FDG PET-CT Imaging Research Articles

Segmentation-Free Outcome Prediction from Head and Neck Cancer PET/CT Images: Deep Learning-Based Feature Extraction from Multi-Angle Maximum Intensity Projections (MA-MIPs).

We introduce an innovative, simple, effective segmentation-free approach for survival analysis of head and neck cancer (HNC) patients from PET/CT images. By harnessing deep learning-based feature extraction techniques and multi-angle maximum intensity projections (MA-MIPs) applied to Fluorodeoxyglucose Positron Emission Tomography (FDG-PET) images, our proposed method eliminates the need for manual segmentations of regions-of-interest (ROIs) such as primary tumors and involved lymph nodes. Instead, a state-of-the-art object detection model is trained utilizing the CT images to perform automatic cropping of the head and neck anatomical area, instead of only the lesions or involved lymph nodes on the PET volumes. A pre-trained deep convolutional neural network backbone is then utilized to extract deep features from MA-MIPs obtained from 72 multi-angel axial rotations of the cropped PET volumes. These deep features extracted from multiple projection views of the PET volumes are then aggregated and fused, and employed to perform recurrence-free survival analysis on a cohort of 489 HNC patients. The proposed approach outperforms the best performing method on the target dataset for the task of recurrence-free survival analysis. By circumventing the manual delineation of the malignancies on the FDG PET-CT images, our approach eliminates the dependency on subjective interpretations and highly enhances the reproducibility of the proposed survival analysis method. The code for this work is publicly released.

Utility of FDG PET-CT in CT Stage IA non-small cell lung cancer: The New Zealand Te Whatu Ora Northern region experience.

Our objective was to investigate the utility of fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT) in assessing CT Stage 1A non-small cell lung cancer (NSCLC) in patients under consideration for curative treatment. Performing FDG PET-CT in these patients may lead to unnecessary delays in treatment if it can be shown to provide no added value. We retrospectively reviewed 735 lesions in 653 patients from the New Zealand Te Whatu Ora Northern region lung cancer database with suspected or pathologically proven Stage 1A NSCLC on CT scan who also underwent FDG PET-CT imaging. We determined how often FDG PET-CT findings upstaged patients and then compared to pathological staging where available. FDG PET-CT provided an overall upstaging rate of 9.7%. Category-specific rates were 0% in Tis, 0.9% in T1mi, 7.4% in T1a, 10% in T1b and 12% in T1c groups. The percentage of lesions upstaged on FDG PET-CT that remained Stage 1A was 100% in T1mi, 100% in T1a, 47.1% in T1b and 40.7% in T1c groups. The P value was statistically significant at 0.004, indicating upstaging beyond Stage 1A was dependent on T category. Our data suggests that FDG PET-CT is indicated for T1b and T1c lesions but is of limited utility in Tis, T1mi and T1a lesions. Adopting a more targeted approach and omitting FDG PET-CT in patients with Tis, T1mi, and T1a lesions may benefit all patients with lung cancer by improving accessibility and treatment timelines.

Abstract PO2-06-13: Promising clinical performance of 89Zirconium-labelled Girentuximab PET-CT for imaging metastatic triple negative breast cancer patients (OPALESCENCE)

Abstract Aim: Triple Negative Breast Cancer (TNBC) is aggressive, often with a metastatic evolution and drug-resistant with limited therapeutic options. Evaluating new markers is an unmet need. Recently, the combination of anti-angiogenic and targeted hypoxia effectors agents proved to enhance therapy response. Indeed, anhydrase Carbonic-IX (CA-IX), a hypoxia-mediated breast tumor growth regulator, is important for the BC stem cells maintenance within hypoxic region and is highly overexpressed in TNBC. This pilot prospective study “OPALESCENCE” (NCT04758780) aimed at assessing PET/CT with 89Zr-labeled girentuximab (89Zr-TLX250) targeting CA-IX in 12 metastatic TNBC patients. Methods: Patients underwent FDG and 89Zr-TLX250 PET-CT and conventional imaging (CI) if needed (CT, US, mammography, brain MRI). Without any premedication or dietary preparation, patients received a single slow intravenous administration of 37±10% MBq 89Zr-TLX250 (10 mg). Day 3 or 5 post injection, a skull to mid-thigh PET/CT was acquired with 10 minutes acquisition time per bed position. The gold standard was determined by FDG PET/CT, CI and follow-up; lesion detected at least by 2 modalities was considered as true positive. Immunohistochemistry (IHC) was performed with Bond RX fully automated research stainer with CA-IX antibody (Leica, clone TH22). Staining was evaluated with semi-quantitative analysis (percentage and intensity of tumor cells expression). Human anti-chimeric antibody (HACA) were sampled but will be determined at study end. Results: Enrolment has been completed, a total of 273 lesions confirmed by gold standard as shown on table 1 were detected in 12 patients (231 by 89Zr-TLX250 and 264 by FDG PET/CT). Overall sensitivity of 89Zr-TLX250 PET/CT was 87.5%, with 100% sensitivity for breast, skin, adrenal gland and brain and 88.0%, 91.9% for nodes and bone respectively. Overall sensitivity for FDG-PET/CT was 96.7%. According to table 2, 6 patients had 100% of their lesions highlighted by 89Zr-TLX250 PET. In addition, for 2 other patients only one of the lesions was not detected by immunoPET. 89Zr-TLX250 PET therefore detected almost all of the metastatic lesions in 67% of the patients. For 8/12 patients, IHC was analysed and for 6 patients, CA-IX expression lesions was from 100% to 10% with an intensity from 3+ to 2+, whereas two patients presented no Ca-IX expression on tumour lesions. No 89Zr-TLX250 safety issue was reported. Conclusion: 89Zr-TLX250 PET/CT seems very promising because it allows the CA IX status lesions knowledge on whole body scale with a minimally invasive way, unlike the information provided by biopsies corresponding to only 1 or 2 lesions studied. Moreover, these results illustrated interest of 89Zr-TLX250 PET/CT as targeting agent for TNBC patients leading above all to a theranostic approach possibility. Study analysis (specially IHC, HACA and semi-quantitative PET/CT analysis) is ongoing and supplementary data will be presented during the congress. This is an investigator initiated trial. Investigational medicinal product was provided by Telix Pharmaceuticals. Table 1: Sensitivity of 89Zr-TLX250 PET, FDG PET, and conventional imaging (US, brain MRI and Mammography). Table 2: Number of confirmed lesions according to Gold Standard detected by 89Zr-TLX250 PET/CT (iPET), FDG PET/CT and CI for each patients. Citation Format: Caroline Rousseau, Marie Francoise Heymann, Jean Sebastien FRENEL, Elise Picot-Dilly, Maelle Le Thiec, Manon Taupin, Alexis Mouton, Emmanuelle Bourbouloux, Agnès Morel, Nadia Allam, Amélie Mallet, Mario Campone, Ludovic Ferrer, Françoise Kraeber-Bodéré. Promising clinical performance of 89Zirconium-labelled Girentuximab PET-CT for imaging metastatic triple negative breast cancer patients (OPALESCENCE) [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-06-13.

Frontline and Relapsed Rhabdomyosarcoma (FAR-RMS) Clinical Trial: A Report from the European Paediatric Soft Tissue Sarcoma Study Group (EpSSG).

The Frontline and Relapsed Rhabdomyosarcoma (FaR-RMS) clinical trial is an overarching, multinational study for children and adults with rhabdomyosarcoma (RMS). The trial, developed by the European Soft Tissue Sarcoma Study Group (EpSSG), incorporates multiple different research questions within a multistage design with a focus on (i) novel regimens for poor prognostic subgroups, (ii) optimal duration of maintenance chemotherapy, and (iii) optimal use of radiotherapy for local control and widespread metastatic disease. Additional sub-studies focusing on biological risk stratification, use of imaging modalities, including [18F]FDG PET-CT and diffusion-weighted MRI imaging (DWI) as prognostic markers, and impact of therapy on quality of life are described. This paper forms part of a Special Issue on rhabdomyosarcoma and outlines the study background, rationale for randomisations and sub-studies, design, and plans for utilisation and dissemination of results.

Evaluation of manual and automated approaches for segmentation and extraction of quantitative indices from [18F]FDG PET-CT images

Utilisation of whole organ volumes to extract anatomical and functional information from computed tomography (CT) and positron emission tomography (PET) images may provide key information for the treatment and follow-up of cancer patients. However, manual organ segmentation, is laborious and time-consuming. In this study, a CT-based deep learning method and a multi-atlas method were evaluated for segmenting the liver and spleen on CT images to extract quantitative tracer information from Fluorine-18 fluorodeoxyglucose ([18F]FDG) PET images of 50 patients with advanced Hodgkin lymphoma (HL). Manual segmentation was used as the reference method. The two automatic methods were also compared with a manually defined volume of interest (VOI) within the organ, a technique commonly performed in clinical settings. Both automatic methods provided accurate CT segmentations, with the deep learning method outperforming the multi-atlas with a DICE coefficient of 0.93 ± 0.03 (mean ± standard deviation) in liver and 0.87 ± 0.17 in spleen compared to 0.87 ± 0.05 (liver) and 0.78 ± 0.11 (spleen) for the multi-atlas. Similarly, a mean relative error of −3.2% for the liver and −3.4% for the spleen across patients was found for the mean standardized uptake value (SUVmean) using the deep learning regions while the corresponding errors for the multi-atlas method were −4.7% and −9.2%, respectively. For the maximum SUV (SUVmax), both methods resulted in higher than 20% overestimation due to the extension of organ boundaries to include neighbouring, high-uptake regions. The conservative VOI method which did not extend into neighbouring tissues, provided a more accurate SUVmax estimate. In conclusion, the automatic, and particularly the deep learning method could be used to rapidly extract information of the SUVmean within the liver and spleen. However, activity from neighbouring organs and lesions can lead to high biases in SUVmax and current practices of manually defining a volume of interest in the organ should be considered instead.

Spatial mapping of tumor heterogeneity in whole-body PET–CT: a feasibility study

BackgroundTumor heterogeneity is recognized as a predictor of treatment response and patient outcome. Quantification of tumor heterogeneity across all scales may therefore provide critical insight that ultimately improves cancer management.MethodsAn image registration-based framework for the study of tumor heterogeneity in whole-body images was evaluated on a dataset of 490 FDG-PET–CT images of lung cancer, lymphoma, and melanoma patients. Voxel-, lesion- and subject-level features were extracted from the subjects’ segmented lesion masks and mapped to female and male template spaces for voxel-wise analysis. Resulting lesion feature maps of the three subsets of cancer patients were studied visually and quantitatively. Lesion volumes and lesion distances in subject spaces were compared with resulting properties in template space. The strength of the association between subject and template space for these properties was evaluated with Pearson’s correlation coefficient.ResultsSpatial heterogeneity in terms of lesion frequency distribution in the body, metabolic activity, and lesion volume was seen between the three subsets of cancer patients. Lesion feature maps showed anatomical locations with low versus high mean feature value among lesions sampled in space and also highlighted sites with high variation between lesions in each cancer subset. Spatial properties of the lesion masks in subject space correlated strongly with the same properties measured in template space (lesion volume, R = 0.986, p < 0.001; total metabolic volume, R = 0.988, p < 0.001; maximum within-patient lesion distance, R = 0.997, p < 0.001). Lesion volume and total metabolic volume increased on average from subject to template space (lesion volume, 3.1 ± 52 ml; total metabolic volume, 53.9 ± 229 ml). Pair-wise lesion distance decreased on average by 0.1 ± 1.6 cm and maximum within-patient lesion distance increased on average by 0.5 ± 2.1 cm from subject to template space.ConclusionsSpatial tumor heterogeneity between subsets of interest in cancer cohorts can successfully be explored in whole-body PET–CT images within the proposed framework. Whole-body studies are, however, especially prone to suffer from regional variation in lesion frequency, and thus statistical power, due to the non-uniform distribution of lesions across a large field of view.

The Effectiveness of Radiological Methods in Predicting Pathological Complete Response After Neoadjuvant Therapy in Locally Advanced Breast Cancer Patients

Abstract&#x0D; &#x0D; Aim: The current innovations in breast cancer treatment have led to an increased utilization of neoadjuvant therapy. Pathological complete response following neoadjuvant therapy is a crucial prognostic factor for predicting survival. The objective of this study is to demonstrate the efficacy of radiological methods in predicting patholojical complete response in our patients with locally advanced breast cancer.&#x0D; Material and Methods: The medical records of patients who received treatment for breast cancer at our hospital between January 2017 and January 2022 were retrospectively reviewed. The study included female patients over the age of 18 with locally advanced unifocal breast cancer who underwent neoadjuvant chemotherapy. Demographic information, menopausal status, molecular subtypes, radiological results, disease stage, treatment and surgical methods, and pathology results were recorded.&#x0D; Results: A total of 4474 patients were treated for breast cancer out of which 94 patients met the criteria for this study. The mean age of the patients was 49.9 ± 11.06 years. Ultrasonography was performed on all patients, while FDG-PetCT was performed on 47 (50%) patients and magnetic resonance imaging (MRI) was performed on 31 (33%) patients for radiological response evaluation. The radiological complete response was highest in the FDG-petCT group (39.4%). The rate of pathological complete response was 35.1%.&#x0D; Conclusion: Although FDG-PETCT has high sensitivity in predicting pathological complete response after neoadjuvant chemotherapy in locally advanced breast cancers, the common use of ultrasonography, FDG-PETCT, and magnetic resonance imaging is more advantageous due to their different benefits.

Rare Case of Ovarian Immature Teratoma with Gliomatosis Peritonei at Follow-Up: Dilemma with F-18 FDG PET CT Imaging

Rare Case of Ovarian Immature Teratoma with Gliomatosis Peritonei at Follow-Up: Dilemma with F-18 FDG PET CT Imaging

Predicting Overall Survival with Deep Learning from 18F-FDG PET-CT Images in Patients with Hepatocellular Carcinoma before Liver Transplantation

Positron emission tomography and computed tomography with 18F-fluorodeoxyglucose (18F-FDG PET-CT) were used to predict outcomes after liver transplantation in patients with hepatocellular carcinoma (HCC). However, few approaches for prediction based on 18F-FDG PET-CT images that leverage automatic liver segmentation and deep learning were proposed. This study evaluated the performance of deep learning from 18F-FDG PET-CT images to predict overall survival in HCC patients before liver transplantation (LT). We retrospectively included 304 patients with HCC who underwent 18F-FDG PET/CT before LT between January 2010 and December 2016. The hepatic areas of 273 of the patients were segmented by software, while the other 31 were delineated manually. We analyzed the predictive value of the deep learning model from both FDG PET/CT images and CT images alone. The results of the developed prognostic model were obtained by combining FDG PET-CT images and combining FDG CT images (0.807 AUC vs. 0.743 AUC). The model based on FDG PET-CT images achieved somewhat better sensitivity than the model based on CT images alone (0.571 SEN vs. 0.432 SEN). Automatic liver segmentation from 18F-FDG PET-CT images is feasible and can be utilized to train deep-learning models. The proposed predictive tool can effectively determine prognosis (i.e., overall survival) and, thereby, select an optimal candidate of LT for patients with HCC.

FDG PET-CT imaging in assessing interim response to neoadjuvant cisplatin-based chemotherapy (NAC) in muscle invasive bladder cancer (MIBC): A prospective study.

460 Background: Muscle invasive bladder cancer (MIBC) is an aggressive local disease where initial staging with conventional CT imaging is often suboptimal. To explore the role of PET-CT in both staging MIBC and assessing response to neoadjuvant chemotherapy (NAC), we conducted a prospective multicentre, randomized trial known as PETMUSE. We report here the first results from the neoadjuvant substudy which assessed interim PET-CT response after 2-3 cycles of NAC and how this correlated with disease free survival (DFS) and overall survival (OS). Methods: Patients with MIBC (T2a-4a, N0-3, M0) based on transurethral resection of their bladder tumor and CT staging were randomized 2:1 to PET-CT or no PET-CT. All PET-CT patients, receiving cisplatin-based NAC underwent a second PET-CT after 2 cycles of gemcitabine and cisplatin (GC) or 3 cycles of dose dense methotrexate, vinblastine, adriamycin, cisplatin (ddMVAC) to assess for interim response. Patients were scored (1-5) by 2 independent reviewers according to the extent of metabolic response on PET-CT. Disease-free survival (DFS) and overall survival (OS) were collected. Results: Between 2016 and 2021, 291 patients were enrolled on PETMUSE of which 46 participated in the neoadjuvant substudy. Median age was 68 (51-86); 36 (78%) were male; 26 were ECOG 0 (57%); 31 (68%) were T2, 13 (28%) were T3/T4; and 35 (76%) were node negative. In terms of NAC regimens: 22 (48%) received GC, 17 (37%) split dose GC, 6 (13%) ddMVAC, and 1 (2%) MVAC. On PET-CT, 23 (50%) had a complete metabolic response, 14 (30%) had a partial metabolic response, 5 (11%) had no change or mixed response and 4 (9%) had progressive disease or new lesion on PET scan. Metabolic response on PET-CT was a statistically significant prognostic factor for both DFS and OS (see Table). Conclusions: In MIBC patients receiving cisplatin-based NAC, metabolic response seen on interim PET-CT was correlated with DFS and OS. PET-CT warrants further study in this setting as a potential early indicator of response to NAC. Clinical trial information: NCT02462239 . [Table: see text][Table: see text]

An Automated Method for Artifical Intelligence Assisted Diagnosis of Active Aortitis Using Radiomic Analysis of FDG PET-CT Images.

The aim of this study was to develop and validate an automated pipeline that could assist the diagnosis of active aortitis using radiomic imaging biomarkers derived from [18F]-Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography (FDG PET-CT) images. The aorta was automatically segmented by convolutional neural network (CNN) on FDG PET-CT of aortitis and control patients. The FDG PET-CT dataset was split into training (43 aortitis:21 control), test (12 aortitis:5 control) and validation (24 aortitis:14 control) cohorts. Radiomic features (RF), including SUV metrics, were extracted from the segmented data and harmonized. Three radiomic fingerprints were constructed: A-RFs with high diagnostic utility removing highly correlated RFs; B used principal component analysis (PCA); C-Random Forest intrinsic feature selection. The diagnostic utility was evaluated with accuracy and area under the receiver operating characteristic curve (AUC). Several RFs and Fingerprints had high AUC values (AUC > 0.8), confirmed by balanced accuracy, across training, test and external validation datasets. Good diagnostic performance achieved across several multi-centre datasets suggests that a radiomic pipeline can be generalizable. These findings could be used to build an automated clinical decision tool to facilitate objective and standardized assessment regardless of observer experience.

PSAT205 A Case of Persistent Primary Hyperparathyroidism Secondary to an Occult Supernumerary Parathyroid Adenoma

Abstract Background Persistent primary hyperparathyroidism accounts for the vast majority of patients who require reexploration. With the advancements in preoperative localization, surgical outcomes have improved over time. However, in patients with failed reoperative parathyroid exploration, an occult supernumerary parathyroid adenoma should be considered. Clinical Case A 60 year-old female diagnosed with primary hyperparathyroidism presented with recurrent nephrolithiasis, osteoporosis and declining eGFR. Initial laboratory evaluation showed elevated serum calcium (1.54 mmol/L, normal 1.09-1.30) and intact PTH (146 pg/mL, normal 18.50-88.0). 99mTc-sestamibi scintigraphy showed a sestamibi-avid focus in the inferior aspect of the right lobe hence, she underwent radionuclide-guided focused right parathyroidectomy. Post-operatively, her intact PTH level was still elevated (171.2 pg/mL). Histopathologic examination showed a normocellular parathyroid gland and a multifocal papillary thyroid carcinoma. The failed 1st surgery was attributed to the false positive scintigraphy from the papillary thyroid carcinoma. She then underwent total thyroidectomy with central neck dissection and 3½ parathyroidectomy with intraoperative parathyroid hormone assay. However, serial PTH monitoring after exploration and parathyroidectomy failed to decrease the PTH level by 50%. Histopathologic examination showed normocellular parathyroid glands. The bilateral carotid sheath, retropharyngeal region and superior mediastinum were explored but no ectopic parathyroid tissues were seen. Post-operatively, calcium and PTH were still elevated (1.48 mmol/L and 200.5 pg/mL, respectively). FDG PET CT imaging failed to show any ectopic parathyroid gland or adenoma. No further surgical intervention was done and she was medically managed with Cinacalcet 30 mg twice daily. 15 months after her parathyroid gland exploration, calcium and PTH were still elevated (1.46 mmol/L and 156.80 pg/mL, respectively). F18 Choline PET CT imaging was done showing a small hypoenhancing persistently FCH-positive focus in the left thyroid bed and sliver of enhancing tissue relating to a parathyroid adenoma. Conclusion This case highlights the diagnostic and therapeutic challenges in a patient with persistent primary hyperparathyroidism after a failed 2nd surgery. Occult parathyroid adenomas can cause significant symptoms regardless of its size and its imperceptible nature on imaging. The role of medical management is emphasized in this case when surgical management was not possible. Furthermore, re-evaluation for growth of the possible occult parathyroid adenoma should be done, which in this case took 15 months until its detection. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.

A methodological framework for AI-assisted diagnosis of active aortitis using radiomic analysis of FDG PET–CT images: Initial analysis

BackgroundThe aim of this study was to explore the feasibility of assisted diagnosis of active (peri-)aortitis using radiomic imaging biomarkers derived from [18F]-Fluorodeoxyglucose Positron Emission Tomography–Computed Tomography (FDG PET–CT) images. MethodsThe aorta was manually segmented on FDG PET–CT in 50 patients with aortitis and 25 controls. Radiomic features (RF) (n = 107), including SUV (Standardized Uptake Value) metrics, were extracted from the segmented data and harmonized using the ComBat technique. Individual RFs and groups of RFs (i.e., signatures) were used as input in Machine Learning classifiers. The diagnostic utility of these classifiers was evaluated with area under the receiver operating characteristic curve (AUC) and accuracy using the clinical diagnosis as the ground truth. ResultsSeveral RFs had high accuracy, 84% to 86%, and AUC scores 0.83 to 0.97 when used individually. Radiomic signatures performed similarly, AUC 0.80 to 1.00. ConclusionA methodological framework for a radiomic-based approach to support diagnosis of aortitis was outlined. Selected RFs, individually or in combination, showed similar performance to the current standard of qualitative assessment in terms of AUC for identifying active aortitis. This framework could support development of a clinical decision-making tool for a more objective and standardized assessment of aortitis.

Quantitative classification and radiomics of [18F]FDG-PET/CT in indeterminate thyroid nodules

PurposeTo evaluate whether quantitative [18F]FDG-PET/CT assessment, including radiomic analysis of [18F]FDG-positive thyroid nodules, improved the preoperative differentiation of indeterminate thyroid nodules of non-Hürthle cell and Hürthle cell cytology.MethodsProspectively included patients with a Bethesda III or IV thyroid nodule underwent [18F]FDG-PET/CT imaging. Receiver operating characteristic (ROC) curve analysis was performed for standardised uptake values (SUV) and SUV-ratios, including assessment of SUV cut-offs at which a malignant/borderline neoplasm was reliably ruled out (≥ 95% sensitivity). [18F]FDG-positive scans were included in radiomic analysis. After segmentation at 50% of SUVpeak, 107 radiomic features were extracted from [18F]FDG-PET and low-dose CT images. Elastic net regression classifiers were trained in a 20-times repeated random split. Dimensionality reduction was incorporated into the splits. Predictive performance of radiomics was presented as mean area under the ROC curve (AUC) across the test sets.ResultsOf 123 included patients, 84 (68%) index nodules were visually [18F]FDG-positive. The malignant/borderline rate was 27% (33/123). SUV-metrices showed AUCs ranging from 0.705 (95% CI, 0.601–0.810) to 0.729 (0.633–0.824), 0.708 (0.580–0.835) to 0.757 (0.650–0.864), and 0.533 (0.320–0.747) to 0.700 (0.502–0.898) in all (n = 123), non-Hürthle (n = 94), and Hürthle cell (n = 29) nodules, respectively. At SUVmax, SUVpeak, SUVmax-ratio, and SUVpeak-ratio cut-offs of 2.1 g/mL, 1.6 g/mL, 1.2, and 0.9, respectively, sensitivity of [18F]FDG-PET/CT was 95.8% (95% CI, 78.9–99.9%) in non-Hürthle cell nodules. In Hürthle cell nodules, cut-offs of 5.2 g/mL, 4.7 g/mL, 3.4, and 2.8, respectively, resulted in 100% sensitivity (95% CI, 66.4–100%). Radiomic analysis of 84 (68%) [18F]FDG-positive nodules showed a mean test set AUC of 0.445 (95% CI, 0.290–0.600) for the PET model.ConclusionQuantitative [18F]FDG-PET/CT assessment ruled out malignancy in indeterminate thyroid nodules. Distinctive, higher SUV cut-offs should be applied in Hürthle cell nodules to optimize rule-out ability. Radiomic analysis did not contribute to the additional differentiation of [18F]FDG-positive nodules.Trial registration numberThis trial is registered with ClinicalTrials.gov: NCT02208544 (5 August 2014), https://clinicaltrials.gov/ct2/show/NCT02208544.

Imaging Lymphoma With F-18 Fluorodeoxyglucose PET-CT: What Should Be Known About Normal Variants, Pitfalls, and Artifacts?

18F fluorodeoxyglucose ([F-18] FDG) PET-CT has gained popularity in the management of many types of malignancies. Today, imaging patients with lymphoma using of [F-18] FDG PET-CT not only is considered as a state-of-the-art tool but also has taken a central place for therapeutic decisions. In fact, accurate staging at diagnosis is imperative to prevent under treatment of individuals with advanced disease. In Hodgkin's lymphoma, in particular, the current role of interim [F-18] FDG PET imaging goes beyond speculations in the adaptation of different therapeutic strategies. Therefore, the use of such a critical imaging modality should go hand in hand with sound interpretation that provides accurate results. As the number patients referred for PET-CT continues to increase, imaging specialists should remain aware of the inherent limitations linked to the integrated imaging system that may introduce potential pitfalls related to the machine or the administered [F-18] FDG. Knowledge of the normal physiologic biodistribution of [F-18] FDG, its physiologic variants, and of all the potential pitfalls and artifacts is paramount to avoid misinterpretation. Recognition of the limitations of [F-18] FDG PET-CT will increase the confidence of practicing clinicians on the modality and impact positively on the management of patients. In this article, we will review the normal physiological variants, technical artifacts, and diagnostic pitfalls in lymphoma. Highlighting the limitations of [F-18] FDG PET-CT imaging should warn interpreting specialists to find measures that mitigate them and improve reporting results.

Baseline FDG PET-CT imaging is necessary for newly diagnosed inflammatory breast cancer patients: a narrative review.

To review and discuss the rationale behind performing baseline 18-fluorodeoxyglucose positron emission tomography-computed tomography imaging for staging of inflammatory breast cancer patients. In the past three decades, the epidemiology of inflammatory breast cancer has resulted in separation of this entity from other breast cancer in staging and treatment. Advances in cancer imaging from 18-fluorodeoxyglucose positron emission tomography to 18-fluorodeoxyglucose positron emission tomography-computed tomography have now allowed for anatomic and functional correlation in evaluating extent of disease in cancer patients. Furthermore, studies throughout the past two decades have highlighted how 18-fluorodeoxyglucose positron emission tomography-computed tomography may play a role in staging inflammatory breast cancer patients given the uniqueness of this entity when compared to other breast cancers. Narrative overview of the literature summarizing findings in the literature from searches in computerized databases and authoritative texts. The use of 18-fluorodeoxyglucose positron emission tomography-computed tomography with respect to regional nodal staging and distant metastasis detection in inflammatory breast cancer patients is reviewed. In addition, an overview of studies conducted to date comparing the sensitivity and specificity of 18-fluorodeoxyglucose positron emission tomography-computed tomography for baseline staging in inflammatory breast cancer patients is also provided. Therapeutic influences and effect on overall survival is discussed. Baseline 18-fluorodeoxyglucose positron emission tomography-computed tomography allows for more optimal nodal staging, which has implications in prognosis and treatment of inflammatory breast cancer patients. It also allows for improved detection of metastasis on baseline presentation allowing therapy to potentially target these additional sites of disease.

Interim-PET As a Predictive Factor in Patients with Hodgkin's Lymphoma

Introduction. PET-CT is the new standard for staging of patients with Hodgkin Lymphoma (HL). However, it is becoming obvious that the role of PET-CT in assessment of response is not limited to imaging at the end-of-treatment. In recent years the prognostic role of interim PET-CT and attempt to use PET response-adapted therapy has come under evaluation across a number of international studies with promising results. Here we report the results of a multicenter retrospective study of interim PET in HL.Methods. 53 patients with HL with a stage I-II (64%), III-IV (36%) who were admitted between August 2012 and May 2017 to 10 Ukrainian hematological centers were included in this retrospective analysis. Metabolic PET-CT imaging was performed at participating PET centers according to routine protocols, compatible with EANM guidelines for FDG PET-CT imaging in malignant tumors. Interim PET (PET2) was performed at 15.5 ±3 days (range, 5-26) after 2d and 4th cycles of traetment in 75% and 25% cases, respectively. Patients were treated with ABVD or BEACOPP-14/esc based on risk group. The primary endpoint was event-free survival (EFS), defined as disease progression or death from HL.Results. Median age of patients at diagnosis was 32 years (range 17-56), and 63% of patients were female. B symptoms were present in 42% (22/53), extranodal disease in 4% (2/53), and bulky disease (>10 cm in any dimension) in 25% (13/53) of pts. Median follow-up was 24 months from diagnosis. Interim PET-CT, performed after chemotherapy, was categorized as Deauville 1-2 in 34 patients (56%), Deauville 3 in 12 (32%), Deauville 4 in 5 (10%), and Deauville 5 in 2 (2%). The threshold of positivity was set for a residual uptake higher than the liver background (grade 4 and 5 of the scale).13% (7/53) and 87% (46/53) patients in our cohort were PET2-positive (PET2+) and negative (PET2-), respectively (p<0.05). In total, disease progression was documented in 43% (3/7) of PET2+ patients and 11% (5/46) if PET2-negative patients (p<0.05). There was 1 death from refractory disease. 3-year EFS for patients with PET2+ vs PET2- was 45% vs 77%, respectively (p<0.05).Also, we compared EFS in patients with PET2 according to the Deauville score subgroups: 1-2 vs 3 vs 4-5 scores. The 3-year EFS was significant difference: 91% for the Deauville 1-2 subgroup versus 86% for Deauville 3 versus 46% for Deauville 4-5, (p < 0.004).Conclusion. Interim PET-CT is an important tool for clinicians in the diagnosis and management of patients with HL. The pronostic role and validity of the Deauville 5PS for interpretation of interim PET should be confirmed prospectively. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

FDG-PET vs. chemical shift MR imaging in differentiating intertrabecular metastasis from hematopoietic bone marrow hyperplasia

PurposeTo evaluate the utility of SUVmax on FDG-PET and chemical shift imaging (CSI) on MRI in the differentiation of intertrabecular metastasis (ITM) from hematopoietic bone marrow hyperplasia (HBMH).Patients and methodsWe retrospectively evaluated 54 indeterminate focal bone marrow lesions in 44 patients detected on FDG-PET. The lesions were assigned to the metastasis group (M group, 29 lesions of 24 patients) and the non-metastasis group (non-M group, 25 lesions of 20 patients) based on the follow-up or the histopathological studies. The lesions were assessed with the maximum standardized uptake value (SUVmax) on FDG-PET CT images and signal change ratio (SCR) on CSI.ResultsThe median SUVmax were 5.62 and 2.91; the median SCR were − 0.08 and − 34.8 in M and non-M groups respectively, with significant difference (p < 0.001). With ROC curve analysis, the optimal cutoff value of SUVmax was 4.48 with a sensitivity of 72.4%, a specificity of 100%, and AUC of 0.905. The cutoff value of SCR was − 6.15 with a sensitivity of 82.8%, a specificity of 80%, and AUC of 0.818.ConclusionFDG-PET and CSI on MRI are useful in distinguishing ITM from HBMH. Though their sensitivities are similar, the specificity of FDG-PET was higher than that of MRI.

Quantitative analysis of myocardial metabolic heterogeneity is superior to visual assessment for the detection of active cardiac sarcoidosis by F-18 FDG PET-CT imaging

Abstract Funding Acknowledgements Type of funding sources: None. Background Myocardial inflammation may occur in the context of a multisystem disease such as sarcoidosis, adversely affecting prognosis. A definitive diagnosis of cardiac sarcoidosis (CS) is essential to implementing life-saving treatment but this is complicated by the invasive nature of endomyocardial biopsy (EMB) and its low accuracy. Positron emission tomography (PET) assists in diagnosis, which relies on visual interpretation of myocardial F-18 FDG uptake. The value of quantitative analysis and its application to clinical practice remain uncertain. Purpose To investigate the power of quantitative F-18 FDG PET-CT imaging analysis for detecting CS in patients with suspected disease. Methods All patients underwent F-18 FDG PET-CT after a 24-hour low-carbohydrate diet and 15-hour fasting as part of their diagnostic work-up for suspected cardiac inflammation. Cardiovascular magnetic resonance acted as gatekeeper to PET-CT in 8 of every 10 scans. Myocardial F-18 FDG uptake was assessed qualitatively and quantitatively using both manually drawn regions of interest and automatic polar maps to measure global and segmental standardised F-18 FDG uptake values (SUV). The coefficient of variation (CoV) was calculated to determine uptake heterogeneity. To confirm diagnosis, follow-up data regarding disease progression, further testing and treatment were collected. To allow for sufficient follow-up time, the first 40 consecutive patients from a prospective registry (n= 214; Sep 2017-Jun 2020) were included. Results A comprehensive clinical picture was obtained successfully in 37 patients (median [IQR], 17 [13.5] months) and a final diagnosis of CS reached in 7 (disease prevalence, 19%). EMB was performed in 2 patients only while 3 underwent PPM/ICD implantation. Significant predictors of CS were fulfilment of Japanese Ministry of Health and Welfare criteria (Wald, 6.44; p = 0.01) and left ventricular dysfunction (Wald 6.72; p = 0.01). Qualitative F-18 FDG PET-CT had a high negative (95%) but low positive (45%) predictive value for CS (sensitivity, 83%; specificity, 77%). F-18 FDG SUV CoV was the strongest imaging predictor (Wald, 6.77; p = 0.009) and was significantly higher in CS than non-CS (CoV median [quartiles], 0.26 [0.21, 0.36] and 0.12 [0.11, 0.14] respectively; p = 0.004). As per ROC curve analysis (AUC, 0.84), a CoV threshold of 0.20 was highly specific (93%) and sensitive (86%) for CS. Conclusion In a referring population with a low prevalence of cardiac sarcoidosis, F-18 FDG PET-CT imaging is sensitive for the detection of myocardial inflammation with active disease unlikely in patients with a negative scan. Quantitative evaluation of metabolic heterogeneity within the myocardium provides a strong, independent marker of active disease and should be considered alongside visual assessment.

FDG PET-CT imaging for pre operative staging in patients with colorectal cancer

FDG PET-CT imaging for pre operative staging in patients with colorectal cancer