cone-beam computed tomography
Also written as: CBCT — Cone-Beam Computed Tomography
On-treatment imaging technique using a cone-shaped X-ray beam to verify patient positioning and anatomical changes.
Full Definition
Cone-beam computed tomography (CBCT) is an imaging technology integrated into modern linear accelerators that provides three-dimensional images of the patient in the treatment position. Unlike diagnostic CT scanners, CBCT uses a cone-shaped X-ray beam and flat-panel detector that rotate around the patient to acquire volumetric images. These images are compared to planning CT scans to verify accurate patient positioning and identify anatomical changes that may require treatment plan modifications. CBCT is a cornerstone of image-guided radiation therapy.
Usage
Usage note: Distinguish from conventional fan-beam CT in technical specifications.
In Context
- "Daily CBCT imaging revealed a 3mm setup error that was corrected before treatment." — Treatment verification log
- "The cone-beam computed tomography scan showed significant tumor regression after 20 fractions." — On-treatment assessment