Maximum Standardized Uptake Value Ratio Research Articles

Predicting diffuse large B-cell lymphoma outcomes with lesion-to-liver maximum standardized uptake value for interim-treatment and end-of-treatment positron emission tomography-computed tomography.

18F-fluorodeoxyglucose (18F-FDG) positron emission tomography-computed tomography (PET-CT) has been used in response evaluation systems for malignant lymphomas and is an important tool for determining efficacy and prognosis. The Deauville 5-point scale (D-5PS) is an 18F-FDG PET-CT image-interpretation protocol for patients with lymphoma. Nevertheless, a number of limitations in visual image interpretation, such as interobserver disagreement and the increase of false-positive results, suggests that new parameters are needed. In this study, we aimed to evaluate the prognostic values of interim-treatment (I-) and end-of-treatment (EOT) PET-CT by comparing D-5PS to the semiquantitative lesion-to-liver maximum standardized uptake value ratio (RLL). A total of 90 patients with diffuse large B-cell lymphoma (DLBCL) (45 I-PET and 45 EOT-PET) were analyzed, and the RLL was calculated. Patients were additionally evaluated using the D-5PS system. We determined the optimal cutoff value of RLL using receiver operating characteristic (ROC) analysis. Kaplan-Meier survival analysis was used to compare the outcome predictions, while multivariate Cox regression analysis was used to identify the predictive factors. Among the patients examined, 41 (20 I-PET and 21 EOT-PET) experienced progression, and 49 (25 I-PET, 24 EOT-PET) did not. The optimal cutoff values of the RLL for predicting disease progression were 1.37 for I-PET (sensitivity 75%, specificity 88%) and 2.03 for EOT-PET (sensitivity 45.5%, specificity 100%), while the cutoffs of the D-5PS were scores 4 for I-PET (sensitivity 80%, specificity 72%) and 5 for EOT-PET (sensitivity 40.9%, specificity 100%). The prognostic efficacy was higher for the RLL at interim than for the D-5PS [area under the curve (AUC) =0.848 vs. 0.741]. The EOT prognostic efficacy of both evaluation methods was essentially equivalent (AUC =0.785 vs. 0.725). Univariate and multivariate analyses showed that RLL and D-5PS were independent factors affecting DLBCL outcomes for both interim and EOT assessment. RLL and D-5PS have independent predictive values for the interim and EOT evaluation of outcomes in patients with DLBCL. The RLL has better interim predictive ability than does D-5PS and can optimize D-5PS interpretation, thus improving interim outcome prediction.

Tumor to liver maximum standardized uptake value ratio of FDG-PET/CT parameters predicts tumor treatment response and survival of stage III non-small cell lung cancer

BackgroundTo assess the predictive values of primary tumor FDG uptake for patients with inoperable stage III non-small cell lung cancer (NSCLC) after concurrent chemoradiotherapy (CCRT).MethodsA total of 107 patients with diagnosis of stage III NSCLC and CCRT were enrolled. The tumor maximum uptake value (SUVmax) was standardized by calculating several ratios between tumor and each background tissues. The receiver operating characteristics curve (ROC) was used to compare the predictive power of prognostic models. The tumor objective response rate (ORR) and overall survival (OS) were compared and analyzed by the Kaplan–Meier method and univariate and multivariate Cox regression models.ResultsThe areas under ROC curve (AUCs) ranged from 0.72 to 0.81 among these tumor SUVmax and standardized SUVmax ratios, and the tumor SUVmax and tumor SUVmax-to-liver SUVmean ratio (TLMR) were more predictive of ORR (AUC, 0.81; 95% CI, 0.73–0.88 for tumor SUVmax and AUC, 0.84; 95%CI, 0.76–0.91 for TLMR) than any of other SUVmax ratios. The patients with lower tumor SUVmax, SUVmean and SUVmax ratios had a significantly better OS than those with their corresponding higher ones. Moreover, both univariate and multivariable analyses revealed that TLMR was significantly associated with better ORR and OS after adjustment with other prognostic variables.ConclusionsTLMR, a standardized tumor SUVmax, was an independent prognostic predictor for tumor ORR and OS of patients with stage III NSCLC after CCRT.

Prognostic prediction using maximum standardized uptake value ratio of lymph node-to-primary tumor in preoperative PET-CT for oral squamous cell carcinoma

This study aimed to calculate the ratio of maximum standardized uptake values of cervical lymph nodes to maximum standardized uptake values of primary tumors measured by preoperative fluorodeoxyglucose positron-emission tomography in oral cancer patients, and to retrospectively examine the prognostic association and evaluate whether it could be a prognostic factor. We retrospectively examined consecutive Japanese patients diagnosed with oral squamous cell carcinoma who underwent oral cancer resection and cervical dissection between January 2014 and December 2018. The study included 52 patients aged 39–89 years (median age 66.5 years), excluding non-cervical dissection surgery and/or non-underwent preoperative positron-emission tomography. The maximum standardized uptake value of the cervical lymph nodes and primary tumor was measured, and the ratio of maximum standardized uptake values of the lymph nodes to that of the primary tumor was calculated. The median follow-up of 52 patients was 1,465 days (198–2,553 days), and overall survival was significantly worse in patients with a high lymph node-to-tumor standardized uptake values ratio (>0.4739) (5 years, 58.8% vs. 88.2%; P<0.05). Pretreatment lymph node-to-tumor standardized uptake values ratio can be easily calculated, and as a predictor of prognosis, it may be of assistance when considering the treatment strategy for oral cancer.

Hypoperfusion Precedes Tau Deposition in the Entorhinal Cortex: A Retrospective Evaluation of ADNI-2 Data.

Tau deposition in the entorhinal cortex is the earliest pathological feature of Alzheimer's disease (AD). However, this feature has also been observed in cognitively normal (CN) individuals and those with mild cognitive impairment (MCI). The precise pathophysiology for the development of tau deposition remains unclear. We hypothesized that reduced cerebral perfusion is associated with the development of tau deposition. A subset of the Alzheimer's Disease Neuroimaging Initiative data set was utilized. Included patients had undergone arterial spin labeling perfusion MRI along with [18F]flortaucipir tau PET at baseline, within 1 year of the MRI, and a follow-up at 6 years. The association between baseline cerebral blood flow (CBF) and the baseline and 6-year tau PET was assessed. Univariate and multivariate linear modeling was performed, with p<0.05 indicating significance. Significant differences were found in the CBF between patients with AD and MCI, and CN individuals in the left entorhinal cortex (p=0.013), but not in the right entorhinal cortex (p=0.076). The difference in maximum standardized uptake value ratio between 6 years and baseline was significantly and inversely associated with the baseline mean CBF (p=0.042, R²=0.54) in the left entorhinal cortex but not the right entorhinal cortex. Linear modeling demonstrated that CBF predicted 6-year tau deposition (p=0.015, R²=0.11). The results of this study suggest that a reduction in CBF at the entorhinal cortex precedes tau deposition. Further work is needed to understand the mechanism underlying tau deposition in aging and disease.

Prognostic impact of an integrative analysis of [18F]FDG PET parameters and infiltrating immune cell scores in lung adenocarcinoma

BackgroundHigh levels of 18F-fluorodeoxyglucose (18F-FDG) tumor uptake are associated with worse prognosis in patients with non-small cell lung cancer (NSCLC). Meanwhile, high levels of immune cell infiltration in primary tumor have been linked to better prognosis in NSCLC. We conducted this study for precisely stratified prognosis of the lung adenocarcinoma patients using the integration of 18F-FDG positron emission tomography (PET) parameters and infiltrating immune cell scores as assessed by a genomic analysis.ResultsUsing an RNA sequencing dataset, the patients were divided into three subtype groups. Additionally, 24 different immune cell scores and cytolytic scores (CYT) were obtained. In 18F-FDG PET scans, PET parameters of the primary tumors were obtained. An ANOVA test, a Chi-square test and a correlation analysis were also conducted. A Kaplan–Meier survival analysis with the log-rank test and multivariable Cox regression test was performed to evaluate prognostic values of the parameters. The terminal respiratory unit (TRU) group demonstrated lower 18F-FDG PET parameters, more females, and lower stages than the other groups. Meanwhile, the proximal inflammatory (PI) group showed a significantly higher CYT score compared to the other groups (P = .001). Also, CYT showed a positive correlation with tumor-to-liver maximum standardized uptake value ratio (TLR) in the PI group (P = .027). A high TLR (P = .01) score of 18F-FDG PET parameters and a high T follicular helper cell (TFH) score (P = .005) of immune cell scores were associated with prognosis with opposite tendencies. Furthermore, TLR and TFH were predictive of overall survival even after adjusting for clinicopathologic features and others (P = .024 and .047).ConclusionsA high TLR score was found to be associated with worse prognosis, while high CD8 T cell and TFH scores predicted better prognosis in lung adenocarcinoma. Furthermore, TLR and TFH can be used to predict prognosis independently in patients with lung adenocarcinoma.

Prognostic value of node-to-primary tumor maximum standardized uptake value ratio in T1-4N1-3M0 non-small cell lung cancer patients treated with concurrent chemo-radiotherapy.

BackgroundThis study aimed to identify whether NTR is the independent risk factor for progression-free survival (PFS) and overall survival (OS) in patients treated with concurrent chemo-radiotherapy (cCRT).MethodsWe retrospectively studied 106 T1-4N1-3M0 non-small cell lung cancer patients treated with cCRT. The maximum standardized uptake value (SUVTumor) of the primary tumor and the metastatic lymph nodes (SUVLN) were measured. The prognostic significance of NTR for predicting PFS and OS was assessed. A multi-adjusted spline regression model was conducted to provide more precise estimates and examine the shape of the associations between NTR and the risk of progression.ResultsFrom 2012 to 2017, 106 eligible patients were analyzed. The median follow-up time was 15.3 months (3.5–44.6 months). We determined the maximizing area under the time-dependent receiver operating characteristic curve was at an NTR of 0.73 for predicting PFS. The two-year PFS was significantly lower in the high-NTR group (35.7% vs. 55.4%, P = 0.02) and two-year OS (43.4% vs. 61.1%, P = 0.03 was also significantly worse. Multivariable analysis revealed that only NTR was an independent prognostic factor for PFS (hazard ratio [HR]: 10.04, P < 0.001) and OS (HR: 4.19, P = 0.03). The restricted cubic spline regression model showed that NTR had a non-linear relationship with log relative risk for progression.ConclusionNTR was an independent risk factor for predicting PFS and OS in T1-4N1-3M0 non-small cell lung cancer patients treated with cCRT.

Adrenal Mass Characterization in the Era of Quantitative Imaging: State of the Art.

Simple SummaryNon-invasive characterization of adrenal lesions requires a rigorous approach. Although CT is the cornerstone of adrenal lesion characterization, a multimodality multiparametric imaging approach helps improve confidence in adrenal lesion characterization. Detection and characterization of adrenal lesions have evolved during the past two decades. Although the role of imaging in adrenal lesions associated with hormonal secretion is usually straightforward, characterization of non-functioning adrenal lesions may be challenging to confidently identify those that need to be resected. Although many adrenal lesions can be readily diagnosed when they display typical imaging features, the diagnosis may be challenging for atypical lesions. Computed tomography (CT) remains the cornerstone of adrenal imaging, but other morphological or functional modalities can be used in combination to reach a diagnosis and avoid useless biopsy or surgery. Early- and delayed-phase contrast-enhanced CT images are essential for diagnosing lipid-poor adenoma. Ongoing studies are evaluating the capabilities of dual-energy CT to provide valid virtual non-contrast attenuation and iodine density measurements from contrast-enhanced examinations. Adrenal lesions with attenuation values between 10 and 30 Hounsfield units (HU) on unenhanced CT can be characterized by MRI when iodinated contrast material injection cannot be performed. 18F-FDG PET/CT helps differentiate between atypical benign and malignant adrenal lesions, with the adrenal-to-liver maximum standardized uptake value ratio being the most discriminative variable. Recent studies evaluating the capabilities of radiomics and artificial intelligence have shown encouraging results.

Prevalence of Increased FDG PET/CT Axillary Lymph Node Uptake Beyond 6 Weeks after mRNA COVID-19 Vaccination.

Ipsilateral avid axillary lymph node uptake at FDG PET/CT persists in 29% (49 of 169) of patients between 7 to 10 weeks after the second dose of the mRNA-based BNT162b2 COVID-19 vaccination.

Influence of Reconstruction FOV and Matrix Size on the Quantitative Accuracy of FDG-PET: Comparison between OSEM and Bayesian Penalized Likelihood

Field of view (FOV) and matrix size determine the pixel size of positron emission tomography (PET) images; however, the effect of any variation in these parameters on the quantitative accuracy is unclear. The FOV and matrix size of PET images are adjusted as per each clinical objective. Therefore, this study aimed to evaluate the quantitative accuracy of PET images under different FOV and matrix sizes. A National Electrical Manufacturers Association (NEMA) body phantom set was filled with 18F-FDG solution, and imaging data were acquired for 30 min. Images were reconstructed using ordered subset expectation maximization (OSEM) and Bayesian penalized likelihood (BPL), both of which were combined with point spread function (PSF) and time of flight (TOF). In each reconstruction method, the image parameters were set to the following: FOV, 20-70 cm; matrix size, 128×128 to 384×384; and pixel size, 1-3 mm. The images were evaluated by physical assessment of the recovery coefficient (RC) and maximum standardized uptake value ratio (SUVmax ratio). The RC of OSEM images was not affected by changes in FOV, whereas the RC of BPL images decreased in small spheres, when FOV was 20 and 30 cm. The SUVmax ratio of the OSEM images was not affected by the difference in pixel size. However, the SUVmax ratio of BPL images degraded in the 1-mm pixel size; this influence was observed only when the FOV was changed.Conclusion: BPL images reconstructed using a small FOV might degrade the quantitative accuracy of small spheres.

Functional imaging with 11C-metomidate PET for subtype diagnosis in primary aldosteronism.

Endocrine Society guidelines recommend adrenal venous sampling (AVS) in primary aldosteronism (PA) if adrenalectomy is considered. We tested whether functional imaging of adrenal cortex with 11C-metomidate (11C-MTO) could offer a noninvasive alternative to AVS in the subtype classification of PA. We prospectively recruited 58 patients with confirmed PA who were eligible for adrenal surgery. Subjects underwent AVS and 11C-MTO-PET without dexamethasone pretreatment in random order. The lateralization of 11C-MTO-PET and adrenal CT were compared with AVS in all subjects and in a prespecified adrenalectomy subgroup in which the diagnosis was confirmed with immunohistochemical staining for CYP11B2. In the whole study population, the concordance of AVS and 11C-MTO-PET was 51% and did not differ from that of AVS and adrenal CT (53%). The concordance of AVS and 11C-MTO-PET was 55% in unilateral and 44% in bilateral PA. In receiver operating characteristics analysis, the maximum standardized uptake value ratio of 1.16 in 11C-MTO-PET had an AUC of 0.507 (P = n.s.) to predict allocation to adrenalectomy or medical therapy with sensitivity of 55% and specificity of 44%. In the prespecified adrenalectomy subgroup, AVS and 11C-MTO-PET were concordant in 10 of 19 subjects with CYP11B2-positive adenoma and in 6 of 10 with CYP11B2-positivity without an adenoma. The concordance of 11C-MTO-PET with AVS was clinically suboptimal, and did not outperform adrenal CT. In a subgroup with CYP11B2-positive adenoma, 11C-MTO-PET identified 53% of cases. 11C-MTO-PET appeared to be inferior to AVS for subtype classification of PA.

FDG PET/MRI Coregistration Helps Predict Response to Gamma Knife Radiosurgery in Patients With Brain Metastases.

The purpose of this study was to determine whether relative standardized uptake value (SUV) measurements at FDG PET/MRI coregistration are predictive of local tumor control in patients with brain metastases treated with stereotactic radiosurgery (SRS). A retrospective review was conducted of the images and clinical characteristics of a cohort of patients with brain metastases from non-CNS neoplasms treated with gamma knife radiosurgery (GKRS) who underwent posttherapy FDG PET because of MRI findings concerning for progression. The PET and contrast-enhanced MR images were fused. Relative SUV measurements were calculated from ROIs placed in the area of highest FDG uptake within the enhancing lesion and in the contralateral normal-appearing white matter. Relative SUV was defined as the ratio of maximum SUV in the tumor to maximum SUV in healthy white matter. Two independent readers evaluated response to GKRS using serial posttherapy MRI performed at least 3 months after GKRS completion. The relation between relative SUV and local tumor progression was evaluated with respect to treatment effect. Eighty-five patients (48 [56.5%] women, 37 [43.5%] men; mean age at diagnosis, 60.5 ± 11.3 years) met the inclusion criteria. Thirty-three (38.8%) lesions progressed after SRS. There was a significant association between relative SUV and local tumor control (p = 0.035). Relative SUV provided a diagnostic ROC AUC of 0.67 (95% CI, 0.55-0.79). Quantitative relative SUV at posttherapy FDG PET serves as a biomarker of response to SRS in patients with brain metastases in cases in which lesion growth is identified at follow-up MRI. This prognostic data may affect management, supporting the need for further therapeutic actions for selected patients.

Prediction of tumor biological characteristics in different colorectal cancer liver metastasis animal models using 18F-FDG and 18F-FLT

BackgroundPositron emission tomography (PET) is a noninvasive method to characterize different metabolic activities of tumors, providing information for staging, prognosis, and therapeutic response of patients with cancer. The aim of this study was to evaluate the feasibility of 18F-fludeoxyglucose (18F-FDG) and 3′-deoxy-3′-18F-fluorothymidine (18F-FLT) PET in predicting tumor biological characteristics of colorectal cancer liver metastasis. MethodsThe uptake rate of 18F-FDG and 18F-FLT in SW480 and SW620 cells was measured via an in vitro cell uptake assay. The region of interest was drawn over the tumor and liver to calculate the maximum standardized uptake value ratio (tumor/liver) from PET images in liver metastasis model. The correlation between tracer uptake in liver metastases and VEGF, Ki67 and CD44 expression was evaluated by linear regression. ResultsCompared to SW620 tumor-bearing mice, SW480 tumor-bearing mice presented a higher rate of liver metastases. The uptake rate of 18F-FDG in SW480 and SW620 cells was 6.07% ± 1.19% and 2.82% ± 0.15%, respectively (t = 4.69, P = 0.04); that of 18F-FLT was 24.81% ± 0.45% and 15.57% ± 0.66%, respectively (t = 19.99, P < 0.001). Micro-PET scan showed that all parameters of FLT were significantly higher in SW480 tumors than those in SW620 tumors. A moderate relationship was detected between metastases in the liver and 18F-FLT uptake in primary tumors (r = 0.73, P = 0.0019). 18F-FLT uptake was also positively correlated with the expression of CD44 in liver metastases (r = 0.81, P = 0.0049). ConclusionsThe uptake of 18F-FLT in metastatic tumor reflects different biological behaviors of colon cancer cells. 18F-FLT can be used to evaluate the metastatic potential of colorectal cancer in nude mice.

Prediction of Axillary Nodal Status according to the Axillary Lymph Node to Primary Breast Tumor Maximum Standardized Uptake Value Ratio on &amp;lt;sup&amp;gt;18&amp;lt;/sup&amp;gt;F-fluorodeoxyglucose Positron Emission Tomography/Computed Tomography

Prediction of Axillary Nodal Status according to the Axillary Lymph Node to Primary Breast Tumor Maximum Standardized Uptake Value Ratio on &amp;lt;sup&amp;gt;18&amp;lt;/sup&amp;gt;F-fluorodeoxyglucose Positron Emission Tomography/Computed Tomography

Tumoral Hypoxia in Osteosarcoma in Rats: Preliminary Study of Blood Oxygenation Level–Dependent Functional MRI and 18F-Misonidazole PET/CT With Diffusion-Weighted MRI Correlation

The prognostic implication of oxygen concentration as a factor in recurrence of solid tumors has been proved. Hypoxic osteosarcoma, imaged with (18)F-misonidazole PET/CT, is the most frequent primary malignant bone tumor. The aim of our study was to determine the role of blood oxygenation level-dependent (BOLD) functional MRI in an osteosarcoma rodent model by comparison of oxygenation levels in BOLD functional MRI and (18)F-misonidazole PET/CT and correlating the findings with those of diffusion-weighted MRI (DWI). After validation of a hypoxic rodent model, 3-T MRI of osteosarcoma grafted in eight rats, including anatomic, DWI, and BOLD sequences in ambient air and after 2 and 3 minutes of impregnation of 8 L/min of oxygen, was performed on days 10, 17, and 24 after tumor grafting. (18)F-misonidazole PET/CT was performed on day 26, and the rats were sacrificed on day 27 for specific screening of markers of hypoxia. We measured BOLD signal intensity in tumors and normal tissue and compared these results with those on apparent diffusion coefficient maps and (18)F-misonidazole uptake according to maximum standardized uptake value ratio between tumor and healthy spongy bone. Hypoxia was confirmed by histologic study in all cases. We found a significant difference (day 17, p = 0.0038; day 24, p = 0.0051) in the decrease in signal intensity of hypoxic tumor in the presence of oxygen compared with ambient air without relation to duration of oxygen impregnation (p = 0.06). We found a significant correlation (p = 0.003) between BOLD signal intensity and maximum standardized uptake value at (18)F-misonidazole PET/CT. We found no correlation between the decrease in BOLD signal intensity and apparent diffusion coefficient (p = 0.07). BOLD functional MRI may be a promising tool for noninvasive functional imaging of bone tumors, but additional developments are necessary to permit its use in clinical practice.

Postchemoradiotherapy Positron Emission Tomography Predicts Pathologic Response and Survival in Patients With Esophageal Cancer

To correlate the prechemoradiotherapy (CRT) and post-CRT metabolic tumor volume (MTV) on positron emission tomography (PET) scanning with the pathologic response and survival in patients receiving preoperative CRT for esophageal cancer. The medical records of 37 patients with histologically confirmed Stage I-IVA esophageal cancer treated with CRT with or without surgical resection were reviewed. Of the 37 patients, 21 received preoperative CRT (57%) and 16 received definitive CRT (43%). All patients had a pre-CRT and 32 had a post-CRT PET scan. The MTV was measured on the pre-CRT PET and post-CRT PET scan, respectively, using a minimum standardized uptake value (SUV) threshold x, where x = 2, 2.5, 3, or the SUV maximum × 50%. The total glycolytic activity (TGA(x)) was defined as the mean SUV × MTV(x). The MTV ratio was defined as the pre-CRT PET MTV/post-CRT MTV. The SUV ratio was defined similarly. A single pathologist scored the pathologic response using a tumor regression grade (TRG) scale. The median follow-up was 1.5 years (range, 0.4-4.9). No significant correlation was found between any parameters on the pre-CRT PET scan and the TRG or overall survival (OS). Multiple post-CRT MTV values and post-TGA values correlated with the TRG and OS; however, the MTV(2.5(Post)) and TGA(2.5(Post)) had the greatest correlation. The MTV(2) ratio correlated with OS. The maximum SUV on either the pre-CRT and post-CRT PET scans or the maximum SUV ratio did not correlate with the TRG or OS. Patients treated preoperatively had survival similar compared with those treated definitively with a good PET response (p = 0.97) and significantly better than that of patients treated definitively with a poor PET response (p < 0.0001). The maximum SUV was not a predictive or prognostic parameter. The MTV(2.5) and TGA(2.5) were useful markers for predicting the response and survival on the post-CRT PET scan. The MTV(2) ratio also correlated with survival. Post-CRT PET can potentially guide therapy after CRT.