Hassan Ali Nedaie

Radiotherapy Oncology Department, Cancer Research Center, Cancer Institute, Tehran University of Medical Sciences, Tehran, Iran.

[ 1 ] - Step-and-Shoot versus Compensator-based IMRT: Calculation and Comparison of Integral Dose in Non-tumoral and Target Organs in Prostate Cancer

Introduction Intensity-Modulated Radiotherapy (IMRT) is becoming an increasingly routine treatment method. IMRT can be delivered by use of conventional Multileaf Collimators (MLCs) and/or physical compensators. One of the most important factors in selecting an appropriate IMRT technique is integral dose. Integral dose is equal to the mean energy deposited in the total irradiated volume of the p...

[ 2 ] - Stereotactic Radiosurgery/Radiotherapy: A Historical Review

"Stereotactic" is an exact radiotherapy treatment modality which implements invasive and non-invasive facilities for improving precise dose delivery. Stereotactic refers to three-dimensional localization of a specific point in space by a unique set of coordinates that relate to a fixed external reference frame. An accurate delivery of radiation is attainable using these techniques with high pre...

[ 3 ] - Evaluating the effect of Zinc Oxide nanoparticles doped with Gadolinium on dose enhancement factor by PRESAGE dosimeter

Background: New treatment modalities are developed with the aim of escalating tumor absorbed dose and simultaneously sparing the normal structures. The use of nanotechnology in cancer treatment offers some possibilities including destroying cancer tumors with minimal damage to healthy tissues. Zinc Oxide nanoparticles (ZnO NPs) are wide band gap semiconductors and seem to have a good effect on ...

[ 4 ] - Dose measurement outside of radiotherapy treatment field (Peripheral dose) using thermoluminesent dosimeters

Background: In radiation therapy, peripheral dose or the dose outside the radiotherapy field, is important when anatomical structures with very low dose tolerances are involved. One of these critical organs in pelvic irradiation is testis. The amount of radiation delivered to the testes in radiotherapy must be kept as small as possible, consistent with the limit dose of this organ. The threshol...

[ 5 ] - Small photon field dosimetry using EBT2 Gafchromic film and Monte Carlo simulation

Background: Small photon fields are increasingly used in modern radiotherapy especially in intensity modulated radiation therapy (IMRT) and stereotactic radiosurgery (SRS) treatments. Accurate beam profile and central axis depth doses measurements of such beams are complicated due to the electron disequilibrium. Hence the EBT2 (external beam therapy) Gafchromic film was used for dosimetry of sm...

[ 6 ] - Radiation exposure of the surgeons in sentinel lymph node biopsy

Background: Sentinel node biopsy (SLNB) is the standard of care for breast cancer treatment and it is getting wide acceptance in Iran. The radiation safety of the procedure has been investigated under controlled conditions, but the standard dose of radiotracer and techniques are not always observed in the community setting. The aim of this study was to assess the magnitude of the absor...

[ 7 ] - Comparison of MCNP4C, 4B and 4A Monte Carlo codes when calculating electron therapy depth doses

ABSTRACT Background: accurate methods of radiation therapy dose calculation. There are different Monte Carlo codesfor simulation of photons, electrons and the coupled transport of electrons and photons. MCNPis a general purpose Monte Carlo code that can be used for electron, photon and coupledphoton-electron transport.Monte Carlo simulation of radiation transport is considered to be one of the ...

[ 8 ] - Evaluation of Dose Calculation Algorithms Accuracy for Eclipse, PCRT3D, and Monaco Treatment Planning Systems Using IAEA TPS commissioning tests in a Heterogeneous Phantom

Introduction: The accuracy of dose calculation algorithm (DCA) is highly considered in the radiotherapy sequences. This study aims at assessing the accuracy of five dose calculation algorithms in tissue inhomogeneity corrections, based on the International Atomic Energy Agency TEC-DOC 1583. Material and Methods: A heterogeneous phantom was sc...

[ 9 ] - Penumbra Measurements and Comparison of In-House and Standard Circular Cones by the Gafchoromic Film, Pinpoint Ion Chamber, and MCNPX Monte Carlo Simulation

Introduction: Penumbra is an important property of the radiation beam to obtain a suitable margin surrounding the target volume. Therefore, the precise penumbra width determination in stereotactic radiotherapy is necessary for treatment planning. This study aimed to compare the obtained results of penumbra width by in-house and standard circul...