Clinical Outcomes in Patients With DLBCL Treated With R-CHOP According to Radiotherapy and Interim PET Response.

Background/Aim: Interim positron emission tomography/computed tomography (PET/CT) scan is a valuable tool for assessing the early metabolic response to chemotherapy in diffuse large B-cell lymphoma (DLBCL). Although radiotherapy is an effective treatment for lymphoma, especially for local tumor control, the role of consolidative radiotherapy in diffuse large B-cell lymphoma (DLBCL) remains controversial. This study analyzed the clinical outcomes of patients with DLBCL treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP), stratified by interim PET response and the administration of radiotherapy. Patients and Methods: We conducted a retrospective review of 107 patients with DLBCL treated with R-CHOP chemotherapy between January 2012 and December 2016. Overall survival (OS), recurrence-free survival (RFS), and freedom from disease progression (FFDP) were calculated using the Kaplan-Meier method and compared using the log-rank test. Results: Forty-six patients were included in this analysis, with a median follow-up time of 65.9 months (range=4.7-125.3 months). The metabolic CR (mCR) group exhibited superior OS, RFS, and FFDP compared with the metabolic PR (mPR) group (p=0.003, p=0.001, and p=0.008, respectively). The 1-, 2-, and 5-year FFDP were 92.97%, 89.3%, and 85.6%, respectively, in the mCR group and 78.6%, 61.9%, and 44.2%, respectively, in the mPR group. In subgroup analysis, the FFDP of the mPR group without radiotherapy was significantly lower than that of the other groups (mCR with/without radiotherapy and mPR with radiotherapy, p=0.001). Conclusion: Consolidative radiation therapy using interim PET can benefit patients who do not achieve mCR. Further well-controlled prospective randomized trials are required.

Thyroid segmentation using perithyroidal halo layer on 99mTc-pertechnetate thyroid SPECT/CT: An easy and reliable method for accurate quantification of thyroid activity.

OBJECTIVE: In previous fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) studies, tumor segmentation using peritumoral halo layer (PHL; SegPHL) was shown to be reliable and accurate segmentation method in various malignant tumors. We found that the halo layer also was observed on the 99mTc-pertechnetate (99mTcO4) thyroid single photon emission computed tomography (SPECT)/CT. In the present study, we attempted to apply thyroid segmentation using the perithyroidal halo layer (PTHL; SegPTHL) on 99mTcO4 thyroid SPECT/CT and compared SegPTHL with CT-based thyroid segmentation (SegCT). SUBJECTS AND METHODS: A total of 33 patients (19 females, 14 males; mean age, 46.91±15.7 years old) were enrolled in this study. For SegCT, three-dimensional volume of interest (VOI) of the thyroid was generated via multiple 2-dimensional regions of interest (ROI) along the thyroid margin on transaxial CT images that were manually drawn slice by slice. The PTHL was easily identified by an abrupt increase in layer thickness with minimal or mild distortion of the main thyroid contour, and the thyroid margin for SegPTHL was determined at the innermost portion of PTHL. An automated VOI generation for SegPTHL was performed using the Q. Volumetrix software. The correlation and reliability tests were performed between the quantification parameters of SegPTHL and SegCT. RESULTS: The PTHL threshold adjusted according to maximal SUV of thyroid were similar to the results of previous SegPHLstudies of 18F-FDG PET/CT. A good correlation was observed between the thyroid volumes of SegCT and SegPTHL (r=0.725; P<0.0001), although the thyroid volume of SegPTHL was slightly larger than that of SegCT (P=0.0017). The % thyroid uptake (TcTU), total lesion activity (TLA), and mean standardized uptake value (SUVmean) of SegPTHL correlated well with those of SegCT (r=0.9877, 0.9883, 0.9875, respectively; P<0.0001). No significant error was observed between the parameters (i.e., TcTU, TLA, and SUVmean) of SegPTHL and SegCT. CONCLUSION: Thyroid segmentation PTHL may be a useful method for reliable quantification of thyroid uptake, because the SPECT/CT parameters of SegPTHL were strongly correlated with those of SegCT, as well as the process of SegPTHL is easier and faster than that of SegCT.

Shaving Papillary Thyroid Carcinoma Involving Functioning Recurrent Laryngeal Nerve: Safety of Incomplete Tumor Resection and Nerve Sparing.

BACKGROUND: Whether to sacrifice or spare the recurrent laryngeal nerve (RLN) when papillary thyroid carcinoma (PTC) involves a functioning RLN remains controversial. Oncological outcomes after shaving PTC with gross remnant on the RLN have been rarely reported. The objective of this study was to evaluate the oncological outcomes of patients who underwent shaving of a PTC from the RLN, leaving a gross residual tumor with the intent of vocal function preservation. METHODS: A retrospective, cohort study was conducted in 47 patients who were determined to have PTC invasion of the RLN via intraoperative inspection and underwent tumor shaving with macroscopic remnant (R2 resection) less than 1 cm in length and 4 mm in thickness. Median follow-up period was 93 (range, 60-215) months. The primary endpoint was the recurrence-free survival and the progression-free survival. Secondary endpoints were biochemical outcomes (serum thyroglobulin) and vocal cord function. RESULTS: Of the 47 patients, five (10.6%) patients showed recurrence (central neck, 3; lateral neck, 2) without death or distant metastasis. The RLN was resected along with the tumor in one (2.1%) patient who presented with progression of the residual tumor. Postoperative temporary vocal cord paralysis occurred in six (12.8%) patients without permanent cases. The final nonstimulated serum thyroglobulin was 0.7 ± 1.8 ng/ml. CONCLUSIONS: Shaving a tumor from a RLN with gross residual disease may be considered an alternative strategy to preserve vocal function when complete tumor resection with nerve preservation is impossible in patients with PTC invading a functioning RLN.

Effects of the material properties and thickness on the minimum formable radius in the subtle feature forming process.

The subtle feature geometry also called a feature line, is considered an important geometric characteristic of automotive outer panels. The influences of material properties and thickness on the radius of curvature of subtle features were investigated in this study. First, the stamping process was simplified to a combined forming process between tensile and bending deformation. Subsequently, test materials, namely, 180B2, 210B2, CR2, CR3, and CR4, with various thickness values were adopted in the finite element analysis and experiments. In addition, the radius of curvature with respect to the material, thickness, punch radius, and punch angle was studied. The simulation results were compared with the experimental results for verification. From this comparison, it was found that the simulation results were in good agreement with the experimental data. Finally, the forming characteristics of the subtle feature-forming process were investigated to determine the effects of the material properties and thickness on the radius of curvature. The reason for the minimum formable radius when the radius of the punch was zero was studied. The results showed that, as the material thickness increased, more concentrated deformation occurred in the central region. In contrast, the radius of curvature of the subtle features increased as the thickness of the central region decreased. Similarly, decreased n-value results were identified for the same reason as the increased radius of curvature.

Cognitive Trajectories and Associated Biomarkers in Patients with Mild Cognitive Impairment.

BACKGROUND: To diagnose mild cognitive impairment (MCI) patients at risk of progression to dementia is clinically important but challenging. OBJECTIVE: We classified MCI patients based on cognitive trajectories and compared biomarkers among groups. METHODS: This study analyzed amnestic MCI patients with at least three Clinical Dementia Rating (CDR) scores available over a minimum of 36 months from the Alzheimer's Disease Neuroimaging Initiative database. Patients were classified based on their progression using trajectory modeling with the CDR-sum of box scores. We compared clinical and neuroimaging biomarkers across groups. RESULTS: Of 569 eligible MCI patients (age 72.7±7.4 years, women n = 223), three trajectory groups were identified: stable (58.2%), slow decliners (24.6%), and fast decliners (17.2%). In the fifth year after diagnosis, the CDR-sum of box scores increased by 1.2, 5.4, and 11.8 points for the stable, slow, and fast decliners, respectively. Biomarkers associated with cognitive decline were amyloid-ß 42, total tau, and phosphorylated tau protein in cerebrospinal fluid, hippocampal volume, cortical metabolism, and amount of cortical and subcortical amyloid deposits. Cortical metabolism and the amount of amyloid deposits were associated with the rate of cognitive decline. CONCLUSION: Data-driven trajectory analysis provides new insights into the various cognitive trajectories of MCI. Baseline brain metabolism, and the amount of cortical and subcortical amyloid burden can provide additional information on the rate of cognitive decline.

Impact of Off-Hour Admission with Subarachnoid Hemorrhage: A Meta-Analysis.

OBJECTIVE: This meta-analysis assessed the impact of off-hour hospitalization (weekends, and evenings or nighttime on weekdays) on mortality and morbidity in patients with nontraumatic subarachnoid hemorrhage (SAH). METHODS: Electronic databases were systematically searched for studies comparing outcomes between patients with nontraumatic SAH hospitalized during off-hour and on-hour periods (daytime on weekdays). The primary outcome was mortality (in-hospital and at different follow-up periods after hospitalization). Secondary outcomes included delays in treatment, and complications. Sensitivity analysis including only studies in which adjusted multivariate analyses were performed for any of the outcomes, and meta-regression controlling for clinically important patient factors, were also performed. RESULTS: Sixteen studies were included. There was no significant difference in in-hospital mortality (adjusted odds ratio, 1.03; 95% confidence interval [CI], 0.97-1.09; P = 0.30) and at all follow-up periods (7/14 days and 1/3/6 months) after hospitalization between SAH patients who were admitted during off-hour compared with on-hour periods, despite adjusted multivariate meta-analysis being performed. However, patients who were admitted during off-hour periods experienced greater delays from their initial scan to treatment (mean difference, 42.7, 25.2-60.1 hours; P < 0.0001) and had higher rates of pneumonia (odds ratio, 1.65, 1.12-2.44; P = 0.011). CONCLUSIONS: This meta-analysis has not shown an increased risk of mortality in the short-term and long-term among patients with nontraumatic SAH who were hospitalized during off-hour compared with on-hour periods, despite adjusting for potentially confounding patient factors. The delays to treatment and higher observed rates of pneumonia highlight areas in which hospital services and resources should be targeted during these off-hour periods in patients presenting with nontraumatic SAH.

Can ECIS Biosensor Technology Be Used to Measure the Cellular Responses of Glioblastoma Stem Cells?

Glioblastoma is considered the most aggressive and lethal form of brain cancer. Glioblastoma tumours are complex, comprising a spectrum of oncogenically transformed cells displaying distinct phenotypes. These can be generated in culture and are called differentiated-glioblastoma cells and glioblastoma stem cells. These cells are phenotypically and functionally distinct, where the stem-like glioblastoma cells give rise to and perpetuate the tumour. Electric cell-substrate impedance sensing (ECIS) is a real-time, label-free, impedance-based method for the analysis of cellular behaviour, based on cellular adhesion. Therefore, we asked the question of whether ECIS was suitable for, and capable of measuring the adhesion of glioblastoma cells. The goal was to identify whether ECIS was capable of measuring glioblastoma cell adhesion, with a particular focus on the glioblastoma stem cells. We reveal that ECIS reliably measures adhesion of the differentiated glioblastoma cells on various array types. We also demonstrate the ability of ECIS to measure the migratory behaviour of differentiated glioblastoma cells onto ECIS electrodes post-ablation. Although the glioblastoma stem cells are adherent, ECIS is substantially less capable at reliably measuring their adhesion, compared with the differentiated counterparts. This means that ECIS has applicability for some glioblastoma cultures but much less utility for weakly adherent stem cell counterparts.

Serum Adiponectin in Alzheimer's Disease (AD): Association with AD Biomarkers and Cognitive Outcome.

BACKGROUND: The association between dementia and serum adiponectin has been evaluated in many studies; however, conclusions remain mixed. OBJECTIVE: We investigated the cross-sectional associations of adiponectin with cognitive function and Alzheimer's disease (AD) biomarkers and whether serum adiponectin levels can predict cognitive outcomes. METHODS: This study included 496 participants from the Alzheimer's Disease Neuroimaging Initiative 1 (ADNI1) with available serum adiponectin levels at baseline and ≥65 years of age. Subjects were stratified based on sex and apolipoprotein ɛ4 (APOE4) carrier status to determine associations between adiponectin and cognitive function. The linear mixed model was used to analyze associations between adiponectin level and cognitive outcome in amnestic mild cognitive impairment (aMCI) patients. RESULTS: Serum adiponectin levels were higher in aMCI and AD than in CN subjects among APOE4 non-carrier males (adiponectin in CN, aMCI, and AD: 0.54±0.24, 0.74±0.25, and 0.85±0.25, respectively, p < 0.001). In this group, serum adiponectin levels were associated with age (p = 0.001), ADAS13 (p < 0.001), memory function (p < 0.001), executive function (p < 0.001), total tau (p < 0.001), and phosphorylated tau (p < 0.001) measures in cerebrospinal fluid (CSF). Higher adiponectin level was not associated with cognitive outcome in aMCI patients in the linear mixed model analysis over 5.3±2.6 years of mean follow-up. CONCLUSION: Serum adiponectin level was associated with cognitive function and CSF AD biomarkers among APOE4 non-carrier males. However, serum adiponectin level was not associated with longitudinal cognitive function outcome in aMCI.

Effect of white matter hyperintensity on dopamine transporter availability of striatum measured by F-18 FP-CIT PET.

PURPOSE: We aimed to evaluate the white matter hyperintensity (WMH) effect on dopamine transporter availability (DAT) of striatum. MATERIALS AND METHODS: A total of 48 patients who showed visually normal F-18 FP-CIT uptake were included in this study. Each FP-CIT image were pre-processed using SPM12. Co-registration and spatial normalization of FP-CIT image conducted using T1-weighted magnetic resonance imaging (MRI). And then smoothing of normalized FP-CIT image was performed. Intensity normalization was performed using cerebellum as a reference region. With pre-defined volume of interest template, the specific binding ratio (SBR) of both side of caudate nucleus and putamen was calculated. Fluid attenuated inversion recovery MRI scans were used to evaluate WMH number and volume. RESULTS: SBRs of left and right caudate nucleus were correlated with age (r = - 0.615; p < 0.0001; n = 48, r = - 0.607; p < 0.0001; n = 48, respectively), high density lipoprotein cholesterol (r = 0.296; p = 0.041; n = 48, r = 0.29; p = 0.0455; n = 48, respectively), and WMH number (r = - 0.459; p = 0.001; n = 48, r = - 0.481; p = 0.0005; n = 48, respectively) and volume (r = - 0.407; p = 0.0041; n = 48, r = - 0.428; p = 0.0024; n = 48, respectively). CONCLUSION: DAT availability of patients who showed visually normal F-18 FP-CIT uptake was correlated with number and volume of WMH.

Differentiation of bone metastases from prostate cancer and benign red marrow depositions of the pelvic bone with multiparametric MRI.

PURPOSE: To investigate the diagnostic utilities of imaging parameters derived from T1-weighted imaging (T1WI), diffusion-weighted imaging (DWI) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to differentiate bone metastases from prostate cancer and benign red marrow depositions of the pelvic bone. MATERIALS AND METHODS: Thirty-six lesions from 36 patients with prostate cancer were analyzed with T1WI, DWI, and DCE-MRI. The lesions were classified in the bone metastases (n = 22) and benign red marrow depositions (n = 14). Lesion-muscle ratio (LMR), apparent diffusion coefficient (ADC), volume transfer constant (Ktrans), reflux rate (Kep), and volume fraction of the extravascular extracellular matrix (Ve) values were obtained from the lesions. The imaging parameters of the both groups were compared using the Mann-Whitney U test, receiver operating characteristics (ROC) curves were analyzed. For the ROC curves, area under the curves (AUCs) were compared. RESULTS: The ADC, Ktrans, Kep, and Ve values of bone metastases were significantly higher than those of benign red marrow depositions (Mann-Whitney U test, p < 0.05). However, there was no significant difference in LMR between the two groups (Mann-Whitney U test, p = 0.360). The AUCs of Ktrans, Kep, ADC, Ve, and LMR were 0.896, 0.844, 0.812, 0.724, and 0.448, respectively. In the pairwise comparison of ROC curves, the AUCs of Ktrans and Kep was significantly higher than LMR. CONCLUSIONS: Ktrans, Kep, Ve, and ADC values can be used as imaging tools to differentiate bone metastases from prostate cancer and benign red marrow depositions of the pelvic bone.

An easy method for the evaluation of visual tumor heterogeneity of 18F-FDG PET/CT using 10-step color scale: A correlative study in patients with lung cancer.

OBJECTIVE: The purpose of this study was to assess the correlation between visual assessment by the peritumoral halo layer (PHL) method and analysis with texture and intensity histogram metrics for evaluating tumor heterogeneity (TH) in fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) of patients with lung cancer. SUBJECTS AND METHODS: We retrospectively reviewed the 64 patients with records of 18F-FDG PET/CT prior to treatment. After tumor segmentation by the PHL method, three visual patterns: the existence of cold defect, the location of hottest core, and number of irregular layers can be obtained on 18F-FDG PET/CT images. To examine the correlation, first-order entropy was extracted by texture analysis and the area under curve-cumulative SUV-volume histogram (AUC-CSH) value was used in the intensity histogram analysis. A correlation between the visual assessment and the parameters of the metrics analysis was evaluated. We also evaluated the inter-correlation among the visual assessment and correlation between metabolic tumor volume (MTV) and parameters of TH. RESULTS: A significant correlation was noted between visual assessment and quantitative indices of texture and intensity histogram analysis with high inter-observer agreement. Additionally, a significant inter-correlation between the existence of cold defect, location of hottest core, and the number of irregular layers was observed. Metabolic tumor volume was correlated with all of the parameters in the 18F-FDG PET/CT images, such as AUC-CSH, entropy, existence of cold defect, location of hottest core, and number of irregular layers. CONCLUSION: In this study, we provide a new visual assessment criterion of TH with a strong inter-observer agreement. The visual analysis using the PHL method could be a potential marker for evaluating heterogeneous tumors.

Usefulness of 18F-FDG PET/CT and Multiphase CT in the Differential Diagnosis of Hepatocellular Carcinoma and Combined Hepatocellular Carcinoma-Cholangiocarcinoma.

Purpose: The purpose of this study was to evaluate the usefulness of multiphasic CT and 18F-fluorodeoxyglucose (FDG) PET/CT for the differentiation of combined hepatocellular carcinomacholangiocarcinoma (cHCC-CCA) from hepatocellular carcinoma (HCC). Materials and Methods: From January 2007 to April 2016, 93 patients with pathologically confirmed HCC (n = 84) or cHCC-CCA (n = 9) underwent CT and PET/CT imaging. Contrast enhancement patterns were divided into three types based on the attenuation of the surrounding liver parenchyma: type I (early arterial enhancement with delayed washout), type II (early arterial enhancement without delayed washout), and type III (early hypovascular, infiltrative appearance, or peripheral rim enhancement). Results: cHCC-CCAs (89%) had a higher PET/CT positive rate than did HCCs (61%), but the PET/CT positive rate did not differ significantly (p = 0.095). Among the 19 cases of the type II enhancement pattern, 3 (21%) of 14 HCCs and 4 (80%) of 5 cHCC-CCAs were PET/CT positive. cHCC-CCAs had a significantly higher PET/CT positive rate (p = 0.020) in the type II enhancement pattern. Conclusion: The PET/CT positive rate of cHCC-CCA was significantly higher than that of HCC in lesions with a type II enhancement pattern. The 18F-FDG PET/CT can be useful for the differentiation of cHCC-CCA from HCC in lesions with a type II enhancement pattern on multiphasic CT.

Quantitative Brain Amyloid Measures Predict Time-to-Progression from Amnestic Mild Cognitive Impairment to Alzheimer's Disease.

BACKGROUND: This study was designed to investigate factors that predict progression from amnestic mild cognitive impairment (aMCI) to probable Alzheimer's disease (AD). OBJECTIVE: We studied the usefulness of quantitative assessment of amyloid burden measured by Florbetapir PET scan. METHODS: The study cohort consisted of aMCI participants older than 65 and those with available Florbetapir PET scan at diagnosis from the ADNI database (http://adni.loni.usc.edu). To assess the prognostic impact of amyloid burden, a staging system based on the global SUVr of the PET scan was applied. We defined the stages as: stage I, negative amyloid scan; stage II, positive amyloid in 1st tertile; stage III, positive amyloid in 2nd tertile; and stage IV, positive amyloid in 3rd tertile. RESULTS: Of 250 eligible aMCI subjects (age 74.1±5.4, female n = 105), 71 (28.4%) were diagnosed with probable AD within 3 years. Higher amyloid stages showed faster cognitive decline by Kaplan-Meier analysis. In multivariate Cox analysis, with stage I as a reference, the hazard ratio (HR) increased as the stage increased: stage II (HR, 4.509; p = 0.015), stage III (HR, 7.616; p = 0.001), and stage IV (HR, 9.421; p < 0.001). Along with amyloid stage, ApoE ɛ4 (HR, 1.943; p = 0.031), score of CDR-SB (HR, 1.845; p < 0.001) and ADAS 11 (HR, 1.144; p < 0.001), and hippocampal volume (HR, 0.002; p = 0.005) were also identified as predictors of dementia progression in aMCI subjects. CONCLUSIONS: Large amyloid burden measured from amyloid PET scan could be a predictor of faster cognitive decline in aMCI patients.

Prediction of future weight change with dopamine transporter in patients with Parkinson's disease.

Fluctuating body weight is a commonly reported nonmotor feature in patients with Parkinson's disease (PD). We hypothesised that striatal dopamine transporter (DAT) density at the time of diagnosis might play an important role in weight regulation in patients with PD. DAT density was measured from 123I-FP-CIT single-photon emission computed tomography. Region-of-interest analyses were performed to measure the specific binding of 123I-FP-CIT to DAT, and the putamen-to-caudate nucleus ratio (PCR) was calculated. Body weight was measured at baseline (W0) and at 48 months (W48). We classified subjects into three groups: weight loss, stable, and weight gain. In final analyses, 163 patients (106 men, 57 women) were included. PCR significantly differed by group in men, but not in women or across all patients. In men, PCR was slightly negatively associated with the percentage change in weight. No such correlation was found across all patients or in women. In univariate and multivariate logistic regression analyses, low PCR was associated with future weight gain in men with PD but not in women. In conclusion, striatal DAT availability at the time of diagnosis could predict subsequent weight change in men with PD.

Single cell-derived clonally expanded mesenchymal progenitor cells from somatic cell nuclear transfer-derived pluripotent stem cells ameliorate the endometrial function in the uterus of a murine model with Asherman's syndrome.

OBJECTIVES: Because primary mesenchymal progenitor cells (adult-MPCs) have various functions that depend on the tissue origin and donor, de novo MPCs from human pluripotent stem cells (hPSCs) would be required in regenerative medicine. However, the characteristics and function of MPCs derived from reprogrammed hPSCs have not been well studied. Thus, we show that functional MPCs can be successfully established from a single cell-derived clonal expansion following MPC derivation from somatic cell nuclear transfer-derived (SCNT)-hPSCs, and these cells can serve as therapeutic contributors in an animal model of Asherman's syndrome (AS). MATERIALS AND METHODS: We developed single cell-derived clonal expansion following MPC derivation from SCNT-hPSCs to offer a pure population and a higher biological activity. Additionally, we investigated the therapeutic effects of SCNT-hPSC-MPCs in model mice of Asherman's syndrome (AS), which is characterized by synechiae or fibrosis with endometrial injury. RESULTS: Their humoral effects in proliferating host cells encouraged angiogenesis and decreased pro-inflammatory factors via a host-dependent mechanism, resulting in reduction in AS. We also addressed that cellular activities such as the cell proliferation and population doubling of SCNT-hPSC-MPCs resemble those of human embryonic stem cell-derived MPCs (hESC-MPCs) and are much higher than those of adult-MPCs. CONCLUSIONS: Somatic cell nuclear transfer-derived-hPSCs-MPCs could be an advanced therapeutic strategy for specific diseases in the field of regenerative medicine.

Accurate FDG PET tumor segmentation using the peritumoral halo layer method: a study in patients with esophageal squamous cell carcinoma.

BACKGROUND: In a previous study, FDG PET tumor segmentation (SegPHL) using the peritumoral halo layer (PHL) was more reliable than fixed threshold methods in patients with thyroid cancer. We performed this study to validate the reliability and accuracy of the PHL method in patients with esophageal squamous cell carcinomas (ESCCs), which can be larger and more heterogeneous than thyroid cancers. METHODS: A total of 121 ESCC patients (FDG avid = 85 (70.2%); FDG non-avid = 36 (29.8%)) were enrolled in this study. In FDG avid ESCCs, metabolic tumor length (ML) using SegPHL (MLPHL), fixed SUV 2.5 threshold (ML2.5), and fixed 40% of maximum SUV (SUVmax) (ML40%) were measured. Regression and Bland-Altman analyses were performed to evaluate associations between ML, endoscopic tumor length (EL), and pathologic tumor length (PL). A comparison test was performed to evaluate the absolute difference between ML and PL. Correlation with tumor threshold determined by the PHL method (PHL tumor threshold) and SUVmax was evaluated. RESULTS: MLPHL, ML2.5, and ML40% correlated well with EL (R2 = 0.6464, 0.5789, 0.3321, respectively; p < 0.001) and PL (R2 = 0.8778, 0.8365, 0.6266, respectively; p < 0.001). However, ML2.5 and ML40% showed significant proportional error with regard to PL; there was no significant error between MLPHL and PL. MLPHL showed the smallest standard deviation on Bland-Altman analyses. The absolute differences between ML and PL were significantly smaller for MLPHL and ML40% than for ML2.5 (p < 0.0001). The PHL tumor threshold showed an inverse correlation with SUVmax (σ = - 0.923, p < 0.0001). CONCLUSIONS: SegPHL was more accurate than fixed threshold methods in ESCC. The PHL tumor threshold was adjusted according to SUVmax of ESCC.

More accurate than MRI measurement of tumor size in breast cancer by using the peri-tumoral halo uptake layer method of the 18F-FDG PET/CT scan.

OBJECTIVE: To evaluate the reliability of a method using the peri-tumoral halo layer (PHL) for assessing tumor size in breast cancer patients on the fluorine-18-fluorodeoxy glucose positron emission tomography/computed tomography (18F-FDG PET/CT) scan compared to MRI and pathology. SUBJECTS AND METHODS: Among 121 patients with breast cancer who underwent both 18F-FDG PET/CT and MRI between March 2013 and June 2016, 59 patients were included in this study. Exclusion criteria were as follows: history of neoadjuvant therapy, history of pre-operative mammotome, insufficient pathologic/radiologic size report, clustered tumor, positive tumor resection margin, 18F-FDG non-avid tumor. The PHL was examined by two nuclear medicine physicians. Tumor sizes (longest diameters) on 18F-FDG PET/CT were estimated using margins defined as the inner line of the PHL. Pathologic tumor sizes were utilized as reference standards. RESULTS: The PHL of each tumor was most commonly designated as the 20%-30% band of the maximum standardized uptake value (SUVmax) it exhibited an inverse correlation with tumor SUVmax. Tumor size on 18F-FDG PET/CT showed a more linear correlation with pathology than that on MRI (r2=0.91 vs 0.65). In Bland-Altman analysis, 18F-FDG PET/CT showed significantly lower bias in size difference relative to pathology, compared with MRI (0.6±9.6cm vs. -1.9±17.3cm). Fluorine-18-FDG PET/CT showed more accurate T staging with pathology, especially in T3 cases, than MRI. CONCLUSION: A method of tumor size determination, using PHL on 18F-FDG PET/CT, showed more linear relationship and smaller size differences with pathology than MRI (average 0.6 vs. 1.9cm). It provides sufficient reliability and reproducibility for measuring tumor size in breast cancer.