Introduction In order to treat uveal Melanoma , first, radioactive seeds are laid on a silicone- made substance which is called Silastic after that they are inserted in the plaque, and finally, this plaque containing silicone-made substance is stitched to the sclera surface. The dose gradient within the tumor and healthy tissues can be varied due to changing the Silastic thickness between scler...

UNLABELLED To varying degrees, radiopharmaceuticals are distributed nonuniformly in tissue. At a macroscopic level, the radiopharmaceutical may appear to be uniformly distributed throughout the tissue. However, on closer inspection, not all cells in the tissue may be labeled with the radiopharmaceutical. Furthermore, the radioactivity in the cells may be localized only in certain compartments w...

  Introduction: Using beta emitter radionuclide is a useful therapeutic modality in the treatment of skin cancers in areas which are difficult to cure by other methods. The aim of this research is to evaluate the tissue response to beta rays of 166Ho and determine the feasibility of beta emitting radionuclide for treatment of skin cancers. Methods: In this...

Background: The same conversion factors (k-factors) of Single CT (SECT) are applied to estimate the Effective Dose (ED) in Dual Energy Computed Tomography (DECT). However, k-factors for different organs need independently validating DECT, due conditions DECT. Objective: This study aimed calculate organ dose and imaging protocols (liver, chest, cardiac, abdomen) male female phantoms. Material Me...

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma of childhood. RMS tumor exhibits the skeletal muscle differentiation [1,2]. The two major histiotypes, embryonal and alveolar, are characterized by specific genetic abnormalities that provide clues to the mechanisms of tumor induction [1]. Contemporary risk-based therapy cures more than two thirds of children with RMS while minimizin...

Introduction: Proton radiotherapy is the one of advanced teletherapy methods. The protons deposit their maximum energy in a position called Bragg peak. Therefore, for treatment of cancer, the tumor should be placed at the Bragg peak or SOBP. The scattered photons and neutrons is a challenge in proton radiotherapy. The aim of this study is calculation of absorbed dose from scatt...

Background: The present study aimed to investigate the equivalent dose in vital organs, including heart and lung, due to secondary particles produced during breast proton therapy. Materials and Methods: The numerical ORNL female-phantom was improved and simulated using the Monte Carlo MCNPX code. The depth-dose profile of proton beams with different energies was simulated. The proper energy ran...

background: hdr brachytherapy is one of the commonest methods of nasopharyngeal cancer treatment. in this method, depending on how advanced one tumor is, 2 to 6 gy dose as intracavitary brachytherapy is prescribed. due to high dose rate and tumor location, accuracy evaluation of treatment planning system (tps) is particularly important. common methods used in tps dosimetry are based on computat...

The purpose of this work is to obtain the voxelization of a series of tomography slices in order to provide a voxelized human phantom throughout a MatLab algorithm, and the consequent simulation of the irradiation of such phantom with the photon beam generated in a Theratron 780® (MDS Nordion) 60 Co radiotherapy unit, using the Monte Carlo transport code MCNP (Monte Carlo N-Particle), version 5...

introduction accurate estimation of the skin-absorbed dose in external radiation therapy is essential to estimating the probability of secondary carcinogenesis induction materials and methods electron contamination in prostate radiotherapy was investigated using the monte carlo (mc) code calculation. in addition, field size dependence of the skin dose was assessed. excess cancer risk induced by...