Parotid gland cancer; 3DCRT; Postoperative radiotherapy techniques; Dose distribution Abstract Introduction: Postoperative radiotherapy of the parotid gland could be achieved with various radiotherapy techniques. However they irradiate differently the surrounding organs at risk (OARs) in particular the cochlea, oral cavity & contralateral parotid causing significant increase in the risk of oral...

PURPOSE Overlapping volume histogram (OVH) and distance-to-target histogram (DTH) calculations rely on the assumption that dose gradients are symmetric with respect to primary target volume (PTV) expansion and minimum distance to PTV surface, respectively. It is desirable to lift this assumption and instead account for achievable modality-specific dose gradients (MSDG) for a given PTV shape. ...

BACKGROUND Acute ankle injuries are one of the most common reasons for presenting to emergency departments, but only a small percentage of patients--approximately 15%--have clinically significant fractures. However, these patients are almost always referred for radiography. The Ottawa Ankle Rules (OARs) have been designed to reduce the number of unnecessary radiographs ordered for these patient...

AIM The aim of this study was to explore the effects of changes in the gross tumor volume (GTV) on dose distribution in organs at risk (OARs) and healthy brain tissue in patients with gliomas. METHODS Eleven patients suffering from gliomas with intensity-modulated radiotherapy (IMRT) plans treated with a simultaneous integrated boost technique planned before therapy (initial plans) were prosp...

BACKGROUND For brachytherapy of cervical cancer, applicator shifts can not be avoided. The present investigation concerned Utrecht interstitial applicator shifts and their effects on organ movement and DVH parameters during 3D CT-based HDR brachytherapy of cervical cancer. MATERIALS AND METHODS After the applicator being implanted, CT imaging was achieved for oncologist contouring CTVhr, CTVi...

This study evaluates three-dimensional conformal radiotherapy (3D CRT), volumetric-modulated arc therapy (VMAT), and dynamic conformal arc therapy (DCAT) planning techniques using dosimetric indices from Radiation Therapy Oncology Group (RTOG) protocols 0236, 0813, and 0915 for the treatment of early-stage non-small cell lung cancer (NSCLC) using stereotactic body radiotherapy (SBRT). Twenty-fi...

BACKGROUND Tumor-Treating Fields (TTFields) are a novel treatment strategy for glioblastoma (GBM) that is approved for the use concomitantly to adjuvant chemotherapy. Preclinical data suggest a synergistic interaction of TTFields and radiotherapy (RT). However, the dosimetric uncertainties caused by the highly dense arrays have led to caution of applying the TTF setup during RT. METHODS In a ...

INTRODUCTION Post-operative radiotherapy (PORT) for stage IIIA completely-resected non-small cell lung cancer (CR-NSCLC) has been shown to improve local control; however, it is unclear that this translates into a survival benefit. One explanation is that the detrimental effect of PORT on critical organs at risk (OARs) negates its benefit. This study reports an in-silico comparative analysis of ...

PURPOSE The purpose of this study is to investigate the dose-volume variations of planning target volume (PTV) and organs-at-risk (OARs) in prostate volumetric modulated arc therapy (VMAT) when using different collimator angles. It is because collimator angle awareness is essential for planner to produce an optimal prostate VMAT plan in a rational time. METHODS Single-arc VMAT plans at differ...

Background: This Study Evaluate two state of Art techniques, Rapid Arc and large-field sliding window IMRT in terms of dosimetric end points and delivery time for head and neck cancer. Materials and Methods: 22 patients with head and neck cancer were selected for a planning comparative study. All patients went to CT-simulation in supine position. PTVs were delineated for two dose level of presc...