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Full-Text Articles in Medicine and Health Sciences
Hepatic Lesion Detectability On Dual Energy Computed Tomography Imaging : Phantom Study, Hataipat Jantawong
Hepatic Lesion Detectability On Dual Energy Computed Tomography Imaging : Phantom Study, Hataipat Jantawong
Chulalongkorn University Theses and Dissertations (Chula ETD)
The purpose of this study is to determine the hepatic lesion detectability in abdomen from various phantom sizes by dual-energy computed tomography (DECT) imaging and to investigate the factors affecting the detectability of hepatic lesion in abdomen by dual-energy CT in phantom study. The anthropomorphic liver with nodule inserted phantom with extension rings simulating the small, medium, and large patients were scanned under DECT acquisitions by varying three kVp combinations (80/-,90/-, and 100/Sn150-kVp). The series of 40-,50-,60-, and 70-keV VMI were generated from DECT data set. All images were used to assess the task-based image quality; task transfer function (TTF), …
Evaluation Of Integral Depth-Dose Curves In Proton Pencil Beam Scanning Using Plane-Parallel Ionization Chambers, Phatthraporn Thasasi
Evaluation Of Integral Depth-Dose Curves In Proton Pencil Beam Scanning Using Plane-Parallel Ionization Chambers, Phatthraporn Thasasi
Chulalongkorn University Theses and Dissertations (Chula ETD)
Proton therapy is an advanced form of radiation therapy treatment that can potentially decrease side effects and increase tumor control probability. The integral depth-dose curve is an essential parameter that has to be determined and introduced into the proton treatment planning system for the dose calculation. Besides the halo, the integral depth-dose curve measurements should be performed with a large-diameter plane-parallel ionization chamber. The purpose of this research is to determine the integral depth-dose curves and assess the geometrical collection efficiency at intermediate depths of different detector diameters in proton pencil beam scanning. The integral depth-dose curves with a proton …
Moderated Neutron Detector For Accumulated Ambient Dose Equivalent In Proton Therapy, Tanawat Tawonwong
Moderated Neutron Detector For Accumulated Ambient Dose Equivalent In Proton Therapy, Tanawat Tawonwong
Chulalongkorn University Theses and Dissertations (Chula ETD)
The Varian ProBeam compact was installed at Her Royal Highness Princess Maha Chakri Sirindhorn Proton Center. Since 2017, the project has started at the King Chulalongkorn Memorial Hospital and after 4 years, during Covid19 pandemic, the 1st patient treatment received proton therapy on August, 2021. The radiation safety of the center was accomplished through firstly, the shielding calculation and secondary, the radiation survey at the milestone points such as cyclotron installation and 1st Beam ON at the treatment room. The only one WENDI-II dosimeter was used in radiation survey. The main purpose of this study is to validate the in-house …
Baselines Of Daily Quality Assurance For Proton Pencil Beam Scanning Using The Sphinx Compact, Tanapat Tiajaroen
Baselines Of Daily Quality Assurance For Proton Pencil Beam Scanning Using The Sphinx Compact, Tanapat Tiajaroen
Chulalongkorn University Theses and Dissertations (Chula ETD)
Quality assurance (QA) is a systematic process used to determine whether the product meets specified requirements. The American Association of Physicists in Medicine (AAPM) published a comprehensive proton therapy machine QA in TG-224 to provide confidence in use. King Chulalongkorn Memorial Hospital (KCMH) recently operated the first proton therapy center in Thailand, and the data of daily QA are not available or established. This study aims to apply the control chart for establishing the baselines of daily QA for the proton pencil beam scanning system using the Sphinx Compact detector. The Sphinx Compact was used to perform the proton daily …
Dosimetric Comparison Of Rapidplan And Manually Optimized Plans For Hippocampus Avoidance Whole Brain Radiation Therapy, Laksamon Phimolasawakun
Dosimetric Comparison Of Rapidplan And Manually Optimized Plans For Hippocampus Avoidance Whole Brain Radiation Therapy, Laksamon Phimolasawakun
Chulalongkorn University Theses and Dissertations (Chula ETD)
Nowadays, whole-brain radiation therapy (WBRT) is a good method to cure brain metastases. However, it has been noted that whole-brain radiation therapy could be a cause to neurological toxicity which could damage the hippocampus that is an important part of forming long-term memories. The HA-WBRT is a complicated plan depending on planner skills, the researcher would like to simplify this problem using knowledge-based planning called RapidPlan. The objective of this study was to compare the dosimetric difference of RapidPlan and manually optimized plans for the treatment of HA-WBRT. The RapidPlan model was created for HA-WBRT. The PTV and OARs constraints …
Determination Of Field Output Correction Factors In Elongated Small Field Photon Beams, Mananchaya Vimolnoch
Determination Of Field Output Correction Factors In Elongated Small Field Photon Beams, Mananchaya Vimolnoch
Chulalongkorn University Theses and Dissertations (Chula ETD)
IAEA along with AAPM have published a code of practice TRS 483 for small field dosimetry. The field correction output factors of various detectors were introduced to correct detector response changes in relative dosimetry. However, the publication of TRS 483 has focused on symmetry field sizes, the correction factors for elongated small fields are not included in the protocol. The overall objective of this work is to determine the field output correction factor in elongated small field. The correction factors of IBA CC01, Sun nuclear EDGE, and Exradin W2 PSD for 6 MV photon beam were determined using Monte Carlo …
Dosimetric Impact Of Interplay Effects Instereotactic Body Radiation Therapy (Sbrt) Lung Cancer, Vanida Poolnapol
Dosimetric Impact Of Interplay Effects Instereotactic Body Radiation Therapy (Sbrt) Lung Cancer, Vanida Poolnapol
Chulalongkorn University Theses and Dissertations (Chula ETD)
Lung cancer patient breathing induced interplay effects in the volumetric modulated arc therapy (VMAT) together with stereotactic body radiation therapy (SBRT), which lead to non-uniform doses within the target volume and unwanted dose to the surrounding tissues. The purpose of this study was to investigate the dosimetric impact of interplay effects in 6 MV FFF of photon beams for lung cancer and to calculate the novel interplay effects factor (IEF) for VMAT-SBRT lung cancer. This study performed the static and dynamic measurements using two dimensions (2D) robotic platform and diode array for 3D-conformal radiation therapy (3D-CRT) plans, while using three …