High Standardized Uptake Value Research Articles

Suvmax in 18-Fluorodeoxyglucose PET/CT Potentially Predict the Estimation of a Positive Biopsy in Cases of Lymphoma

IntroductionThe significance of 18-fluorodeoxyglucose PET/CT for predicting the estimation of a positive biopsy in cases of lymphoma is unknown. Diagnosis of lymphoma is based on a lymph node biopsy, however, the use of 18-fluorodeoxyglucose PET/CT for selecting a biopsy site that would provide the best the yield for accurate diagnosis remains unknown.Patients and MethodsData on 165 patients with initial suspicion of lymphoma that underwent PET/CT scans and biopsy as part of their initial evaluation were prospectively collected and reviewed. Standadized uptake value (SUVmax) of the biopsy site and others was collected from radiology reports. The association between the SUVmax on FDG-PET/CT before excision and the estimation of lymphoma diagnosis at biopsy was examined using a receiver operating characteristics curve analysis (ROC).Results159/165 (84.5%) cases suspected of lymphoma underwent PET/CT scan performed prior excisional/FNA biopsy. Ninety six cases were diagnosed of diffuse large B cell lymphoma (DLBCL), 24 follicular lymphoma, 34 Hodgkin lymphoma, 15 plasmablastic lymphomas, and 6 marginal zone lymphoma. Receiver operating characteristics curve analysis demonstrated an area under the curve (AUC) of 0.6 with a borderline p-value of 0.06, which reached level of significance when the methodology of diagnosis only involved fine needle aspiration (FNA, AUC: 0.645, p= 0.05) or when the analysis was performed in patients with a diagnosis of follicular lymphoma (AUC:0.8, p<0.05). We identified several factors that influence SUVmax intensity, which included lymphoma subtype, stage and LDH. Consistent with prior reviews, tumor type was associated with higher SUVmax withDLBCL and plasmablastic with the highest SUV, followed by Hodgkin lymphoma and low grade lymphoma (p<0.05). Tumors with advance stage (stage 4) and high LDH levels were also associated with higher SUVmax.ConclusionSUVmax on FDG-PET/CT is potentially useful for guiding biopsy sites that will provide the best yield to diagnose lymphoma. SUVmax is particularly useful to diagnose lymphoma when FNA is performed as diagnostic procedure of choice. We identified that tumor type, stage and LDH can affect SUV intensity. Performing a Receiver operating characteristics curve analysis of the SUVmax on FDG-PET/CT in a larger samples size is warranted for defining thresholds that predict the estimation of a positive biopsy. DisclosuresCohen:Celgene, Pharmacyclics, Millennium, Seattle Genetics: Consultancy; BMS, Janssen: Research Funding. Flowers:TG Therapeutics: Research Funding; Seattle Genetics: Consultancy; Acerta: Research Funding; Pharmacyclics: Research Funding; Spectrum: Research Funding; Genentech: Research Funding; Onyx Pharmaceuticals: Research Funding; Takeda: Research Funding; AbbVie: Research Funding; Infinity Pharmaceuticals: Research Funding; Gilead Sciences: Research Funding; Celgene: Research Funding; OptumRx: Consultancy; Janssen: Research Funding. Bernal-Mizrachi:Takeda: Research Funding; Empire Genomics: Consultancy, Patents & Royalties.

Association between [18F]-fluoro-2-deoxyglucose uptake and expressions of hypoxia-induced factor 1α and glucose transporter 1 in non-small cell lung cancer

High maximal standardized uptake values (SUVmax) on [18F]-fluoro-2-deoxyglucose positron emission tomography (FDG-PET) are associated with inferior survival in non-small cell lung cancer (NSCLC).

Prognostic significance of (18)FDG PET/CT in colorectal cancer patients with liver metastases: a meta-analysis.

BackgroundThe role of 18-fluorodeoxyglucose positron emission tomography CT (18FDG PET/CT), as a prognostic factor for survival in colorectal cancer patients with liver metastases, is still controversial. We sought to perform a meta-analysis of the literature to address this issue.MethodsA systematic literature search was performed to identify the studies that associated 18FDG PET/CT to clinical survival outcomes of patients with liver metastases. Methodological qualities of the included studies were also assessed. The summarized hazard ratio (HR) was estimated by using fixed- or random-effect model according to heterogeneity between trails.ResultsBy analyzing a total of 867 patients from 15 studies, we found that PET/CT for metabolic response to the therapy was capable of predicting event-free survival (EFS) and overall survival (OS) with statistical significance, and the HR was 0.45 (95 % confidence interval [CI], 0.26–0.78) and 0.36 (95 % CI, 0.18–0.71), respectively. Furthermore, pre-treatment 18FDG PET/CT with high standardized uptake value (SUV) was also significantly associated with poorer OS HR, 1.24; (95 % CI, 1.06–1.45). However, we did not find a statistically significant effect of post-treatment SUV for predicting OS HR, 1.68; (95 % CI, 0.63–4.52).ConclusionsThe present meta-analysis confirms that 18FDG PET/CT is a useful tool to help predict survival outcomes in patients with liver metastases.Electronic supplementary materialThe online version of this article (doi:10.1186/s40644-015-0055-z) contains supplementary material, which is available to authorized users.

Prognostic value of 2-[18 F]fluoro-2-deoxy-D-glucose positron emission tomography for patients with oral squamous cell carcinoma treated with retrograde superselective intra-arterial chemotherapy and daily concurrent radiotherapy

To investigate whether 2-[(18) F]fluoro-2-deoxy-D-glucose (FDG) uptake of primary tumor in oral squamous cell carcinoma (OSCC) could predict prognosis. Sixty-nine patients with OSCC who underwent retrograde superselective intra-arterial chemoradiotherapy were recruited and underwent dual-time-point FDG positron emission tomography twice, before treatment and 4 weeks after treatment. FDG uptake was defined as the standardized uptake value (SUVmax). The retention index (RI) and the percent change in SUV (% change SUV), derived from the dual-time-point scan, were calculated. On univariate analysis, patients with high pre-SUV, RI, and percent change SUV values had significantly worse overall survival and disease-free survival compared with patients with low values. On multivariate analysis, high pre-RI (≥20.6%) and high percent change SUV (≥60.0%) (delayed-image) were associated with significantly worse overall survival. High pre-SUV (≥9.6) (delayed-image) and high pre-RI (≥20.6%) were associated with significantly shorter disease-free survival. Dual-time-point FDG positron emission tomography in OSCC provided prognostic information and predicted patient outcome.

Limited Prognostic Value of SUVmax Measured by F-18 FDG PET/CT in Newly Diagnosed Small Cell Lung Cancer Patients

Background: The purpose of this study was to evaluate the prognostic value of the maximum standard uptake value (SUV_max) measured by 18-F fluoro-2-deoxy-d-glucose (F-18 FDG) positron emission tomography/computed tomography (PET/CT) in newly diagnosed small cell lung cancer (SCLC) patients. Methods: We reviewed the medical records of newly diagnosed SCLC patients who were given a histological diagnosis from June 2008 to June 2014. 82 patients who satisfied the inclusion criteria were enrolled for final analysis (male n = 75, female n = 7). The relationship between SUV_max and overall survival (OS) and progression-free survival (PFS) was evaluated. Results: Median follow-up was 25.0 months (range 11.6-55.5 months). The median OS was 11.2 months (range 1.6-55.5 months), and the median PFS was 6.1 months (range 0.9-55.5 months). Survival analysis showed no statistical differences in OS and PFS between high and low SUV_max groups. Conclusion: This study does not support the use of SUV_max of pretreatment F-18 FDG PET/CT scans as a prognostic tool for patients with SCLC.

Standardized uptake value on positron emission tomography/computed tomography predicts prognosis in patients with locally advanced pancreatic cancer.

The aim of the present study was to investigate the use and value of maximum standardized uptake value (SUV max) on positron emission tomography/computed tomography (PET/CT) images as a prognostic marker for patients with locally advanced pancreatic cancer (LAPC). The medical records of all consecutive patients who underwent PET/CT examination in our institution were retrospectively reviewed. Inclusion criteria were histologically or cytologically proven LAPC. Patients with distant metastasis were excluded. For statistical analysis, the SUV max of primary pancreatic cancer was measured. Survival rates were calculated using the Kaplan-Meier method, and multivariable analysis was performed to determine the association of SUV max with overall survival (OS) and progression-free survival (PFS) using a Cox proportional hazards model. Between July 2006 and June 2013, 69 patients were enrolled in the present study. OS and PFS were 14.9 months [95% confidence interval (CI) 13.1-16.7] and 8.3 months (95% CI 7.1-9.5), respectively. A high SUV max (>5.5) was observed in 35 patients, who had significantly worse OS and PFS than the remaining patients with a low SUV max (P = 0.025 and P = 0.003). Univariate analysis showed that SUV max and tumor size were prognostic factors for OS, with a hazard ratio of 1.90 and 1.81, respectively. A high SUV max was an independent prognostic factor, with a hazard ratio of 1.89 (95% CI 1.015-3.519, P = 0.045). The present study suggests that increased SUV max is a predictor of poor prognosis in patients with LAPC.

Standardized Uptake Value on 18F-FDG PET/CT as a Prognostic Factor for Survival of Women with Malignant Uterine Tumors: A Meta-Analysis

Background: Malignant uterine tumors are crucial in the evaluation of prognosis and the determination of therapeutic strategy. Aim: This meta-analysis of the available literature aimed to investigate the prognostic value of standardized uptake value (SUV) on fluorine-18-fluorodeoxyglucose positron emission tomography with computed tomography (¹⁸F-FDG PET/CT) in uterine malignancies before treatment. Methods: The PubMed, MEDLINE and EMBASE databases (1990 to February 2014) were searched to identify studies evaluating SUV on ¹⁸F-FDG PET/CT as a prognostic tool for predicting long-term survival in patients with carcinomas of the uterus. The χ² test and the I² index were used to estimate heterogeneity among the trials selected in the meta-analysis. The combined hazard ratio was calculated by using a fixed- or random-effects model according to heterogeneity. Results: Thirteen studies with a total of 1,196 patients were eligible for analysis. High pretreatment SUV_max was significantly associated with poorer event-free survival and overall survival, and the summarized hazard ratio was 3.33 (95% confidence interval 2.34-4.74) and 1.31 (95% confidence interval 1.03-1.67), respectively. Conclusion: The present evidence indicates that SUV on ¹⁸F-FDG PET/CT seems to be a valuable prognostic indicator for survival of patients with malignant uterine tumors. Given that ¹⁸F-FDG PET/CT can provide both morphologic and functional information, we suggest utilizing PET/CT and its quantitative marker in uterine malignancies before treatment.

18F]fluorodeoxyglucose uptake as a predictor of large joint destruction in patients with rheumatoid arthritis.

The present retrospective study investigated the relationship between [(18)F]fluorodeoxyglucose-positron emission tomography (FDG-PET) findings and subsequent progression of joint destruction on plain X-ray. Nineteen rheumatoid arthritis (RA) patients (59 joints) who underwent FDG-PET and whose joints could be evaluated on plain X-ray 5 years later were included in this retrospective investigation. The relationship between the standardized uptake value (SUV) on FDG-PET and Larsen grade progression on plain X-ray was investigated for each joint. Factors related to progression of joint destruction were also investigated. Joints with advanced joint destruction (Larsen grades IV and V) on X-ray imaging at the time of FDG-PET were excluded. On initial plain X-ray images taken at the time of FDG-PET, a significant correlation was observed between the initial SUV of each joint and the progression of joint destruction 5 years later (R = 0.47, P < 0.01). Significant correlations between the SUV and progression of joint destruction were observed in both load-bearing (R = 0.52, P < 0.01) and non-load-bearing joints (R = 0.52, P < 0.01). On logistic regression analysis, higher SUV and lower prednisolone dose were associated with greater risk of progressive joint destruction (P < 0.05). On receiver operating characteristics curve analysis, the optimum threshold for identifying preceding joint destruction was an SUVmean of 1.33. In RA joints, FDG uptake was seen mostly by inflammatory cells; therefore, FDG uptake reflected joint inflammation. Additionally, the activity seen on FDG-PET might be associated with future radiographic changes in RA patients.

Abstract 1486: Fatty acid and phospholipid profiling of liver tumor tissue: correlation with in vivo molecular PET imaging of phosphocholine synthesis

Abstract Alterations in phospholipid and fatty acid metabolism may play key roles in hepatocarcinogenesis. Phosphocholine synthesis can be imaged and quantified in-vivo by positron emission tomography (PET) using radiopharmaceuticals bearing the choline moiety. Results from this PET assessment of tissue phospholipid metabolism were compared to phospholipid and fatty acid profiles of both tumor and liver parenchymal tissues in patients with liver cancer undergoing hepatectomy. Fluorine-18 fluorocholine PET/CT of the liver was completed &amp;lt;2 weeks prior to surgery as part of a clinicaltrials.gov-registered (NCT01395030) IRB-approved clinical study with written informed consent. Paired tumor and parenchymal tissue samples were collected in liquid nitrogen (20 hepatocellular carcinoma, 3 with intrahepatic cholangiocarcinoma), freeze-dried, homogenized and extracted with methanol/CHCl3/water containing BHT as preservative. The organic phase was analyzed by orbitrap LCMS after electrospray ionization in positive mode to quantify fatty acids (after derivatization) and phospholipid metabolites. Tumor and liver standardized uptake value (SUV) measurements were obtained from static PET images. Tumors exhibited significantly lower levels of docosahexaenoic acid, docasopentanoic acid, alpha-linolenic acid and significantly higher levels of palmitoleic acid, eicosadienoic acid, arachadonic acid, and linoleic acid than peritumoral liver tissue. Tumors also exhibited significantly higher SUVs than surrounding liver. Highest tumor SUV correlated significantly with tumor levels of palmitoleic acid, gamma linolenic acid, CDP choline, phosphatidylcholine, phosphatidylethanolamine and phosphatidylinsolitol. In contrast, no significant correlations were noted between tumor SUV and peri-tumoral levels of these compounds. Peritumoral liver SUV was significantly correlated with levels of myristic acid, eicosaptaenoic acid, gamma-linolenic acid, palmitoleic acid, docosapentaenoic acid, linoleic acid, oleic acid, and palmitic acid in peritumoral liver tissue. Furthermore, parenchymal liver SUV was inversely correlated with the Knodell histologic activity index (HAI), as well as histologic features of portal inflammation, piecemeal necrosis, and fibrosis. These histology features were also inversely correlated with liver tissue concentrations of docosahexaenoic acid, CDP-choline, total phosphaticylcholine, and total phosphatidylinositol. No significant correlations were found between tumor fatty acid/phospholipid levels and Edmonson-Steiner tumor grade. These preliminary results may indicate multiple inter-related metabolic alterations involving phospholipid and fatty acid metabolism in primary liver cancer. Chronic liver disease appears to be associated with diminishing hepatic phospholipid reserve. Note: This abstract was not presented at the meeting. Citation Format: Sandi Alexander Kwee, Adrian A. Franke, Laurie J. Custer, Xingnan Li, Linda L. Wong. Fatty acid and phospholipid profiling of liver tumor tissue: correlation with in vivo molecular PET imaging of phosphocholine synthesis. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1486. doi:10.1158/1538-7445.AM2015-1486

XV. Clinical aspects of transformed lymphoma.

XV. Clinical aspects of transformed lymphoma.

Positron Emission Tomography/Computed Tomography for the Pleural Staging of Malignant Pleural Mesothelioma: How Accurate Is It?

Background: Careful clinical staging in patients with malignant pleural mesothelioma (MPM) is fundamental in management planning. Positron emission tomography/computed tomography (PET/CT) is increasingly recognized as an important staging modality. Objectives: The purpose of this study was to assess whether the metabolic activity of the pleural tumor detected with PET/CT correlates with specific endoscopic features and pleural distribution of the lesions as assessed by medical thoracoscopy. Methods: Consecutive patients with MPM and available PET/CT performed before thoracoscopy were separated into 2 groups, according to their standardized uptake value (SUV). Kaplan-Meier-analysis for survival was performed on groups with low and high SUV. Agreement between PET/CT and thoracoscopy evaluation was analyzed using Cohen's kappa coefficient. The Wilcoxon test was used to compare the median SUV, and the χ² test was used to evaluate differences in endoscopic findings. Results: A total of 32 patients were included. The median maximum SUV (SUV max) was 6.1 and patients were separated into 2 groups based on this cutoff. Patients with SUV max <6.1 had a better survival than those with SUV max ≥6.1 (p = 0.005). The comparison between PET/CT and thoracoscopy showed a fair agreement for visceral and diaphragmatic pleural involvement and moderate agreement for the presence of nodular lesions. There was a statistically significant association between median SUV max and visceral pleural involvement; nodular lesions and visceral pleural involvement were more common in the high-SUV group than in the low-SUV group (p = 0.0012 and p = 0.03, respectively). Conclusions: PET/CT data may be predictive of thoracoscopic features of MPM associated with prognosis and staging, but the correlation is moderate at best. A degree of disagreement exists between these two modalities, which supports thoracoscopy as the gold standard for assessment of local invasion in MPM.

CORRELATION BETWEEN STANDARDIZED UPTAKE VALUE AND HISTOPATHOLOGY OF OESOPHAGEAL CARCINOMA: A SINGLE CENTER ANALYSIS

Aim: This study aims to evaluate the correlation between oesophageal cancer histopathology and the standardised uptake value (SUV) of the primary lesion on positron emission tomography/computed tomography (PET/CT) scan.Methods: We reviewed clinical data of consecutive newly diagnosed oesophageal cancer patients who underwent positron emission tomography with 2-deoxy-2-[ uorine-18] uoro-D glucose integrated with CT (18F-FDG PET/CT) between September 2009 and July 2014. Results: A total of 289 baseline scans were performed in this 55-month period. Of these, 171 (59%) were male. The mean age was 52.6 years (standard deviation ± 12.4 years). On histological review, 214 were squamous cell carcinomas (SCCa) and 75 were adenocarcinomas. Of the SCCa, 15.9% were poorly differentiated, 70.6% were moderately differentiated and 13.5% were well differentiated. Of the adenocarcinomas, 20% were poorly differentiated, 45% were moderately differentiated, 28% were well differentiated and signet ring cell was 7%. Mean maximum SUV (SUVmax) for SCCa was 12.6 ± 5.14 and 10.5 ± 6.2 for adenocarcinomas. In bivariate analysis, being a female was associated with a higher SUV in the primary lesion by 1.66 units (P = 0.011) compared to males. Adenocarcinomas were associated with a lower SUV by 2.14 units (P = 0.004) compared to SCCa. In bivariate analysis, no signi cant correlation was found between the T-stage of the tumour and the SUVmax of the primary tumour (P = 0.339). Multivariate analyses showed no association of the SUV of the primary oesophageal tumour with the degree of differentiation of either SCCa or adenocarcinoma. There was no correlation between the SUVmax of the primary lesion and the presence or activity level of a metastatic focus, whether visceral or nodal. Conclusion: At our centre, three-fourths of patients with oesophageal carcinoma had squamous cell carcinoma on histology. Adenocarcinoma is associated with a lower SUV compared to SCCa. There is no association between the SUVmax and degree of differentiation of the primary oesophageal cancer. Key words: Fluorodeoxyglucose, oesophageal adenocarcinoma, oesophageal squamous cell carcinoma, positron emission tomography/computed tomography, standardised uptake value

Results of 68Gallium-DOTATATE PET/CT Scanning in Patients with Multiple Endocrine Neoplasia Type 1

Screening for neuroendocrine tumors (NETs) in patients with multiple endocrine neoplasia type 1 (MEN1) is recommended to detect primary and metastatic tumors, which can result in significant morbidity and mortality. The utility of somatostatin receptor imaging (68)Gallium-DOTATATE PET/CT in patients with MEN1 is not known. The aim of this study was to prospectively determine the accuracy of (68)Gallium-DOTATATE PET/CT vs (111)In- pentetreotide single-photon emission CT (SPECT)/CT and anatomic imaging in patients with MEN1. We performed a prospective study comparing (68)Gallium-DOTATATE PET/CT, (111)In-pentetreotide SPECT/CT, and triphasic CT scan to clinical, biochemical, and pathologic data in 26 patients with MEN1. (68)Gallium-DOTATATE PET/CT detected 107 lesions; (111)In-pentetreotide SPECT/CT detected 33 lesions; and CT scan detected 48 lesions. Lesions detected on (68)Gallium-DOTATATE PET/CT had high standard uptake value (SUV)(max) (median SUV(max) = 72.8 [range 19 to 191]). In 7 of the 26 patients (27%), (68)Gallium-DOTATATE PET/CT was positive, with a negative (111)In-pentetreotide SPECT/CT, and in 10 patients (38.5%), additional metastases were detected (range 0.3 cm to 1.5 cm). In 8 of the 26 patients (31%), there was a change in management recommendations as a result of the findings on (68)Gallium-DOTATATE PET/CT that were not seen on (111)In-pentetreotide SPECT/CT and CT scan. (68)Gallium-DOTATATE PET/CT is more sensitive for detecting NETs than (111)In-pentetreotide SPECT/CT and CT scan in patients with MEN1. This imaging technique should be integrated into radiologic screening and surveillance of patients with MEN1 because it can significantly alter management recommendations.

18F-FDG-PET/CT parameters as imaging biomarkers in oral cavity squamous cell carcinoma, is visual analysis of PET and contrast enhanced CT better than the numbers?

PurposeThis study was designed to seek associations between positron emission tomography/computed tomography (PET/CT) parameters, contrast enhanced neck computed tomography (CECT) and pathological findings, and to determine the potential prognostic value of PET/CT and CECT parameters in oral cavity squamous cell carcinoma (OCSCC). Materials and method36 OCSCC patients underwent staging PET/CT and 30/36 of patients had CECT. PET/CT parameters were measured for the primary tumor and the hottest involved node, including maximum, mean, and peak standardized uptake values (SUV max, SUV mean, and SUV peak), metabolic tumor volume (MTV), total lesion glycolysis (TLG), standardized added metabolic activity (SAM), and normalized standardized added metabolic activity (N SAM). Qualitative assessment of PET/CT and CECT were also performed. Pathological outcomes included: perineural invasion, lymphovascular invasion, nodal extracapsular spread, grade, pathologic T and N stages. Multivariable logistic regression models were fit for each parameter and outcome adjusting for potentially confounding variables. Multivariable Cox proportional hazards models were used for progression free survival (PFS), locoregional recurrence free survival (LRFS), overall survival (OS) and distant metastasis free survival (DMFS). ResultsIn multivariable analysis, patients with high (≥ median) tumor SUV max (OR 6.3), SUV mean (OR 6.3), MTV (OR 19.0), TLG (OR 19.0), SAM (OR 11.7) and N SAM (OR 19.0) had high pathological T-stage (T3/T4) (p<0.05). Ring/heterogeneous pattern on CECT qualitative assessment was associated with worse DMFS and OS. ConclusionHigh PET/CT parameters were associated with pathologically advanced T stage (T3/T4). Qualitative assessment of CECT has prognostic value. PET/CT parameters did not predict clinical outcome.

Molecular Imaging Biomarkers of Resistance to Radiation Therapy for Spontaneous Nasal Tumors in Canines

Imaging biomarkers of resistance to radiation therapy can inform and guide treatment management. Most studies have so far focused on assessing a single imaging biomarker. The goal of this study was to explore a number of different molecular imaging biomarkers as surrogates of resistance to radiation therapy. Twenty-two canine patients with spontaneous sinonasal tumors were treated with accelerated hypofractionated radiation therapy, receiving either 10 fractions of 4.2 Gy each or 10 fractions of 5.0 Gy each to the gross tumor volume. Patients underwent fluorodeoxyglucose (FDG)-, fluorothymidine (FLT)-, and Cu(II)-diacetyl-bis(N4-methylthiosemicarbazone) (Cu-ATSM)-labeled positron emission tomography/computed tomography (PET/CT) imaging before therapy and FLT and Cu-ATSM PET/CT imaging during therapy. In addition to conventional maximum and mean standardized uptake values (SUV(max); SUV(mean)) measurements, imaging metrics providing response and spatiotemporal information were extracted for each patient. Progression-free survival was assessed according to response evaluation criteria in solid tumor. The prognostic value of each imaging biomarker was evaluated using univariable Cox proportional hazards regression. Multivariable analysis was also performed but was restricted to 2 predictor variables due to the limited number of patients. The best bivariable model was selected according to pseudo-R(2). The following variables were significantly associated with poor clinical outcome following radiation therapy according to univariable analysis: tumor volume (P=.011), midtreatment FLT SUV(mean) (P=.018), and midtreatment FLT SUV(max) (P=.006). Large decreases in FLT SUV(mean) from pretreatment to midtreatment were associated with worse clinical outcome (P=.013). In the bivariable model, the best 2-variable combination for predicting poor outcome was high midtreatment FLT SUV(max) (P=.022) in combination with large FLT response from pretreatment to midtreatment (P=.041). In addition to tumor volume, pronounced tumor proliferative response quantified using FLT PET, especially when associated with high residual FLT PET at midtreatment, is a negative prognostic biomarker of outcome in canine tumors following radiation therapy. Neither FDG PET nor Cu-ATSM PET were predictive of outcome.

Metabolic PET/CT-guided lung lesion biopsies: impact on diagnostic accuracy and rate of sampling error.

CT-guided fine-needle aspiration (FNA) of lung lesions is subject to sampling errors. The current study assessed whether information provided by (18)F-FDG PET/CT will decrease the false-negative (FN) rate and thus improve the accuracy of CT-guided FNA. Data from 311 consecutive patients with lung nodules who underwent (18)F-FDG PET/CT and CT-guided FNA within an interval of less than 30 d were retrospectively assessed. In-house-developed software was used to register CT images performed for the FNA procedure (CT FNA) with corresponding slices of the PET/CT study. The quality of registration was rated on a scale of 1 (excellent) to 5 (misregistration). Only cases scored 1 or 2 were further evaluated. The software provided the highest standardized uptake value (SUV) within the lesion and at the location of the tip of the aspirating needle. The distance between the tip and the area with the highest SUV within the lesion was measured. The mean distance from the tip of the needle to the focus with the highest SUV, as well as the mean difference between the maximum SUV in the whole lesion and at the needle tip, was calculated and compared for cases with true-positive (TP) and FN FNA results. Anatomic and metabolic parameters of lesions included in these 2 groups were also compared. There were 267 patients (86%) with score 1 or 2 registration quality for CT FNA and PET/CT/CT images, including 179 TP (67%), 5 false-positive (FP, 2%), 49 true-negative (TN, 18%), and 34 FN (13%) FNA results. The distance between the location of the needle tip and the focus with the highest SUV in the lesion was significantly greater in the FN group (15.4 ± 14 mm) than in the TP group (5.9 ± 13.4 mm, P < 0.001). The maximum SUV at the location of the aspirating needle tip was significantly higher in the TP group, at 6.4 ± 6.4, than in the FN group, at 4 ± 4.7 (P < 0.05). The present results demonstrate a relationship between the degree of metabolism at the site of tissue-sampling aspiration in lung lesions and the accuracy of FNA results. Anatomy- and metabolism-based FNA guidance using information provided by both (18)F-FDG PET and CT may improve the accuracy of histologic examinations, decrease the rate of FN results, and thus increase the probability of achieving a definitive diagnosis.

Multiparametric analysis of bone marrow in cancer patients using simultaneous PET/MR imaging: Correlation of fat fraction, diffusivity, metabolic activity, and anthropometric data.

To analyze the regional composition of bone marrow (BM) in correlation with metabolic activity and diffusivity using simultaneous positron emission tomography (PET)/MRI. Retrospective analysis of 18F-FDG-PET/MR scans of 110 patients was performed. A three-dimensional gradient-echo sequence with Dixon-based fat-water separation was used for fat quantification. Dixon images, diffusion-weighted images (DWI) and 18F-FDG-PET were co-registered. Mean values of fat fraction (FF), standardized uptake value (SUV), and apparent diffusion coefficient (ADC) of BM were measured in different anatomical regions. Correlation of FF, SUV, and ADC and association of BM fat content and metabolic activity with anthropometric data was analyzed (Pearson). BM fat content and metabolic activity was compared in patients with and without chemotherapy (t-test). Regional differences in BM were found with highest fat content (93 ± 8%) and lowest ADC (0.22 ± 0.18 × 10(-3) mm(2) /s) in the peripheral skeleton and highest SUV in the spine (1.77 ± 0.6). There was a significant inverse correlation between FF and SUV (r = -0.73; P < 0.0001) and a significant inverse correlation between FF and ADC (r = -0.62; P < 0.0001). In patients with chemotherapy, a tendency to higher fat content and lower metabolic activity was observed in the proximal skeleton, although no statistical significance was reached. BM shows distinct regional variations in FF, SUV, and ADC. The inverse correlation of FF and SUV in BM suggests that BM adipose tissue does not have a comparable high metabolic activity as brown adipose tissue.

The predictive value of metabolic tumor volume on FDG PET/CT for transarterial chemoembolization and transarterial chemotherapy infusion in hepatocellular carcinoma patients without extrahepatic metastasis.

The aim of this study was to evaluate the prognostic value of metabolic tumor volume (MTV) on pre-treatment F-18 fluorodeoxyglucose (FDG) PET/CT in patients with hepatocellular carcinoma (HCC). A total of 59 HCC patients who underwent FDG PET/CT before transarterial chemoembolization (TACE) or transarterial chemotherapy infusion (TACI) were retrospectively enrolled. The region of interest was drawn in the HCC and normal liver tissue. MTV2SD, defined as the sum of the voxels with higher standardized uptake values (SUV) than the SUV of the 97.5th percentile of voxels of the normal liver for each patient, was calculated using an intensity-volume histogram (IVH). The ratio of the maximum SUV of the tumor to the mean SUV of normal liver (T max/L mean) was also calculated. The prognostic significance of MTV2SD and Tmax/Lmean for progression-free survival (PFS) and overall survival (OS) was evaluated along with other clinical factors. The tumor number, Tmax/Lmean, and MTV2SD were significant prognostic factors affecting PFS (p<0.05), whereas tumor number, serum alpha-fetoprotein level, tumor stage, portal vein thrombosis, Tmax/Lmean, and MTV2SD were significant prognostic factors for OS (p<0.05). In multivariate analysis, the tumor number and MTV2SD were independent prognostic factors for PFS (p<0.05), whereas the independent prognostic factors for OS were tumor number, tumor stage, and MTV2SD (p<0.05). The mean PFS and OS in patients with low MTV2SD (15.4 and 63.1months, respectively) were significantly longer than those in patients with high MTV2SD (6.0 and 15.2months, respectively; p=0.005 and p<0.0001, respectively). Metabolic tumor volume was an independent prognostic factor for PFS and OS in patients with HCC. Therefore, FDG PET/CT can provide valuable prognostic information for HCC patients who undergo TACE or TACI.

Primary Tumor Standardized Uptake Value Predicts Survival in Head and Neck Squamous Cell Carcinoma

Background: The purpose of this study was to determine whether the pretreatment primary tumor standardized uptake value (SUV), as measured by positron emission tomography (PET), can add prognostic information for predicting survival in patients with head and neck squamous cell carcinoma (HNSCC). Materials and Methods: 7 articles were identified by searching electronic databases. Statistical analysis was performed with RevMan 4.2.2. SUV measurement and SUV threshold for defining high SUV were studied dependently. For each publication, we first obtained an estimate of the relative risk (RR) for comparing patients with a low or a high SUV. Subsequently, we aggregated the individual RRs into a combined RR, using a fixed-effect model. Publication bias was assessed using a funnel plot. Results: The study included 7 clinical trials dedicated to HNSCC, involving 674 patients who underwent fluoro-2-deoxy-<smlcap>D</smlcap>-glucose-PET scanning before treatment. The combined RR from the 7 reports for the survival was 0.53 (95% confidence interval: 0.46-0.62). The funnel plot showed symmetrical distribution, indicating no evidence of any substantial publication bias. Conclusion: Our meta-analysis indicates that patients with HNSCC who have a primary tumor with a high SUV have poor survival; this should be further confirmed in a meta-analysis based on individual patient data.

Diagnostic yield of non‐guided flexible bronchoscopy for peripheral pulmonary neoplasia

BackgroundThe role of conventional bronchoscopy for peripheral pulmonary neoplasia remains controversial. We aimed to assess the diagnostic yield and the added value of non-guided bronchial aspiration, bronchoalveolar lavage (BAL), and brushing for the diagnosis of pulmonary neoplasia not visible endoscopically.MethodsWe retrospectively assessed 207 consecutive patients with a final diagnosis of peripheral lung malignancy who underwent bronchoscopy with non-guided aspiration, brushing, and BAL as their initial evaluation. The influence of clinical and radiological factors on diagnostic yield was assessed using univariate logistic regression analyses.ResultsThe overall sensitivity of non-guided bronchoscopy was 25.6%, whereas sensitivities for bronchial aspiration, BAL, and brushing were 14.2%, 11.6%, and 16.5%, respectively. Younger age, larger lesion, central/intermediate distance from the hilum, presence of a bronchus sign, and higher standardized uptake value (SUV) on positron emission tomography scan were predictors of a higher diagnostic yield. Conversely, forced expiratory volume in one second, fellow implication in the procedure, and tumor histology did not influence sensitivity. The overall sensitivity of bronshoscopy was >40% for tumors >4 cm, located in the central/intermediate thirds of the lung, showing a bronchus sign, with an SUV >12 or occurring in patients <50 years of age. Conversely, the sensitivity was <10% for tumors <2 cm, located peripherally or with an SUV <4.ConclusionNeoplasia characteristics may help targeting situations in which conventional bronchoscopy could be used as the initial diagnostic procedure when advanced techniques are unavailable. However, advanced diagnostic tools should probably be proposed as the initial modality for the diagnosis of peripheral malignant lesions when available.