field matching
The technique of aligning adjacent radiation fields to ensure uniform dose distribution at field junctions.
Full Definition
Field matching is a critical planning technique used when the target volume is too large to be treated with a single field, requiring multiple adjacent fields to achieve complete coverage. The primary challenge is ensuring uniform dose distribution at the junction between fields while avoiding both overdose (hot spots) and underdose (cold spots). Traditional field matching uses geometric techniques like half-beam blocking or feathering the junction. Modern approaches may employ field-in-field techniques or IMRT optimization to create seamless dose distributions across field boundaries. Proper field matching is essential in treatments like craniospinal irradiation or extended field lymphatic irradiation.
In Context
- "Careful field matching eliminated the hot spot at the spinal junction." — Craniospinal treatment plan
- "Field matching techniques ensure uniform dose across adjacent treatment areas." — Planning protocol