Impact of combined 18F-FDG PET/CT in head and neck tumours

To compare the interobserver agreement and degree of confidence in anatomical localisation of lesions using 2-[fluorine-18]fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) and 18F-FDG PET alone in patients with head and neck tumours. A prospective study of 24 patients (16 male, eight female, median age 59 years) with head and neck tumours was undertaken. 18F-FDG PET/CT was performed for staging purposes. 2D images were acquired over the head and neck area using a GE Discovery LS™ PET/CT scanner. 18F-FDG PET images were interpreted by three independent observers. The observers were asked to localise abnormal 18F-FDG activity to an anatomical territory and score the degree of confidence in localisation on a scale from 1 to 3 (1=exact region unknown; 2=probable; 3=definite). For all 18F-FDG-avid lesions, standardised uptake values (SUVs) were also calculated. After 3 weeks, the same exercise was carried out using 18F-FDG PET/CT images, where CT and fused volume data were made available to observers. The degree of interobserver agreement was measured in both instances. A total of six primary lesions with abnormal 18F-FDG uptake (SUV range 7.2–22) were identified on 18F-FDG PET alone and on 18F-FDG PET/CT. In all, 15 nonprimary tumour sites were identified with 18F-FDG PET only (SUV range 4.5–11.7), while 17 were identified on 18F-FDG PET/CT. Using 18F-FDG PET only, correct localisation was documented in three of six primary lesions, while 18F-FDG PET/CT correctly identified all primary sites. In nonprimary tumour sites, 18F-FDG PET/CT improved the degree of confidence in anatomical localisation by 51%. Interobserver agreement in assigning primary and nonprimary lesions to anatomical territories was moderate using 18F-FDG PET alone (kappa coefficients of 0.45 and 0.54, respectively), but almost perfect with 18F-FDG PET/CT (kappa coefficients of 0.90 and 0.93, respectively). We conclude that 18F-FDG PET/CT significantly increases interobserver agreement and confidence in disease localisation of 18F-FDG-avid lesions in patients with head and neck cancers

18F-FDG PET/MRI for staging and interim response assessment in pediatric and adolescent Hodgkin lymphoma: a prospective study with 18F-FDG PET/CT as reference standard

Rationale: Treatment regimens for pediatric Hodgkin's lymphoma (HL) depend on accurate staging and treatment response assessment, based on accurate disease distribution and metabolic activity depiction. With the aim of radiation dose reduction, we compared the diagnostic performance of 18F-FDG PET/MR to a 18F-FDG PET/CT reference standard for staging and response assessment. Methods: Twenty-four patients (mean age 15.4 years, range 8-19.5 years) with histologically proven HL were prospectively and consecutively recruited in 2015 and 2016, undergoing both 18F-FDG PET/CT and 18F-FDG PET/MRI at initial staging (N n = 24) and at response assessment (N n = 21). Diagnostic accuracy of 18F-FDG PET/MRI for both nodal and extra-nodal disease was compared to 18F-FDG PET/CT, which was considered as the reference standard. Discrepancies were retrospectively classified as perceptual or technical errors and 18F-FDG PET/MRI and 18F-FDG PET/CT were corrected by removing perceptual error. Agreement with Ann-Arbor staging and Deauville grading was also assessed. Results: For nodal and extranodal sites combined, corrected staging 18F-FDG PET/MRI sensitivity was 100% (95% confidence interval (CI) 96.7%-100%), specificity 99.5% (95%CI 98.3%-99.9%). Corrected response assessment 18F-FDG PET/MRI sensitivity was 83.3% (95%CI 36.5%-99.1%), specificity 100% (95%CI 99.2%-100%). Modified Ann-Arbor staging agreement between F18-FDG PET/CT and 18F-FDG PET/MRI was perfect (k = 1.0, P = 0.000). Deauville grading agreement between 18F-FDG PET/MRI and 18F-FDG PET/CT was excellent (k = 0.835, P = 0.000). Conclusion:18F-FDG PET/MRI is a promising alternative to 18F-FDG PET/CT for staging and response assessment in children with Hodgkin lymphoma

18F-FET PET/CT in Advanced Head and Neck Squamous Cell Carcinoma: an Intra-individual Comparison with 18F-FDG PET/CT

Purpose: To assess the diagnostic value of O-2-fluoro-18(F)-ethyl-l-tyrosine (18F-FET) positron emission tomography/computed tomography (PET/CT) for patients with advanced head and neck squamous cell carcinoma compared with 18F-fluoro-2-deoxy-d-glucose (18F-FDG) PET/CT at initial staging and following radiochemotherapy. Procedures: Thirteen patients were prospectively enrolled; each of them underwent an 18F-FDG PET/CT and 18F-FET PET/CT before treatment. Ten of those were scanned 10weeks after treatment. Results: Sensitivity, specificity, and accuracy for 18F-FDG PET/CT (primary and lymph node metastases) at initial staging were 89%, 50%, and 81%. For 18F-FET PET/CT the numbers were 70%, 90%, and 74%. Sensitivity, specificity, and accuracy for 18F-FDG PET/CT at follow-up were 71%, 65%, and 67%. For 18F-FET PET/CT the numbers were 29%, 100%, and 83%. Additionally, 18F-FDG PET/CT detected a higher number of second malignancies or distant metastases. Conclusions: 18F-FET is no substitute for 18F-FDG. Although it is more specific, too many malignant lesions are missed due to its lower sensitivit

Usefulness of 18 F-FDG PET-CT for the management of invasive fungal infections: A retrospective cohort from a tertiary university hospital

Background: 18F-FDG PET-CT is a potentially useful technique to help manage invasive fungal infection (IFI), but information on this topic is scarce. Objectives: To describe our experience using 18F-FDG PET-CT for IFI management. Patients/Methods: Retrospective cohort of IFI episodes in a university hospital from 2018 to 2023 with a18F-FDG PET-CT performed during the episode. We analysed its impact on IFI management compared to conventional imaging. Results: Thirty-five patients diagnosed with 36 episodes of IFI (52.8% moulds, 44.4% yeasts and 2.8% Pneumocystis) underwent 55 18F-FDG PET-CT. 74.3% were immunocompromised, including 45.7% solid organ transplant recipients. Indications for 18F-FDG PET-CT were diagnostic (10.9%), staging (47.3%) and follow-up (41.8%). Altogether 18F-FDG PET-CT added value to IFI management in 50.9% episodes. In 26 patients who had both staging 18F-FDG PET-CT and conventional imaging, sites of IFI dissemination were detected in 53.8% and 19.2%, respectively. Staging 18F-FDG PET-CT unveiled occult sites in 34.6%, uncovering unknown dissemination in 19.2%. In the evaluation of endocarditis in patients with fungemia, it contributed in at least 38.5%. Follow-up 18F-FDG PET-CTs had an added value in 47.8% episodes. They were allowed to de-escalate antifungal therapy in 26.1%. There were discordant findings between 18F-FDG PET-CT and CT follow-up in 40% cases. Conclusions: Overall, 18F-FDG PET-CT added value to IFI management in more than 50% of the episodes. It increased the diagnosis of occult sites, unveiled disseminated disease missed out by conventional imaging, and contributed to diagnose or rule out endocarditis in fungemia. Follow-up 18F-FDG PET-CT helped adjust the treatment duration and deserves further stud

Reappraisal of [18F]FDG-PET/CT for diagnosis and management of cardiac implantable electronic device infections

Introduction and objectives: The role of [18F]FDG-PET/CT in cardiac implantable electronic device (CIED) infections requires better evaluation, especially in the diagnosis of systemic infections. We aimed to determine the following: a) the diagnostic accuracy of [18F]FDG-PET/CT in each CIED topographical region, b) the added value of [18F]FDG-PET/CT over transesophageal echocardiography (TEE) in diagnosing systemic infections, c) spleen and bone marrow uptake in differentiating isolated local infections from systemic infections, and d) the potential application of [18F]FDG-PET/CT in follow-up. Methods: Retrospective single-center study including 54 cases and 54 controls from 2014 to 2021. The Primary endpoint was the diagnostic yield of [18F]FDG-PET/CT in each topographical CIED region. Secondary analyses described the performance of [18F]FDG-PET/CT compared with that of TEE in systemic infections, bone marrow and spleen uptake in systemic and isolated local infections, and the potential application of [18F]FDG-PET/CT in guiding cessation of chronic antibiotic suppression when completed device removal is not performed. Results: We analyzed 13 (24%) isolated local infections and 41 (76%) systemic infections. Overall, the specificity of [18F]FDG-PET/CT was 100% and sensitivity 85% (79% pocket, 57% subcutaneous lead, 22% endovascular lead, 10% intracardiac lead). When combined with TEE, [18F]FDG-PET/CT increased definite diagnosis o fsystemic infections from 34% to 56% (P=.04). Systemic infections with bacteremia showed higher spleen (P=.05) and bone marrow metabolism (P=.04) than local infections. Thirteen patients without complete device removal underwent a follow-up [18F]FDG-PET/CT, with no relapses after discontinuation of chronic antibiotic suppression in 6 cases with negative follow-up [18F]FDG-PET/CT. Conclusions: The sensitivity of [18F]FDG-PET/CT for evaluating CIED infections was high in local infections but much lower in systemic infections. However, accuracy increased when [18F]FDG-PET/CT was combined with TEE in endovascular lead bacteremic infection. Spleen and bone marrow hypermetabolism could differentiate bacteremic systemic infection from local infection. Although further prospective studies are needed, follow-up [18F]FDG-PET/CT could play a potential role in the management of chronic antibiotic suppression therapy when complete device removal is unachievable

The Added Value of [18F]FDG PET/CT in the Management of Invasive Fungal Infections

Anatomy-based imaging methods are the usual imaging methods used in assessing invasive fungal infections (IFIs). [18F]FDG PET/CT has also been used in the evaluation of IFIs. We assessed the added value of [18F]FDG PET/CT when added to the most frequently used anatomy-based studies in the evaluation of IFIs. The study was conducted in two University Medical Centers in the Netherlands. Reports of [18F]FDG PET/CT and anatomy-based imaging performed within two weeks of the [18F]FDG PET/CT scan were retrieved, and the presence and sites of IFI lesions were documented for each procedure. We included 155 [18F]FDG PET/CT scans performed in 73 patients. A total of 216 anatomy-based studies including 80 chest X-rays, 89 computed tomography studies, 14 magnetic resonance imaging studies, and 33 ultrasound imaging studies were studied. The anatomy-based studies were concordant with the [18F]FDG PET/CT for 94.4% of the scans performed. [18F]FDG PET/CT detected IFI lesions outside of the areas imaged by the anatomy-based studies in 48.6% of the scans. In 74% of the patients, [18F]FDG PET/CT added value in the management of the IFIs

Comparison of Nasopharyngeal MR, 18 F-FDG PET/CT, and 18 F-FDG PET/MR for Local Detection of Natural Killer/T-Cell Lymphoma, Nasal Type.

Objectives The present study aims to compare the diagnostic efficacy of MR, 18F-FDG PET/CT, and 18F-FDG PET/MR for the local detection of early-stage extranodal natural killer/T-cell lymphoma, nasal type (ENKTL). Patients and Methods Thirty-six patients with histologically proven early-stage ENKTL were enrolled from a phase 2 study (Cohort A). Eight nasopharyngeal anatomical regions from each patient were imaged using 18F-FDG PET/CT and MR. A further nine patients were prospectively enrolled from a multicenter, phase 3 study; these patients underwent 18F-FDG PET/CT and PET/MR after a single 18F-FDG injection (Cohort B). Region-based sensitivity and specificity were calculated. The standardized uptake values (SUV) obtained from PET/CT and PET/MR were compared, and the relationship between the SUV and apparent diffusion coefficients (ADC) of PET/MR were analyzed. Results In Cohort A, of the 288 anatomic regions, 86 demonstrated lymphoma involvement. All lesions were detected by 18F-FDG PET/CT, while only 70 were detected by MR. 18F-FDG PET/CT exhibited a higher sensitivity than MR (100% vs. 81.4%, χ2 = 17.641, P < 0.001) for local detection of malignancies. The specificity of 18F-FDG PET/CT and MR were 98.5 and 97.5%, respectively (χ2 = 0.510, P = 0.475). The accuracy of 18F-FDG PET/CT was 99.0% and the accuracy of MR was 92.7% (χ2 = 14.087, P < 0.001). In Cohort B, 72 anatomical regions were analyzed. PET/CT and PET/MR have a sensitivity of 100% and a specificity of 92.5%. The two methods were consistent (κ = 0.833, P < 0.001). There was a significant correlation between PET/MR SUVmax and PET/CT SUVmax (r = 0.711, P < 0.001), and SUVmean (r = 0.685, P < 0.001). No correlation was observed between the SUV and the ADC. Conclusion In early-stage ENKTL, nasopharyngeal MR showed a lower sensitivity and a similar specificity when compared with 18F-FDG PET/CT. PET/MR showed similar performance compared with PET/CT

Role of [18F]FDG PET/CT in the management of G1 gastro-entero-pancreatic neuroendocrine tumors

Purpose: Since the role of [18F]FDG PET/CT in low-grade gastroenteropancreatic (GEP) neuroendocrine neoplasia (NET) is not well established, this study was aimed to evaluate the role of [18F]FDG PET/CT in grade 1 (G1) GEP-NETs. Methods: This is a retrospective study including patients with G1 GEP-NETs who underwent [18F]FDG PET/CT. Results: 55 patients were evaluated, including 24 (43.6%) with pancreatic NETs and 31 (56.4%) with gastrointestinal NETs. At the time of diagnosis, 28 (51%) patients had metastatic disease, and 50 (91%) patients were positive by 68-Ga sstr PET/CT. Overall, 27 patients (49%) had positive findings on [18F]FDG PET/CT. Following [18F]FDG PET/CT, therapeutic management was modified in 29 (52.7%) patients. Progression-free survival was longer in patients with negative [18F]FDG PET/CT compared with positive [18F]FDG PET/CT (median PFS was not reached and 24 months, respectively, p = 0.04). This significance was particularly evident in the pancreatic group (p = 0.008). Conclusions: Despite having low proliferative activity, approximately half of GEP-NETs G1 showed positive [18F]FDG PET/CT, with a corresponding negative impact on patients’ clinical outcomes. These data are in favor of a more “open” attitude toward the potential use of [18F]FDG PET/CT in the diagnostic work-up of G1 GEP-NETs, which may be used in selected cases to detect those at higher risk for an unfavorable disease course

The value of 18F-FDG-PET/CT imaging for sinonasal malignant melanoma

The aim this study was to evaluate imaging findings using position emission tomography (PET) in combination with computed tomography (CT) and 18F-fluorodeoxyglucose (18F-FDG) in sinonasal malignant melanoma (SNMM) of the head and neck in a retrospective analysis of a consecutive cohort of patients. 18F-FDG-PET/CT examinations were performed for initial staging and compared with CT or magnetic resonance tomography (MRI), and 18F-FDG-PET alone. Medical records were reviewed retrospectively with regard to the location and the size of the tumor. Furthermore, locoregional and distant metastases with a consecutive change in therapy detected by 18F-FDG-PET/CT were assessed. Ten patients suffering from sinonasal malignant melanoma were staged and followed by 18F-FDG-PET/CT imaging. A total of 34 examinations were obtained. 18F-FDG-PET/CT depicted all primary tumors adequately. Aside from one cerebral metastasis all regional and distant metastases were truly identified by using this method. In summary, if available, 18F-FDG-PET/CT is a valuable imaging modality for staging and re-staging sinonasal malignant melanoma to evaluate expansion of the primary tumor, locoregional disease, and distant metastase

F18-fluorodeoxyglucose-positron emission tomography and computed tomography is not accurate in preoperative staging of gastric cancer

Purpose: To investigate the clinical benefits of F18-fluorodeoxyglucose-positron emission tomography and computed tomography (18F-FDG-PET/CT) over multi-detector row CT (MDCT) in preoperative staging of gastric cancer. Methods: FDG-PET/CT and MDCT were performed on 78 patients with gastric cancer pathologically diagnosed by endoscopy. The accuracy of radiologic staging retrospectively was compared to pathologic result after curative resection. Results: Primary tumors were detected in 51 (65.4%) patients with 18F-FDG-PET/CT, and 47 (60.3%) patients with MDCT. Regarding detection of lymph node metastasis, the sensitivity of FDG-PET/CT was 51.5% with an accuracy of 71.8%, whereas those of MDCT were 69.7% and 69.2%, respectively. The sensitivity of 18F-FDG-PET/CT for a primary tumor with signet ring cell carcinoma was lower than that of 18F-FDG-PET/CT for a primary tumor with non-signet ring cell carcinoma (35.3% vs. 73.8%, P ??? 0.01). Conclusion: Due to its low sensitivity, 18F-FDG-PET/CT alone shows no definite clinical benefit for prediction of lymph node metastasis in preoperative staging of gastric cancer.Due to its low sensitivity, 18F-FDG-PET/CT alone shows no definite clinical benefit for prediction of lymph node metastasis in preoperative staging of gastric cancer