An approximate correction method for the CT value-electron density curve of CBCT was established, through comparison and fitting with FBCT images, and applied to evaluate the therapeutic dose of IMRT. The precision of using CBCT for plan calculation was validated by comparing the dose distribution between CBCT- and FBCT-based IMRT plans. Also setup deviations were simulated to evaluate the abil...

The invention of computed tomography (CT) technique revolutionized diagnostic imaging. Compared to conventional X-ray imaging procedures, CT involves higher radiation doses. Recently, cone-beam CT (CBCT) specifically designed for maxillofacial imaging was introduced. CBCT technique is based on a cone-shaped X-ray beam centered on a twodimensional (2D) detector. The detector system performs one ...

Cone beam computed tomography (CBCT) provides a new method to evaluate the craniofacial region. The goal of our project was to introduce into the predoctoral dental curriculum a student-initiated, student-led introduction to CBCT and how to use it, with minimal expenditure of financial resources. A third-year student worked with two faculty members to design a course in which a small number of ...

PURPOSE The imaging characteristics of two popular kV cone-beam CT (CBCT) and two MVCT systems utilised in image-guided radiation therapy (IGRT) were evaluated. MATERIALS AND METHODS The study was performed on Varian Clinac iX, Elekta Synergy S, Siemens Oncor, and Tomotherapy. A CT phantom (Catphan-504, Phantom Laboratory, Salem, NY) was scanned for measurements of image quality including ima...

BACKGROUND With the introduction, development and commercialization of Cone Beam Computerized Tomography (CBCT) technologies in the field of head and neck reconstruction, clinicians now have increased access to the technology. Given the growth of this new user group, there is an increasing concern regarding proper use, understanding, quality and patient safety. METHODS The present study was c...

PURPOSE Cone beam CT (CBCT) in image-guided radiotherapy (IGRT) offers a tremendous advantage for treatment guidance. The associated imaging dose is a clinical concern. One unique feature of CBCT-based IGRT is that the same patient is repeatedly scanned during a treatment course, and the contents of CBCT images at different fractions are similar. The authors propose a progressive dose control (...

PURPOSE To prepare for yttrium-90 ((90)Y) microsphere radioembolization therapy, digital subtraction angiography (DSA) and technetium- 99m-labeled macroaggregated albumin ((99m)Tc MAA) scintigraphy are used for treatment planning and detection of potential nontarget embolization. The present study was performed to determine if cone-beam computed tomography (CBCT) affects treatment planning as a...

PURPOSE (a) To investigate the accuracy of cone-beam computed tomography (CBCT)-derived dose distributions relative to fanbeam-based simulation CT-derived dose distributions; and (b) to study the feasibility of CBCT dosimetry for guiding the appropriateness of replanning. METHODS AND MATERIALS Image data corresponding to 40 patients (10 head and neck [HN], 10 lung, 10 pancreas, 10 pelvis) who...

The growing use of cone-beam computed tomography (CBCT) for IGRT has increased concerns over the additional radiation dose to patients. The in-field dose of IGRT and the peripheral dose (PD) from kilovoltage CBCT (KV-CBCT) imaging have been well quantified. The purpose of this work is to evaluate the peripheral dose from megavoltage CBCT (MV-CBCT) imaging for nasopharyngeal carcinoma IGRT, to d...

Cone-beam computed tomography (CBCT) systems have been designed for imaging hard tissues of the maxillofacial region. CBCT is capable of providing sub-millimetre resolution in images of high diagnostic quality, with short scanning times (10-70 seconds) and radiation dosages reportedly up to 15 times lower than those of conventional CT scans. Increasing availability of this technology provides t...