2017_SBRT_Course Book

Auto detection and Beam Hold

• User defines a spherical ROI around these markers : TI limit – COG marker on TI is marked with a cross – If marker on TI is inside TI Limit, circle is projected as green – If marker outside TI Limit circle is red – and if marker can’t be detected, circle is projected as orange • If >=1 markers outside TI limit treatment system can hold (pause) the treatment beam: beam hold (BH) – If time is chosen as trigger and beam is held the system keeps shooting TI – If all markers return within TI limit system continues beam automatically

• ABH can act in passive or active mode