A new development of a linear accelerator machine has been installed in Indonesia for the first time. There is no dosimetric protocol specifically discussing measurement absorbed dose to water Halcyon linac. But, few global protocols determine linac which at same substance. This paper describes dosimetry parameter 6 MV flattening filter-free (FFF) photon beam produced from model Varian using IA...

PURPOSE The goal of the present study was to evaluate the efficacy of intracerebral (i.c.) administration of carboplatin by means of convection-enhanced delivery (CED) in combination with fractionated, external beam photon irradiation for the treatment of F98 glioma-bearing rats. EXPERIMENTAL DESIGN Carboplatin (20 microg/20 microL) was administrated i.c. by CED to F98 glioma-bearing rats, 13...

PURPOSE With the advent of state-of-the-art treatment technologies, the use of small fields has increased, and dosimetry in small fields is highly challenging. In this study, the potential use of Varian electronic portal imaging device (EPID) for small field measurements was explored for 6 and 15 MV photon beams. MATERIALS AND METHODS The output factors and profiles were measured for a range ...

Acceptance testing and commissioning of a CyberKnife robotic stereotactic radiosurgery system was performed in April 2006. The CyberKnife linear accelerator produces a photon beam of 6 MV nominal energy, without the use of a flattening filter. Clinically measured tissue-phantom ratios, off-center ratios, and output factors are presented and compared with similar data from other CyberKnife sites...

The present work is devoted to develop a computational model using the Monte Carlo code MCNP5 (Monte Carlo N-Particle) for the simulation of a 6 MV photon beam given by Elekta Precise medical linear accelerator treatment head. The model includes the major components of the multileaf accelerator head and a cube-shaped water tank. Calculations were performed for a photon beam with 10 cm x 10 cm i...

The measurement of stereotactic radiosurgical dose distributions requires an integrating, high-resolution dosimeter capable of providing a spatial map of absorbed dose. Although radiographic film is an accessible dosimeter fulfilling these criteria, for larger radiotherapy photon fields the sensitivity of film emulsion exhibits significant dependencies on both depth in phantom and field size. W...

Introduction: In radiation therapy, the accuracy of dose calculations by a treatment planning system (TPS) is important to achieve tumor control and to spare normal tissue. Treatment planning system calculations in the heterogeneous situation may present significant inaccuracies. In this study, three different dose calculation algorithms, pencil beam (PB), collapsed cone (CC), ...

The purpose of this work was to compare the risk of developing a second cancer after craniospinal irradiation using photon versus proton radiotherapy by means of simulation studies designed to account for the effects of neutron exposures. Craniospinal irradiation of a male phantom was calculated for passively-scattered and scanned-beam proton treatment units. Organ doses were estimated from tre...

There is a growing interest in the use of megavoltage cone-beam computed tomography (MV CBCT) data for radiotherapy treatment planning. To calculate accurate dose distributions, knowledge of the electron density (ED) of the tissues being irradiated is required. In the case of MV CBCT, it is necessary to determine a calibration-relating CT number to ED, utilizing the photon beam produced for MV ...