AbstractID: 7857 Title: Practical Examples, Including IMRT, TBI, SRS
NCRP Report No. 151(December 2005), titled “Structural Shielding Design and
Evaluation for Megavoltage X- and Gamma-Ray Radiotherapy Facilities”, presents
updated methods and data for radiation therapy room shielding design. These calculation
methods are applied in examples representing the more common shielding design
situations. A radiation therapy vault with a maze barrier and intended for use with IMRT
and TBI procedures is the principal example. Detailed calculations of the barriers and
door shielding structures are presented. Procedures for evaluating compliance with the
NRC licensing constraint on dose equivalent in-any-one-hour are presented. An
example of a high-energy room where photoneutron production is of concern is presented
with focus on assessing the dose equivalent at the entrance and the maze door design.
Objectives: Learn by worked examples (1) how to apply the methods and data presented
in NCRP 151 for designing high energy therapy vault barriers; (2) how to determine
prospectively if the barrier design is adequate to satisfy the public areas “2 mrem in-anyone-hour” constraint when it is applicable.