Radiation Medicine Commons^™

Automated Method Of Corrected Effective Diameter For Ssde In Thoracic Imaging Ct Using Cnn, Sakultala Ruenjit

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study aimed to automatically determine the corrected effective diameter (Deffcorr) using convolutional neural network (CNN) for simplified SSDE calculation in thoracic CT. Transaxial images of 108 adult patients underwent thoracic CT without contrast at King Chulalongkorn Memorial Hospital (KCMH) were collected. To calculate the Deffcorr according to Mihailidis et al., the average relative electron densities for lung tissue (ρelung=0.3), for other tissues (ρetissue=1.0) and for bone (ρebone=1.2) were employed to correct the lateral and anteroposterior dimension. The CNN network architecture based on the U-Net algorithm was used for automated image segmentation. The 108 thoracic CT images and generated segmentation …

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 …

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 …

Identification Of Biomarkers For The Prediction Of Radiation Toxicity In Prostate Cancer Patients, Daniel Cullen

Doctoral

The success of radiotherapy in tumour control depends on the total dose given. However, the tolerance of the normal tissues surrounding the tumour limits this dose. It is not known why some patients develop radiation toxicity and, currently, it is not possible to predict before treatment which patients will experience adverse effects. Thus, there is an unmet clinical need for a new test to identify patients at risk of radiation toxicity. The aim of this study was to determine if spectral variations in blood lymphocytes from PCa patients may suggest Raman spectral bands that could be used in future research …

The Study Of Local Diagnostic Reference Levels Of Computed Tomography Procedures At Phramongkutklao Hospital, Sutasinee Mahasub

Chulalongkorn University Theses and Dissertations (Chula ETD)

Computed Tomography (CT) is a medical modality of 3D imaging technique using the X-ray photons rotate, transmit and detect the radiation by the multi-detectors. The CT examination results in the higher patient dose than the general radiography. The objective of this study was to establish the Local DRLs of patient radiation dose in CT procedures at Phramongkutklao Hospital. This study is a retrospective analysis at a single center from January-August 2021. Two CT scanners: 160 slices MDCT manufactured by Canon, model AquilionTM Prime and 640 slices MDCT manufactured by Canon, model AquilionTM One Prism have been used to collect the …

Comparative Dosimetry Between 2d Planar-Based And Hybrid-Based Method For Personalized 177 Lu-Psma I&T And 177lu-Dotatate Therapy, Wuri Handayani

Chulalongkorn University Theses and Dissertations (Chula ETD)

Targeted radionuclide therapy (TRT) uses unsealed radiation sources that are accumulated in the target tissues to deliver a damaging radiation dose to the cancerous cells, and a part of the radiopharmaceutical will end up in non-targeted tissues. To avoid treatment-related side effects, dosimetry is mandatory for TRT for each treatment cycle. This study aimed to evaluate and compare the feasibility of 2D planar-based dosimetry and hybrid-based dosimetry for 177Lu-PSMA I&T and 177Lu-DOTATATE therapy. Whole-body planar images and SPECT/CT images were acquired from 27 treatment cycles, 18 patients (13 patients for 177Lu-PSMA I&T and 5 patients for 177Lu-DOTATATE treatment) at immediately, …

The Potential Of Biology-Guided Radiation Therapy In Thoracic Cancer: A Preliminary Treatment Planning Study, Steven N Seyedin, Rostem Bassalow, Osama R Mawlawi, Lehendrick M Turner, Roshal R Patel, Samuel R Mazin, Oluwaseyi M Oderinde, Yevgen Voronenko, Cody A Wages, Peter D Olcott, Joe Y Chang, Peter A Balter, James W Welsh

Faculty, Staff and Student Publications

PURPOSE: We investigated the feasibility of biology-guided radiotherapy (BgRT), a technique that utilizes real-time positron emission imaging to minimize tumor motion uncertainties, to spare nearby organs at risk.

METHODS: Volumetric modulated arc therapy (VMAT), intensity-modulated proton (IMPT) therapy, and BgRT plans were created for a paratracheal node recurrence (case 1; 60 Gy in 10 fractions) and a primary peripheral left upper lobe adenocarcinoma (case 2; 50 Gy in four fractions).

RESULTS: For case 1, BgRT produced lower bronchus V40 values compared to VMAT and IMPT. For case 2, total lung V20 was lower in the BgRT case compared to VMAT …

Multiagent Chemotherapy And Stereotactic Body Radiation Therapy In Patients With Unresectable Pancreatic Adenocarcinoma: A Prospective Nonrandomized Controlled Trial, Colin S Hill, Lauren Rosati, Hao Wang, Hua-Ling Tsai, Jin He, Amy Hacker-Prietz, Daniel A Laheru, Lei Zheng, Shuchi Sehgal, Vincent Bernard, Dung T Le, Timothy M Pawlik, Matthew J Weiss, Amol K Narang, Joseph M Herman

Faculty, Staff and Student Publications

PURPOSE: In a prospective multicenter study, gemcitabine monotherapy followed by stereotactic body radiation therapy (SBRT) was well tolerated with outcomes comparable to chemoradiation for locally advanced pancreatic cancer (LAPC). Recent trials have reported improved survival with multiagent chemotherapy (MA-CTX) alone. This prospective trial explored whether SBRT could be safely delivered after MA-CTX. Herein, we report the long-term outcomes of adding SBRT after MA-CTX in LAPC patients and evaluate whether genetic profiles of specimens obtained before SBRT influence outcomes.

METHODS AND MATERIALS: This prospective nonrandomized controlled phase 2 trial enrolled 44 LAPC and 4 locally recurrent patients after multidisciplinary evaluation between …