VMAT SX1

Name (ID): SBRT, PROSTATE (AAMD_RSS2016PS)
Plan or PlanSum ID: 79Gy4A_0815_T

VMAT technique was chosen and 4 almost complete arcs were used.  Each arc used a different start and stop angle (offset by 1 degree) to stagger the available control points throughout each arc rotation.  There really weren’t too many challenges in this case, the only metric that provided a challenge was achieving the minimum PTV coverage constraint.  When a protocol enforces a minimum dose to the target, the temptation is to simply perform a uniform expansion on the target and optimize on the expanded target.  However, in this case, an optimization PTV was created and stretched outward only along the edges of the real PTV where the minimum dose was not met.  Careful attention was paid to minimize stretching where the target interfaced/overlapped with an OAR (rectum).

Simple prostate only case, fractionated. All constraints on the bladder, rectum, bowel are met. This is a clinically acceptable plan.

_{Any reference to a "plan study" are simply what the organizers call each case and may not be a "study" in the FDA sense as they may not have been published in a peer reviewed journal.
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