Advanced technologies in image-guided radiation therapy.

In addition to rapid developments in the use of stationary radiographs and computed tomography scans in treatment rooms, a variety of additional technologies is on the horizon to aid in guided treatment. Some of these (fluoroscopy and tomosynthesis) are variations on the use of existing hardware, whereas others (electromagnetic localization, magnetic resonance imaging) represent significant departures from recently adopted technologic concepts. This review introduces these methods and explores their potential for initial use in guidance.