Advanced Physics for Brachytherapy 2018

Inter-/intrafraction variation in cervix cancer BT

1 plan evaluated for images at different time points. Anatomical changes between irradiations may lead to large random dosimetric uncertainties

Inter-/intrafraction variation in cervix cancer BT Klug F2 fraction 2 fraction 3 fraction 4

fraction 1

Klug F1

© Lang et al. 2013, Radiother Oncol 107

variation

# patients treatment

fractions

time range

Image type

images

1

21

HDR

4

18-20 hrs

MRI

84

Intra-app.

2

21

HDR

3

5 hrs

MRI

72

Intra-app.

3

9

PDR

2 x 29 / 32

22 hrs

MRI

36

Intra-app.

4

14

HDR

5

1-22 days

CT

69

Inter-app.

5

27

HDR

4

7-10 days

MRI

54

Inter-app.

6

31

PDR

2 x 20

1 week

MRI

62

Inter-app.

123 patients

5 h – 3 weeks

377 3 + 3

Nesvacil et al. 2013, Radiother Oncol 107