1. Modern Treatment Planning
Florian Cremers
Klinik für Strahlentherapie
Campus Lübeck

2. Dose effect curves: in vitro und in vivo
Murine tumour AT 17
cell culture
Number of clonogenic tumor cells
Clones of surviving cells
after irradiation
Deep ascent of local control within a small dose range
mouse model
Local tumour control

3. Tumor control versus tissue damage
local tumor control (T)
Damage of
healthy tissue (N)
Probability [%]
Complicationless
cure H = T(1-N)
Dose
Bild modified according to: Holthusen H: Erfahrungen über die Verträglichkeitsgrenze für Röntgenstrahlen und deren Nutzanwendung. Strahlentherapie 1936; 57:

4. Goal of Radiotherapy
Supply the tumor with sufficient dose while optimally sparing the healthy tissue

5. Linear Accelerator Radiation Equipment Basics
Linear Accelerator CLINAC 2100 DHX (clinical linear accelerator)
different beam qualities and energies
photons: 6 MV X and 18 MV X
electrons: 6 MeV, 9 MeV, 12 MeV, 16 MeV, 20 MeV

6. Computed tomography CT (Basis for treatment planning)
tomography (greek „τομή tome“ = slice and „γράφειν graphein“ = write)
CT is a computer based evaluation of multiple X-ray photographs of an object from different directions (projections)  reconstruction of 2D/3D images

7. Oncologic Volumes according to ICRU
ITV
CTV
GTV
ICRU: International Commission of Radiation Units

8. Oncologic volumes according to ICRU
PTV
ITV
CTV
GTV

9. Oncologic volumes

10. Example: Recurrence of a GlioblastomaCT

11. Example: Recurrence of a GlioblastomaMR

12. Example: Recurrence of a Glioblastoma
CT with
GTV and PTV

13. Example: Recurrence of a Glioblastoma
Overview

14. Example: Recurrence of a Glioblastoma
3D view

15. Goal of treatment planning
Supply the tumor with sufficient dose while optimally sparing the healthy tissue
No less than 95% and no more than 107% of the prescription dose to the PTV (ICRU recommendation)
PTV
ITV
CTV
95%
GTV
Tissue outside the PTV cannot be completely spared as in all transmitted healthy tissues dose will be applied as well!
ALARA principle!!!
„As Low As Reasonably Achievable“

16. Example Breast cancer (Mamma carcinoma)

17. Different fields in Colourwash

18. Plan evaluation (Dose-Volume Histogram DVH)
? %
20 %
20%
20 Gy
20 Gy

19. Dosis-Volume Histogram (Mamma + Supra)
100
Planning Target
Volume
(PTV)
Volumen [%]
Organ At Risk (OAR)
20 %
20 Gy
Dose [%]
100

20. Dose-Volume Histogram (Mamma + Supra)
100
Planning Target
Volume
(PTV)
Volume [%]
Organ At Risk (OAR)
20 %
20 Gy
Dose [%]
100

21. Example: Bronchial Carcinoma
bronchial carcinoma – treatment planning

22. Cảm ơn nhiều !