Jang Yoo

Prognostic significance of volume-based metabolic parameters in uterine cervical cancer determined using 18F-fluorodeoxyglucose positron emission tomography.

ObjectiveWe compared the prognostic value of volume-based metabolic parameters determined using fluorine 18 (18F) fluorodeoxyglucose (FDG) positron emission tomography (PET) (18F-FDG PET) (with other prognostic parameters in uterine cervical cancer. MethodsThe subjects were 73 female patients who had an initial diagnosis of uterine cervical cancer and who underwent 18F-FDG PET. Various metabolic or volume-based PET parameters including maximum and average standardized uptake values, metabolic tumor volume, and total lesion glycolysis (TLG) were measured in primary cervical tumors. Survival analysis for disease-free survival or progression-free survival was performed with a Kaplan-Meier method using PET parameters and other clinical variables. For determining independent prognostic factors, Cox regression analysis was performed. ResultsRecurrence or disease progression occurred in 23 patients (31.5%). In univariate analysis, patient age (cutoff, 57 years, P < 0.05), International Federation of Gynecology and Obstetrics stage (P = 0.07), primary tumor size (cutoff, 6.7 cm; P < 0.05), lymph node status on PET (P < 0.005), treatment method (P < 0.01), metabolic tumor volume (cutoff, 82 cm3; P = 0.001), and TLG (cutoff, 7600; P = 0.005) were significant predictors of recurrence or progression. In multivariate analysis, both lymph node status on PET (hazard ratio, 1.042 [negative vs intrapelvic metastasis only], 7.008 [negative vs extrapelvic metastasis]; P < 0.001) and TLG (cutoff, 7600; hazard ratio, 2.981; P < 0.05) were independent prognostic factors for predicting recurrence. ConclusionsIn uterine cervical cancer, TLG, a volume-based metabolic parameter, and lymph node status on PET may be significant independent prognostic factors for event-free survival.Objective We compared the prognostic value of volume-based metabolic parameters determined using fluorine 18 (18F) fluorodeoxyglucose (FDG) positron emission tomography (PET) (18F-FDG PET) (with other prognostic parameters in uterine cervical cancer. Methods The subjects were 73 female patients who had an initial diagnosis of uterine cervical cancer and who underwent 18F-FDG PET. Various metabolic or volume-based PET parameters including maximum and average standardized uptake values, metabolic tumor volume, and total lesion glycolysis (TLG) were measured in primary cervical tumors. Survival analysis for disease-free survival or progression-free survival was performed with a Kaplan-Meier method using PET parameters and other clinical variables. For determining independent prognostic factors, Cox regression analysis was performed. Results Recurrence or disease progression occurred in 23 patients (31.5%). In univariate analysis, patient age (cutoff, 57 years, P < 0.05), International Federation of Gynecology and Obstetrics stage (P = 0.07), primary tumor size (cutoff, 6.7 cm; P < 0.05), lymph node status on PET (P < 0.005), treatment method (P < 0.01), metabolic tumor volume (cutoff, 82 cm3; P = 0.001), and TLG (cutoff, 7600; P = 0.005) were significant predictors of recurrence or progression. In multivariate analysis, both lymph node status on PET (hazard ratio, 1.042 [negative vs intrapelvic metastasis only], 7.008 [negative vs extrapelvic metastasis]; P < 0.001) and TLG (cutoff, 7600; hazard ratio, 2.981; P < 0.05) were independent prognostic factors for predicting recurrence. Conclusions In uterine cervical cancer, TLG, a volume-based metabolic parameter, and lymph node status on PET may be significant independent prognostic factors for event-free survival.

Prognostic value of volumetric metabolic parameters measured by [18F]Fluorodeoxyglucose-positron emission tomography/computed tomography in patients with small cell lung cancer

BackgroundWe evaluated the prognostic value of volume-based metabolic positron emission tomography (PET) parameters in patients with small cell lung cancer (SCLC) compared with other factors.MethodsThe subjects were 202 patients with pathologically proven SCLC who underwent pretreatment 18F-fluorodeoxyglucose (FDG) PET/computed tomography (CT). Volumetric metabolic parameters of intrathoracic malignant hypermetabolic lesions, including maximum and average standardized uptake value, sum of metabolic tumor volume (MTV), and sum of total lesion glycolysis (TLG) were measured.Results164 patients had died during follow-up (median 17.4 months) and median overall survival was 14 months. On univariate survival analysis, age, stage, treatment modality, sum of MTV (cutoff = 100 cm3), and sum of TLG (cutoff = 555) were significant predictors of survival. There was a very high correlation between the sum of MTV and the sum of TLG (r = 0.963, P < 0.001). On multivariate survival analysis, age (HR = 1.04, P < 0.001), stage (HR = 2.442, P < 0.001), and sum of MTV (HR = 1.662, P = 0.002) were independent prognostic factors. On subgroup analysis based on limited disease (LD) and extensive disease (ED), sum of MTV and sum of TLG were significant prognostic factors only in LD.ConclusionBoth sum of MTV and sum of TLG of intrathoracic malignant hypermetabolic lesions are important independent prognostic factors for survival in patients with SCLC, in addition to age and clinical stage. However, it may be more useful in limited disease rather than in extensive disease.

The Application of a Low Temperature GaN Buffer Layer to Thick GaN Film Growth on ZnO/Si Substrate

The effect of a low temperature GaN (LT-GaN) buffer layer on the properties of thick GaN grown on Si substrate by hydride vapor phase epitaxy (HVPE) was investigated to obtain thick GaN films of high quality. ZnO was deposited by sputtering as the first buffer layer. LT-GaN buffer layers were grown for 2 to 7 min at 600 °C. The optimization of the LT-GaN buffer layer was done using low temperature PL, AFM and XRD analysis. A Zn-related impurity peak was observed in PL spectra of LT-GaN/ZnO/Si. A strong orientation along (0002) was observed in thick GaN/LT-GaN/ZnO/Si. A red shift in PL spectra of thick GaN due to the strain was found. The LT-GaN buffer improved the crystalline and optical properties of thick GaN grown on Si substrate.

Diagnostic Criteria on 18 F-FDG PET/CT for Differentiating Benign from Malignant Focal Hypermetabolic Lesions of Parotid Gland

PurposeWe investigated PET/CT diagnostic criteria for differentiating benign from malignant parotid lesions with focal 18F-FDG uptake.MethodsThe subjects of the study were 272 patients who exhibited focal 18F-FDG uptake of the parotid gland. Sixty-eight pathologically confirmed parotid lesions from 67 patients were included. The maximum SUV (SUVmax), uptake patterns (homogeneous vs. heterogeneous), size measured by CT, maximum Hounsfield units (HUmax) and margins on CT (well vs. ill defined) of each parotid lesion on PET/CT images were compared with final diagnoses.ResultsThirty-two parotid lesions were histologically proven to be malignant. There were significant differences in uptake patterns (cancer incidence, heterogeneous:homogeneous = 79.2%:29.5%, p < 0.0001) and margins on CT (cancer incidence, ill:well defined = 84.4%:13.3%, p < 0.0001) between benign and malignant lesions. The cancer risks of parotid lesions were 89.5% with heterogeneous uptake and ill-defined margins, 70.6% with heterogeneous uptake or ill-defined margins (no overlap in subjects) and 9.3% with homogeneous uptake and well-defined margins (p < 0.0001). When any lesion with heterogeneous uptake or ill-defined margins was regarded as malignant, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 90.6% (29/32), 80.6% (29/36), 80.6% (29/36), 90.6% (29/32) and 85.6% (58/68), respectively. For predicting malignancy, combined PET/CT criteria showed better sensitivity, NPV and accuracy than PET-only criteria, and had a tendency to have more accurate results than CT-only criteria. There were no significant differences in SUVmax, size or HUmax between benign and malignant lesions.ConclusionUptake patterns and margins on CT are useful PET/CT diagnostic criteria for differentiating benign from malignant lesions.

Effects of coverage extent and slice skipping on mean and maximum arterial 18F-FDG uptake ratios in patients with carotid plaque

PurposeTo investigate the effects of variable measurement methods on mean and maximum SUV ratios of 18F-FDG uptake in carotid arteries.Methods18F-FDG PET/CT images of 74 subjects with carotid plaque were analyzed for mean and maximum target-to-background ratio (TBR) of uptake. Agreement was analyzed between TBR scores obtained using different vessel coverage and slice skipping.ResultsMean TBR was increased by extending coverage from common carotid artery (CCA; 1.25) to carotid artery (CA; 1.33) and inclusion of ascending aorta (CA/AA; 1.34). Maximum TBR was increased from 1.47 to 1.54 and 1.61 by respective extensions. Both mean and maximum TBR were closely correlated between vessels. ICC and Kappa statistics revealed near perfect agreement between TBR obtained using every 2 or 3 segments and that without sipping. Bland–Altman plots showed bias by slice skipping to remain small, particularly for mean TBR. Finally, high correlations were displayed between mean and maximum TBR.ConclusionsAnalysis of mean and maximum arterial 18F-FDG uptake in patients with carotid plaque is likely to benefit from extending coverage to segments above and below the CCA. The extra burden of measurement, in turn, can be lightened by skipping up to every 2 of 3 slices without compromising accuracy of results.

Etch characteristics of optical waveguides using inductively coupled plasmas with multidipole magnets

In this study, silica glass etch characteristics of inductively coupled plasmas with and without the multidipole magnets were investigated using CF4 and SF6 as the etch gases. A Langmuir probe and optical emission spectroscopy were used to investigate the characteristics of the plasmas. When the silica glass was etched with the multidipole magnets, a significant increase in etch rate was obtained with the magnets for both CF4 and SF6 together with an increase in ion saturation current as measured by the Langmuir probe. F radicals estimated by Ar actinometry also increased with the addition of the magnets. When the etch characteristics of CF4 and SF6 with magnets were compared at the same etch conditions, SF6 showed the higher etch rates (>800 nm/min) while CF4 showed the higher etch selectivity (>70:1) over the Cr mask material used in the study. With the magnets, a vertical etch profile was obtained with CF4 while the etch profile with SF6 was a little re-entrant. A 10 μm deep anisotropic silica glass et...

Percentage change of primary tumor on 18F-FDG PET/CT as a prognostic factor for invasive ductal breast cancer with axillary lymph node metastasis: Comparison with MRI.

Abstract We evaluated the prognostic value of quantitative parameters using dual time point (DTP) 18F-FDG PET/CT (PET/CT) in invasive ductal breast cancer (IDC) with metastatic axillary lymph nodes (ALN) as compared with dynamic contrast-enhanced (DCE) and diffusion-weighted (DW) MRI. Seventy patients with IDC and metastatic ALN were retrospectively registered. Static PET parameters including maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), total lesion glycolysis (TLG) of primary tumor, SUVmax of ALN (SUVALN), and percentage changes (&Dgr;%) in those parameters were measured with DTP PET/CT. From DCE MRI, peak enhancement value, total tumor angio volume, and proportions of kinetic curve types on delayed-phases were investigated. The average apparent diffusion coefficient (ADCavg) was estimated on DWI. To demonstrate the prognostic value of quantitative imaging parameters for recurrence-free survival (RFS), univariate and multivariate analyses were performed using those parameters and clinicohistologic variables. All static PET parameters, %&Dgr;SUVmax, %&Dgr;MTV, and %&Dgr;SUVALN on DTP PET/CT and ADCavg on DWI were significantly predictive for disease recurrence. Of clinicohistologic variables, pathologic tumor (pT) diameter, pathologic ALN stage, tumor grade, and hormonal status also were significantly prognostic. After multivariate analysis, %&Dgr;SUVmax > 25.05 (P = .043), ADCavg ⩽ 1016.55 (P = .020), pT diameter > 3 cm (P = .001), and ER negative status (P = .002) were independent prognostic factors for poor outcome. Only %&Dgr;SUVmax of the primary tumor on PET/CT together with ADCavg, pT diameter, and ER status was an independent prognostic factor for predicting relapse in IDC with metastatic ALN. Percentage change of primary tumor on preoperative PET/CT may be a valuable imaging marker for selecting IDC patients that require adjunct treatment to prevent relapse.

Glucose metabolism of visceral adipose tissue measured by 18f-fdg Pet/ct is related to the presence of colonic adenoma

Abstract This study investigated the relationships between the area and metabolic activity of adipose tissue and the presence of colorectal adenoma (CRA). Our institutional review board approved the study and waived informed consent. A total of 212 subjects who underwent fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) and colonoscopy for routine health check-ups were enrolled. The volumetric parameters of areas of visceral (VATav), subcutaneous (SATav), and total adipose tissue (TATav) and calculated visceral-to-subcutaneous adipose tissue ratio (VSR) and visceral-to-total adipose tissue ratio (VAR) were considered. Metabolic parameters of standardized uptake value (SUV) of visceral (vcSUVmax, vcSUVmean), subcutaneous (scSUVmax, scSUVmean), and calculated visceral-to-subcutaneous adipose tissue ratio (VSRmax, VSRmean) were considered. Anthropometric data of height, weight, body mass index (BMI), waist circumference (WC), body fat mass (BFM), skeletal muscle mass (SMM), and diverse laboratory data were also considered as variables. Sixty-six subjects were placed in the CRA group and 146 subjects in the non-CRA group. The presence of CRA was significantly correlated with older age (P  =  .001), male sex (P  =  .041), higher BMI (P  =  .004), higher WC (P  =  .001), higher BFM (P  =  .024), higher VATav (P < .001), higher TATav (P  =  .004), higher VSR (P < .001), higher VAR (P < .001), lower vcSUVmax (P  =  .002), lower vcSUVmean (P < .001), and lower VSRmean (P  =  .002). On multiple regression analysis, vcSUVmax and vcSUVmean were independently associated with the presence of CRA (P  =  .009 and P  =  .045). Lower glucose metabolism of visceral adipose tissue was related to the presence of CRA. Our findings identify the value of visceral metabolic dysfunction as a potential surrogate marker of elevated risk for CRA.

Differential findings of tc-99m sestamibi dual-phase parathyroid scintigraphy between benign and malignant parathyroid lesions in patients with primary hyperparathyroidism.

PurposeThis study aimed to investigate the differential findings in clinical and biochemical features, and Tc-99m sestamibi (MIBI) dual-phase parathyroid scintigraphy for malignant and benign parathyroid lesions in patients with primary hyperparathyroidism.MethodsSubjects were 102 parathyroid lesions from 91 patients with primary hyperparathyroidism. Scintigraphic findings included radioactivity grade, uptake pattern, uptake contour, lesion size on early and delayed images, and degree of washout. Clinical and biochemical features were also evaluated. Histopathology confirmed the final diagnosis for all the patients.ResultsFinal diagnoses were 94 benign parathyroid lesions and 8 parathyroid carcinomas. The patients with parathyroid carcinoma were significantly older (p = 0.002) and had significantly higher serum parathyroid hormone concentrations than those with benign parathyroid lesions (p < 0.001). All malignant parathyroid lesions showed intense radioactivity similar to or greater than the submandibular gland activity on delayed images (p = 0.007), and little radioactivity difference between early and delayed images (p = 0.012). The cancer incidence for parathyroid lesions with both intense radioactivity and no washout was 17.0% (8/47). When parathyroid lesions with all of the above-mentioned findings were regarded as malignant, the cancer incidence significantly increased from 17.0% to 33.3% (8/24, p < 0.001).ConclusionFor Tc-99m MIBI dual-phase parathyroid scintigraphy, uptake grade on delayed images and washout were significantly useful diagnostic criteria for differentiating benign from malignant parathyroid lesions, along with age and parathyroid hormone serum concentration.

Prognostic value of diffuse splenic FDG uptake on PET/CT in patients with gastric cancer

Background This study investigated the prognostic value of diffuse splenic uptake on F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) in gastric cancer (GC) patients. Methods A total of 134 pathology confirmed GC patients who underwent PET/CT for staging work-ups were enrolled. The maximal standardized uptake value (SUVmax) of primary tumor (Tmax), spleen (Smax), and spleen to liver uptake ratio (SLR) were measured. The prognostic value of PET-measured parameters in GC patients for predicting recurrence-free survival (RFS) and overall survival (OS) were assessed. And the relationships of the parameters with hematological and inflammatory parameters were also investigated. Results During follow-up period, 19 patients (14.1%) had disease recurrence and 12 (8.9%) died from GC. In univariate analysis, hematocrit (p<0.001 and p = 0.002), neutrophil to lymphocyte ratio (NLR; p = 0.021 and p = 0.040), AJCC staging (p<0.001 and p<0.001), adjuvant chemotherapy (p<0.001 and p<0.001), Tmax (p = 0.004 and p = 0.005), and SLR (p = 0.005 and p = 0.016) were significant prognostic factors for RFS and OS, whereas platelet to lymphocyte ratio (PLR; p = 0.034) was a significant prognostic factor for RFS. In multivariate analysis, only SLR was an independent prognostic factor for RFS (p = 0.018, adjusted HR = 3.011, 95% CI = 1.207–7.511). SLR were significantly associated with serum hematocrit level (r = -0.256, p = 0.002), PLR (r = 0.362, p = 0.001), and Tmax (r = 0.280, p = 0.001). Conclusion Diffuse splenic uptake on FDG PET/CT was correlated with the level of hematological and inflammatory parameters and was an independent predictor for RFS in GC.