IMRT fluence map editing to control hot and cold spots

• Published in: Medical dosimetry : official journal of the American Association of Medical Dosimetrists Vol. 30; no. 4; p. 201
• Main Authors: Cook, J Taylor, Tobler, Matt, Leavitt, Dennis D, Watson, Gordon
• Format: Journal Article
• Language: English
• Published: United States 2005
• Subjects: Head and Neck Neoplasms - diagnostic imaging; Head and Neck Neoplasms - radiotherapy; Humans; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted - methods; Radiotherapy, Intensity-Modulated; Tomography, X-Ray Computed; Treatment Outcome
• ISSN: 0958-3947
• DOI: 10.1016/j.meddos.2005.08.001

Manually editing intensity-modulated radiation therapy (IMRT) fluence maps effectively controls hot and cold spots that the IMRT optimization cannot control. Many times, re-optimizing does not reduce the hot spots or increase the cold spots. In fact, re-optimizing only places the hot and cold spots in different locations. Fluence-map editing provides manual control of dose delivery and provides the best treatment plan possible. Several IMRT treatments were planned using the Varian Eclipse planning system. We compare the effects on dose distributions between fluence-map editing and re-optimization, discuss techniques for fluence-map editing, and analyze differences between fluence editing on one beam vs. multiple beams. When editing a beam's fluence map, it is essential to choose a beam that least affects dose to the tumor and critical structures. Editing fluence maps gives an advantage in treatment planning and provides controlled delivery of IMRT dose.