INTRODUCTION In radiation therapy centers across Iran, protection of normal tissues is usually accomplished by either Cerrobend or lead block shielding. In this study, the influence of these two shielding methods on central axis dose distribution of photon beam a Cobalt unit was investigated in clinical conditions. MATERIALS AND METHODS All measurements were performed for 60Co γ-ray beams and...

Introduction: In radiation therapy centers across Iran, protection of normal tissues is usually accomplished by either Cerrobend or lead block shielding. In this study, the influence of these two shielding methods on central axis dose distribution of photon beam a Cobalt unit was investigated in clinical conditions. Materials and Methods: All measurements were performed for 60Co γ-ray beams an...

PURPOSE It is essential to assess the lung dose during TBI to reduce toxicity. Here we characterize the accuracy of the AAA and Acuros algorithms when using cerrobend lung shielding blocks at an extended distance for TBI. METHODS We positioned a 30×30×30 cm3 solid water slab phantom at 400 cm SSD and measured PDDs (Exradin A12 and PTW parallel plate ion chambers). A 2 cm thick, 10×10 cm2 cerr...

normal 0 false false false en-us x-none fa introduction: in radiation therapy centers across iran, protection of normal tissues is usually accomplished by either cerrobend or lead block shielding. in this study, the influence of these two shielding methods on central axis dose distribution of photon beam a cobalt unit was investigated in clinical conditions. materials and methods: all measureme...

background: in radiation therapy, the sparing of normal tissues can be performed using either multi-leaf collimators or cerrobend blocks. the current work focuses on the physical characteristics of cerrobend blocks including attenuation coefficient, effective penumbra width and isodose curves undulation in penumbral regions. materials and methods: all measurements were performed using a dual en...

background: during radiotherapy treatment, critical organs are shielded using lead and cerrobend blocks. the objective of this study is to compare the effects of lead and cerrobend shielding blocks on incident photon beam. methods: collimator scatter factors were measured for open square fields (3 x 3 cm to 40 x 40 cm) defined by collimator jaws and for fields blocked down to smaller asymmetric...

Introduction: Protecting the vital organs in radiation therapy is one of the most important issues. Cerrobend alloy, the most common material used as the shield, is melted several times and used for different patients. In this study changes in attenuation coefficient of cerrobend due to melting was investigated.   Materials and Methods: In melting furnace, ...

The purpose of the present work was to measure the performance characteristics in the penumbra region and on the leaf-end of an innovative dual-layer micro multileaf collimator (DmMLC). The DmMLC consists of two orthogonal (upper and lower) layers of leaves; a standard MLC consists of one layer. The DmMLC provides unique performance characteristics in smoothing dose undulation, reducing leaf-en...

Background: In Radiation Therapy, the sparing of normal tissues can be performed using either multi-leaf collimators or Cerrobend blocks. The current work focuses on the physical characteristics of Cerrobend blocks including attenuation coefficient, effective penumbra width and isodose curves undulation in penumbral regions. Materials and Methods: All measurements were performed using ...

background: the shielding methods in radiotherapy due to delivering an accurate radiation dose to cancer tissues and avoiding unnecessary dose to normal tissues are very important. these methods include lead standard blocks, individual molding and multi leaf collimator (mlc). the mlc method is not still common in iran radiotherapy centers. individual molding is better than the lead block shield...