Calibration of the EBT3 Gafchromic Film Using HNN Deep Learning.

To achieve a dose distribution conformal to the target volume while sparing normal tissues, intensity modulation with steep dose gradient is used for treatment planning. To successfully deliver such treatment, high spatial and dosimetric accuracy are crucial and need to be verified. With high 2D dosimetry resolution and a self-development property, the Ashland Inc.

Calibration of Gafchromic EBT Film Using the Microtek ScanMaker 9800XL Plus Flatbed Scanner with a Modified One Red-Channel after Three-Channel Method.

Purpose: Using the Microtek ScanMaker 9800XL Plus (9800XL) flatbed scanner, a method is presented to accurately calibrate EBT film, which cannot be calibrated simply using a general three-channel method because of the nonhomogeneous scanning.

Materials And Methods: Through the percentage-depth-dose method, 6-MV photon beams with two different monitor units were delivered to eight EBT2 films, each of which was tightly sandwiched in a 30-cm cubic polystyrene phantom and positioned parallel to the central axis of the beam. Before and after irradiation, all films were scanned using the Microtek 9800XL scanner and the pixel values (PVs) were measured along the central axis of the beam on the film and fitted to the corresponding depth doses.

Investigated geometrical characteristics and image density of left ventricle of multi-detector computed tomography in early coronary artery disease patients.

Background: Coronary artery disease (CAD) remains the leading cause of death worldwide. Currently, cardiac multi-detector computed tomography (MDCT) is widely used to diagnose CAD. The purpose in this study is to identify informative and useful predictors from left ventricular (LV) in the early CAD patients using cardiac MDCT images.

Ir-192 Calibration in Air with Farmer Chamber for HDR Brachytherapy.

A comprehensive review for the in-air calibration of an Ir-192 high-dose-rate brachytherapy source in terms of air kerma strength (AKS) and reference air kerma rate (RAKR) using the Farmer chamber was conducted. The reviewed calibration methods include the National Physical Laboratory (NPL) calibration standard in the UK, the 7-distance technique with the standard calibration of the National Institute of Standards and Technology and Accredited Dosimetry Calibration Laboratory in the US, the calibration conducted in Australia following recommendations of the International Atomic Energy Agency with the chamber primarily calibrated by the Australian Radiation Protection and Nuclear Safety Agency, the calibration conducted in India following the Deutsche Gesellschaft fur Medizinische Physik recommendation, and the convenient empirical method used in Taiwan. The calibrated AKS (or RAKR) and uncertainty obtained using Farmer chambers are similar to those obtained using well chambers.

Calibration of EBT2 film using a red-channel PDD method in combination with a modified three-channel technique.

Purpose: Ashland Inc. EBT2 and EBT3 films are widely used in quality assurance for radiation therapy; however, there remains a relatively high degree of uncertainty [B. Hartmann, M.

Using [¹⁸F]FBAU for imaging brain tumor progression in an F98/tk-luc glioma-bearing rat model.

1-(2-Deoxy-2-[18F]fluoro-β-D-arabinofuranosyl)-5-bromouracil ([18F]FBAU), a substitute for thymine, has been reported as an effective reporter probe by which to trace cellular metabolism with its positron emission. In the present study, a rat xenograft model bearing F98 glioma transfected with dual reporter genes, herpes simplex virus type 1 thymidine kinase (HSV1-tk) and firefly luciferase (luc) was used for monitoring tumor progression by multimodalities of molecular imaging using [18F]FBAU and D-luciferase as probes. Rat F98 glioma cells were transfected with the pC1-tk-IRES-luc vectors.

Dependency of EBT2 film calibration curve on postirradiation time.

Purpose: The Ashland Inc. product EBT2 film model is a widely used quality assurance tool, especially for verification of 2-dimensional dose distributions. In general, the calibration film and the dose measurement film are irradiated, scanned, and calibrated at the same postirradiation time (PIT), 1-2 days after the films are irradiated.

Pretreatment metabolic tumor volumes to predict the short-term outcome of unresectable locally advanced squamous cell carcinoma of the esophagus treated with definitive chemoradiotherapy.

Purpose: The aim of the study was to investigate the predictive role of pretreatment metabolic tumor volume (MTV) in patients with squamous cell carcinoma of locally advanced esophageal cancer treated with definitive chemoradiotherapy.

Patients And Methods: Ninety patients received pretreatment with (18)F-fluorodeoxyglucose ((18)F-FDG) PET/CT, and two types of MTVs were measured on the basis of either a maximal standardized uptake value (SUVmax) of 2.5 (MTV2.

FDG PET or PET/CT in evaluation of renal angiomyolipoma.

Objective: Angiomyolipoma is the most common benign kidney tumor. However, literature describing FDG PET findings on renal angiomyolipoma (AML) is limited. This study reports the FDG PET and PET/CT findings of 21 cases of renal AML.

Meta-analysis of the diagnostic performance of [18F]FDG-PET and PET/CT in renal cell carcinoma.

Objectives: Positron emission tomography (PET) using fluorodeoxyglucose (FDG) is useful for restaging renal cell carcinoma (RCC) and detecting metastatic diseases but is less satisfactory for detecting primary disease. We evaluated whether the integration of computed tomography (CT) scans with the PET system could increase the applicability of FDG-PET for RCC.

Methods: The MEDLINE databases were searched for relevant studies published since 2001.

A systematic review and meta-analysis of pretherapeutic lymph node staging of colorectal cancer by 18F-FDG PET or PET/CT.

The purpose of the present study was to conduct a systematic review and meta-analysis of the published literature to evaluate the diagnostic performance of fluorine-18 2-fluoro-2-deoxy-D-glucose (18F-FDG) PET in the pretherapeutic assessment of nodal staging in patients with colorectal cancer (CRC). We conducted a systematic MEDLINE search of articles in the published literature (last update, February 2012). Two reviewers independently assessed the methodological quality of each study.

Use of pretreatment metabolic tumor volumes on PET-CT to predict the survival of patients with squamous cell carcinoma of esophagus treated by curative surgery.

Aim: To investigate the prognostic role of the pretreatment metabolic tumor volume (MTV) as determined by Positron emission tomography--computed tomography (PET-CT) in patients with esophageal cancer undergoing curative surgery.

Patients And Methods: We retrospectively reviewed the data of 26 patients with squamous cell carcinoma of the esophagus, who underwent 18F-Fluorodeoxyglucose PET-CT before surgery. MTVs were defined as the volumes with FDG uptake above a standardized uptake value (SUV) of 2.

Calibration of EBT2 film by the PDD method with scanner non-uniformity correction.

The EBT2 film together with a flatbed scanner is a convenient dosimetry QA tool for verification of clinical radiotherapy treatments. However, it suffers from a relatively high degree of uncertainty and a tedious film calibration process for every new lot of films, including cutting the films into several small pieces, exposing with different doses, restoring them back and selecting the proper region of interest (ROI) for each piece for curve fitting. In this work, we present a percentage depth dose (PDD) method that can accurately calibrate the EBT2 film together with the scanner non-uniformity correction and provide an easy way to perform film dosimetry.

Detection of gastroesophageal reflux esophagitis using 2-fluoro-2-deoxy-d-glucose positron emission tomography.

Background: Gastroesophageal reflux disease (GERD) is a common disease and a major upper gastrointestinal problem. The purpose of the present study is to evaluate the use of noninvasive 2-fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) to detect gastroesophageal reflux esophagitis.

Materials And Methods: This is a retrospective study reviewing 408 healthy check-up subjects (169 females and 239 men), who underwent both FDG-PET and upper gastrointestinal endoscopy during September 2008 to December 2009.

Potential value of dual-time-point ¹⁸F-FDG PET compared with initial single-time-point imaging in differentiating malignant from benign pulmonary nodules: a systematic review and meta-analysis.

We performed a meta-analysis to assess the potential value of dual-time-point (DTP) imaging as compared with initial single-time-point (STP) scanning with 18F-fluorodeoxyglucose (18F-FDG) PET in differentiating malignant from benign single pulmonary nodules. Data on the performance of DTP 18F-FDG PET imaging in assessing lung nodules were extracted from articles of prospective or retrospective original research published between January 2001 and April 2010. The Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool was used to assess the quality of study methodology.

Analyzing coronary artery disease in patients with low CAC scores by 64-slice MDCT.

Purpose: Coronary artery calcification (CAC) scores are widely used to determine risk for Coronary Artery Disease (CAD). A CAC score does not have the diagnostic accuracy needed for CAD. This work uses a novel efficient approach to predict CAD in patients with low CAC scores.

Clinically unrecognized pulmonary aspiration during gastrointestinal endoscopy with sedation: a potential pitfall interfering the performance of 18F-FDG PET for cancer screening.

Purpose: We found several cases with unexpected pulmonary abnormalities on the 18F-FDG PET scan after the gastrointestinal endoscopy with sedation during a compact health check-up course, interfering the interpretations of 18F-FDG PET scan for cancer screening. The current studies aimed to analyze the incidence and the clinical relevance of this pulmonary finding.

Materials And Methods: From June to December 2009, 127 subjects undergoing the sequential gastrointestinal endoscopy with sedation and 18F-FDG PET scan within 48 h as part of routine health check-up were retrospectively enrolled in this study.

Sex- and age-related differences in brain FDG metabolism of healthy adults: an SPM analysis.

Background And Purpose: The purpose of our study was aimed to analyze the sex- and age-related differences of brain metabolism in healthy individuals.

Methods: Consecutive 100 healthy subjects, 50 males and 50 females, undergoing routine 2-[(18)F]-fluoro-2-deoxy-d-glucose positron emission tomography (FDG PET) for health checkup in our hospital were retrospectively enrolled in this study. Statistical parametric mapping (SPM) was used for analyses of the FDG PET images to disclose the possible effects of age on brain metabolism in males and females as well as the differences of brain metabolism between male and female groups.

Utility of TL-201 SPECT in clarifying false-positive FDG-PET findings due to osteoradionecrosis in head and neck cancer.

Background: This study aimed to determine whether Tl-201 single photon emission CT (SPECT) is potentially useful in differentiating false-positive fluorodeoxyglucose positron emission tomography (FDG-PET) findings caused by osteoradionecrosis (ORN) from recurrent head and neck cancer after radiotherapy.

Methods: Five patients were recruited. Dual-phase FDG-PET and dual-phase Tl-201 SPECT were performed for each patient.

Preliminary study of detecting urothelial malignancy with FDG PET in Taiwanese ESRD patients.

Unlabelled: The study aimed to evaluate the possibility of applying 18F-fluorodeoxyglucose positron-emission tomography (FDG PET) for detecting primary urothelial malignancies in end-stage renal disease (ESRD) patients and the possible absence of interference by normal physiological excretory urinary radioactivity.

Patients And Methods: Fifteen consecutive ESRD patients who had undergone preoperative FDG PET and computed tomography (CT) for their suspected urothelial malignancies from December 2002 to March 2004, were retrospectively enrolled for comparison with the postoperative histological findings.

Results: The histological findings revealed 27 urothelial malignancies.

F-18 FDG PET in detecting uterine leiomyoma.

Purpose: Uterine leiomyoma, benign tumors of the human uterus, are clinically apparent in about 25% of women and the most common solid pelvic tumors. The purpose of this study was to investigate the F-18 2-fluoro-2-deoxy-D-glucose (FDG) uptake in the uterine leiomyoma and assess the correlation between the intensity of FDG uptake in the uterine leiomyomas and menstrual cycle.

Methods: A total of 589 charts of healthy females examined by whole body FDG positron emission tomography (PET) for health screening examination were reviewed retrospectively.

Correlation between the intensity of breast FDG uptake and menstrual cycle.

Rationale And Objectives: [18F]fluorodeoxyglucose positron emission tomography (F-18 FDG PET), a functional imaging modality has opened a new field in clinical imaging that informs about glucose metabolism of tissues. However, increased FDG uptake is not limited to malignant tissues alone. We hypothesize that the intensity of physical FDG uptake in the normal breast tissues would affect the detect ability of breast cancer; therefore, good knowledge of physical FDG uptake in the healthy population is important for the correct interpretation of FDG PET images of pathologic processes.

Positive correlation between standardized uptake values of FDG uptake in the stomach and the value of the C-13 urea breath test.

Purpose: The distribution of FDG uptake in the stomach is variable. Gastritis is one of the causes of elevated FDG uptake. Helicobacter pylori (HP) infection was found in approximately 80% of patients with peptic ulcer and 30% to 60% of symptomatic gastritis.

Evaluating the prevalence of silent coronary artery disease in asymptomatic patients with spinal cord injury.

To evaluate the prevalence of coronary artery disease (CAD) in patients with spinal cord injury (SCI), 47 clinically asymptomatic SCI patients received thallium-201 myocardial perfusion single photon emission computed tomography (Tl-201 SPECT) after dipyridamole administration for the diagnosis of CAD. There were 4 groups as follows; group 1: 13 patients with quadriplegia and complete SCI, group 2: 11 patients with quadriplegia and incomplete SCI, group 3: 11 patients with paraplegia and complete SCI, and group 4: 12 patients with paraplegia and incomplete SCI. There were no significant differences in sex distribution, ages, SCI duration, or CAD risk factors among the SCI patients in the 4 groups.