Randomized Study Comparing Two Dosing Schedules for Hypofractionated Image-Guided Radiation Therapy

Pts in both the hypofractionated \& single dose arms will receive the same following standard procedures. The only difference between the arms is the dose delivered at each treatment. 20 MSKCC pts (10 per treatment arm) will be accrued to undergo baseline DW-MRI \& DCE-MRI pretreatment for both arms \& 1 hour after their initial treatment for single fraction pts, \& within one hour of their initial \& final radiation treatment for the hypofractionated pts. Pts will be considered for this scan based on compliance to scan schedule \& MRI availability for performing the scan within one hour of the planned IGRT. 24 MSKCC pts (12 per treatment arm) will be accrued for the blood collection (optional) up to 4 hours prior, 50-90 minutes after, \& approximately 24 hours \[MCPG2.3\]after treatment for single fraction pts. For pts partaking in both sub-studies, the post-treatment blood collection may be done in a 50-120 minute window to account for scheduling conflicts with the research MRI.

Pts in both the hypofractionated \& single dose arms will receive the same following standard procedures. The only difference between the arms is the dose delivered at each treatment. 20 MSKCC pts (10 per treatment arm) will be accrued to undergo baseline DW-MRI \& DCE-MRI pretreatment for both arms \& within 1 hour after their initial treatment for single fraction pts, \& within one hour of their initial \& final radiation treatment for the hypofractionated pts. Pts will be considered for this scan based on compliance to scan schedule \& MRI availability for performing the scan within one hour of the planned IGRT. 24 MSKCC pts (12 per treatment arm) will be accrued for the blood collection (optional) up to 4 hours prior, 50-90 minutes after, \& approximately 24 hours \[MCPG2.3\]after treatment for single fraction pts. For pts partaking in both sub-studies, the post-treatment blood collection may be done in a 50-120 minute window to account for scheduling conflicts with the research MRI.