Beam's eye view (abbreviated BEV) is an imaging technique used in radiation therapy for quality assurance and planning of

external beam radiotherapy External beam radiotherapy (EBRT) is the most common form of radiotherapy (radiation therapy). The patient sits or lies on a couch and an external source of ionizing radiation is pointed at a particular part of the body. In contrast to brachyt ...

(EBRT). These are primarily used to ensure that the relative orientation of the patient and the treatment machine are correct. The BEV image will typically include the images of the patient's anatomy and the beam modifiers, such as jaws or multi-leaf collimators (MLCs).

Generation of Beam's Eye Views

* Physical Construction: ** BEV's can be generated by exposing a high energy film (similar to

photographic film Photographic film is a strip or sheet of transparent film base coated on one side with a gelatin photographic emulsion, emulsion containing microscopically small light-sensitive silver halide crystals. The sizes and other characteristics of th ...

) or an Electronic Portal Imaging Device (EPID) with the treatment beam itself after it passes through the patient and any beam modifiers (such as blocks). Although this type of image is an excellent indication of the basic quality of the treatment plan, the quality of film images can be poor. ** A BEV can be created using a radiation therapy simulator which mimics the treatment geometry (couch angle, gantry angle, etc.) using an X-ray source instead of the higher energy treatment source. The jaws and blocks can be imaged on the same film as the patient's landmarks. * Artificial Reconstruction: The BEV can be created using a

Digitally Reconstructed Radiograph A computed tomography scan (CT scan; formerly called computed axial tomography scan or CAT scan) is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers ...

(or DRR) that is created from a

computed tomography A computed tomography scan (CT scan; formerly called computed axial tomography scan or CAT scan) is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers ...

(or CT) data set. This image would contain the same treatment plan information, but the patient image is reconstructed from the CT image data using a physics model.

References

* Faiz Kahn and Roger Potish (Eds.) (1998).''Treatment Planning in Radiation Oncology''. Williams & Wilkins. . * Jacob Van Dyk (Ed.) (1999). ''The Modern Technology of Radiation Oncology''. Medical Physics Publishing. . * Ross I. Berbeco (Ed.) (2018). ''Beam's Eye View Imaging in Radiation Oncology''. CRC Press. {{ISBN, 978-1-4987-3634-3. * Louis Lemieux, Roger Jagoe, David R. Fish, Neil D. Kitchen, David G. Thomas, ''A patient-to-computed-tomography image registration method based on digitally reconstructed radiographs.'' Med. Phys. 21(11), 1749–1760 (1994). https://doi.org/10.1118/1.597276 Radiobiology Medical physics