Beam's eye view (abbreviated BEV) is an imaging technique used in

radiation therapy Radiation therapy or radiotherapy (RT, RTx, or XRT) is a therapy, treatment using ionizing radiation, generally provided as part of treatment of cancer, cancer therapy to either kill or control the growth of malignancy, malignant cell (biology), ...

for quality assurance and planning of

external beam radiotherapy External beam radiation therapy (EBRT) is a form of radiotherapy that utilizes a high-energy collimated beam of ionizing radiation, from a source outside the body, to target and kill cancer cells. The radiotherapy beam is composed of particl ...

(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: ** BEVs 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 the ...

) 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 that mimics the treatment geometry (couch angle, gantry angle, etc.) using an

X-ray An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ran ...

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 (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 (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 ...

(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