Patent attributes
Brachytherapy is carried out with a needle to inject a radioactive seed into a patient's body. A space-fixed detector detects radiation from radiation emitters to determine the position of a deposited seed from the needle with reference to a space-fixed coordinate system. Markers may be affixed to the patient's body such that a body-fixed coordinate system can be determined in real time by an imaging device. Alternatively, earlier obtained patient's anatomical data may be referenced. After positions of earlier injected seeds are thus ascertained in real time in the body-fixed coordinate system, the stored anatomical data may be updated and a radiation dose distribution can be calculated from the determined seed positions. The calculated radiation dose distribution can be displayed and compared with a planned distribution.