Asghar Mesbahi

Tabriz University of Medical Sciences

[ 1 ] - Radiobiological Model-Based Comparison of Three-Dimensional Conformal and Intensity-Modulated Radiation Therapy Plans for Nasopharyngeal Carcinoma

Introduction: Radiobiological modeling of radiotherapy plans are used for treatment plan comparisons. The current study aimed to compare the three-dimensional conformal radiation therapy (3DCRT) and intensity-modulated radiation therapy (IMRT) plans for nasopharyngeal cancer using radiobiological modeling. Materials and Methods: This study was conducted on 10 patients with nasopharyngeal carci...

[ 2 ] - The Impact of Residual Geometric Inaccuracies on Normal Organ Doses in Image Guided-Radiation Therapy of Prostate Cancer Using On-Board Kilovoltage Cone-Beam Computed Tomography

Introduction: The aim of this retrospective study was to evaluate the variations in delivered dose to the bladder, rectum, and femoral heads of prostate cancer patients during a course of treatment by image-guided radiation therapy (IGRT). Materials and Methods: Overall, 15 patients with prostate cancer were selected and. Each week, for each patient five consecutive cone beam computed tomograph...

[ 3 ] - Monte Carlo calculation of shielding properties of newly developed heavy concretes for megavoltage photon beam spectra used in radiation therapy

Introduction: Globally, the need for radiotherapy as a part of cancer management increases every year. Thus, the shielding for megavoltage radiotherapy rooms is of great importance. Materials and Methods: In the present study, 14 types of developed high-density concrete with densities ranging from 2.45 to 5.11 were simulated by using Monte Carlo method. The linear attenuation coefficient and t...

[ 4 ] - Impact of Photon Spectra on the Sensitivity of Polymer Gel Dosimetry by X-Ray Computed Tomography

Introduction: The purpose of the current study was to investigate the effect of X-ray spectra on the sensitivity of a polymer gel dosimeter imaged with a conventional computed tomography (CT) scanner. Material and Methods: The whole process of CT imaging of an irradiated polymer gel was simulated by MCNPX Monte Carlo (MC) code. The imaging of polyacrylamide gel was accomplished by means of a co...

[ 5 ] - Monte Carlo calculation of shielding parameters for fast neutrons in newly developed heavy concretes

Introduction: The role of radiotherapy as a part of cancer management increases every year around the world. Thus, Radiation protection in the design of radiotherapy rooms are of great importance.   Materials and Methods: In present study using Monte Carlo method, MCNPX code, fourteen types of developed high density concretes with densities ranging from 2.45 ...

[ 6 ] - Comparison between artificial neural network and radiobiological modeling for prediction of thyroid gland complications of after radiotherapy

Introduction: Hypothyroidism is one of the frequent side effects of radiotherapy of head and neck cancers, breast cancer, and Hodgkin's lymphoma. It is recommended to estimate the normal tissue complication probability of thyroid gland using radiobiological modeling during treatment planning. Moreover, the use of artificial neural network is also proposed as a new method for t...

[ 7 ] - Graphene Quantum Dots-Coated Bismuth Nanoparticles for X-ray CT Imaging-Guided Photothermal therapy of Cancer Cells

Introduction: Theranostic nanoparticles, which integrate both diagnostic and therapeutic capabilities into one nanoagent, has great promise to ablate more effective tumoral tissue by optimizing and real-time monitoring treatment interventions, as well as monitoring therapeutic response to corresponding effect. Multifunctional theranostic nanoagent based on graphene quantum dots...

[ 8 ] - The Role of radiobiological parameters on Tumor control probability (TCP) in prostate cancer

Introduction: The aim of this study was to evaluation radiobiological modeling parameters on tumor control probability (TCP) for prostate cancer in three different models. These parameters included α⁄β ratios and cell surviving fraction at 2 Gy (SF2). Materials and Methods: The Poisson, equivalent uniform dose (EUD) and linear quadratic (LQ) models was used as...

[ 9 ] - A study on the esophageal cancer radiotherapy effects on the patient’s lung health

Introduction:   Radiotherapy with or without surgery plays an important role in the treatment of patients with esophageal cancer. In the treatment planning of esophageal cancer, usually normal lung volume was observed in the treatment fields and probably received high radiation dose. The incidence of radiation pneumonitis (RP) after radiotherapy (RT) for sensitive organ of lu...

[ 10 ] - Bimodal magnetic resonance imaging-computed tomography nanoprobes: A Review

Bimodal imaging combines two imaging modalities in order to benefit from their advantages and compensate the limitations of each modality. This technique could accurately detect diseases for diagnostic purposes. Nanoparticles simultaneously offer diagnostic data via various imaging modalities owing to their unique properties. Moreover, bimodal nanoprobes could be incorporated into theranostic s...

[ 11 ] - Radiation Shielding Features of Ordinary and High-Density Concretes Loaded With PbO Micro and Nanoparticles against High-Energy Photons

Introduction: The present study aimed to evaluate the impact of PbO nano and micro-sized fillers on ordinary and heavy concretes for different photon energies. Material and Methods: The MCNPX Monte Carlo code (version 2.6.0) was used for all simulations in the present study. A model of narrow-beam geometry was validated and utilized to calcul...

[ 12 ] - Radiobiological Modeling of Acute Esophagitis Following Radiotherapy of Thorax and Head-Neck Tumors: A Comparison of Lyman Kutcher Burman with Equivalent Uniform Dose-Based Models

Introduction: The current study aimed to compare the performance of radiobiological models in predicting acute esophagitis (AE) complications after three-dimensional conformal radiation therapy (3D-CRT). Material and Methods: Out of a total of 100 patients, 50 patients with concurrent chemotherapy and 50 patients without such therapy wer...