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Full-Text Articles in Medicine and Health Sciences
Effect Of Inter-Observer Delineation Variability On Radiomics Features In Nasopharyngeal Cancer, Pongpitch Panyura
Effect Of Inter-Observer Delineation Variability On Radiomics Features In Nasopharyngeal Cancer, Pongpitch Panyura
Chulalongkorn University Theses and Dissertations (Chula ETD)
Nasopharyngeal cancer (NPC) is a type of head and neck cancer that is prevalent in China and Southeast Asia. The standard treatment for NPC is radiation therapy (RT), which requires accurate target volume delineation (TVD) to ensure an effective radiation dose while minimizing damage to surrounding healthy tissues. However, TVD is subject to intra- and inter-observer variability, which can affect the accuracy of RT and lead to unstable results in radiomics analysis. Radiomics is a technique that extracts quantitative data from medical images, but it is currently limited by the manual process of tumor delineation. This study aims to investigate …
Dosimetric Differences Between Scheduled And Adapted Plans Generated From Ethos Adaptive Radiotherapy For Patients With Prostate Cancer, Sarita Suvira
Dosimetric Differences Between Scheduled And Adapted Plans Generated From Ethos Adaptive Radiotherapy For Patients With Prostate Cancer, Sarita Suvira
Chulalongkorn University Theses and Dissertations (Chula ETD)
Prostate is one of the organs that can easily move or change during the treatment fractions. Adaptive radiotherapy can help to reduce the uncertainty of interfraction and decrease the side effects produced from the radiation given to the patients. The objective of this study was to provide evidence of the efficiency of adaptive radiotherapy for prostate cancer patients by investigating the dosimetric differences between the scheduled and adapted plans generated from Ethos. The treatment data of 100 fractions of prostate cancer patients who had previously been treated on Ethos daily adaptive radiotherapy were collected. The treatment data in each fraction …
Accuracy Of Small-Field High Energy Photon Using Plastic Scintillation Detector In Heterogenous Media Compared With Model-Based Algorithm Calculation, Thanat Kaewsuksri
Accuracy Of Small-Field High Energy Photon Using Plastic Scintillation Detector In Heterogenous Media Compared With Model-Based Algorithm Calculation, Thanat Kaewsuksri
Chulalongkorn University Theses and Dissertations (Chula ETD)
Some radiotherapy techniques such as stereotactic body radiotherapy (SBRT) has the challenges in small field dosimetry in heterogenous media. This study aims at evaluating the accuracy of W2 plastic scintillation detector (PSD) compared with the calculation from algorithms for small-field high energy photon in heterogenous media. The characteristics of W2-PSD were studied. The percentage depth dose (PDD) of 6 FFF and 10 FFF with various field sizes ranging from 1x1 to 4x4 cm2 were measured in solid water phantom with low-density inhomogeneities slabs of air (Styrofoam) and lung (cork) and high-density inhomogeneity slab of aluminum. The characteristics of W2 plastic …
Development Of End-To-End Test Phantom For Stereotactic Radiosurgery Using Alanine Dosimeter, Aungsumalin Intang
Development Of End-To-End Test Phantom For Stereotactic Radiosurgery Using Alanine Dosimeter, Aungsumalin Intang
Chulalongkorn University Theses and Dissertations (Chula ETD)
Alanine dosimeters are generally used in high-dose dosimetry, while accurate and precise dose delivery verification procedures are important in stereotactic radiosurgery (SRS). Hence, an end-to-end test is required. In addition, no end-to-end SRS test employing an alanine dosimeter has been established in Thailand. The objective of this study was to determine the dose accuracy of SRS VMAT plans in end-to-end test phantom using alanine dosimeter. The electron paramagnetic resonance (EPR) parameters were optimized in the 1-2000 cGy dose range. Following that, suitable parameters were used to investigate the alanine characteristics and estimate the uncertainty in radiation therapy dose range. The …
Comparison Of Radiation Dose And Image Quality Between Fast Kvp Switching Dual-Energy Ct And Routine Single-Energy Ct For Whole Abdomen At King Chulalongkorn Memorial Hospital, Chanthawan Khemkhangboon
Comparison Of Radiation Dose And Image Quality Between Fast Kvp Switching Dual-Energy Ct And Routine Single-Energy Ct For Whole Abdomen At King Chulalongkorn Memorial Hospital, Chanthawan Khemkhangboon
Chulalongkorn University Theses and Dissertations (Chula ETD)
Abdominal computed tomography (CT) using a single energy protocol is a common imaging procedure in hospitals. As CT technology has continued to evolve, dual-energy protocols (DECT) have emerged as a new option. A spectral CT scanner with fast kVp switching was installed at King Chulalongkorn Memorial Hospital in 2017, and its clinical utility in emergency patients has not yet been studied. This study aims to compare the radiation dose and image quality between DECT and SECT in abdominal CT for emergency patients. The study retrospectively collected CT data from 130 standard-sized adult patients who underwent contrast-enhanced using the 256-slice MDCT. …
Accuracy In Classification Of Liver Lesion Ultrasound Using Artificial Intelligence, Sutthirak Tangruangkiat
Accuracy In Classification Of Liver Lesion Ultrasound Using Artificial Intelligence, Sutthirak Tangruangkiat
Chulalongkorn University Theses and Dissertations (Chula ETD)
B-mode ultrasound imaging is the standard method for hepatocellular carcinoma (HCC) screening. If a lesion has a unique appearance, a conventional detector can be applied. However, if the lesion shares its appearance with other lesion, a large training dataset is required, which may be unavailable. Therefore, a two-stage method is proposed. In the first stage, lesions are detected but not differentiated into any particular class. The detected lesions are then classified in the second stage using a conventional convolutional neural network (CNN). The aims of the dissertation are to design an artificial intelligent system model and to investigate the most …
In Vivo Dosimetry Of 3d Gynecological Brachytherapy Using The Glass Dosimeter: A Phantom Study, Itsaraporn Konlak
In Vivo Dosimetry Of 3d Gynecological Brachytherapy Using The Glass Dosimeter: A Phantom Study, Itsaraporn Konlak
Chulalongkorn University Theses and Dissertations (Chula ETD)
Brachytherapy can deliver high doses to the target while sparing healthy tissues due to its steep dose gradient property. However, treatment was only performed according to the dose calculated by a treatment planning system without verification of the dose due to the characteristics. Therefore, the aim of this study was to design the in-house phantom to evaluate the dosimetric differences of gynecological brachytherapy under clinical conditions between calculation by the treatment planning system and measurement by the RPLGDs. An in-house phantom consisting of the glass dosimeter holder and the holder of the applicator was created. This holder was designed to …