Validation of dosimetry programs (Olinda & IDAC) for evaluation of absorbed dose in LuPSMA therapy of metastatic castration-resistant prostate cancer (mCRPC) using Monte Carlo simulation.

Purpose: Clinical trials have yielded promising results for Lutetium Prostate Specific Membrane Antigen (Lu-PSMA) therapy in metastatic castration resistant prostate cancer (mCRPC) patients. However, the development of precise methods for internal dosimetry and accurate dose estimation has been considered ongoing research. This study aimed to calculate the absorbed dose to the critical organs and metastasis regions using GATE 9.

Deep learning-based automated liver contouring using a small sample of radiotherapy planning computed tomography images.

Introduction: No study has yet investigated the minimum amount of data required for deep learning-based liver contouring. Therefore, this study aimed to investigate the feasibility of automated liver contouring using limited data.

Methods: Radiotherapy planning Computed tomography (CT) images were subjected to various preprocessing methods, such as denoising and windowing.

Calculation of Organ Dose Distribution (in-field and Out-of-field) in Breast Cancer Radiotherapy on RANDO Phantom Using GEANT4 Application for Tomographic Emission (Gate) Monte Carlo Simulation.

Introduction: Organ dose distribution calculation in radiotherapy and knowledge about its side effects in cancer etiology is the most concern for medical physicists. Calculation of organ dose distribution for breast cancer treatment plans with Monte Carlo (MC) simulation is the main goal of this study.

Materials And Methods: Elekta Precise linear accelerator (LINAC) photon mode was simulated and verified using the GEANT4 application for tomographic emission.

The effect of considering eye movement time in evaluating the efficiency of attentional networks.

The attention network test (ANT) is a tool for assessing the executive, alerting, and orienting components of attention. However, conflicting findings exist regarding the nature and correlation between attention networks. This study aims to investigate the influence of eye movement time on the assessment of attention network efficiency.

The effect and efficiency of attentional networks and the brain electrophysiology.

The attention networks test (ANT) is frequently utilized to evaluate executive, alerting, and orienting attentional components. Additionally, it serves as an activation task in neuroimaging studies. This study aimed to examine the relationship between attention networks and brain electrophysiology.

Deep-learning Method for the Prediction of Three-Dimensional Dose Distribution for Left Breast Cancer Conformal Radiation Therapy.

Aims: An increase in the demand of a new generation of radiotherapy planning systems based on learning approaches has been reported. At this stage, the new approach is able to improve the planning speed while saving a reasonable level of plan quality, compared with available planning systems. We believe that new achievements, such as deep-learning models, will be able to review the issue from a different point of view.

Multicenter quantitative F-fluorodeoxyglucose positron emission tomography performance harmonization: use of hottest voxels towards more robust quantification.

Background: Harmonization methods reduce variability between different make and models of positron emission tomography (PET) scanners. The study aims to explore harmonization strategies that lead to comparable and robust quantitative metrics in a multicenter setting.

Methods: NEMA IEC Phantom data acquisition was performed for low and high spheres-to-background ratios (SBR4:1 and 10:1) on six PET/CT (computed tomography) scanners.

Dosimetric verification of IMRT and 3D conformal treatment delivery using EPID.

Purpose: Electronic portal imaging devices (EPIDs) could potentially be useful for either in-vivo or pre-treatment dosimetric verification of external beam radiation therapy. The accuracy of EPID for dosimetric purposes is highly dependent on the specific method used for the determination of dose-response characteristics. The aim of this study was to develop a simple and time-saving EPID back-projection dosimetry algorithm for 2D dose verification in 3D conformal and intensity-modulated beams.

PET NEMA IQ Phantom dataset: image reconstruction settings for quantitative PET imaging.

The data presented here provide information about the role of reconstruction parameters on Positron Emission Tomography (PET) image quantification. Multiple phantom measurements in four different Spheres to Background Ratio (SBR) were performed on Biograph 6 TruePoint TrueV PET/CT scanner. PET raw data were reconstructed with/without resolution recovery algorithm using six various iteration x subsets with five different Full-Width Half-Maximum (FWHM) values of Gaussian post-smoothing filter.

Gated Radiotherapy Development and its Expansion.

One of the most important challenges in treatment of patients with cancerous tumors of chest and abdominal areas is organ movement. The delivery of treatment radiation doses to tumor tissue is a challenging matter while protecting healthy and radio sensitive tissues. Since the movement of organs due to respiration causes a discrepancy in the middle of planned and delivered dose distributions.

Evaluation of the heart and lung dosimetric parameters in deep inspiration breath hold using 3D Slicer.

Purpose: The present study was conducted to compare dosimetric parameters for the heart and left lung between free breathing (FB) and deep inspiration breath hold (DIBH) and determine the most important potential factors associated with increasing the lung dose for left-sided breast radiotherapy using image analysis with 3D Slicer software.

Materials And Methods: Computed tomography-simulation scans in FB and DIBH were obtained from 17 patients with left-sided breast cancer. After contouring, three-dimensional conformal plans were generated for them.

An Empirical Transmitted EPID Dosimetry Method using a Back-Projection Algorithm.

Background: The present study aimed to introduce a rapid transmission dosimetry through an electronic portal-imaging device (EPID) to achieve two-dimensional (2D) dose distribution for homogenous environments.

Material And Methods: In this Phantom study, first, the EPID calibration curve and correction coefficients for field size were obtained from EPID and ionization chamber. Second, the EPID off-axis pixel response was measured, and the grey-scale image of the EPID was converted into portal dose image using the calibration curve.

Evaluation of Breast Cancer Radiation Therapy Techniques in Outfield Organs of Rando Phantom with Thermoluminescence Dosimeter.

Background: Given the importance of scattered and low doses in secondary cancer caused by radiation treatment, the point dose of critical organs, which were not subjected to radiation treatment in breast cancer radiotherapy, was measured.

Objective: The purpose of this study is to evaluate the peripheral dose in two techniques of breast cancer radiotherapy with two energies.

Material And Methods: Eight different plans in two techniques (conventional and conformal) and two photon energies (6 and 15 MeV) were applied to Rando Alderson Phantom's DICOM images.

Design and Construction of A Laser-Based Respiratory Gating System For Implementation of Deep Inspiration Breathe Hold Technique in Radiotherapy Clinics.

Background: Deep inspiration breath-hold (DIBH) is known as a radiotherapy method for the treatment of patients with left-sided breast cancer. In this method, patient is under exposure only while he/she is at the end of a deep inspiration cycle and holds his/her breath. In this situation, the volume of the lung tissue is enhanced and the heart tissue is pushed away from the treating breast.

Evaluation of application of EPID for rapid QC testing of linear accelerator.

Aim: Evaluation of application of EPID for rapid QC testing of linear accelerator.

Background: Quality control of a linear accelerator device is a time and energy intensive process. In this study, attempts have been made to perform the linear accelerator quality control using electronic portal imaging device (EPID), which is mounted on most accelerators.

In vivo Exposure Effects of Tc-methoxyisobutylisonitrile on the and Genes Expression in Human Peripheral Blood Lymphocytes.

Objectives: In recent years, the application of radiopharmaceuticals in nuclear medicine has increased substantially. Following the diagnostic procedures performed in nuclear medicine departments, such as myocardial perfusion imaging, patients generally receive considerable doses of radiation. Normally, radiation-induced DNA damages are expected following exposure to a low-dose ionizing radiation.

An Update of Couch Effect on the Attenuation of Megavoltage Radiotherapy Beam and the Variation of Absorbed Dose in the Build-up Region.

Purpose: Fiber carbon is the most common material used in treating couch as it causes less beam attenuation than other materials. Beam attenuation replaces build-up region, reduces skin-sparing effect and causes target volume under dosage. In this study, we aimed to evaluate beam attenuation and variation of build-up region in 550 TxT radiotherapy couch.

Specific Absorbed Fractions of Internal Photon and Electron Emitters in a Human Voxel-based Phantom: A Monte Carlo Study.

The specific absorbed fraction (SAF) of energy is an essential element of internal dose assessment. Here reported a set of SAFs calculated for selected organs of a human voxel-based phantom. The Monte Carlo transport code GATE version 6.

A 3D Monte Carlo Method for Estimation of Patient-specific Internal Organs Absorbed Dose for (99m)Tc-hynic-Tyr(3)-octreotide Imaging.

Single-photon emission computed tomography (SPECT)-based tracers are easily available and more widely used than positron emission tomography (PET)-based tracers, and SPECT imaging still remains the most prevalent nuclear medicine imaging modality worldwide. The aim of this study is to implement an image-based Monte Carlo method for patient-specific three-dimensional (3D) absorbed dose calculation in patients after injection of (99m)Tc-hydrazinonicotinamide (hynic)-Tyr(3)-octreotide as a SPECT radiotracer. (99m)Tc patient-specific S values and the absorbed doses were calculated with GATE code for each source-target organ pair in four patients who were imaged for suspected neuroendocrine tumors.

Monte Carlo and experimental internal radionuclide dosimetry in RANDO head phantom.

Monte Carlo techniques are widely employed in internal dosimetry to obtain better estimates of absorbed dose distributions from irradiation sources in medicine. Accurate 3D absorbed dosimetry would be useful for risk assessment of inducing deterministic and stochastic biological effects for both therapeutic and diagnostic radiopharmaceuticals in nuclear medicine. The goal of this study was to experimentally evaluate the use of Geant4 application for tomographic emission (GATE) Monte Carlo package for 3D internal dosimetry using the head portion of the RANDO phantom.

Monte Carlo Simulation of a 6 MV X-Ray Beam for Open and Wedge Radiation Fields, Using GATE Code.

The aim of this study is to provide a control software system, based on Monte Carlo simulation, and calculations of dosimetric parameters of standard and wedge radiation fields, using a Monte Carlo method. GATE version 6.1 (OpenGATE Collaboration), was used to simulate a compact 6 MV linear accelerator system.

A Comparison Between GATE and MCNPX Monte Carlo Codes in Simulation of Medical Linear Accelerator.

Radiotherapy dose calculations can be evaluated by Monte Carlo (MC) simulations with acceptable accuracy for dose prediction in complicated treatment plans. In this work, Standard, Livermore and Penelope electromagnetic (EM) physics packages of GEANT4 application for tomographic emission (GATE) 6.1 were compared versus Monte Carlo N-Particle eXtended (MCNPX) 2.