Accuracy

Cyberknife Radiosurgery	One-millimeter accuracy protects surrounding tissues
External Beam Radiotherapy (EBRT)
Intensity-Modulated Radiotherapy (IMRT)	Target area is expanded to include the prostate plus 5-10 millimeters to account for uncertainty
Calypso-Guided EEBRT/IMRT	Target area is expanded to include the prostate plus approximately 5 millimeters to account for uncertainty
High-Dose-Rate (HDR) Brachytherapy	Custom radiation plan delivers radiation dose to within 2-3 millimeters of the target, which spares surrounding tissues
Low-Dose-Rate (LDR) Brachytherapy (Seed Implant)	Seeds positioned with 3-5 millimeters accuracy; occasionally some seeds migrate to the lung(s)

	Correcting for movement	Method of targeting/tracking
Cyberknife Radiosurgery	Throughout treatment robot automatically adjusts for any movement or rotation	Robot autmotatically locates fiducials
External Beam Radiotherapy (EBRT)
Intensity-Modulated Radiotherapy (IMRT)	Technician manually adjusts prior to each treatment session; no real-time correction for any movement or rotation during treatment	Patient's skin is marked and therapist aligns on those two marks, or targets fiducials using X-ray images
Calypso-Guided EEBRT/IMRT	If movement exceeds error threshold (3 mm), treatment stops and technician manually adjusts treatment table; no correction for rotation	Radio-frequency detector determines beacon location. Therapist manually adjusts treatment table accordingly
High-Dose Rate (HDR) Brachytherapy	Physician manually places catheters using ultrasound images for guidance; a customized treatment plan accounts for variation in catheter position	Ultrasound probe placed in rectum visualizes prostate and needle/catheter position
Low-Dose Rate (LDR) Brachytherapy (Seed Implant)	Physician manually places needles using ultrasound images for guidance; no corrections possible after seeds have been implanted	Ultrasound probe placed in rectum visualizes prostate and needle/seed position