Introduction: Integrated radiation therapy - MRI systems are capable of delivering high doses to the target tissues near sensitive organs and achieve better therapeutic results; however, the Applied magnetic fields for imaging, can influence the charged path, change the penetration depth and deflect the particles, laterally, leading to dose distribution variations. Therefore, i...

the aim of radiation therapy treatment planning is to achieve an optimal balance between delivering a high dose to target volume and a low dose to healthy tissues. in order to refrain any complications resulting from the dose to the surrounding normal organs, the role of treatment plan has been critically evaluated in term of how large the volume or mass of normal tissues exposed in the radiati...

introduction: this study was designed to evaluate dosimetric parameters such as rectal dose, bladder dose, integral dose (id), homogeneity index (hi) and conformity index (ci) in various treatment plans for prostate cancer. materials and methods: pelvic computed tomography (ct) scans of 27 patients were acquired and transferred to the rtdoseplan treatment planning system. for each patient, 8 co...

Introduction: Tumor control and treatment quality depend on accuracy of delivered dose. Various methods have been studied for treatment dosimetry verification. Among these methods, the use of electronic portal imaging device (EPID) is highly considered. Many efforts are underway to improve the results of this context.   Materials and Methods: In this study, ...

aims: it was aimed to investigate postoperative conformal radiotherapy planning that provides the best target volume and the least dose for critical organs in cancers of stomach. methods: this study was conducted on the ct simulation images of thirty patients diagnosed with gastric cancer. target volumes and the organs at risk were contoured. ap-pa reciprocal parallel field conventional plan an...

Introduction: In 3DCRT the number of therapeutic fields has dramatic impact on treatment results especially in stomach cancer. Traditionally, for radiotherapy of stomach cancer the therapeutic procedure was using two fields (AP- PA or AP Lateral with wedge) to achieve smooth and homogeneous dose distribution in tumor. But nowadays, adding lateral or oblique fields to aforement...

Introduction Wedge modifiers are commonly applied in external beam radiotherapy to change the dose distribution corresponding to the body contour and to obtain a uniform dose distribution within the target volume. Since the radiation dose delivered to the target must be within ±5% of the prescribed dose, accurate dose calculation by a treatment planning system (TPS) is important. The objective ...