ESTRO course on Image Guided Radiotherapy in Clinical Practice 2018

How flexible is the neck ? Results: PTV (larynx)

How flexible is the neck ?

Count of Larynx found within margin after online registration in 249 CBCT scans

Count occurrence of ROI within certain margin

110.0

100.0

90.0

ROI:

80.0

70.0

• PTV(larynx)

60.0

Org. Reg.

50.0

• OAR (C3-C5)

40.0 Count (%)

Larynx - Multi Match

30.0

Larynx - Overall ROI

Margin 0..10 mm (1 mm)

20.0

Larynx - Larynx

10.0

0.0

0

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

1

Margin(cm)

How flexible is the neck ? Results: OAR/lymphnode

Side things learned from imaging

Count of C3-C5 found within margin after online registration in 249 CBCT scans

 Bad tongue depressor  Tumor borders moving outside the field  Old school patient positioning advise  Keep your eye open to unexpected recurrences (Close the feedbackloop)

100.0 110.0

0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 90.0

Org. Reg.

C3-C5 - Multi Match

Count (%)

C3-C5 - OverallROI

C3-C5 - Larynx

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Margin(cm)

Tongue depressor New Old

Two examples on the side

 Positioning of the patient  Interaction of image guidance and treatment planning – How to ease the life of your treatment planner

6