Dose-volume histogram

A dose-volume histogram (DVH) is a histogram relating radiation dose to tissue volume in radiation therapy planning. DVHs are most commonly used as a plan evaluation tool and to compare doses from different plans or to structures. DVHs were introduced by Michael Goitein (who introduced radiation therapy concepts such as the 'beam's-eye-view,' 'digitally reconstructed radiograph,' and uncertainty/error in planning and positioning, among others) and Verhey in 1979. DVH summarizes 3D dose distributions in a graphical 2D format. In modern radiation therapy, 3D dose distributions are typically created in a computerized treatment planning system (TPS) based on a 3D reconstruction of a CT scan. The 'volume' referred to in DVH analysis is a target of radiation treatment, a healthy organ nearby a target, or an arbitrary structure. A dose-volume histogram (DVH) is a histogram relating radiation dose to tissue volume in radiation therapy planning. DVHs are most commonly used as a plan evaluation tool and to compare doses from different plans or to structures. DVHs were introduced by Michael Goitein (who introduced radiation therapy concepts such as the 'beam's-eye-view,' 'digitally reconstructed radiograph,' and uncertainty/error in planning and positioning, among others) and Verhey in 1979. DVH summarizes 3D dose distributions in a graphical 2D format. In modern radiation therapy, 3D dose distributions are typically created in a computerized treatment planning system (TPS) based on a 3D reconstruction of a CT scan. The 'volume' referred to in DVH analysis is a target of radiation treatment, a healthy organ nearby a target, or an arbitrary structure. DVHs can be visualized in either of two ways: differential DVHs or cumulative DVHs. A DVH is created by first determining the size of the dose bins of the histogram. Bins can be of arbitrary size, e.g. 0–1 Gy, 1.001–2.000 Gy, 2.001–3.000 Gy, etc. In a differential DVH, bar or column height indicates the volume of structure receiving a dose given by the bin. Bin doses are along the horizontal axis, and structure volumes (either percent or absolute volumes) are on the vertical. The differential DVH takes the appearance of a typical histogram. It reads like the volume of the organ that receives the dose of the correspondent dose - bin. It is built by the sum of the number of voxels characterized by a specified range of dosage for the organ considered. It is helpful in providing information about changes in dose within the structure considered and to easily visualize minimum and maximum dose.