Accurate dose delivery is essential for the success of intensity-modulated radiation therapy (IMRT) for patients with head-and-neck (HN) cancer. Reproducibility of IMRT dose delivery to HN regions can be critically influenced by treatment-related changes in body contours. Moreover, some set-up margins may not be adaptable to positional uncertainties of HN structures at every treatment. To obtai...

The improvement in conformal radiotherapy techniques enables us to achieve steep dose gradients around the target which allows the delivery of higher doses to a tumor volume while maintaining the sparing of surrounding normal tissue. One of the reasons for this improvement was the implementation of intensity-modulated radio therapy (IMRT) by using linear accelerators fitted with multi-leaf coll...

RATIONALE Cone Beam Computed Tomography imaging has become increasingly important in many fields of interventional therapies. OBJECTIVE Lung navigation study which is an uncommon soft tissue approach. METHODS As no effective organ radiation dose levels were available for this kind of Cone Beam Computed Tomography application we simulated in our DynaCT (Siemens AG, Forchheim, Germany) suite ...

PURPOSE To assess the quality of cone beam computed tomography images obtained by a robotic arm-based and image-guided small animal conformal radiation therapy device. METHOD AND MATERIALS The small animal conformal radiation therapy device is equipped with a 40 to 225 kV X-ray tube mounted on a custom made gantry, a 1024 × 1024 pixels flat panel detector (200 μm resolution), a programmable 6...

objectives this study aimed to assess the effect of object position in the field of view (fov) of cbct on detection of vrfs in teeth with intra-canal posts. materials and methods the crowns of 60 extracted premolar teeth were cut at the level of cementoenamel junction (cej). root canals were filled with gutta-percha and filling of the coronal 2/3 of the root canals was subsequently removed to f...

objective: diagnosis of vertical root fractures (vrfs) is critical in endodontics. cone beam computed tomography (cbct)  has significantly enhanced image quality compared to digital radiography (dr) and greatly aids the diagnosis of vrfs but, metal artifacts has remained as a problem in vrf detection.  this study evaluated the effect of intra canal posts on the diagnostic accuracy of cbct and d...

introduction: due to the importance of apical transportation during root canal preparation, the aim of the current study was to use cone-beam computed tomography (cbct) to assess the extent of apical transportation caused by protaper and mtwo files. methods and materials: forty extracted maxillary first molars with 19-22 mm length and 20-40 degrees of curvature were selected. the mesiobuccal ca...

introduction : the aim of this in vitro study was to compare the effect of gates-glidden and peeso reamer drills on residual dentin thickness during post space preparation in order to discover which method has minimum root structure damage. materials and methods: thirty extracted human maxillary premolars with bifurcations at root middle were horizontally cut 15 mm coronal to the apical end aft...