Terms Of SUVmax Research Articles

Detecting recurrent disease and surgical outcomes in patients with locally advanced tongue cancer after multimodal treatment using ¹⁸F-FDG-PET/CT

The purpose of this study was to evaluate the utility of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (FPCT) parameters for detecting recurrent disease and the outcomes of salvage surgery in patients with locally advanced oral tongue squamous cell carcinoma (TSCC) after multimodal treatment. In total, 69 patients with locally advanced TSCC were treated with multimodal therapy. All patients underwent whole-body FPCT scans 4–10 months after the initial surgery. The analysis included FPCT parameters, such as maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG). Histological examination was used as the reference standard. Patients with recurrent TSCC underwent salvage surgery or surgery plus systemic treatment. This study included 69 patients: 36 in the recurrent TSCC group and 33 in the non-recurrent TSCC group. The SUVmax, MTV, and TLG in the recurrent TSCC group were 11.3 ± 3.6, 28.3 ± 15.6 cm3, and 113.2 ± 46.8 g, respectively; these values were 5.9 ± 3.6, 5.1 ± 2.2 cm3, and 13.4 ± 4.8 g, in the non-recurrent TSCC group respectively. The two groups had significant differences in terms of SUVmax, MTV, and TLG. In the recurrent TSCC group, 91.6 % of patients presented with local, locoregional, and regional disease and underwent salvage surgery plus systemic therapy, whereas 8.4 % had locoregional recurrence with distant metastases alone and underwent surgery plus systemic therapy. The patients were followed up for 12–60 months; 19 and 20 patients in the recurrent and non-recurrent TSCC groups showed no evidence of disease, whereas 11 and 8 were alive with the disease. Local recurrence or distant metastases led to the deaths of six patients in the recurrent TSCC group and five in the non-recurrent TSCC group. No significant differences in survival were observed between the two groups. FPCT parameters can detect the recurrence of locally advanced TSCC after multimodal treatment. Early salvage surgery can improve the treatment outcomes for recurrent TSCC.

Intra-Individual Comparison of Physiologic [68Ga]Ga-PSMA-11 and [18F]PSMA-1007 Uptake in Ganglia in Patients with Prostate Cancer: A Retrospective, Monocentric Analysis.

Several studies indicate, particularly in the case of [18F]PSMA-1007, a relatively high rate of detection of ganglia in PSMA PET imaging. Ganglia are an integral part of the sympathetic portion of the autonomous nervous system. To date, no studies have directly compared [68Ga]Ga-PSMA-11 and [18F]PSMA-1007 ganglionic uptake intra-individually and analyzed the underlying molecular and physical mechanisms of different detection rates. With this monocentric retrospective study, we sought to evaluate the intra-individual physiological ganglion uptake of these different PSMA ligands in evidence-based imaging for prostate cancer. Our cohort consists of 19 male patients (median age 72 ± 9 with a range of 56-85) with biochemical recurrence of prostate cancer who underwent both [68Ga]Ga-PSMA-11 and [18F]PSMA-1007 PET/CT in our clinic on the same scanner per standard care between March 2015 and March 2022. Tracer uptake was quantified according to maximum standardized uptake value (SUVmax) for both [68Ga]Ga-PSMA-11 and [18F]PSMA-1007 PET/CT scans. Ganglia-to-background ratios (GBRs) were determined to quantify the image contrast through dividing the SUVmax of the ganglia by the background value (SUVmax of blood pool in the descending aorta, fatty tissue, and skeletal muscle in gluteal region). We used descriptive analyses for demographics and tumor characteristics and performed two-way repeated-measures ANOVA (analysis of variance) for SUV metrics including GBR measurements. In total, we examined 101 ganglia with [18F]PSMA-1007 scanning, localized mostly in pairs as stellate, coeliac, and sacral, of which 76 were also detected with [68Ga]Ga-PSMA-11 PET/CT scanning. There was no statistically significant difference in PSMA uptake in terms of SUVmax between [18F]PSMA-1007 and [68Ga]Ga-PSMA-11 (p value: 0.052). In contrast, the comparison of GBRs revealed a higher detectability rate of ganglia with [18F]PSMA-1007 imaging (p < 0.001). Furthermore, a separate comparison of ganglia with respect to their anatomical location also demonstrated statistically significant differences both within and between [18F]PSMA-1007 and [68Ga]Ga-PSMA-11 PET/CT scans. Given the impression of more accentuated [18F]PSMA-1007 uptake in ganglia compared with 68Ga-labelled counterparts, our study demonstrated that the better detectability of ganglia is not due to more intense [18F]PSMA-1007 uptake by these small structures but to much more favorable physical properties of the radionuclide 18F. The most relevant limitations of our study are its retrospective design and the small patient cohort.

Characterization of Mediastinal Bulky Lymphomas with FDG-PET-Based Radiomics and Machine Learning Techniques.

This study tested the diagnostic value of 18F-FDG PET/CT (FDG-PET) volumetric and texture parameters in the histological differentiation of mediastinal bulky disease due to classical Hodgkin lymphoma (cHL), primary mediastinal B-cell lymphoma (PMBCL) and grey zone lymphoma (GZL), using machine learning techniques. We reviewed 80 cHL, 29 PMBCL and 8 GZL adult patients with mediastinal bulky disease and histopathological diagnoses who underwent FDG-PET pre-treatment. Volumetric and radiomic parameters were measured using FDG-PET both for bulky lesions (BL) and for all lesions (AL) using LIFEx software (threshold SUV ≥ 2.5). Binary and multiclass classifications were performed with various machine learning techniques fed by a relevant subset of radiomic features. The analysis showed significant differences between the lymphoma groups in terms of SUVmax, SUVmean, MTV, TLG and several textural features of both first- and second-order grey level. Among machine learning classifiers, the tree-based ensembles achieved the best performance both for binary and multiclass classifications in histological differentiation. Our results support the value of metabolic heterogeneity as an imaging biomarker, and the use of radiomic features for early characterization of mediastinal bulky lymphoma.

Abstract P6-01-42: BASELINE 18FDG-PET METABOLIC TUMOUR VOLUME (MTV) AS A POTENTIAL PREDICTIVE FACTOR OF RESPONSE TO METRONOMIC CHEMOTHERAPY (mCHT) IN HR+/HER2- METASTATIC BREAST CANCER (MBC) PATIENTS (pts). PRELIMINARY RESULTS OF THE METRO-PET STUDY

Abstract Background: MBC is an incurable disease and chemotherapy (CHT) represents one option of treatment upfront, in TNBC pts, or at failure of an endocrine therapy + targeted agents in HR+ ones. mCHT was extensively studied in different types of ABC pts and is largely used in clinical practice. 18FDG-PET is often used as a tool for disease staging at baseline and for disease restaging during treatment. Different quantitative and semi-quantitative 18FDG-PET parameters have been investigated as predictive and prognostic biomarkers in NSCLC and other tumours. Aim of the present study is to evaluate the role of baseline SUVmax , global SUVmean, SUVpeak, Metabolic Tumour Volume (MTV) and Total Lesion Glycolysis (TLG) as predictive factors of response to mCHT. Patients and Methods: We identified 36 MBC pts treated with mCHT between 2014 and 2021, with at least two separate 18FDG-PET evaluations. Patients and biological tumour characteristics, previous treatments, site of relapse as well as quantitative pre-treatment 18FDG-PET parameters have been collected. Tumour response was assessed using PERCIST Criteria. Median and mean ± SD 18FDG-PET parameters have been reported according to the type of response. Complete and Partial responses have been grouped together with Stable Disease. Results: Median age was 69 (33-82). Luminal pts were 25 (67.6%), TNBC pts were 16.2%); most were heavily pre-treated for their metastatic disease (≥ 3 lines: 14, 37.8%) and presented ≥ 3 metastatic sites (14, 37.8%). All pts received mCHT, 26 (70.3%) as combination therapy (VRL+CAPE or VRL+CAPE+CTX), or single agent (VRL, 11). Bone was the commonest metastatic site (62.2%). ORR was 43.2%; 7 pts had SD (18.9%), the remaining developed PD (37.8%). Similar values have been observed between the 2 groups in terms of SUVmax , global SUVmean and SUVpeak,. Mean MTV was higher in responder (n=22) vs non responder (n=14) pts, as TLG. Details are reported in Table 1. Conclusions: High mean baseline MTV and TLG seem to be related to response to mCHT in MBC pts. Our observation is in contrast to what is described for other cancer types, especially NSCLC, and for standard neoadjuvant treatment of BC. Considering the peculiar mechanisms of action of mCHT, our preliminary findings warrant further exploration in a larger series of BC pts. Table 1 Baseline 18FDG-PET uptake values in responder and non responder patients Citation Format: Marco Meazza Prina, Irene Gotuzzo, Marina Elena Cazzaniga, Elisabetta De Bernardi, Pietro Cafaro, Serena Capici, Viola Cogliati, Francesca Fulvia Pepe, Federica Cicchiello, Francesca Riva, Nicoletta Cordani, Maria Grazia Cerrito, Elia Anna Turolla, Claudio Landoni, Federica Elisei, Cinzia Crivellaro, Leonardo Virdone, Lavinia Monaco, Alessandro Guidi, Luca Guerra. BASELINE 18FDG-PET METABOLIC TUMOUR VOLUME (MTV) AS A POTENTIAL PREDICTIVE FACTOR OF RESPONSE TO METRONOMIC CHEMOTHERAPY (mCHT) IN HR+/HER2- METASTATIC BREAST CANCER (MBC) PATIENTS (pts). PRELIMINARY RESULTS OF THE METRO-PET STUDY [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P6-01-42.

Total Lesion Glycolysis Obtained by FDG PET/CT in Diagnosing Solitary Pulmonary Nodules.

To evaluate the diagnostic performance of total lesion glycolysis (TLG) obtained by 18F-FDG PET/ CT to differentiate malignant solitary pulmonary nodules (SPNs) from benign ones. Observational study. Department of Nuclear Medicine, Istanbul Medeniyet University School of Medicine, Istanbul, Turkey, from January 2018 to April 2022. Eighty patients, who were found to have SPNs and underwent PET/CT imaging, were enrolled in this retrospective study. Parameters of PET-CT such as metabolic, volumetric, and metabolovolumetric were assessed concerning diagnostic value. Moreover, maximum standard uptake value (SUVmax) and TLG were combined and compared to improve diagnostic accuracy. The number of the detected benign and malignant SPNs was 38 and 42, respectively. Compared to the benign lesions, the malignant nodules presented significantly higher values in terms of SUVmax, TLG, and the volumes of metabolic tumour (MTV) and CT. Considering all parameters, the highest area under the curve (AUC) was occupied by TLG and SUVmax. The values for the sensitivity, specificity, and accuracy of SUVmax, TLG, and SUVmax combined with TLG were as follows respectively: 97.6%, 63.2%, and 81.2%; 85.7%, 92.1%, and 88.7%; and 85.7%, 94.7%, and 90%. The conventional value of SUVmax does not yield satisfactory results in order to separate the malignant nodules from the benign ones. The SUVmax value could be more valuable if it is used with TLG measurement in diagnosing SPNs. 18F-FDG PET/CT, SUVmax, TLG, Pulmonary nodule.

Prognostic value of PET parameters in patients with pleomorphic lung cancer: Results from a single institution

ObjectivesPleomorphic lung carcinoma (PLC) is a rare histotype of non-small cell lung cancer (NSCLC) characterized by aggressive clinical course, poor response to therapy and poor prognosis. Therefore, aim of our study is to analyze with 18F-FDG PET/CT a subset of patients affected by PLC to evaluate their metabolic characteristics in terms of SUVmax, MTV and TLG, in order to correlate them with overall survival (OS) and disease-free survival (DFS). Material and methodsWe retrospectively analyzed 49 consecutive patients with histologically defined PLC occurred to our Institution between 2003 and 2014. All patients underwent F18-FDG PET-CT before surgery and primary tumor was automatically segmented using an isocontour threshold method. SUV threshold for tumor segmentation was defined as the 41 % of lesion SUVmax. Total volume of the segmented VOI (MTV, centimeters cubed) and average SUV (SUVavg, grams per milliliter) in the segmented VOI were measured. ResultsIn our population men were significantly more affected than women (42:7). According to Youden criteria, SUVmax, MTV41 and TLG41 best cut-off values to predict 2-year mortality were, 18.95, 27.89 and 290.45, respectively, with TLG41 showing best specificity (85 %) and positive predictive value (82.4 %). As concerning 2-year recurrence, SUVmax, MTV41 and TLG41 best cut-off values were 10.08, 27.89 and 134.85, with SUVmax showing best sensitivity (96.7 %) and negative predictive value (85.7 %). ROC curves confirmed that SUVmax, MTV41 and TLG41 were equally accurate to predict 2-year mortality and 2-year recurrence in our population. ConclusionMetabolic biomarkers such as SUVmax, MTV and TLG can be used as a prognostic index for disease progression, recurrence and death in patients with PLC, independently from other clinical/pathological prognostic elements.

Association between 18F-FDG metabolic activity and programmed death ligand-1 (PD-L1) expression using 22C3 immunohistochemistry assays in non-small cell lung cancer (NSCLC) resection specimens.

This study sought to investigate the association between 18F-fludeoxyglucose (18F-FDG) uptake in positron emission tomography/CT (PET/CT) scans and different programmed death ligand-1 (PD-L1) expression conditions in non-small cell lung cancer (NSCLC). From October 2017 to December 2019, NSCLC was retrospectively identified in 419 consecutive patients who underwent 18F-FDG PET/CT scans and PD-L1 expression tests using the PD-L1 22C3 assay. The association between clinicopathological characteristics and PD-L1 expression was assessed. The frequency of PD-L1-positive tumours was 38.2% (160/419) in NSCLC. In NSCLC, the multivariate analysis showed a high maximum standardised uptake value (SUVmax) (p < 0.0001) and an EGFR wild type genotype (p = 0.027) was significantly associated with PD-L1-positivity. In adenocarcinoma (ADC), the multivariate analysis showed that a high SUVmax (p < 0.0001) was significantly associated with PD-L1-positivity. In NSCLC and ADC, a Mann-Whitney U test showed significant differences between groups with PD-L1 high expression and PD-L1 low expression levels in terms of SUVmax (p = 0.011 and p = 0.013, respectively). The results of the receiver operating characteristic curve analysis showed that the area under the curve of the SUVmax was 0.767 (95% CI, 0.720-0.814; p < 0.0001) and 0.712 (95% CI, 0.651-0.774; p < 0.0001) in NSCLC and ADC, respectively. The study demonstrates that the SUVmax was significantly associated with PD-L1 expression in NSCLC and ADC. The SUVmax was significantly different between the PD-L1 high and low expression conditions, as quantified using a PD-L1 22C3 assay. This study provides direct evidence that SUVmax as a metabolic biomarker may help select patients with NSCLC likely to benefit from pembrolizumab.

4D-CT Attenuation Correction in Respiratory-Gated PET for Hypoxia Imaging: Is It Really Beneficial?

Previous literature has shown that 4D respiratory-gated positron emission tomography (PET) is beneficial for quantitative analysis and defining targets for boosting therapy. However the case for addition of a phase-matched 4D-computed tomography (CT) for attenuation correction (AC) is less clear. We seek to validate the use of 4D-CT for AC and investigate the impact of motion correction for low signal-to-background PET imaging of hypoxia using radiotracers such as FAZA and FMISO. A new insert for the Modus Medicals' QUASAR™ Programmable Respiratory Motion Phantom was developed in which a 3D-printed sphere was placed within the “lung” compartment while an additional compartment is added to simulate muscle/blood compartment required for hypoxia quantification. Experiments are performed at 4:1 or 2:1 signal-to-background ratio consistent with clinical FAZA and FMISO imaging. Motion blur was significant in terms of SUVmax, mean, and peak for motion ≥1 cm and could be significantly reduced (from 20% to 8% at 2-cm motion) for all 4D-PET-gated reconstructions. The effect of attenuation method on precision was significant (σ2 hCT-AC = 5.5%/4.7%/2.7% vs σ2 4D-CT-AC = 0.5%/0.6%/0.7% [max%/peak%/mean% variance]). The simulated hypoxic fraction also significantly decreased under conditions of 2-cm amplitude motion from 55% to 20% and was almost fully recovered (HF = 0.52 for phase-matched 4D-CT) using gated PET. 4D-gated PET is valuable under conditions of low radiotracer uptake found in hypoxia imaging. This work demonstrates the importance of using 4D-CT for AC when performing gated PET based on its significantly improved precision over helical CT.

The role of 18FDG PET/CT imaging of aortic atherosclerosis: prospective study and technique optimization

BackgroundAtherosclerosis is an inflammatory disease of the inner wall of large and medium-sized arteries. The progress of atherosclerosis based on a lot of factors, including systemic involvement of disease, the precise vascular arterial affection, and the degree of flow obstruction. We aim in this study to estimate the FDG uptake of the aortic wall in the early and delayed imaging and to correlate this with the morphologic changes detected by CT.ResultsThis is a prospective study that was performed through 1 year. The study included 50 patients [30 males (60%) and 20 females (40%)] with male to female mean ratio 1.5:1 and their mean age 58.3 ± 15.7 years. Each patient underwent dual time-point 18F-FDG PET CT imaging at ~ 60 min (Early images) and 180 min (delayed images) after the administration of 18F-FDG. For each patient, the global 18F-FDG uptake in the aorta was determined by manually drawing regions of interest (ROIs) around the outer part of the arterial wall on every slice of the attenuation-corrected transverse PET CT images. Per-patient, per-time-point, per-vessel, and per-ROI radiotracer decay-corrected and body weight-corrected SUVs were calculated, resulting in a single mean value of maximum SUV for the aorta. The aortic wall FDG uptake was measured in both early and delayed images and expressed in terms of SUVmax. Then Retention index percentage of the aorta was measured. The retention index percentage was calculated by subtracting the SUVmax in early images from the SUVmax in delayed images and dividing by SUVmax in early images.ConclusionAortic wall FDG uptake can be used as an additional parameter as well as a biomarker on evaluation of the arterial atherosclerotic activity. Delayed post 3 h FDG imaging is more accurate than the routine early post 1 h imaging in evaluating the atherosclerotic activity.

18F-Sodium fluoride PET/CT predicts overall survival in patients with advanced genitourinary malignancies treated with cabozantinib and nivolumab with or without ipilimumab

PurposeWe evaluated the prognostic value of 18F-sodium fluoride (NaF) PET/CT in patients with urological malignancies treated with cabozantinib and nivolumab with or without ipilimumab.MethodsWe prospectively recruited patients with advanced urological malignancies into a phase I trial of cabozantinib plus nivolumab with or without ipilimumab. NaF PET/CT scans were performed pre- and 8 weeks post-treatment. We measured the total volume of fluoride avid bone (FTV) using a standardized uptake value (SUV) threshold of 10. We used Kaplan-Meier analysis to predict the overall survival (OS) of patients in terms of SUVmax, FTV, total lesion fluoride (TLF) uptake at baseline and 8 weeks post-treatment, and percent change in FTV and TLF.ResultOf 111 patients who underwent NaF PET/CT, 30 had bone metastases at baseline. Four of the 30 patients survived for the duration of the study period. OS ranged from 0.23 to 34 months (m) (median 6.0 m). The baseline FTV of all 30 patients ranged from 9.6 to 1570 ml (median 439 ml). The FTV 8 weeks post-treatment was 56–6296 ml (median 448 ml) from 19 available patients. Patients with higher TLF at baseline had shorter OS than patients with lower TLF (3.4 vs 14 m; p = 0.022). Patients with higher SUVmax at follow-up had shorter OS than patients with lower SUVmax (5.6 vs 24 m; p = 0.010). However, FTV and TLF 8 weeks post-treatment did not show a significant difference between groups (5.6 vs 17 m; p = 0.49), and the percent changes in FTV (12 vs 14 m; p = 0.49) and TLF (5.6 vs 17 m; p = 0.54) also were not significant.ConclusionHigher TLF at baseline and higher SUVmax at follow-up NaF PET/CT corresponded with shorter survival in patients with bone metastases from urological malignancies who underwent treatment. NaF PET/CT may be a useful predictor of OS in this population.

The clinical value of F-18 FDG PET/CT in differentiating malignant from benign lesions in pneumoconiosis patients.

We reviewed PET/CT findings of pneumoconiosis and determined the ability of PET/CT to differentiate lung cancer from progressive massive fibrosis (PMF), and metastatic lymph nodes (LNs) from underlying reactive LN hyperplasia. This was a retrospective study of patients with pneumoconiosis and suspected lung cancer. Maximum standardized uptake value (SUVmax), long- and short-axis diameters (DL and DS), ratio of DL to DS (DL/S), and Hounsfield unit (HU) from the lung mass and mediastinal LNs were measured. The cutoff values of each parameter were obtained by ROC analysis, and we evaluated the diagnostic sensitivity. Forty-nine pneumoconiosis patients were included. Eighty-three lung masses were detected, of which 42 were confirmed as lung cancer (23 squamous cell carcinomas, 12 adenocarcinomas, and 7 small cell carcinomas) and 41 were PMF. There were significant differences between lung cancer and PMF in terms of SUVmax, DS, DL/S, and HU (all p < 0.05). The sensitivity, specificity, and accuracy for diagnosis of lung cancer were 81.0%, 73.2%, and 77.1%, respectively, with an SUVmax cutoff value of 7.4; and 92.8%, 87.8%, and 90.4%, respectively, with a HU cutoff value of 45.5. Among the 40 LNs with available pathological results, 7 were metastatic. Metastatic LNs showed higher SUVmax, larger DS, and lower HU than benign lesions (all p < 0.05). The sensitivity, specificity, and accuracy for predicting metastatic LNs by PET/CT were 85.7%, 93.9%, and 92.5%, respectively. By applying PET and CT parameters in combination, the accuracy for differentiating malignant from benign lesions could be increased. PET/CT can play a central role in the discrimination of lung cancer and PMF. • Lung cancer showed significantly higher SUVmax than PMF. • Lung cancer showed similar D L but longer D S , resulting in a smaller D L/S than PMF. • SUVmax demonstrated additive value in differentiating lung cancer from PMF, compared with HU alone.

Does 18F FDG PET/CT paramaters predict histopathologic response to the neoadjuvant therapy in patients with non-small cell lung cancer?

Objective: Progression-free and overall survival are better correlated with metabolically active tumor volume (MTV) and total lesion glycolysis (TLG), as compared to the maximum standardized uptake value (SUVmax) in NSCLC patients. In this study, we aimed to evaluate the correlation between the PET-CT parameters and histopathologic tumor regression score in non-small cell lung cancer(NSCLC) patients after treatment with neoadjuvant chemotherapy.(1) Methods: This retrospective study evaluated stage III lung cancer patients who were treated with neoadjuvant chemotherapy followed by surgical resection at a single institution between 2014 and 2018. The 3-dimensional volumes of interest were drawn in primary tumor and largest lymph node on the pretreatment examination and corresponding location on the post-treatment examination to obtain a pre- and post-treatment SUVmax, SUVmean, MTV and TLG. All hematoxylin- and eosin-stained surgery specimens were assessed based on a 4-tiered scale. Results: Patients who had lower than 10% histologic response established higher values of SUVmax, in tumor as compared to good responders in basal PET CT assessment (p:0.014). Patients who established higher than 10% pathologic response showed higher reduction rates in terms of SUVmax (p:0.002), mean tumor volume (p:0.024), and total lesion glycolysis (p:0.009). The overall survival for patients with <10% histologic response was 15.26 months while the patients with good histologic response had 35.36 months and the difference was statistical significance (p<0.001). Due to univariate analysis, the higher SUVmax, TLG and MTV reduction have been found in association with better overall survival. Conclusion: PET CT parameters may be useful to predict histopathologic response for NSCLC patients who received neoadjuvant chemotherapy

Uptake Patterns of Untreated Primary Gastrointestinal Extranodal Lymphomas on Initial Staging 18F-FDG PET/CT and Metabolic Tumor Parameters.

Objective:Non-Hodgkin’s lymphomas arising from tissues other than primary lymphatic sites are classified as primary extranodal lymphomas (PEL). PELs of the gastrointestinal system (PGISL) originate from the lymphatic tissues within the gastrointestinal tract. The prognostic value of 18F-FDG PET/CT in lymphomas is high in terms of both overall survival (OS) and disease-free survival (DFS). Our aim was to investigate the uptake patterns and properties of low-grade and high-grade PGISL on primary staging 18F-FDG PET/CT, as well as the prognostic significance of metabolic tumor parameters in high grade PGISL.Methods:Thirty-nine patients with PGISL were enrolled in this retrospective cohort study between 2004-2015. Primary staging 18F-FDG PET/CT have been performed and quantitative parameters of SUVmax, SUVmean, metabolic tumor volume (MTV), total lesion glycolysis (TLG) have been calculated for all patients prior to treatment. Low-grade and high-grade PGISL were compared in terms of metabolic tumor parameters. Cox regression models were performed to determine factors that correlate with DFS in high-grade PGISL.Results:There were statistically significant differences between high-grade and low-grade PGISL in terms of SUVmax, SUVmean, MTV, TLG, recurrence, mortality, DFS and OS. None of the potential risk factors (sex, age, site, SUVmax, SUVmean, MTV, TLG) for recurrence and metastasis in high grade PGISL was identified as a risk factor on univariate and multivariate Cox regression analysis.Conclusion:Metabolic tumor parameters are not predictive markers in high-grade PGISL, especially in diffuse large B cell variant and primary gastric lymphoma. The first implications suggest they will not play a role in patient management.

Primary Sarcomatoid Carcinoma of the Lung: Radiometabolic ((18)F-FDG PET/CT) Findings and Correlation with Clinico-Pathological and Survival Results.

Pulmonary sarcomatoid carcinoma (PSC) is a very rare and uninvestigated subtype of non-small cell lung cancer (NSCLC). The aims of this study were to define the radiometabolic features (by (18)F-FDG PET/CT) in a bi-centric cohort of 49 PSC patients and to explore their relation with clinico-pathological characteristics and long-term survival results after surgical treatment. There were 40 males and 9 females aged 65.2±10.47years. Overall long-term survival was 26.7% at 5years. Mean and median values of SUVmax were 15.21 and 15, respectively (SD ±5.5). Performing an age-, gender- and staging-matched analysis comparing PSC Stage-I only with a cohort of Stage-I NSCLC (n=93), we observed significantly higher SUVmax values in PSC group (15.11 vs 7.66, p=0.001). No differences in terms of SUVmax were found with regard to tumour dimensions, histology (pure vs mixed, pleomorphic vs others), pathological stage and pattern of recurrence. P-stage, surgical radicality, vascular/lymphatic invasion but not SUVmax affected long-term survival in PSC.

Morphologic and Metabolic Comparison of Treatment Responsiveness with 18Fludeoxyglucose-Positron Emission Tomography/Computed Tomography According to Lung Cancer Type.

Objective:The aim of the present study was to evaluate the response to treatment by histopathologic type in patients with lung cancer and under follow-up with 18F-fluoro-2deoxy-glucose-positron emission tomography/computed tomography (18F-FDG PET/CT) imaging by using Response Evaluation Criteria in Solid Tumors (RECIST) and European Organisation for Research and Treatment of Cancer (EORTC) criteria that evaluate morphologic and metabolic parameters.Methods:On two separate (pre- and post-treatment) 18F-FDG PET/CT images, the longest dimension of primary tumor as well as of secondary lesions were measured and sum of these two measurements was recorded as the total dimension in 40 patients. PET parameters such as standardized uptake value (SUVmax), metabolic volume and total lesion glycolysis (TLG) were also recorded for these target lesions on two separate 18F-FDG PET/CT images. The percent (%) change was calculated for all these parameters. Morphologic evaluation was based on RECIST 1.1 and the metabolic evaluation was based on EORTC.Results:When evaluated before and after treatment, in spite of the statistically significant change (p<0.05) in SUVmax, the change was not significant in TLG, in the longest total size and in the longest size (p>0.05). In histopathologic typing, when we compare the post-treatment phase change with the treatment responses of RECIST 1.1 and EORTC criteria; for RECIST 1.1 in squamous cell lung cancer group, progression was observed in sixteen patients (57%), stability in seven patients (25%), partial response in five patients (18%); and for EORTC progression was detected in four patients (14%), stability in thirteen patients (47%), partial response in eleven patients (39%), in 12 of these patients an increase in stage (43%), in 4 of them a decrease in stage (14%), and in 12 of them stability in stage (43%) were determined. But in adenocancer patients (n=7), for RECIST 1.1, progression was determined in four patients (57%), stability in two patients (29%), partial response in one patient (14%); for EORTC, progression in one patient (14%), stability in four patients (57%), partial response in two patients (29%) were observed and in these patients, an increase in stage was detected in 3 of them (43%), while 4 of them remained stable. According to histopathologic diagnosis, between squamous cell cancer and adenocancer cases, no significant difference was determined in terms of SUVmax (p>0.05). Post-treatment SUVmax was significantly different in primary tumor but was not significantly different in nodal involvement and metastatic lesions for squamous cell carcinoma patients as compared to the pre-treatment SUVmax measurements. Similarly, there was no significant difference between primary tumor and nodal involvement for adenocarcinoma patients.Conclusion:Whether metabolic or morphologic changes are more accurate in evaluating treatment response in lung cancer remains unknown, and there is no gold standard diagnostic method on this issue yet. The most reliable results can only be achieved by survival curve parameters. However, we believe SUVmax seems to provide more easy and practical data for the evaluation of treatment response.

Volumetric FDG-PET predicts overall and progression- free survival after 14 days of targeted therapy in metastatic renal cell carcinoma.

BackgroundTo determine whether changes in the metabolism of metastatic renal cell carcinoma (mRCC) assessed by F18-FDG-PET after 14 and 28 days of treatment with tyrosine kinase inhibitors can predict overall and progression- free patient survival.MethodsThirty-nine consecutive patients with mRCC were included prospectively and underwent PET examinations prior to and after 14 and 28 days of standard treatment with sunitinib (n = 18), sorafenib (n = 19) or pazopanib (n = 2). The PET response was analyzed in terms of SUVmax, SULpeak, and total lesion glycolysis and a positive response (defined as a 30% reduction) compared to overall and progression- free survival.ResultsThirty-five patients with at least one metabolically active metastatic lesion prior to treatment underwent additional FDG-PET examinations after 14 (n = 32) and/or 28 days (n = 30) of treatment. Changes in either SULpeak or total lesion glycolysis were correlated to both progression-free and overall survival (for TLG2.5 responders, HR = 0.38 (95% CI: 0.18-0.83) and 0.22 (95% CI: 0.09-0.53), and for TLG50 responders, HR = 0.25 (0.10-0.62) and 0.25 (95% CI: 0.11-0.57) and for SULpeak responders, HR = 0.39 (95% CI: 0.17-0.91) and 0.38 (95% CI: 0.15-0.93), respectively). In contrast SUVmax response did not predict progression- free or overall survival (HR = 0.43 (95% CI: 0.18-1.01) and 0.50 (95% CI: 0.21-1.19), respectively).ConclusionsAssessment of early changes in SULpeak and total lesion glycolysis undergoing treatment with tyrosine kinase inhibitors by FDG-PET can possibly predict progression- free and overall survival in patients with mRCC.

N staging of lung cancer patients with PET/MRI using a three-segment model attenuation correction algorithm: Initial experience

Evaluate the performance of PET/MRI at tissue interfaces with different attenuation values for detecting lymph node (LN) metastases and for accurately measuring maximum standardised uptake values (SUVmax) in lung cancer patients. Eleven patients underwent PET/CT and PET/MRI for staging, restaging or follow-up of suspected or known lung cancer. Four experienced readers determined the N stage of the patients for each imaging method in a randomised blinded way. Concerning metastases, SUVmax of FDG-avid LNs were measured in PET/CT and PET/MRI in all patients. A standard of reference was created with a fifth experienced independent reader in combination with a chart review. Results were analysed to determine interobserver agreement, SUVmax correlation between CT and MRI (three-segment model) attenuation correction and diagnostic performance of the two techniques. Overall interobserver agreement was high (κ = 0.86) for PET/CT and substantial (κ = 0.70) for PET/MRI. SUVmax showed strong positive correlation (Spearman's correlation coefficient = 0.93, P < 0.001) between the two techniques. Diagnostic performance of PET/MRI was slightly inferior to that of PET/CT, without statistical significance (P > 0.05). PET/MRI using three-segment model attenuation correction for LN staging in lung cancer shows a strong parallel to PET/CT in terms of SUVmax, interobserver agreement and diagnostic performance. •F18-FDG PET/MRI shows similar performance to F18-FDG PET/CT in lung cancer N staging. •PET/MRI has substantial interobserver agreement in N staging. •A three-segment model attenuation correction is reliable for assessing the mediastinum.

Correlation between [18F]FDG PET/CT and volume perfusion CT in primary tumours and mediastinal lymph nodes of non-small-cell lung cancer

The aim of this study was to investigate correlations between glucose metabolism as determined by [(18)F]FDG PET/CT and tumour perfusion as quantified by volume perfusion CT in primary tumours and mediastinal lymph nodes (MLN) of patients with non-small-cell lung cancer (NSCLC). Enrolled in the study were 17 patients with NSCLC. [(18)F]FDG uptake was quantified in terms of SUVmax and SUVavg. Blood flow (BF), blood volume (BV) and flow extraction product (K(trans)) were determined as perfusion parameters. The correlations between the perfusion parameters and [(18)F]FDG uptake values were subsequently evaluated. For the primary tumours, no correlations were found between perfusion parameters and [(18)F]FDG uptake. In MLN, there were negative correlations between BF and SUVavg (r = -0.383), BV and SUVavg (r = -0.406), and BV and SUVmax (r = -0.377), but not between BF and SUVmax, K(trans) and SUVavg, or K(trans) and SUVmax. Additionally, in MLN with SUVmax >2.5 there were negative correlations between BF and SUVavg (r = -0.510), BV and SUVavg (r = -0.390), BF and SUVmax (r = -0.536), as well as BV and SUVmax (r = -0.346). Perfusion and glucose metabolism seemed to be uncoupled in large primary tumours, but an inverse correlation was observed in MLN. This information may help improve therapy planning and response evaluation.