndrome (VHLS) and polycythemia. We describe a case of a 65-year-old man with a neuroendocrine tumor of the ileum presenting with cervical pain who underwent a 68Ga-DOTATOC positron emission tomography/computed tomography (PET/CT) scan that incidentally underlines the presence of hemangioblastoma of the cervical spinal cord. The patient does not have a family history of VHLS nor does he suffer from polycythemia and he is currently waiting for genetic testing. Despite being rare, hemangioblastomas could be possible findings of central nervous system incidentaloma at 68Ga-DOTATOC PET/CT scan, especially in patients with anamnesis with possible related condition.

Role of Radiomics Features and Machine Learning for the Histological Classification of Stage I and Stage II NSCLC at [18F]FDG PET/CT: A Comparison between Two PET/CT Scanners.

The aim of this study was to compare two different PET/CT tomographs for the evaluation of the role of radiomics features (RaF) and machine learning (ML) in the prediction of the histological classification of stage I and II non-small-cell lung cancer (NSCLC) at baseline [18F]FDG PET/CT. A total of 227 patients were retrospectively included and, after volumetric segmentation, RaF were extracted. All of the features were tested for significant differences between the two scanners and considering both the scanners together, and their performances in predicting the histology of NSCLC were analyzed by testing of different ML approaches: Logistic Regressor (LR), k-Nearest Neighbors (kNN), Decision Tree (DT) and Random Forest (RF). In general, the models with best performances for all the scanners were kNN and LR and moreover the kNN model had better performances compared to the other. The impact of the PET/CT scanner used for the acquisition of the scans on the performances of RaF was evident: mean area under the curve (AUC) values for scanner 2 were lower compared to scanner 1 and both the scanner considered together. In conclusion, our study enabled the selection of some [18F]FDG PET/CT RaF and ML models that are able to predict with good performances the histological subtype of NSCLC. Furthermore, the type of PET/CT scanner may influence these performances.

Prognostic Role of 2-[18F]FDG PET/CT Metabolic Volume Parameters in Patients Affected by Differentiated Thyroid Carcinoma with High Thyroglobulin Level, Negative 131I WBS and Positive 2-[18F]-FDG PET/CT.

The clinical and prognostic role of 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography (2-[18F]FDG PET/CT) in the study of patients affected by differentiated thyroid carcinoma (DTC) with positive serum thyroglobulin (Tg) level and negative [131I] whole-body scan ([131I]WBS) has already been demonstrated. However, the potential prognostic role of semi-quantitative PET metabolic volume features, such as metabolic tumor volume (MTV) and total lesion glycolysis (TLG), has not yet been clearly investigated. The aim of this retrospective study was to investigate whether the main metabolic PET/CT parameters may predict the prognosis. We retrospectively included 122 patients with a positive 2-[18F]FDG PET/CT for DTC disease after a negative [131I]WBS with Tg > 10 ng/mL. The maximum and mean standardized uptake value (SUVmax and SUVmean), MTV and TLG of the hypermetabolic lesion, total MTV (tMTV) and total TLG (tTLG) were measured for each scan. Progression-free survival (PFS) and overall survival (OS) curves were plotted according to the Kaplan-Meier analysis. After a median follow up of 53 months, relapse/progression of disease occurred in 87 patients and death in 42. The median PFS and OS were 19 months (range 1-132 months) and 46 months (range 1-145 months). tMTV and tTLG were the only independent prognostic factors for OS. No variables were significantly correlated with PFS. The best thresholds derived in our sample were 6.6 cm3 for MTV and 119.4 for TLG. In patients with negative WBS and Tg > 10 ng/mL, 2-[18F]FDG PET/CT metabolic volume parameters (tMTV and tTLG) may help to predict OS.

Prognostic Impact of Pretreatment 2-[18F]-FDG PET/CT Parameters in Primary Gastric DLBCL.

Background and Objectives: Primary gastric diffuse large-B cell lymphoma (DLBCL) is an aggressive lymphoma subtype with high 18F-FDG avidity but unclear criteria for 2-[18F]-FDG PET/CT in the evaluation of treatment response and prognostication. Our aim was to investigate whether the pretreatment 2-[18F]-FDG PET/CT variables may predict treatment response (at end of first-line therapy) and prognosis in primary gastric DLBCL. Materials and Methods: we included 57 patients with a diagnosis of primary gastric DLBCL and a baseline 2-[18F]-FDG PET/CT and an end of treatment PET/CT after 6 cycles of R-CHOP chemotherapy. We analyzed PET images qualitatively and semi-quantitatively by deriving the maximum standardized uptake value body weight (SUVbw), the maximum standardized uptake value lean body mass (SUVlbm), the maximum standardized uptake value body surface area (SUVbsa), lesion to liver SUVmax ratio (L-L SUV R), lesion to blood-pool SUVmax ratio (L-BP SUV R), metabolic tumor volume and total lesion glycolysis of gastric lesion (gMTV and gTLG), and total MTV (tMTV) and TLG. Survival curves were plotted according to the Kaplan-Meier analysis. Results: at a median follow up of 80 months, the median PFS and OS were 69 and 80 months. Baseline gMTV, gTLG, tMTV, and TLG were significantly higher in patients with incomplete response (partial response and progression) compared to complete response group. tMTV and TLG were confirmed to be independent prognostic factors both for PFS (p = 0.023 and p = 0.038) and OS (p = 0.038 and p = 0.026); instead, the other metabolic parameters were not related to outcome survival. Conclusions: high tMTV and TLG were significantly correlated with shorter survival (PFS and OS) and may predict incomplete response after therapy.