International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Sep 2005
Retrospective analysis of prostate cancer patients with implanted gold markers using off-line and adaptive therapy protocols.
To determine the efficacy of applying adaptive and off-line setup correction models to bony anatomy and gold fiducial markers implanted in the prostate, relative to daily alignment to skin tattoos and daily on-line corrections of the implanted gold markers. ⋯ Changes in a prostate cancer patient's systematic and random setup characteristics during the course of therapy often violate the gaussian assumptions of adaptive and off-line correction models. Thus, off-line setup correction procedures, especially those directed at prostate localization using markers, will result in limited benefit to a minority of patients. The relative benefit of on-line localization is still potentially significant if the intrafraction motion is relatively small.