background: prediction of the absorbed dose in irradiated volume plays an important role in the outcome of radiotherapy. application of small fields for radiotherapy of thorax makes the dose calculation process inaccurate due to the existence of electronic disequilibrium and intrinsic deficiencies in dose calculation algorithms. to study the lung absorbed dose in radiotherapy with small fields,...

Introduction: The use of ionizing radiation in diagnostic medicine is expanding, and considering the fact that the practical dosimeter in a precise way is almost impossible, the Monte Carlo computational methods help researchers, to have coming up the lowest cost and error of the distribution of doses in the patient's body.   Materials and Methods: In this st...

Introduction: Esophageal cancer is one of the most frequently occurring cancers in Iran and having a  high  incidence  rate  among  other  countries.  Radiotherapy  is  one  of  the  three  methods  (surgery,  radiotherapy and chemotherapy) for radical or palliative treatment of esophageal cancer. In this method  of treatment, the organs such as heart and spinal cord are regarded as organs at r...

Introduction: The complex geometry of breast and also lung and heart inhomogeneities near the planning target volume (PTV) result in perturbations in dose distribution. This problem can result in overdosage or underdosage in the match region of the three treatment fields. The purpose of this study is to create a homogeneous dose distribution in the match region between the supraclavicular and t...

background: to determine which radiotherapy parameters are associated with the tumor response of locally advanced non-small cell lung cancer (nsclc) patients undergoing concurrent chemoradiotherapy. materials and methods: thirty one patients with iiia/iiib nsclc underwent chemoradiotherapy with a median dose of 63 gy. on our actual treatments, we made radiotherapy planning to cover the planning...

Background: We aimed to compare field-in-field technique (FIF) with conformal tangential field radiotherapy (CRT) in terms of dosimetric benefits for early stage breast cancer radiotherapy. Materials and Methods: Twenty consecutive left-side breast cancer patients who underwent breast-conserving surgery were included to the study. For each patient, two different treatment plans were cr...

In many thoracic cancers, the radiation dose that can safely be delivered to the target volume is limited by the tolerance dose of the surrounding lung tissue. It has been hypothesized that irradiation of the heart may be an additional risk factor for the development of early radiation-induced lung morbidity. In the current study, the dependence of lung tolerance dose on heart irradiation is de...

Introduction: The proton beam produced in particle accelerators has an appropriate therapeutic potential. In this research, proton therapy of breast cancer is simulated using the MCNPX code in a MIRD phantom, also the contribution of scattered neutron dose during the proton therapy were calculated for the Heart, Lung and Liver.   Materials and Methods: For si...