Multileaf collimator and compensator for radiotherapy machines
US4868843A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 10, 1987 |
| Grant date | Sep 19, 1989 |
| Priority date | — |
| Expiry date | Jul 10, 2007 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61N2005/1095
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
In a radiation therapy machine it is desirable to produce irregular radiation field shapes in order to shield critical organs not invaded by the tumor. A system is provided using a multileaf collimator formed of a multiplicity of heavy metal bar leaves driven relative to a pair of frames which are driven relative to jaws of a rectangular field collimator. A multiplicity of compensators, one attached to each leaf on one of the pair of frames is used to adjust the local intensity of the radiation within the field. The x-ray beam is limited to a fan with the jaws, the ends and selected parts of the fan are blocked by the multileaf collimator, and the intensity within various portions of the remaining beam is adjusted with compensators. The field of the fan beam is dynamically controlled by these means while the patient table is moved perpendicular to the plane of the fan beam.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.