Strahlposition

Strahlposition is a term used to describe the spatial configuration of a radiation beam relative to a target, detector, or imaging plane. It is a general concept applied across medical imaging, radiotherapy, and industrial or experimental contexts. The Strahlposition encompasses the beam’s origin, direction, and point of incidence, as well as its distance to the target.

In diagnostic radiology and radiotherapy, the Strahlposition is defined by several parameters, including the beam axis, the gantry angle, the position of the patient or couch, and the source-to-image or source-to-axis distance. Shaping devices such as collimators or multileaf collimators also determine the Strahlposition by constraining the beam footprint. Correct beam positioning ensures that the exposure or dose is delivered to the intended region while minimizing unnecessary irradiation of healthy tissue.

Determining and maintaining the proper Strahlposition relies on alignment lasers, anatomical landmarks or fiducial markers, and imaging verification such as planar radiographs or cone-beam CT. Modern systems use automated couch and gantry motions with image-guided verification to achieve reproducibility between treatment fractions or imaging sessions. Quality assurance programs regularly test and document the accuracy and stability of beam positioning.

In other contexts, such as industrial radiography or particle-physics experiments, Strahlposition describes the beam’s incidence on a detector or object, influencing projection geometry, resolution, and calibration. Across applications, careful control of Strahlposition is essential for reliable imaging, precise dose delivery, and accurate experimental results.