Dose Course 2018_Flipping book

Additional uncertainties

• Internal uncertainties (target position, size and shape) • Tumour growth/treatment response • Weight gain/loss • Breathing • Bowel and rectal filling • Bladder filling • Heartbeat, swallowing, coughing • External uncertainties (patient and beam positioning)

• Muscle relaxation/tension • Fixation and immobilisation • Mechanical and dosimetric uncertainty