2017_SBRT_Course Book

Observation of Motion

▪ Tumor motion varies widely (0-50 mm) ▪ 12 mm on average in CC direction

▪ 2 mm on average in AP and LR direction ▪ The tumor position in the exhale phase is more stable than the tumor position in the inhale phase

  t

  

  

n 2

y

A y cos

 





0

Seppenwoolde et al. Int. J. Radiation Oncology Biol. Phys., Vol. 53, No. 4, pp. 822–834, 2002