Head-to-Head Comparison of [18F]FDG PET Imaging and MRI for the Detection of Recurrence or Residual Tumor in Patients with Nasopharyngeal Carcinoma: A Meta-Analysis.

BACKGROUND: This meta-analysis compared the diagnostic performance of [18F] fluorodeoxyglucose ([18F]FDG) positron emission tomography/computed tomography (PET/CT) or PET versus Magnetic resonance imaging (MRI) in detecting recurrence or residual tumors at the primary site in patients with nasopharyngeal carcinoma (NPC). METHODS: A comprehensive literature search was conducted in the PubMed/MEDLINE and CENTRAL databases to find studies with at least 20 patients with NPC undergoing both [18F]FDG PET/CT (or [18F]FDG PET) and MRI for detecting recurrence or assessing residual disease at the primary site. The pooled sensitivity and specificity of PET/CT and MRI were calculated with 95% confidence intervals (CIs) and compared. RESULTS: Five studies, including 1908 patients (six patient groups), were included. PET imaging had higher sensitivity [93.3% (95% CI: 91.3-94.9%); I2 = 52.6%] compared to MRI [80.1% (95% CI: 77.2-82.8%); I2 = 68.3%], but the specificity of the two modalities was similar: 93.8% (95% CI: 92.2-95.2%; I2 = 0%) for PET/CT and 91.8% (95% CI: 90.1-93.4%; I2 = 94.3%) for MRI. The areas under the curve (AUCs) for PET/CT and MRI were 0.978 and 0.924, respectively, without significant difference (p = 0.23). CONCLUSIONS: This meta-analysis suggests that [18F]FDG PET imaging and MRI do not significantly differ in diagnostic performance. Nevertheless, [18F]FDG PET imaging shows higher sensitivity than MRI.

The Role of [18F]FDG PET/CT in Predicting Toxicity in Patients with NHL Treated with CAR-T: A Systematic Review.

CAR-T-cell therapy, also referred to as chimeric antigen receptor T-cell therapy, is a novel method in the field of immunotherapy for the treatment of non-Hodgkin's lymphoma (NHL). In patients receiving CAR-T-cell therapy, fluorodeoxyglucose Positron Emission Tomography/Computer Tomography ([18F]FDG PET/CT) plays a critical role in tracking treatment response and evaluating the immunotherapy's overall efficacy. The aim of this study is to provide a systematic review of the literature on the studies aiming to assess and predict toxicity by means of [18F]FDG PET/CT in patients with NHL receiving CAR-T-cell therapy. PubMed/MEDLINE and Cochrane Central Register of Controlled Trials (CENTRAL) databases were interrogated by two investigators to seek studies involving the use of [18F]FDG PET/CT in patients with lymphoma undergoing CAR-T-cell therapy. The comprehensive computer literature search allowed 11 studies to be included. The risk of bias for the studies included in the systematic review was scored as low by using version 2 of the "Quality Assessment of Diagnostic Accuracy Studies" tool (QUADAS-2). The current literature emphasizes the role of [18F]FDG PET/CT in assessing and predicting toxicity in patients with NHL receiving CAR-T-cell therapy, highlighting the evolving nature of research in CAR-T-cell therapy. Additional studies are warranted to increase the collected evidence in the literature.

The Correlation of Body Mass Index with Risk of Recurrence in Post-Menopausal Women with Breast Cancer Undergoing Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography.

Background: The aim of this study was to investigate whether high body mass index (BMI) increases the risk of recurrence and correlates with higher glucose uptake in recurrent lesions in post-menopausal female patients with breast cancer. Methods: A hospital database was searched to retrieve breast cancer patients who had undergone an [18F]FDG PET/CT scan before neoadjuvant chemotherapy and curative-intent surgery. BMI was calculated at the baseline [18F]FDG PET/CT scan. There was a median follow-up of 5 years after the baseline PET/CT scan to identify recurrence in the breast (T_rec); lymph nodes (N_rec); and distant locations (M_rec). Furthermore, SUVmax was measured at the sites of recurrence. A chi-square test was used to investigate any difference in the frequency of any recurrence, T_rec, N_rec, and M_rec, between overweight women (BMI ≥ 25 kg/m2) and women with a BMI < 25 kg/m2 (p < 0.05). SUVmax was compared using a t-test (p < 0.05) between the two groups. Results: A total of 142 post-menopausal patients (BMI: 26.84 ± 5.59; 84 overweight and 58 with normal weight) were retrieved from the database. There were 48 recurrences at the follow-up. The chi-square test demonstrated in overweight women an increased frequency of any recurrence (35 vs. 13; p = 0.025) and T_rec (15 vs. 2; p = 0.018) and a higher T_rec SUVmax (4.74 ± 2.90 vs. 1.85 ± 0.63; p = 0.09) compared to women with a BMI < 25 kg/m2. Conclusions: BMI seems to correlate with an increased rate of recurrence, especially in the breast, and a higher glucose uptake in post-menopausal patients with recurrent breast cancer.

Can Baseline [18F]FDG PET/CT Predict Response to Immunotherapy After 6 Months and Overall Survival in Patients with Lung Cancer or Malignant Melanoma? A Multicenter Retrospective Study.

Aim: To assess the role of baseline 18F-fluorodeoxyglucose ([18F]FDG)-positron emission tomography/computed tomography (PET/CT) in predicting response to immunotherapy after 6 months and overall survival (OS) in patients with lung cancer (LC) or malignant melanoma (MM). Materials and Methods: Data from a multicenter, retrospective study conducted between March and November 2021 were analyzed. Patients >18 years old with a confirmed diagnosis of LC or MM, who underwent a baseline [18F]FDG-PET/CT within 1-2 months before starting immunotherapy and had a follow-up of at least 12 months were included. PET scans were examined visually and semiquantitatively by physicians at peripheral centers. The metabolic tumor burden (number of lesions with [18F]FDG-uptake) and other parameters were recorded. Clinical response was assessed at 3 and 6 months after starting immunotherapy, and OS was calculated as the time elapsing between the PET scan and death or latest follow-up. Results: The study concerned 177 patients with LC and 101 with MM. Baseline PET/CT was positive in primary or local recurrent lesions in 78.5% and 9.9% of cases, in local/distant lymph nodes in 71.8% and 36.6%, in distant metastases in 58.8% and 84%, respectively, in LC and in MM patients. Among patients with LC, [18F]FDG-uptake in primary/recurrent lung lesions was more often associated with no clinical response to immunotherapy after 6 months than in cases without any tracer uptake. After a mean 21 months, 46.5% of patients with LC and 37.1% with MM had died. A significant correlation emerged between the site/number of [18F]FDG foci and death among patients with LC, but not among those with MM. Conclusions: In patients with LC who are candidates for immunotherapy, baseline [18F]FDG-PET/CT can help to predict response to this therapy after 6 months, and to identify those with a poor prognosis based on their metabolic parameters. For patients with MM, there was only a weak correlation between baseline PET/CT parameters, response to therapy, and survival.

ITA-IMMUNO-PET: The Role of [18F]FDG PET/CT for Assessing Response to Immunotherapy in Patients with Some Solid Tumors.

AIM: To examine the role of [18F]FDG PET/CT for assessing response to immunotherapy in patients with some solid tumors. METHODS: Data recorded in a multicenter (n = 17), retrospective database between March and November 2021 were analyzed. The sample included patients with a confirmed diagnosis of a solid tumor who underwent serial [18F]FDG PET/CT (before and after one or more cycles of immunotherapy), who were >18 years of age, and had a follow-up of at least 12 months after their first PET/CT scan. Patients enrolled in clinical trials or without a confirmed diagnosis of cancer were excluded. The authors classified cases as having a complete or partial metabolic response to immunotherapy, or stable or progressive metabolic disease, based on a visual and semiquantitative analysis according to the EORTC criteria. Clinical response to immunotherapy was assessed at much the same time points as the serial PET scans, and both the obtained responses were compared. RESULTS: The study concerned 311 patients (median age: 67; range: 31-89 years) in all. The most common neoplasm was lung cancer (56.9%), followed by malignant melanoma (32.5%). Nivolumab was administered in 46.3%, and pembrolizumab in 40.5% of patients. Baseline PET and a first PET scan performed at a median 3 months after starting immunotherapy were available for all 311 patients, while subsequent PET scans were obtained after a median 6, 12, 16, and 21 months for 199 (64%), 102 (33%), 46 (15%), and 23 (7%) patients, respectively. Clinical response to therapy was recorded at around the same time points after starting immunotherapy for 252 (81%), 173 (56%), 85 (27%), 40 (13%), and 22 (7%) patients, respectively. After a median 18 (1-137) months, 113 (36.3%) patients had died. On Kaplan-Meier analysis, metabolic responders on the first two serial PET scans showed a better prognosis than non-responders, while clinical response became prognostically informative from the second assessment after starting immunotherapy onwards. CONCLUSIONS: [18F]FDG PET/CT could have a role in the assessment of response to immunotherapy in patients with some solid tumors. It can provide prognostic information and thus contribute to a patient's appropriate treatment. Prospective randomized controlled trials are mandatory.

Genotyping analysis and ¹8FDG uptake in breast cancer patients: a preliminary research.

BACKGROUND: Diagnostic imaging plays a relevant role in the care of patients with breast cancer (BC). Positron Emission Tomography (PET) with 18F-fluoro-2-deoxy-D-glucose (FDG) has been widely proven to be a clinical tool suitable for BC detection and staging in which the glucose analog supplies metabolic information about the tumor. A limited number of studies, sometimes controversial, describe possible associations between FDG uptake and single nucleotide polymorphisms (SNPs). For this reason this field has to be explored and clarified. We investigated the association of SNPs in GLUT1, HIF-1a, EPAS1, APEX1, VEGFA and MTHFR genes with the FDG uptake in BC. METHODS: In 26 caucasian individuals with primary BC, whole-body PET-CT scans were obtained and quantitative analysis was performed by calculating the maximum Standardized Uptake Value normalized to body-weight (SUVmax) and the mean SUV normalized to body-weight corrected for partial volume effect (SUVpvc). Human Gene Mutation Database and dbSNP Short Genetic Variations database were used to analyze gene regions containing the selected SNPs. Patient genotypes were obtained using Sanger DNA sequencing analysis performed by Capillary Electrophoresis. RESULTS: BC patients were genotyped for the following nine SNPs: GLUT1: rs841853 and rs710218; HIF-1a: rs11549465 and rs11549467; EPAS1: rs137853037 and rs137853036; APEX1: rs1130409; VEGFA: rs3025039 and MTHFR: rs1801133. In this work correlations between the nine potentially useful polymorphisms selected and previously suggested with tracer uptake (using both SUVmax and SUVpvc) were not found. CONCLUSIONS: The possible functional influence of specific SNPs on FDG uptake needs further studies in human cancer. In summary, this is the first pilot study, to our knowledge, which investigates the association between a large panel of SNPs and FDG uptake specifically in BC patients. This work represents a multidisciplinary and translational medicine approach to study BC where, the possible correlation between SNPs and tracer uptake, may be considered to improve personalized cancer treatment and care.