Tsair-fwu Lee | KUAS - Academia.edu (original) (raw)

Papers by Tsair-fwu Lee

Research paper thumbnail of Dosimetric Parameters Related to Acute Radiation Dermatitis of Patients with Nasopharyngeal Carcinoma Treated by Intensity-Modulated Proton Therapy

Journal of Personalized Medicine

Background: Growing patients with nasopharyngeal carcinoma (NPC) were treated with intensity-modu... more Background: Growing patients with nasopharyngeal carcinoma (NPC) were treated with intensity-modulated proton therapy (IMPT). However, a high probability of severe acute radiation dermatitis (ARD) was observed. The objective of the study is to investigate the dosimetric parameters related to ARD for NPC patients treated with IMPT. Methods: Sixty-two patients with newly diagnosed NPC were analyzed. The ARD was recorded based on the criteria of Common Terminology Criteria for Adverse Events version 4.0. Logistic regression model was performed to identify the clinical and dosimetric parameters related to ARD. Receiver operating characteristic (ROC) curve analysis and the area under the curve (AUC) were used to evaluate the performance of the models. Results: The maximum ARD grade was 1, 2, and 3 in 27 (43.5%), 26 (42.0%), and 9 (14.5%) of the patients, respectively. Statistically significant differences (p < 0.01) in average volume to skin 5 mm with the respective doses were observe...

Research paper thumbnail of Health-related Quality of life in 640 head and neck cancer survivors after radiotherapy using EORTC QLQ-C30 and QLQ-H&N35 questionnaires

BMC Cancer, 2011

Background With the advances in modern radiotherapy (RT), many patients with head and neck cancer... more Background With the advances in modern radiotherapy (RT), many patients with head and neck cancer (HNC) can be effectively cured, and their health-related quality of life (HR-QoL) has become an important issue. In this study, we evaluated the prognosticators of HR-QoL in a large cohort of HNC patients, with a focus on the result from technological advances in RT. Methods A cross-sectional investigation was conducted to assess the HR-QoL of 640 HNC patients with cancer-free survival of more than 2 years. Among them, 371 patients were treated by two-dimensional RT (2DRT), 127 by three-dimensional conformal RT (3DCRT), and 142 by intensity-modulated RT (IMRT). The EORTC QLQ-C30 questionnaire and QLQ-H&N35 module were used. A general linear model multivariate analysis of variance was used to analyze the prognosticators of HR-QoL. Results By multivariate analysis, the variables of gender, annual family income, tumor site, AJCC stage, treatment methods, and RT technique were prognosticato...

Research paper thumbnail of The suitable dose range for the calibration of EBT2 film by the PDD method with a comparison of two curve fitting algorithms

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2015

ABSTRACT EBT2 film is a convenient dosimetry quality-assurance (QA) tool with high 2D dosimetry r... more ABSTRACT EBT2 film is a convenient dosimetry quality-assurance (QA) tool with high 2D dosimetry resolution and a self-development property for use in verifications of radiation therapy treatment planning and special projects; however, the user will suffer from a relatively higher degree of uncertainty (more than ±6% by Hartmann et al. [29]), and the trouble of cutting one piece of film into small pieces and then reintegrating them each time. To prevent this tedious cutting work, and save calibration time and budget, a dose range analysis is presented in this study for EBT2 film calibration using the Percentage–Depth–Dose (PDD) method. Different combinations of the three dose ranges, 9–26 cGy, 33–97 cGy and 109–320 cGy, with two types of curve fitting algorithms, film pixel values and net optical densities converting into doses, were tested and compared. With the lowest error and acceptable inaccuracy of less than 3 cGy for the clinical dose range (9–320 cGy), a single film calibrated by the net optical density algorithm with the dose range 109–320 cGy was suggested for routine calibration.

Research paper thumbnail of Quantitative analysis of normal tissue effects in the clinic (QUANTEC) guideline validation using quality of life questionnaire datasets for parotid gland constraints to avoid causing xerostomia during head-and-neck radiotherapy

Radiotherapy and Oncology, 2013

To perform a validation test of the quantitative analysis of normal tissue effects in the clinic ... more To perform a validation test of the quantitative analysis of normal tissue effects in the clinic (QUANTEC) guidelines against quality of life (QoL) questionnaire datasets collected prospectively from patients with head and neck (HN) cancers, including HN squamous cell carcinoma (HNSCC) and nasopharyngeal carcinoma (NPC). QoL questionnaire datasets from 95 patients with NPC and 142 with HNSCC were analyzed separately. The European Organization for Research and Treatment of Cancer H&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;N35 QoL questionnaire was used as the endpoint evaluation. The primary endpoint (grade 3(+) xerostomia) was defined as moderate to severe xerostomia 3 and 12 months after the completion of RT, and excluded patients with grade 3(+) xerostomia at the baseline. The Lyman-Kutcher-Burman normal tissue complication probability (NTCP) model was used to describe the incidence of xerostomia. Negative predictive values (NPVs) were used to determine the rate of correctly predicting the lack of complications. NTCP fitted parameters were TD₅₀=37.8 Gy (CI: 29.1-46.9 Gy), m=0.59 (CI: 0.48-0.80) and TD50=43.9 Gy (CI: 33.2-52.8 Gy), m=0.48 (CI: 0.37-0.76) at the 3-month and 12-month time points, respectively. For QUANTEC validation, HN and HNSCC data validation gave similar results at 3 months; at mean doses to the spared parotid of ≤20 and ≤25 Gy, the QoL dataset showed approximately 22% and 28% rates of xerostomia, respectively. At 12 months, the rates of xerostomia were approximately 13% and 19%, respectively. For NPC cases, the dataset showed approximately 0% and 33% (∼67% NPV) rates of xerostomia at 3 months. At 12 months, both rates of xerostomia were approximately 0% (∼100% NPV), which differed significantly from the results for the HNSCC cohort. The QoL datasets validated the QUANTEC guidelines and suggested that the modified QUANTEC 20/20-Gy spared-gland guideline is suitable for clinical use in HNSCC cohorts to effectively avoid xerostomia, and the QUANTEC 25-Gy guideline is justified for NPC cohorts.

Research paper thumbnail of Health-related Quality of life in 640 head and neck cancer survivors after radiotherapy using EORTC QLQ-C30 and QLQ-H&N35 questionnaires

BMC Cancer, 2011

Background: With the advances in modern radiotherapy (RT), many patients with head and neck cance... more Background: With the advances in modern radiotherapy (RT), many patients with head and neck cancer (HNC) can be effectively cured, and their health-related quality of life (HR-QoL) has become an important issue. In this study, we evaluated the prognosticators of HR-QoL in a large cohort of HNC patients, with a focus on the result from technological advances in RT. Methods: A cross-sectional investigation was conducted to assess the HR-QoL of 640 HNC patients with cancerfree survival of more than 2 years. Among them, 371 patients were treated by two-dimensional RT (2DRT), 127 by three-dimensional conformal RT (3DCRT), and 142 by intensity-modulated RT (IMRT). The EORTC QLQ-C30 questionnaire and QLQ-H&N35 module were used. A general linear model multivariate analysis of variance was used to analyze the prognosticators of HR-QoL.

Research paper thumbnail of Radiation Oncology and Medical Physics

BioMed Research International, 2015

Research paper thumbnail of 3D Volumetric Visualization with Automatic Rigid and Deformable Hybrid Image Registration for Adaptive Radiotherapy

Journal of Cancer Science & Therapy, 2009

To provide more clinically convenient image fusions for adaptive radiotherapy (ART), an automatic... more To provide more clinically convenient image fusions for adaptive radiotherapy (ART), an automatic rigid and deformable image registration framework (AIRF) is developed for multimodal visualization of multiple chronological images and multiple radiotherapy (RT) plans. Our hybrid image registration framework, AIRF, uses a faster but less accurate rigid registration method to provide an initial registration, followed by a slower but more accurate deformable registration method to fine tune the final registration. A multi-resolution approach is also employed in the image registration process to further improve the registration accuracy, robustness and efficiency. Volume visualization is provided to guide the automatic image registration process because it can reduce the global positioning error that results from a partial 3D visual presentation in the three conventional orthogonal planar views (axial, sagittal, and coronal). The AIRF can automatically align multiple volumetric images of patients taken over an extended period of time and can merge multiple radiotherapy plans based on different planning computed tomography (CT) images. It offers illustrative 3D volumetric visualization, hybrid rigid and deformable image registration, and automatic transfer of RT dose distribution and RT structure models such as treatment targets and organs at risk (OARs) onto chronological images. The AIRF can automatically register multiple volumetric image datasets of patients taken over an extended period of time and can merge multiple RT plans based on different planning CT images for 4D or adaptive radiotherapy.

Research paper thumbnail of Precise Segmentation Rendering for Medical Images Based on Maximum Entropy Processing

Lecture Notes in Computer Science, 2005

Precision is definitely required in medical treatments, however, most three-dimensional (3-D) ren... more Precision is definitely required in medical treatments, however, most three-dimensional (3-D) renderings of medical images lack for required precision. This study aimed at the development of a precise 3-D image processing method to discriminate clearly the edges. Since conventional Computed Tomography (CT), Positron Emission Tomography (PET), or Magnetic Resonance Imaging (MRI) medical images are all slice-based stacked 3-D images, one

Research paper thumbnail of Fault Diagnosis of Power Transformers Using SVM/ANN with Clonal Selection Algorithm for Features and Kernel Parameters Selection

First International Conference on Innovative Computing, Information and Control - Volume I (ICICIC'06), 2006

... It is capable of filtering out irrelevant input features, leading to improve prediction accur... more ... It is capable of filtering out irrelevant input features, leading to improve prediction accuracy. ... A clonal selection algorithm (CSA) for features and parameters selection is developed to improve the accuracy of the SVM and ANN predictors. ...

Research paper thumbnail of Diagnosis of Incipient Fault of Power Transformers Using SVM with Clonal Selection Algorithms Optimization

Lecture Notes in Computer Science, 2006

In this study we explore the feasibility of applying Artificial Neural Networks (ANN) and Support... more In this study we explore the feasibility of applying Artificial Neural Networks (ANN) and Support Vector Machines (SVM) to the prediction of incipient power transformer faults. A clonal selection algorithm (CSA) is introduced for the first time in the literature to select optimal input features and RBF kernel parameters. CSA is shown to be capable of improving the speed and

Research paper thumbnail of Boundary Finding Combining Wavelet and Markov Random Field Segmentation Based on Maximum Entropy Theory

2009 Fourth International Conference on Innovative Computing, Information and Control (ICICIC), 2009

Boundary finding is one of the most important aspects in medical image processing. Wavelet edge d... more Boundary finding is one of the most important aspects in medical image processing. Wavelet edge detector becomes popular in recent years but is known to degrade in noisy situations. This study aimed to develop an advance precision image segmentation algorithm to enhance the blurred edges clearly for medical target definition. A new method of combining wavelet analysis with Markov random

Research paper thumbnail of A Novel Offline-Based DWBA Algorithm with Sorting REPORT for WDM-EPON System

2010 International Conference on Communications and Mobile Computing, 2010

Broadband access networks using passive optical network technology can extend the transmission di... more Broadband access networks using passive optical network technology can extend the transmission distance and increase the transmission capacity of carrier networks, but the bandwidth capacity of single channel will be unable to offer the enough demand for the digital life of the future. Therefore, to build the WDM-EPON architecture to satisfy huge bandwidth request is a perfect choice. This paper proposes a WDM-EPON with sort-based dynamic wavelength and bandwidth allocation (Sort-DWBA) algorithm that sorts all REPORT messages by the request length at the next transmission cycle in channel to fully utilize the idle time between cycles as long as at least one ONU requests a long enough transmission window. Alternately, when no grant length is long enough, then some of ONUs requests are laid out together in the idle period to utilize the otherwise wasted idle time. Moreover, the proposed algorithm also includes a queue management scheme which improves efficiency further by decreasing the number of REPORT messages when ONU queues are long. By the simulation results show that Sort-DWBA can significantly improve the network performance in terms of packet delay and throughput, as compared with the well-known online-based DWBA-IPACT and offline-based - DWBA and DWBA2 with fair-excess algorithms.

Research paper thumbnail of An Observer-Based Method for Secure Communication

2009 Fifth International Conference on Intelligent Information Hiding and Multimedia Signal Processing, 2009

In this paper, Chua's circuit is adopted to be the chaotic system in both of transmitter and... more In this paper, Chua's circuit is adopted to be the chaotic system in both of transmitter and receiver. According to the Pecore-Carroll's synchronous chaos theory, an n-dimensional chaotic system can be separated as a drive and response subsystem. The drive signal is transmitted to the response system for achieving the system synchronization between the corresponding transmitter and receiver. A dynamic error equation is obtained from the state equations of the driving and responding part, which describe the behaviors of a controller for the chaotic system in the receiver. If the chaotic system that we use is totally controllable, then the poles of the close-loop system may be placed at any desired locations by means of state feedback through an appropriate state feedback gain matrix. The simulating results are shown that the synchronization error reduces to zero as time elapses. In other words, the dynamic error reduces to zero rapidly if the state feedback gain matrix is chosen appropriately.

Research paper thumbnail of A multimodality image registration framework for synchronous visualization of radiotherapy plans with longitudinal imaging studies

Proceedings of the 3rd International Conference on Ubiquitous Information Management and Communication - ICUIMC '09, 2009

The introduction of adaptive image-guided radiotherapy (IGRT) in the radiotherapy environment has... more The introduction of adaptive image-guided radiotherapy (IGRT) in the radiotherapy environment has contributed to the rapid accumulation of medical image data, often making it difficult to consolidate information on a single patient. For oncology patients, the lack of data integration can negatively impact on patient care. We propose a multimodality image registration framework (MIRF) for radiotherapy plans to be registered

Research paper thumbnail of Developing Multivariable Normal Tissue Complication Probability Model to Predict the Incidence of Symptomatic Radiation Pneumonitis among Breast Cancer Patients

PloS one, 2015

Symptomatic radiation pneumonitis (SRP), which decreases quality of life (QoL), is the most commo... more Symptomatic radiation pneumonitis (SRP), which decreases quality of life (QoL), is the most common pulmonary complication in patients receiving breast irradiation. If it occurs, acute SRP usually develops 4-12 weeks after completion of radiotherapy and presents as a dry cough, dyspnea and low-grade fever. If the incidence of SRP is reduced, not only the QoL but also the compliance of breast cancer patients may be improved. Therefore, we investigated the incidence SRP in breast cancer patients after hybrid intensity modulated radiotherapy (IMRT) to find the risk factors, which may have important effects on the risk of radiation-induced complications. In total, 93 patients with breast cancer were evaluated. The final endpoint for acute SRP was defined as those who had density changes together with symptoms, as measured using computed tomography. The risk factors for a multivariate normal tissue complication probability model of SRP were determined using the least absolute shrinkage an...

Research paper thumbnail of Experience with Quality Assurance Programming for Helical TomoTherapy

International Conference on Innovative Computing, Information and Control, 2007

In this paper, we present a quality assurance (QA) programming for the Helical TomoTherapy and sh... more In this paper, we present a quality assurance (QA) programming for the Helical TomoTherapy and share the QA practical experiences with this state-of-the-art machine in radiation therapy. According to the Ionizing Radiation Protection Act (Article. 17, item 3), the regulations of medical exposure quality assurance in Taiwan, has to include the items of daily, monthly, and annual schedule for every

Research paper thumbnail of Long-term late toxicities and quality of life for survivors of nasopharyngeal carcinoma treated by intensity modulated radiotherapy (IMRT) VERSUS non-IMRT

Head & neck, Jan 3, 2015

The aim of this study was to investigate late toxicities and quality of life (QoL) of nasopharyng... more The aim of this study was to investigate late toxicities and quality of life (QoL) of nasopharyngeal carcinoma (NPC) patients with long-term survival after treatment by intensity-modulated radiotherapy (IMRT) versus non-IMRT. An observational, cross-sectional study of QoL and late toxicities was conducted in 242 NPC patients with survival of more than 5 years after treatment with IMRT (n=100) or non-IMRT (n=142) by using physician-assessed toxicities (CTCAE v.4) and the patient-reported EORTC QLQ-C30 and H&N35 module. The IMRT group had both statistically (p < 0.05) and clinically (difference of predicted mean scores ≧10 points) better outcome in global QoL, cognitive functioning, social functioning, fatigue, and eleven scales of the head and neck module. Late toxicities including neuropathy, hearing loss, dysphagia, xerostomia, and neck fibrosis were significantly less severe in the IMRT group. Multivariate analysis revealed that the radiotherapy technique was statistically sign...

Research paper thumbnail of Optimization of Reactive Power Compensation and Voltage Regulation Using Artificial Immune Algorithm for Radial Transmission Networks

2007 International Conference on Intelligent Systems Applications to Power Systems, 2007

This paper addresses the problem of optimal settings of reactive power compensation and bus volta... more This paper addresses the problem of optimal settings of reactive power compensation and bus voltage regulation. To be able to solve the problem for real-world cases, the artificial immune algorithm (AIA) technique is used to generate an optimal or near-optimal control strategy for reactive power compensation and bus voltage regulation. Two real-world cases are tested to demonstrate the effectiveness and high efficiency of the proposed approach.

Research paper thumbnail of Intensity Modulated Radiotherapy Target Volume Definition by Means of Wavelet Segmentation

Lecture Notes in Computer Science, 2006

This study aimed to develop an advance precision three-dimensional (3-D) image segmentation algor... more This study aimed to develop an advance precision three-dimensional (3-D) image segmentation algorithm to enhance the blurred edges clearly and then introduce the result onto the intensity modulated radiotherapy (IMRT) for tumor target volume definition. This ...

Research paper thumbnail of A Volume Visualization System with Augmented Reality Interaction for Evaluation of Radiotherapy Plans

2009 Fourth International Conference on Innovative Computing, Information and Control (ICICIC), 2009

The introduction of adaptive image-guided radiotherapy (ART) has contributed to the rapid accumul... more The introduction of adaptive image-guided radiotherapy (ART) has contributed to the rapid accumulation of spatiotemporal medical image data, often making it difficult to consolidate information on a single patient. For oncology patients, the lack of data integration can negatively impact on patient care. We developed a volume visualization system with augmented reality interaction to display radiotherapy plan contents including computed

Research paper thumbnail of Dosimetric Parameters Related to Acute Radiation Dermatitis of Patients with Nasopharyngeal Carcinoma Treated by Intensity-Modulated Proton Therapy

Journal of Personalized Medicine

Background: Growing patients with nasopharyngeal carcinoma (NPC) were treated with intensity-modu... more Background: Growing patients with nasopharyngeal carcinoma (NPC) were treated with intensity-modulated proton therapy (IMPT). However, a high probability of severe acute radiation dermatitis (ARD) was observed. The objective of the study is to investigate the dosimetric parameters related to ARD for NPC patients treated with IMPT. Methods: Sixty-two patients with newly diagnosed NPC were analyzed. The ARD was recorded based on the criteria of Common Terminology Criteria for Adverse Events version 4.0. Logistic regression model was performed to identify the clinical and dosimetric parameters related to ARD. Receiver operating characteristic (ROC) curve analysis and the area under the curve (AUC) were used to evaluate the performance of the models. Results: The maximum ARD grade was 1, 2, and 3 in 27 (43.5%), 26 (42.0%), and 9 (14.5%) of the patients, respectively. Statistically significant differences (p < 0.01) in average volume to skin 5 mm with the respective doses were observe...

Research paper thumbnail of Health-related Quality of life in 640 head and neck cancer survivors after radiotherapy using EORTC QLQ-C30 and QLQ-H&N35 questionnaires

BMC Cancer, 2011

Background With the advances in modern radiotherapy (RT), many patients with head and neck cancer... more Background With the advances in modern radiotherapy (RT), many patients with head and neck cancer (HNC) can be effectively cured, and their health-related quality of life (HR-QoL) has become an important issue. In this study, we evaluated the prognosticators of HR-QoL in a large cohort of HNC patients, with a focus on the result from technological advances in RT. Methods A cross-sectional investigation was conducted to assess the HR-QoL of 640 HNC patients with cancer-free survival of more than 2 years. Among them, 371 patients were treated by two-dimensional RT (2DRT), 127 by three-dimensional conformal RT (3DCRT), and 142 by intensity-modulated RT (IMRT). The EORTC QLQ-C30 questionnaire and QLQ-H&N35 module were used. A general linear model multivariate analysis of variance was used to analyze the prognosticators of HR-QoL. Results By multivariate analysis, the variables of gender, annual family income, tumor site, AJCC stage, treatment methods, and RT technique were prognosticato...

Research paper thumbnail of The suitable dose range for the calibration of EBT2 film by the PDD method with a comparison of two curve fitting algorithms

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2015

ABSTRACT EBT2 film is a convenient dosimetry quality-assurance (QA) tool with high 2D dosimetry r... more ABSTRACT EBT2 film is a convenient dosimetry quality-assurance (QA) tool with high 2D dosimetry resolution and a self-development property for use in verifications of radiation therapy treatment planning and special projects; however, the user will suffer from a relatively higher degree of uncertainty (more than ±6% by Hartmann et al. [29]), and the trouble of cutting one piece of film into small pieces and then reintegrating them each time. To prevent this tedious cutting work, and save calibration time and budget, a dose range analysis is presented in this study for EBT2 film calibration using the Percentage–Depth–Dose (PDD) method. Different combinations of the three dose ranges, 9–26 cGy, 33–97 cGy and 109–320 cGy, with two types of curve fitting algorithms, film pixel values and net optical densities converting into doses, were tested and compared. With the lowest error and acceptable inaccuracy of less than 3 cGy for the clinical dose range (9–320 cGy), a single film calibrated by the net optical density algorithm with the dose range 109–320 cGy was suggested for routine calibration.

Research paper thumbnail of Quantitative analysis of normal tissue effects in the clinic (QUANTEC) guideline validation using quality of life questionnaire datasets for parotid gland constraints to avoid causing xerostomia during head-and-neck radiotherapy

Radiotherapy and Oncology, 2013

To perform a validation test of the quantitative analysis of normal tissue effects in the clinic ... more To perform a validation test of the quantitative analysis of normal tissue effects in the clinic (QUANTEC) guidelines against quality of life (QoL) questionnaire datasets collected prospectively from patients with head and neck (HN) cancers, including HN squamous cell carcinoma (HNSCC) and nasopharyngeal carcinoma (NPC). QoL questionnaire datasets from 95 patients with NPC and 142 with HNSCC were analyzed separately. The European Organization for Research and Treatment of Cancer H&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;N35 QoL questionnaire was used as the endpoint evaluation. The primary endpoint (grade 3(+) xerostomia) was defined as moderate to severe xerostomia 3 and 12 months after the completion of RT, and excluded patients with grade 3(+) xerostomia at the baseline. The Lyman-Kutcher-Burman normal tissue complication probability (NTCP) model was used to describe the incidence of xerostomia. Negative predictive values (NPVs) were used to determine the rate of correctly predicting the lack of complications. NTCP fitted parameters were TD₅₀=37.8 Gy (CI: 29.1-46.9 Gy), m=0.59 (CI: 0.48-0.80) and TD50=43.9 Gy (CI: 33.2-52.8 Gy), m=0.48 (CI: 0.37-0.76) at the 3-month and 12-month time points, respectively. For QUANTEC validation, HN and HNSCC data validation gave similar results at 3 months; at mean doses to the spared parotid of ≤20 and ≤25 Gy, the QoL dataset showed approximately 22% and 28% rates of xerostomia, respectively. At 12 months, the rates of xerostomia were approximately 13% and 19%, respectively. For NPC cases, the dataset showed approximately 0% and 33% (∼67% NPV) rates of xerostomia at 3 months. At 12 months, both rates of xerostomia were approximately 0% (∼100% NPV), which differed significantly from the results for the HNSCC cohort. The QoL datasets validated the QUANTEC guidelines and suggested that the modified QUANTEC 20/20-Gy spared-gland guideline is suitable for clinical use in HNSCC cohorts to effectively avoid xerostomia, and the QUANTEC 25-Gy guideline is justified for NPC cohorts.

Research paper thumbnail of Health-related Quality of life in 640 head and neck cancer survivors after radiotherapy using EORTC QLQ-C30 and QLQ-H&N35 questionnaires

BMC Cancer, 2011

Background: With the advances in modern radiotherapy (RT), many patients with head and neck cance... more Background: With the advances in modern radiotherapy (RT), many patients with head and neck cancer (HNC) can be effectively cured, and their health-related quality of life (HR-QoL) has become an important issue. In this study, we evaluated the prognosticators of HR-QoL in a large cohort of HNC patients, with a focus on the result from technological advances in RT. Methods: A cross-sectional investigation was conducted to assess the HR-QoL of 640 HNC patients with cancerfree survival of more than 2 years. Among them, 371 patients were treated by two-dimensional RT (2DRT), 127 by three-dimensional conformal RT (3DCRT), and 142 by intensity-modulated RT (IMRT). The EORTC QLQ-C30 questionnaire and QLQ-H&N35 module were used. A general linear model multivariate analysis of variance was used to analyze the prognosticators of HR-QoL.

Research paper thumbnail of Radiation Oncology and Medical Physics

BioMed Research International, 2015

Research paper thumbnail of 3D Volumetric Visualization with Automatic Rigid and Deformable Hybrid Image Registration for Adaptive Radiotherapy

Journal of Cancer Science & Therapy, 2009

To provide more clinically convenient image fusions for adaptive radiotherapy (ART), an automatic... more To provide more clinically convenient image fusions for adaptive radiotherapy (ART), an automatic rigid and deformable image registration framework (AIRF) is developed for multimodal visualization of multiple chronological images and multiple radiotherapy (RT) plans. Our hybrid image registration framework, AIRF, uses a faster but less accurate rigid registration method to provide an initial registration, followed by a slower but more accurate deformable registration method to fine tune the final registration. A multi-resolution approach is also employed in the image registration process to further improve the registration accuracy, robustness and efficiency. Volume visualization is provided to guide the automatic image registration process because it can reduce the global positioning error that results from a partial 3D visual presentation in the three conventional orthogonal planar views (axial, sagittal, and coronal). The AIRF can automatically align multiple volumetric images of patients taken over an extended period of time and can merge multiple radiotherapy plans based on different planning computed tomography (CT) images. It offers illustrative 3D volumetric visualization, hybrid rigid and deformable image registration, and automatic transfer of RT dose distribution and RT structure models such as treatment targets and organs at risk (OARs) onto chronological images. The AIRF can automatically register multiple volumetric image datasets of patients taken over an extended period of time and can merge multiple RT plans based on different planning CT images for 4D or adaptive radiotherapy.

Research paper thumbnail of Precise Segmentation Rendering for Medical Images Based on Maximum Entropy Processing

Lecture Notes in Computer Science, 2005

Precision is definitely required in medical treatments, however, most three-dimensional (3-D) ren... more Precision is definitely required in medical treatments, however, most three-dimensional (3-D) renderings of medical images lack for required precision. This study aimed at the development of a precise 3-D image processing method to discriminate clearly the edges. Since conventional Computed Tomography (CT), Positron Emission Tomography (PET), or Magnetic Resonance Imaging (MRI) medical images are all slice-based stacked 3-D images, one

Research paper thumbnail of Fault Diagnosis of Power Transformers Using SVM/ANN with Clonal Selection Algorithm for Features and Kernel Parameters Selection

First International Conference on Innovative Computing, Information and Control - Volume I (ICICIC'06), 2006

... It is capable of filtering out irrelevant input features, leading to improve prediction accur... more ... It is capable of filtering out irrelevant input features, leading to improve prediction accuracy. ... A clonal selection algorithm (CSA) for features and parameters selection is developed to improve the accuracy of the SVM and ANN predictors. ...

Research paper thumbnail of Diagnosis of Incipient Fault of Power Transformers Using SVM with Clonal Selection Algorithms Optimization

Lecture Notes in Computer Science, 2006

In this study we explore the feasibility of applying Artificial Neural Networks (ANN) and Support... more In this study we explore the feasibility of applying Artificial Neural Networks (ANN) and Support Vector Machines (SVM) to the prediction of incipient power transformer faults. A clonal selection algorithm (CSA) is introduced for the first time in the literature to select optimal input features and RBF kernel parameters. CSA is shown to be capable of improving the speed and

Research paper thumbnail of Boundary Finding Combining Wavelet and Markov Random Field Segmentation Based on Maximum Entropy Theory

2009 Fourth International Conference on Innovative Computing, Information and Control (ICICIC), 2009

Boundary finding is one of the most important aspects in medical image processing. Wavelet edge d... more Boundary finding is one of the most important aspects in medical image processing. Wavelet edge detector becomes popular in recent years but is known to degrade in noisy situations. This study aimed to develop an advance precision image segmentation algorithm to enhance the blurred edges clearly for medical target definition. A new method of combining wavelet analysis with Markov random

Research paper thumbnail of A Novel Offline-Based DWBA Algorithm with Sorting REPORT for WDM-EPON System

2010 International Conference on Communications and Mobile Computing, 2010

Broadband access networks using passive optical network technology can extend the transmission di... more Broadband access networks using passive optical network technology can extend the transmission distance and increase the transmission capacity of carrier networks, but the bandwidth capacity of single channel will be unable to offer the enough demand for the digital life of the future. Therefore, to build the WDM-EPON architecture to satisfy huge bandwidth request is a perfect choice. This paper proposes a WDM-EPON with sort-based dynamic wavelength and bandwidth allocation (Sort-DWBA) algorithm that sorts all REPORT messages by the request length at the next transmission cycle in channel to fully utilize the idle time between cycles as long as at least one ONU requests a long enough transmission window. Alternately, when no grant length is long enough, then some of ONUs requests are laid out together in the idle period to utilize the otherwise wasted idle time. Moreover, the proposed algorithm also includes a queue management scheme which improves efficiency further by decreasing the number of REPORT messages when ONU queues are long. By the simulation results show that Sort-DWBA can significantly improve the network performance in terms of packet delay and throughput, as compared with the well-known online-based DWBA-IPACT and offline-based - DWBA and DWBA2 with fair-excess algorithms.

Research paper thumbnail of An Observer-Based Method for Secure Communication

2009 Fifth International Conference on Intelligent Information Hiding and Multimedia Signal Processing, 2009

In this paper, Chua's circuit is adopted to be the chaotic system in both of transmitter and... more In this paper, Chua's circuit is adopted to be the chaotic system in both of transmitter and receiver. According to the Pecore-Carroll's synchronous chaos theory, an n-dimensional chaotic system can be separated as a drive and response subsystem. The drive signal is transmitted to the response system for achieving the system synchronization between the corresponding transmitter and receiver. A dynamic error equation is obtained from the state equations of the driving and responding part, which describe the behaviors of a controller for the chaotic system in the receiver. If the chaotic system that we use is totally controllable, then the poles of the close-loop system may be placed at any desired locations by means of state feedback through an appropriate state feedback gain matrix. The simulating results are shown that the synchronization error reduces to zero as time elapses. In other words, the dynamic error reduces to zero rapidly if the state feedback gain matrix is chosen appropriately.

Research paper thumbnail of A multimodality image registration framework for synchronous visualization of radiotherapy plans with longitudinal imaging studies

Proceedings of the 3rd International Conference on Ubiquitous Information Management and Communication - ICUIMC '09, 2009

The introduction of adaptive image-guided radiotherapy (IGRT) in the radiotherapy environment has... more The introduction of adaptive image-guided radiotherapy (IGRT) in the radiotherapy environment has contributed to the rapid accumulation of medical image data, often making it difficult to consolidate information on a single patient. For oncology patients, the lack of data integration can negatively impact on patient care. We propose a multimodality image registration framework (MIRF) for radiotherapy plans to be registered

Research paper thumbnail of Developing Multivariable Normal Tissue Complication Probability Model to Predict the Incidence of Symptomatic Radiation Pneumonitis among Breast Cancer Patients

PloS one, 2015

Symptomatic radiation pneumonitis (SRP), which decreases quality of life (QoL), is the most commo... more Symptomatic radiation pneumonitis (SRP), which decreases quality of life (QoL), is the most common pulmonary complication in patients receiving breast irradiation. If it occurs, acute SRP usually develops 4-12 weeks after completion of radiotherapy and presents as a dry cough, dyspnea and low-grade fever. If the incidence of SRP is reduced, not only the QoL but also the compliance of breast cancer patients may be improved. Therefore, we investigated the incidence SRP in breast cancer patients after hybrid intensity modulated radiotherapy (IMRT) to find the risk factors, which may have important effects on the risk of radiation-induced complications. In total, 93 patients with breast cancer were evaluated. The final endpoint for acute SRP was defined as those who had density changes together with symptoms, as measured using computed tomography. The risk factors for a multivariate normal tissue complication probability model of SRP were determined using the least absolute shrinkage an...

Research paper thumbnail of Experience with Quality Assurance Programming for Helical TomoTherapy

International Conference on Innovative Computing, Information and Control, 2007

In this paper, we present a quality assurance (QA) programming for the Helical TomoTherapy and sh... more In this paper, we present a quality assurance (QA) programming for the Helical TomoTherapy and share the QA practical experiences with this state-of-the-art machine in radiation therapy. According to the Ionizing Radiation Protection Act (Article. 17, item 3), the regulations of medical exposure quality assurance in Taiwan, has to include the items of daily, monthly, and annual schedule for every

Research paper thumbnail of Long-term late toxicities and quality of life for survivors of nasopharyngeal carcinoma treated by intensity modulated radiotherapy (IMRT) VERSUS non-IMRT

Head & neck, Jan 3, 2015

The aim of this study was to investigate late toxicities and quality of life (QoL) of nasopharyng... more The aim of this study was to investigate late toxicities and quality of life (QoL) of nasopharyngeal carcinoma (NPC) patients with long-term survival after treatment by intensity-modulated radiotherapy (IMRT) versus non-IMRT. An observational, cross-sectional study of QoL and late toxicities was conducted in 242 NPC patients with survival of more than 5 years after treatment with IMRT (n=100) or non-IMRT (n=142) by using physician-assessed toxicities (CTCAE v.4) and the patient-reported EORTC QLQ-C30 and H&N35 module. The IMRT group had both statistically (p < 0.05) and clinically (difference of predicted mean scores ≧10 points) better outcome in global QoL, cognitive functioning, social functioning, fatigue, and eleven scales of the head and neck module. Late toxicities including neuropathy, hearing loss, dysphagia, xerostomia, and neck fibrosis were significantly less severe in the IMRT group. Multivariate analysis revealed that the radiotherapy technique was statistically sign...

Research paper thumbnail of Optimization of Reactive Power Compensation and Voltage Regulation Using Artificial Immune Algorithm for Radial Transmission Networks

2007 International Conference on Intelligent Systems Applications to Power Systems, 2007

This paper addresses the problem of optimal settings of reactive power compensation and bus volta... more This paper addresses the problem of optimal settings of reactive power compensation and bus voltage regulation. To be able to solve the problem for real-world cases, the artificial immune algorithm (AIA) technique is used to generate an optimal or near-optimal control strategy for reactive power compensation and bus voltage regulation. Two real-world cases are tested to demonstrate the effectiveness and high efficiency of the proposed approach.

Research paper thumbnail of Intensity Modulated Radiotherapy Target Volume Definition by Means of Wavelet Segmentation

Lecture Notes in Computer Science, 2006

This study aimed to develop an advance precision three-dimensional (3-D) image segmentation algor... more This study aimed to develop an advance precision three-dimensional (3-D) image segmentation algorithm to enhance the blurred edges clearly and then introduce the result onto the intensity modulated radiotherapy (IMRT) for tumor target volume definition. This ...

Research paper thumbnail of A Volume Visualization System with Augmented Reality Interaction for Evaluation of Radiotherapy Plans

2009 Fourth International Conference on Innovative Computing, Information and Control (ICICIC), 2009

The introduction of adaptive image-guided radiotherapy (ART) has contributed to the rapid accumul... more The introduction of adaptive image-guided radiotherapy (ART) has contributed to the rapid accumulation of spatiotemporal medical image data, often making it difficult to consolidate information on a single patient. For oncology patients, the lack of data integration can negatively impact on patient care. We developed a volume visualization system with augmented reality interaction to display radiotherapy plan contents including computed