Assessment of skin dose delivered to patients from radiotherapy x-ray beams should be performed both inside and outside the prescribed treatment fields. A multilayer Gafchromic film detector which has high sensitivity for detection of radiation can be used to measure skin dose in a two-dimensional map over the skin surface if required. This is an advantage over other detectors, which only provi...

Introduction: Due to the effect of radiation on both the tumor and the surrounding normal tissues, the side effects of radiation in normal tissues are expected. One of the important complications in the head and neck radiotherapy is the doses reached to the larynx and spinal cord of patients with non-laryngeal head and neck tumors.   Materials and Methods: ...

background: attenuation coefficient (μ) plays an important role in calculations of treatment planning systems, as well as determination of dose distributions in external beam therapy, dosimetry, protection, phantom materials and industry. so, its exact measurement or calculation is very important. the aim of this study was to evaluate the μ in different points in the water phantom analytically ...

background: accurate small radiation field dosimetry is essential in modern radiotherapy techniques such as stereotactic radiosurgery (srs) and intensity modulated radiotherapy (imrt). precise measurement of dosimetric parameters such as beam profile, percentage depth doses and output factor of these beams are complicated due to the electron disequilibrium and the steep dose gradients. in the p...

background: pet/ct imaging using [18f]-fdg is utilized in clinical oncology for tumor detecting, staging and responding to therapy procedures. essential consideration must be taken for radiation staff due to high gamma radiation in pet/ct and cyclotron center. the aim of this study was to assess the staff exposure regarding whole body and organ dose and to evaluate environment dose in pet/ct an...

These experiments compare the out-of-field dose delivered during different treatment techniques (photons, active and passive delivered protons and carbon ions) in standardized conditions. A water phantom is used as tissueequivalent material and is irradiated with a rectangular field. The dose is measured in lateral direction in the plane of the field as shown in Fig. 1. The composition of the o...

Introduction: Inclusion of inhomogeneities such as air-filled cavities in the head and neck treatment fields may result in potential dosimetric disagreement which was caused by electronic disequilibrium. Most of treatments planning systems (TPS) are not able to predict dose distribution of inhomogeneous regions accurately. EBT2 films are used frequently in radiotherapy quality ass...

Background: Radiotherapy with large mantle field is an effective technique in increasing the risk of secondary cancers among HL (Hodgkin Lymphoma) patients; therefore, it is essential to choose an effective treatment field including the least medical conditions in radiotherapy.Objective: The present study aimed to plan separate fields for neck and mediastinum using various energies, to compare ...

Introduction: In radiotherapy, treatment planning methods are evaluating and transforming every day, so precision in calculation and determination of dose delivery process is performing more important role in radiotherapy than past. In modern radiotherapy treatments, deramatically increase of small fields utilization, causes the polymeric gels has known as the most reliable dos...