Radiation Medicine Commons^™

Determination Of Field Output Correction Factors Of Radiophoto Luminescent Glass Dosimeter In 6 Mv Small Photon Beams, Sumalee Yabsantia

Chulalongkorn University Theses and Dissertations (Chula ETD)

The objective of this study was to determine the field output correction factors of radiophotoluminescent glass dosimeter (RPLGD) for 6 MV photon beams by using Monte Carlo (MC) simulation. The ratios of absorbed dose of water and RPLGD were calculated using egs_chamber code for 6 MV, 90-cm SSD, 10-cm depth, and field size range from 0.5 × 0.5 to 10 × 10 cm2. Then the field output correction factors of RPLGD in perpendicular and parallel orientations were determined. Also, the volume averaging correction factors were discovered for supporting our results. Moreover, the comparison of measurement field output factors of RPLGD …

Patient-Specific Organ Dose Calculated By Dose Tracking Software Based On Monte Carlo Simulation In Pediatric Abdominal Ct, Yuparak Innan

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study aimed to determine the patient-specific organ doses using Radimetrics dose tracking software in pediatric abdominal CT at Praram9 Hospital. The organ doses were measured using the anthropomorphic Rando phantom inserted with radiophotoluminescent glass dosimeters (RPLGDs) to verify the organ doses calculated by Radimetrics program. The retrospective data were collected from pediatric abdominal CT 164 studies (78 patients), age range 0-15 years-old), who underwent single phase abdominal CT at Praram9 Hospital. The tube voltages ranged between 80 and 135 kVp were adjusted according to the size and age of patients, and rotation time 0.35-0.5 sec. All patients were acquired …

Spatially Fractionated Radiation Therapy: History, Present And The Future, Weisi Yan, Mohammad K. Khan, Xiaodong Wu, Charles B. Simone Ii, Jiajin Fan, Eric Gressen, Xin Zhang, Charles L. Limoli, Houda Bahig, Slavisa Tubin, Waleed F. Mourad

Department of Radiation Oncology Faculty Papers

No abstract provided.

Development Of A Robust Treatment Delivery Framework For Stereotactic Body Radiotherapy (Sbrt) Of Synchronous Multiple Lung Lesions, Lana Catherine Critchfield

Theses and Dissertations--Radiation Medicine

Stereotactic body radiation therapy (SBRT) of lung tumors uses high doses of radiation to deliver high biological effective doses (BED) in very few fractions (1-5). With the use of highly conformal fields to cover the tumor without depositing large doses to non-cancerous structures, this technique has proven time and again to be successful at achieving high local control. However, frequently patients receiving SBRT are elderly with multiple medical comorbidities who may not tolerate long treatment times. Furthermore, many patients present with oligometastatic or multiple primary lung tumors. The success of SBRT on oligometastatic lung disease relies on physician experience with …

Phase Iib, Randomized, Double-Blind Trial Of Gc4419 Versus Placebo To Reduce Severe Oral Mucositis Due To Concurrent Radiotherapy And Cisplatin For Head And Neck Cancer., Carryn M. Anderson, Christopher M Lee, Deborah P. Saunders, Amarinthia Curtis, Neal Dunlap, Chaitali Nangia, Arielle S. Lee, Sharon M. Gordon, Philip Kovoor, Roberto Arevalo-Araujo, Voichita Bar-Ad, Abhinand Peddada, Kyle Colvett, Douglas Miller, Anshu K. Jain, James Wheeler, Dukagjin Blakaj, Marcelo Bonomi, Sanjiv S. Agarwala, Madhur Garg, Francis Worden, Jon Holmlund, Jeffrey M. Brill, Matt Downs, Stephen T. Sonis, Sanford Katz, John M. Buatti

Department of Radiation Oncology Faculty Papers

PURPOSE: Oral mucositis (OM) remains a common, debilitating toxicity of radiation therapy (RT) for head and neck cancer. The goal of this phase IIb, multi-institutional, randomized, double-blind trial was to compare the efficacy and safety of GC4419, a superoxide dismutase mimetic, with placebo to reduce the duration, incidence, and severity of severe OM (SOM).

PATIENTS AND METHODS: A total of 223 patients (from 44 institutions) with locally advanced oral cavity or oropharynx cancer planned to be treated with definitive or postoperative intensity-modulated RT (IMRT; 60 to 72 Gy [≥ 50 Gy to two or more oral sites]) plus cisplatin (weekly …

Combined Modality Therapies For High-Risk Prostate Cancer: Narrative Review Of Current Understanding And New Directions., Benjamin A. Greenberger, Victor E. Chen, Robert B. Den

Department of Radiation Oncology Faculty Papers

Despite the many prospective randomized trials that have been available in the past decade regarding the optimization of radiation, hormonal, and surgical therapies for high-risk prostate cancer (PCa), many questions remain. There is currently a lack of level I evidence regarding the relative efficacy of radical prostatectomy (RP) followed by adjuvant radiation compared to radiation therapy (RT) combined with androgen deprivation therapy (ADT) for high-risk PCa. Current retrospective series have also described an improvement in biochemical outcomes and PCa-specific mortality through the use of augmented radiation strategies incorporating brachytherapy. The relative efficacy of modern augmented RT compared to RP is …

Prediction Of Anal Cancer Recurrence After Chemoradiotherapy Using Quantitative Image Features Extracted From Serial (18)F-Fdg Pet/Ct, Michael Chuong

Michael Chuong

No abstract provided.

Characterization And Longitudinal Assessment Of Daily Quality Assurance For An Mr-Guided Radiotherapy (Mrgrt) Linac, Kathryn Mittauer

All Publications

No abstract provided.

Recent Updates In The Management Of Merkel Cell Carcinoma, Ahmed Nadeem Abbasi, Syed Mustajab Ahmed, Bilal Mazhar Qureshi

Department of Radiation Oncology

Merkel cell carcinoma is an aggressive non-melanomatous cutaneous tumour of neuroendocrine origin with an increasing incidence in the recent years. It is a tumour of the elderly and immunosuppressed, which most often appears on sun-exposed areas of the body. The clinical features of the cutaneous or subcutaneous lesions hardly contribute to the diagnosis, and, hence, histopathology and immunohistochemistry play a vital role in diagnosis. The latest staging system by the American Joint Committee on Cancer includes non-nodal invasion to adjacent structures i.e. bone, muscle, fascia, or cartilage into the criteria, in additionto size and depth of invasion. The management reliesheavily …

Value Of Elastography In Differentiating Benign From Malignant Breast Lesions Keeping Histopathology As Gold Standard, Faryal Farooq, Syed Mubarak, Shaista Shaukat, Noman Khan, Kahkashan Jafar, Tariq Mahmood, Muhammad Arif Saeed

Department of Radiology

Background: Breast cancer is the most common cancer in females, both in developed and developing countries. Pakistan has the highest breast cancer incidence rate in Asia. Guidelines recommend screening for detecting breast cancer with mammography and ultrasonography (US). Shear-wave elastography (SWE) is a newer technique that can aid additional characterization of breast lesions.
Objective: The aim of this study was to determine the diagnostic accuracy of breast ultrasound elastography in differentiating benign from malignant breast lesions using histology diagnosis as the gold standard.
Materials and methods: The study was conducted at the Abbasi Shaheed Hospital and Jinnah Post Graduate Medical …

Prediction Of Anal Cancer Recurrence After Chemoradiotherapy Using Quantitative Image Features Extracted From Serial (18)F-Fdg Pet/Ct, Michael Chuong

All Publications

No abstract provided.

Wilms Tumor Survivorship: Does Childhood Cancer Treatment Predict Late-Term Adverse Effects?, Ava Bibergal

Grace Peterson Nursing Research Colloquium

Abstract

Background: Wilms tumor is the leading cancer to affect the kidneys in children most commonly between the age of 3 and 5 years old. Treatment of Wilms tumor typically consists of chemotherapy, radiation, or a combination of the two – which are often successful in eradicating the cancer. However, current treatment options often leave patients with a high risk of late-term adverse effects such as cardiac diseases or secondary cancers later in life. Wilms’ tumor patients currently have a 90% survival rate from their disease, however face a future of indeterminate health problems due to their treatment regimen.

Objectives: …

Mice Exposed To Combined Chronic Low-Dose Irradiation And Modeled Microgravity Develop Long-Term Neurological Sequelae, Amber M. Paul, Eliah G. Overbey, William A. Da Silveira, Candice G.T. Tahimic, Sigrid S. Reinsch, Nathaniel Szewczyk, Seta Stanbouly, Charles Wang, Jonathan M. Galazka, Xiao Wen Mao

Publications

Spaceflight poses many challenges for humans. Ground-based analogs typically focus on single parameters of spaceflight and their associated acute effects. This study assesses the long-term transcriptional effects following single and combination spaceflight analog conditions using the mouse model: simulated microgravity via hindlimb unloading (HLU) and/or low-dose γ-ray irradiation (LDR) for 21 days, followed by 4 months of readaptation. Changes in gene expression and epigenetic modifications in brain samples during readaptation were analyzed by whole transcriptome shotgun sequencing (RNA-seq) and reduced representation bisulfite sequencing (RRBS). The results showed minimal gene expression and cytosine methylation alterations at 4 months readaptation within single …

Response Of Human Small Intestinal Epithelium To Fractionated Irradiation: Dynamical Modeling Approach, Francis A. Cucinotta, Olga A. Smirnova

Health Physics & Diagnostic Sciences Faculty Publications

A biologically motivated mathematical model of the dynamics of the small intestinal epithelium in humans treated with fractionated radiotherapy has been developed and is further investigated here. This model, originating from our previous work, is implemented as a system of nonlinear ordinary differential equations, in which the variables and parameters have a clear biological meaning. The model also includes, as input, the key parameters of fractionated irradiation. The modeling results on the dynamical response of the human normal small intestinal epithelium to fractionated radiation therapy regimens were in agreement with the corresponding empirical data, which, in turn, demonstrates the capability …

Meta-Analysis Of Cognitive Performance By Novel Object Recognition After Proton And Heavy Ion Exposures, Eliedonna Cacao, Francis A. Cucinotta

Health Physics & Diagnostic Sciences Faculty Publications

Experimental studies of cognitive detriments in mice and rats after proton and heavy ion exposures have been performed by several laboratories to investigate possible risks to astronauts exposed to cosmic rays in space travel and patients treated for brain cancers with proton and carbon beams in Hadron therapy. However, distinct radiation types and doses, cognitive tests and rodent models have been used by different laboratories, while few studies have considered detailed dose-response characterizations, including estimates of relative biological effectiveness (RBE). Here we report on the first quantitative meta-analysis of the dose response for proton and heavy ion rodent studies of …

Following The Growth Of Sarah's Baby: An Ipe Activity For Medical Nutrition & Diagnostic Sonography Students, Tanya M. Custer, Megan Timmerman, Cynthia M. Schmidt, Teresa L. Hartman, Harlan Sayles, Kathryn Wampler, Lea Lambing, Kim Michael

Posters and Presentations: Medical Imaging & Therapeutic Sciences

Objectives: Interprofessional education (IPE) involves collaborative learning among students from different professions. While acceptance of these types of activities is increasing, there are opportunities to expand the number of health care professions involved in IPE. The purpose of this study was to explore student perceptions and outcomes after participation in a Diagnostic Medical Sonography (DMS) and Medical Nutrition Education (MNE) interprofessional education activity centered around a clinical case study on fetal growth. Subjects & Methods: The IPE activity was administered to four student cohorts from academic years to 2015-2016 to 2018-2019. Participants included 66 students (n=39 DMS and n=27 MNE). …

Modeling Proton Relative Biological Effectiveness Using Monte Carlo Simulations Of Microdosimetry, Mark A. Newpower

Dissertations & Theses (Open Access)

Proton therapy is a radiotherapy modality that can offer a better physical dose distribution when compared to photon radiotherapy by taking advantage of the Bragg peak, a narrow region of rapid energy loss. Proton therapy is also known to offer an enhanced relative biological effectiveness (RBE) compared to photons. In the current clinical standard, RBE is fixed at 1.1 at all points along the proton beam, meaning protons are assumed to require 10% less dose than photons to achieve target coverage and organ at risk (OAR) sparing. However, there is mounting clinical evidence, and a significant number of in vitro …

Impact Of Peer Review In The Radiation Treatment Planning Process: Experience Of A Tertiary Care University Hospital In Pakistan, Bilal Mazhar Qureshi, Muhammad Atif Mansha, Muneeb Uddin Karim, Asim Hafiz, Nasir Ali, Benazir Mir, Fatima Shaukat, Maria Tariq, Ahmed Nadeem Abbasi

Department of Radiation Oncology

Purpose: To evaluate and report the frequency of changes in radiation therapy treatment plans after peer review in a simulation review meeting once a week.
Materials and Methods: Between July 1 and August 31, 2016, the radiation plans of 116 patients were discussed in departmental simulation review meetings. All plans were finalized by the primary radiation oncologist before presenting them in the meeting. A team of radiation oncologists reviewed each plan, and their suggestions were documented as no change, major change, minor change, or missing contour. Changes were further classified as changes in clinical target volume, treatment field, or dose. …

Fasting Reduces Intestinal Radiotoxicity Enabling Dose-Escalated Radiotherapy For Pancreatic Cancer, Marimar De La Cruz Bonilla

Dissertations & Theses (Open Access)

Surgical resection is the only potentially curative treatment for pancreatic cancer, but only 15-20% of patients have resectable tumors. In unresectable cases, stereotactic body radiotherapy (SBRT) may be used to give tumor-directed radiotherapy (RT). Unfortunately, this can cause severe gastrointestinal (GI) toxicity due to proximity of the pancreatic head to the duodenum. Protecting the intestine from the toxic side-effects of radiation may enable dose-escalation that could achieve more effective local control of disease. We and others have previously shown that a fast of 24 hours protects mice from lethal doses of the DNA-damaging agent etoposide. In this study, we demonstrate …

Report Of The First Patient Treated For Pelvic Sarcoma With A Directional 103pd Brachytherapy Device., Serguei A. Castaneda, Marian Khalili, Jacqueline Emrich, Veronica M Zoghbi, Michael S Weingarten, Mark J Rivard, Wilbur B Bowne, Jaganmohan Poli

Department of Radiation Oncology Faculty Papers

No abstract provided.