Positron emission tomography (PET) is a radioisotope imaging
method for obtaining information on the status of organs
and metabolisms within the human body. The imaging principle
used in PET is the coincidence detection of two 511 KeV
annihilation photons-originated electron-positron annihilation.
In practice, a radiopharmaceutical (e.g., F-18-FDG)
obtained by uniting a positron emitter radioisotope (e.g., C-11, N-13, O-15, F-18) and glucose molecule is given to the
patient by way of blood injection. PET detects these 511 KeV
annihilation photons accumulated in the abnormal structures
and then three-dimensional imaging of the body is created by
the computer. In this review of the imaging principle of PET,
scintillation crystals, PET radioisotopes and PET for radiotherapy
treatment planning are discussed.
Keywords: Biological target volume; positron- electron annihilation; positron emission tomography; radiotherapy treatment planning
