ESTRO course on Image Guided Radiotherapy in Clinical Practice 2018

Old School IMRT in Head and Neck 1994  19 predefined fields optimisation overnight  Co planar fields  Test the difference between head tilted backwards (chin-up) vs neutral/comfortable position (chin-down) in terms of dose to the parotid gland.

Patient position and IMRT

“Chin down”

“Chin up”

Patient example of interaction on planning and setup  50.4+ 70 Gy  Lnn metastasis melanoma of the skin  High dose near the brainstem, 54 Gy (ED2) – But with steep gradient towards more  How to deal? – Lower the target dose – Fractionate more – Decrease you CTV-PTV margin – Local guided setup

Patient position and IMRT

Dose to the parotid gland (chin down)

100

80

Right parotid

60

Left parotid

40

Vol.%

20

0

0

10

20

30

40

50

60

Dose to the parotid gland (chin up)

Dose (Gy)

100

80

Right parotid

60

Left parotid

40

Vol.%

20

0

0

10

20

30

40

50

60

Dose (Gy)

7