Samuel Chang

Limited Prognostic Value of SUV max 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 (SUVmax) 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 SUVmax 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 SUVmax groups. Conclusion: This study does not support the use of SUVmax of pretreatment F-18 FDG PET/CT scans as a prognostic tool for patients with SCLC.

Determination of regional lymph node status using (18)F-FDG PET/CT parameters in oesophageal cancer patients: comparison of SUV, volumetric parameters and intratumoral heterogeneity.

OBJECTIVE We aimed to investigate whether the standardized uptake values, volumetric parameters and intratumoral heterogeneity of fluorine-18-fludeoxyglucose ((18)F-FDG) uptake could predict regional lymph node (rLN) metastasis in oesophageal cancer. METHODS 51 patients with surgically resected oesophageal cancer were included in the present study. The (18)F-FDG positron emission tomography (PET)/CT findings and rLN metastasis were compared with the histopathological results. The intratumoral metabolic heterogeneity was represented by the heterogeneity factor (HF), which was determined for each patient. Univariate and multivariate analyses were used to analyse the associations between the rLN metastasis and clinical findings, standardized uptake values, metabolic tumour volume (MTV), total lesion glycolysis (TLG) and HF. RESULTS The rLN(+) group showed statistically significant higher values of MTV (median, 13.59 vs 6.6; p = 0.0085), TLG (median, 119.18 vs 35.96; p = 0.0072) and HF (median, 3.07 vs 2.384; p = 0.0002) than the rLN(-) group. Univariate analysis showed that maximum standardized uptake value, mean standardized uptake value, MTV, TLG and HF were significantly associated with pathologic rLN involvement. However, in multivariate analysis, the HF was a potent associated factor for the prediction of pathologic rLN metastasis in oesophageal cancer. CONCLUSION In conclusion, (18)F-FDG PET/CT parameters such as maximum standardized uptake value, mean standardized uptake value, MTV, TLG and HF were useful for the prediction of pathologic rLN status in patients with oesophageal cancer. However, HF might be the most powerful predictor of rLN metastasis of patients with oesophageal cancer. ADVANCES IN KNOWLEDGE Assessment of intratumoral heterogeneity of (18)F-FDG PET/CT may be a useful adjunct for rLN staging of oesophageal cancer.

Obesity and Diabetes: Newer Concepts in Imaging

Quantifying body fat is currently an area of active research. Recent studies have shown that the quantity and location of fat in different compartments have varying clinical significance. This information can now be obtained from computed tomography (CT) or magnetic resonance (MR), and it can inform clinical decision making for patient management. Diabetes patients with insulin resistance and hyperinsulinemia have nonalcoholic fatty liver disease (NAFLD) ranging from steatosis to nonalcoholic steatohepatitis (NASH) and cirrhosis, typically diagnosed by liver biopsy or serum markers. There is now an emerging role of noninvasive imaging tests such as MR imaging or MR spectroscopy or elastography, which can provide quantitative information and have potential to avoid biopsy. Obese patients with diabetes are also at risk for cardiovascular disease and cancer. There is an emerging role for imaging in early detection of not only structural but also functional abnormalities of myocardium at a subclinical stage. Screening for cancer is currently recommended only for breast, colon, prostate, and cervix. Given wider availability and advances in imaging techniques such as positron emission tomography/CT (faster scans with higher resolution and less ionizing radiation) and better understanding of molecular biology and risk-stratification, more and more cancers are being detected in early stages with better clinical outcomes. Concerns related to cost, overdiagnosis, and unnecessary interventions must be addressed before population-based screening for other cancers is recommended. Based on ongoing imaging research, it is expected that it will be possible to provide more precise measurement of body fat and detect cardiovascular disease and cancers earlier in their course.

Initial Experience of 18F-FDG PET/MRI in Thymic Epithelial Tumors: Morphologic, Functional, and Metabolic Biomarkers.

Purpose The aim of this study was to investigate the value of morphologic, functional, and metabolic biomarkers acquired concurrently at PET/MRI in patients with thymic epithelial tumors. Patients and Methods During 1 year, 9 patients with suspected thymic epithelial tumors at contrast-enhanced chest CT were prospectively enrolled and underwent preoperative 18F-FDG PET/MRI. Two chest radiologists prospectively reviewed the CT and MRI scans of PET/MRI in consensus, and 2 nuclear physicians reviewed the PET images. Visual assessment of the tumor morphology, functional biomarkers such as apparent diffusion coefficient from diffusion-weighted images, and metabolic biomarkers (including SUVmax, metabolic tumor volume, total lesion glycolysis, and heterogeneity index) were recorded. All patients underwent operation, and their pathologic reports served as the reference standard. Results Thymic epithelial tumors were demonstrated in all 9 patients at pathologic examination. Tumor contour (P = 0.012) and shape (P = 0.033) had an association with the World Health Organization subtype, and the presence of septum (P = 0.048) on MRI scans had an association with the Masaoka stage. In terms of functional and metabolic biomarkers, SUVmax (&rgr; = 0.683, P = 0.042) and SUV/apparent diffusion coefficient (&rgr; = 0.703, P = 0.035) correlated with the Masaoka stage. Metabolic tumor volume (P = 0.024), heterogeneity index (P = 0.024), and total lesion glycolysis (P = 0.048) were useful for classification between low- and high-risk thymic epithelial tumors. Conclusions Although limited by the small number of patients enrolled, morphologic, functional, and metabolic biomarkers derived from PET/MRI scans were useful for the stratification of thymic epithelial tumors.

Volumetric parameters changes of sequential 18F-FDG PET/CT for early prediction of recurrence and death in patients with locally advanced rectal cancer treated with preoperative chemoradiotherapy.

&NA; The goal of the present study was to determine whether volumetric parameters such as metabolic tumor volume (MTV) and total lesion glycolysis (TLG) measured by sequential 18F-FDG PET/CT imaging could be used as prognostic factors in patients with locally advanced rectal cancer (LARC) who received preoperative concurrent chemoradiotherapy. Methods A total 64 patients with LARC patients were included in the current study. All patients were evaluated by 18F-FDG PET/CT before and after 45 Gy of radiotherapy with concurrent oral capecitabine chemotherapy. Initial, second, and the percent changes ([INCREMENT], %) of semiquantitative and volumetric parameters were used to calculate recurrence-free survival (RFS) and overall survival (OS). The cutoff values of semiquantitative and volumetric parameters were determined by receiver operating characteristic curve analysis. The prognostic significance was assessed using univariate and multivariate Cox proportional hazard regression analysis. Results For RFS, American Joint Committee on Cancer (AJCC) stage (&khgr;2 = 10.7, P = 0.002), surgical margin (+) (&khgr;2 = 3.39, P = 0.037), lymphatic invasion (+) (&khgr;2 = 6.8, P = 0.0078), RECIST (Response Evaluation Criteria in Solid Tumors) (&khgr;2 = 46.3, P < 0.0001), SUVmax1 (&khgr;2 = 10.1, P = 0.025), &Dgr;SUVmax (&khgr;2 = 20.4, P < 0.0001), &Dgr;SUVmean (&khgr;2 = 28.8, P < 0.0001), MTV1 (&khgr;2 = 24.1, P < 0.0001), &Dgr;MTV (&khgr;2 = 27.4, P < 0.0001), TLG1 (&khgr;2 = 21.9, P < 0.0001), TLG2 (&khgr;2 = 23.3, P < 0.0001), and &Dgr;TLG (&khgr;2 = 55.6, P < 0.0001) are associated prognostic factors. For OS, AJCC stage (&khgr;2 = 6.0, P = 0.021), surgical margin (+) (&khgr;2 = 3.2, P = 0.042), lymphatic invasion (+) (&khgr;2 = 3.8, P = 0.048), RECIST (&khgr;2 = 10.4, P = 0.0015), &Dgr;SUVmax (&khgr;2 = 6.0, P = 0.013), &Dgr;SUVmean (&khgr;2 = 10.5, P = 0.0009), MTV1 (&khgr;2 = 14.5, P = 0.0008), &Dgr;MTV (&khgr;2 = 14.7, P = 0.0002), TLG1 (&khgr;2 = 15.8, P = 0.0002), TLG2 (&khgr;2 = 13.5, P = 0.0006), and &Dgr;TLG (&khgr;2 = 17.5, P < 0.0001) are potent predictors. Multivariate Cox proportional hazard regression analyses revealed that the initial MTV (MTV1) and &Dgr;TLG were the potent predictors for RFS and OS. Conclusions Our data suggest that MTV on initial pretreatment 18F-FDG PET/CT and &Dgr;TLG of sequential 18F-FDG PET/CT after preoperative concurrent chemoradiotherapy in LARC patients could provide prognostic information.

Interim Fluorine-18 Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography to Predict Pathologic Response to Preoperative Chemoradiotherapy and Prognosis in Patients With Locally Advanced Rectal Cancer.

INTRODUCTION The goal of the present study was to investigate the predictive and prognostic values of interim fluorine-18 (18F) fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) parameters for the prediction of a complete pathologic response (pCR) in patients with locally advanced rectal cancer (LARC) who had received preoperative chemoradiotherapy (PCRT). PATIENTS AND METHODS A total 103 patients with LARC were included in the present study. All the patients were evaluated by 18F FDG PET/CT before and after 45 Gy of radiotherapy with concurrent oral capecitabine chemotherapy. The quantitative, volumetric parameters and their percentage of change (Δ%) were used to predict the pCR and calculate the overall survival (OS). The predictive value for a pCR of 18F FDG PET/CT cutoff values were determined by receiver operating characteristic analysis. The prognostic significance was assessed using Kaplan-Meier analysis. RESULTS A pCR occurred in 22 patients (21.4%). Univariate and multivariate analyses demonstrated that the post-PCRT maximum standardized uptake value (SUVmax2) and change in the SUVmax (ΔSUVmax) as significant factors for the prediction of pCR, with a sensitivity of 68.2% and specificity of 87.7% and sensitivity of 90.9% and specificity of 80.3%, respectively. Kaplan-Meier analysis showed that a low SUVmax2 (< 2.5) and high ΔSUVmax (≥ 62.2%) were potent predictors for OS. CONCLUSION The present study has shown the capability of interim 18F FDG PET/CT parameters to predict the achievement of pCR after PCRT in patients with LARC. Of the parameters, SUVmax2 and ΔSUVmax were potent predictors for pCR and well associated with OS.

Changes in Total Lesion Glycolysis Evaluated by Repeated F-18 FDG PET/CT as Prognostic Factor in Locally Advanced Esophageal Cancer Patients Treated with Preoperative Chemoradiotherapy

Aims: The present study was aimed to investigate whether volumetric parameters measured by sequential F-18 fluoro-D-glucose (F-18 FDG) positron emission tomography/computed tomography (PET/CT) could be used as prognostic factors in patients with locally advanced esophageal cancer (LAEC) who received preoperative chemoradiotherapy (CRT). Methods: A total of 61 patients with LAEC were included in the current study. All patients were evaluated by F-18 FDG PET/CT before and after 46 Gy of radiotherapy with a concurrent cisplatin-based chemotherapy. Initial, second, and percent changes (Δ, %) of semiquantitative and volumetric parameters were used to calculate recurrence-free survival (RFS) and overall survival (OS). The median values of each parameter were used as cutoff values. The prognostic significance was assessed using univariate and multivariate Cox proportional hazard regression analyses. Results: Cox proportional hazard regression analyses revealed that change in total lesion glycolysis (ΔTLG) was a potent predictor of RFS and OS. Kaplan-Meier survival curves showed better prognosis in higher ΔTLG. Conclusion: Our data suggest that ΔTLG measured by sequential F-18 FDG PET/CT after preoperative CRT could provide prognostic information in LAEC patients.

Prediction of Recurrence and Mortality of Locally Advanced Esophageal Cancer Patients Using Pretreatment F-18 FDG PET/CT Parameters: Intratumoral Heterogeneity, SUV, and Volumetric Parameters.

OBJECTIVE This study was aimed to define the predictive values of preoperative Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) parameters and compared to define effective parameters for prediction of overall survival (OS) and recurrent free survival (RFS) in locally advanced esophageal cancer (LAEC). MATERIALS AND METHODS This study included 44 patients with LAEC who received F-18 FDG PET/CT. Univariate and multivariate analyses were used to calculate survival, and the survival curves were estimated by clinical factors and F-18 FDG PET/CT-derived parameters. RESULTS Higher values of F-18 FDG PET/CT parameters (SUVmax, SUVmean, metabolic tumor volume [MTV], total lesion glycolysis [TLG]) and advanced tumor-node-metastasis (TNM) staging showed higher mortality. The Cox proportional hazard regression model demonstrated advanced TNM stage and high MTV as poor OS factors. The early TNM stage, lower MTV, lower TLG, lymph node (LN) (-), and lower heterogeneity factor (HF) were also associated with better RFS. The MTV was the potent predictor for RFS. CONCLUSIONS In conclusion, although the newly described parameter of HF measured by F-18 FDG PET/CT could be a prognostic factor, the MTV is the most potent prognostic predictor in LAEC.

The design and fabrication of two portal vein flow phantoms by different methods

PURPOSE This study outlines the design and fabrication techniques for two portal vein flow phantoms. METHODS A materials study was performed as a precursor to this phantom fabrication effort and the desired material properties are restated for continuity. A three-dimensional portal vein pattern was created from the Visual Human database. The portal vein pattern was used to fabricate two flow phantoms by different methods with identical interior surface geometry using computer aided design software tools and rapid prototyping techniques. One portal flow phantom was fabricated within a solid block of clear silicone for use on a table with Ultrasound or within medical imaging systems such as MRI, CT, PET, or SPECT. The other portal flow phantom was fabricated as a thin walled tubular latex structure for use in water tanks with Ultrasound imaging. Both phantoms were evaluated for usability and durability. RESULTS Both phantoms were fabricated successfully and passed durability criteria for flow testing in the next project phase. CONCLUSIONS The fabrication methods and materials employed for the study yielded durable portal vein phantoms.

Response of Retinoic Acid in Patients with Radioactive Iodine-Refractory Thyroid Cancer: A Meta-Analysis

Purpose: The purpose of this study was to evaluate the response of retinoic acid (RA) in radioactive iodine (RAI)-refractory differentiated thyroid cancer (DTC). Methods: Systematic searches of MEDLINE (from inception to December 2016) and of EMBASE (from inception to December 2016) were performed for English-language publications on thyroid cancer treated with RA. Studies were classified according to the response criteria used: (1) 123I or 131I whole body scintigraphy (WBS), (2) serum thyroglobulin (Tg) level, (3) the response evaluation criteria in solid tumors (RECIST) version 1.0, and (4) World Health Organization (WHO) criteria. Results: Disease response rates as determined by WBS ranged widely between 6.2% and 46.1% with a pooled disease response rate of 27.6% (95% confidence interval: 21.7-34.0%). Response rates as determined by Tg level ranged from 56.6% to 83.3% (pooled response rate 61.3% (51.0-70.9%)), RECIST response rates from 0% to 45.5% (pooled response rate 17.0% (1.4-44.5%)), and according to WHO criteria, the pooled response rate was 30.8% (12.7-52.7%). Conclusions: A minority of patients with RAI-refractory DTC respond to RA treatment.