Introduction: Orthogonal radial fields are those in which the central axes are perpendicular to each other. An example of these orthogonal fields is the set of craniospinal orthogonal fields that are used for radiotherapy of medulloblastoma. Craniospinal radial fields consist of two parallel-opposed fields for brain exposure and one or two posterior spinal fields for spinal cord exposure. The m...

In order to achive best results in radiotherapeutic treatment of tumor tissue, one needs to precisely reconstruct the setup defined in therapy planning before the treatment can start. Inaccuracies in either defining the treatment parameters or transferring positioning markers to the patient’s body, errors in treatment device setup or patient motion during the treatment result in a displacement ...

INTRODUCTION To compare the differences in setup errors measured with electronic portal image (EPI) and cone-beam computed tomography (CBCT) in patients undergoing tangential breast radiotherapy (RT). Relationship between setup errors, body mass index (BMI) and breast size was assessed. METHODS Twenty-five patients undergoing postoperative RT to the breast were consented for this study. Weekl...

In modern day radiotherapy, the emphasis on reduction on volume exposed to high radiotherapy doses, improving treatment precision as well as reducing radiation-related normal tissue toxicity has increased, and thus there is greater importance given to accurate position verification and correction before delivering radiotherapy. At present, several techniques that accomplish these goals impeccab...

background and aim. knowledge of the common radiographic errors and their prevention could prevent imposing redundant radiation, time and money to patient and the dentist. the aim of this study was to assess the common radiographic errors on panoramic radiographs in a radiology department. materials and methods. 250 panoramic radiographs (100 male and 150 female; mean age, 24.3) taken at the de...

Background & Aims: Owing to the significant role of CT images in diagnosis and follow up of patients affected with coronavirus, the imaging section of cancer centers in some countries engaged in providing services to COVID-19 patients. The aim of this study was to introduce a CT-independent photographic-based QA method in some radiotherapy departments where CTs are involved with COVID-19 patien...

Introduction: The close proximity of the rectum tissue to the prostate gland results in rectal toxicity during prostate radiotherapy. Rectal Retractor (RR) is a rectal displacement technique that inserts into the rectum, as a result, the lateral and dorsal part of the rectal wall push away from high dose areas. The aim of this study was to investigate the dosimetric consequence...

In adaptive radiotherapy, measured patient-specific setup variations are used to modify the patient setup and treatment plan, potentially many times during the treatment course. To estimate the setup adjustments and re-plan the treatment, the measured data are usually processed using Kalman filtering or by computing running averages. We propose, as an alternative, the use of Bayesian statistica...