Mohammad Amin Mosleh-Shirazi
Physics Unit, Department of Radiotherapy and Oncology, Namazi Hospital, Shiraz University of Medical Sciences, Shiraz, Iran 2- Ionizing and Non-ionizing Radiation Protection Research Center, School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran
[ 1 ] - Medium-Term Stability of the Photon Beam Energy of An Elekta CompactTM Linear Accelerator Based on Daily Measurements of Beam Quality Factor
Introduction In this study, we aimed to assess the medium-term energy stability of a 6MV Elekta CompactTM linear accelerator. To the best of our knowledge, this is the first published article to evaluate this linear accelerator in terms of energy stability. As well as investigating the stability of the linear accelerator energy over a period of several weeks, the results will be useful for esti...
[ 2 ] - Assessment of an Unshielded Electron Field Diode Dosimeter for Beam Scanning in Small- to Medium-Sized 6 MV Photon Fields
Introduction Radiotherapy planning systems require many percentage depth dose (PDD) and profile measurements and there are various dosimeters that can be used to obtain these scans. As dose perturbation is particularly troublesome in smaller photon fields, using a low-perturbation, unshielded electron field diode (EFD) in these fields is of interest. The aim of this work was to investigate the ...
[ 3 ] - Breast Cancer and its Radiotherapeutic Methods
Breast cancer is the most common cancer in women after skin cancer. In Iran, the presentation age of this cancer is younger than the global average. There are different therapeutic methods for treatment of breast cancer and the choice of treatment depends on the stage of the disease as well as its type and characteristics. Therapeutic methods include surgery, radiotherapy, and systemic therapie...
[ 4 ] - CT-Based Brachytherapy Treatment Planning using Monte Carlo Simulation Aided by an Interface Software
Introduction: In brachytherapy, radioactive sources are placed close to the tumor, therefore, small changes in their positions can cause large changes in the dose distribution. This emphasizes the need for computerized treatment planning. The usual method for treatment planning of cervix brachytherapy uses conventional radiographs in the Manchester system. Nowadays, because of their advantages ...
[ 5 ] - Optimization of Beam Orientation and Weight in Radiotherapy Treatment Planning using a Genetic Algorithm
Introduction: The selection of suitable beam angles and weights in external-beam radiotherapy is at present generally based upon the experience of the planner. Therefore, automated selection of beam angles and weights in forward-planned radiotherapy will be beneficial. Material and Methods: In this work, an efficient method is presented within the MATLAB environment to investigate how to improv...
[ 6 ] - A fast model for prediction of respiratory lung motion for image-guided radiotherapy: A feasibility study
Background: The aim of this work was to study the feasibility of constructing a fast thorax model suitable for simulating lung motion due to respiration using only one CT dataset. Materials and Methods: For each of six patients with different thorax sizes, two sets of CT images were obtained in single-breath-hold inhale and exhale stages in the supine position. The CT images were then ...
[ 7 ] - Simulation of the shielding effects of an applicator on the AAPM TG-43 parameters of CS-137 Selectron LDR brachytherapy sources
Background: The dose rate distribution delivered by a low dose rate 137Cs pellet source, a spherical source used within the source trains of the Selectron gynecological brachytherapy system, was investigated using the MCNP4C Monte Carlo code. Materials and Methods: The calculations were performed in both water and Plexiglas and the absolute dose rate distribution for a single pellet s...
[ 8 ] - A prospective radiobiological study of acute esophagitis and swallowing dysfunction in head-and-neck radiotherapy
Introduction: Esophagitis is one of the main causes of swallowing dysfunction after radiation therapy (RT) for head and neck cancer (HNC).It significantly affects patients’ quality of life as well as having a potentially negative impact on their long term survival. However, little has been investigated on the dose-response and normal tissue complication probability (NTCP) of es...
[ 9 ] - Hadron Therapy in Iran: Patient Indication Estimation and Challenges Ahead
Introduction: Radiotherapy with heavy charged particles such as protons and carbon ions (hadron therapy) has been recognized as an advanced technique for the treatment of various cancers. For some indications such as pediatric and radio-resistant tumors, it is considered the preferred method. However, despite its remarkable benefits, development of hadron therapy centers in the...
[ 10 ] - Calculation of wedged dose distributions using an analytical method
Introduction: Wedge filters are used in radiotherapy to modify photon beam and improve dose uniformity in the target volume. Determination of wedge dose distribution is important to improve treatment planning accuracy. The utilization of treatment planning software to obtain dose distribution is not always available. In this work an analytical model has been developed to calcu...
[ 11 ] - Comparing of different normal tissue complication probability models for plan evaluation of radical radiotherapy for esophageal cancer
Introduction: Chemoradiation is a well-established protocol for management of localized esophageal cancer. However, some early and late toxicities are associated with this therapy. Plan evaluation in term of normal tissue complication probability (NTCP) may help clinicians to tailor this therapy more individually. Given the variety of present radiobiological models, the choice...
[ 12 ] - A free user friendly program for evaluation of radiotherapy plans based on different dose response models
Introduction: Radiotherapy (RT) plan evaluation using dose response models has become a feasible approach in routine clinical practice. Although there are several tools for this task, they suffer from limitations including number of different dose response models and parameters. In the present study, we aimed to develop a free program for RT plan evaluation based on a variety ...
[ 13 ] - Comparison of ScintSim1 and Geant4 Monte Carlo simulation codes for optical photon transport in thick segmented scintillator arrays
Introduction: Arrays of segmented scintillation crystals are useful in megavoltage x-ray imaging detectors for image-guided radiotherapy. Most previous theoretical studies on these detectors have modelled only ionizing-radiation transport. Scintillation light also affects detector performance. ScintSim1, our previously reported optical Monte Carlo code for such detector...
[ 14 ] - Design and Fabrication of a Four-Dimensional Respiratory Phantom for Studying Tumor Movement in Radiotherapy with Magnetic Resonance Imaging
Introduction: In radiation therapy, determining the location of the tumor accurately during irradiation is one of the most important requirements. However, lung tumors are not fixed in a single location and move during irradiation due to respiratory motion. Due to limitations in assessing such movements, using a lung phantom can be useful and operational for their fast, easy an...
[ 15 ] - Independent assessment of source transit time for the BEBIG SagiNova® high dose rate brachytherapy afterloader
Introduction: The dwell time and transit time components contribute to the overall delivered dose to patients in high dose rate (HDR) brachytherapy treatments. The transit time results from source entry and exit as well as source movements between dwell positions. It depends on various parameters such as the source speed profile, source indexer distance to dwell position, and ...
[ 16 ] - Discrepancies in dose distributions due to age- dependent bone electron density in pediatric MRI-only treatment planning: A Monte Carlo study
Introduction: MRI-only treatment planning (TP) can be advantageous in paediatric radiotherapy. However, electron density extraction is necessary for dose calculation. Normally, after bone segmentation, a bulk density is assigned. However, the variation of bone bulk density in patients makes the creation of pseudo CTs challenging. This study aims to assess the effects of bone den...
[ 17 ] - A Preliminary Study on the Estimation of the Number of Cancer Patients Eligible for Hadron Therapy in Iran and Fars Province
Hadron therapy (HT) with protons and carbon ions is an advanced radiotherapy technique. As the first report addressing this topic, the present study aimed to estimate the number of patients eligible for HT in Fars province and the whole of Iran. The data were collected through direct inspection of medical records of the patients treated at the Radiotherapy Department, Namazi Hospital, Shiraz, I...
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