Stereotactic radiotherapy

Transcription

1 Stereotactic radiotherapy Influence of patient positioning and fixation on treatment planning - clinical results Frank Zimmermann Institut für Radioonkologie Universitätsspital Basel Petersgraben 4 CH 4031 Basel radioonkologiebasel.ch

2 Techniques in Radiation Therapy Conformal RT Intensity modulated RT (IMRT) Stereotactic RT (brain: SRT; body: SBRT) Image-guided RT (IGRT) Protons Heavy Ions Neutrons

3 Indications for stereotactic radiotherapy Brain metastases Recurrent glioma Non-small-cell lung cancer stage I (and II?) Lung metastases Liver metastases Pancreatic cancer Prostate cancer

4 Frame for - biopsies - radiosurgery Coming from neurosurgery

5 Definition of a 3-D-room Y Z X System creates a 3-D-area: - strong correlation of xyz-coordinates in patient and in frame - precise fixation of the patient!!!! Image from BrainLab

6 No Relevance Type of beam: Linac Cyberknife Tomotherapy Protons Neutrons Heavy particles

7 No Relevance Fractionation schedule: Conventional fractionation Hypofractionation Hyperfractionation

8 No relevance Beam: Shape Direction Number

9 Relevant Type of isocenter definition Type of immobilization

10 Fixation systems: precision Invasive frame Stereotactic mask Body masks Conventional head mask Skin markers < 1 mm < 2 mm < 5 mm < 5 mm < 10 mm

11 SBRT and IGRT + Integrating image-guidance in treatment room: precision with bony landmarks about 2 mm! Need for special fixation? Only body mask systems! Images from BrainLab and Elekta

12 Body

13 Techniques available Pure stereotactic treatment Pure image-guidance Mixed stereotactic positioning and imageguidance Breath-hold and 4-D-CT Nothing at all

14 Competition and Problems Companies with their products Increasing speed of development of techniques we never asked for Quality assurance? Radiation-oncology institutions Internet-platform Pressure of DRGs and Tarmed Increasing number of systems Pure image-guidance increasing Patients demands Although not reasonable

15 SBRT: Immobilization Different systems: none proven superior!

16 Navigation: Frame and Laser

17 Precision of SBRT-immobilization Yeung et al. IJROBP 2009

18 Body fixation + Image-guided RT (IGRT) + Integrating image-guidance in treatment room or CT: precision around 3 mm Further techniques needed?

19 SBRT: Immobilization systems in Japan Nagata Y, et al. IJROBP 2009

20 SBRT: Immobilization systems in Japan Nagata Y, et al. IJROBP 2009 Upper image from J. Wulf

21 SBRT: documentation of pos. in Japan Nagata Y, et al. IJROBP 2009

22 Breath control + IGRT

23 Influence of breathing control in IGRT Masi et al. Acta Oncol 2008

24 Influence of IGRT on bone-target-relation Tumor positioning errors are reduced by breathing control Masi et al. Acta Oncol 2008

25 Clinical data

26 Fractionation schedules in SBRT Hypofractionated RT (2-5 fractions) Single fraction (radiosurgery) But: In literature often not correct Combination with IGRT common

27 Radiosurgery: single fraction

28 Radiosurgery with Linac Gy in isocenter, 80%-Isodose surrounding 42 patients, median follow-up: 15 months Hof et al., Cancer 2007

29 Side effects 64,3 % lung tissue alterations 0 % toxizity CTC III-IV Hof et al., Cancer 2007

30 Radiosurgery with linac 30 Gy in isocenter Median follow-up: 20 months Local control: 81 % at 3 years Fritz et al., Lung Cancer 2008

31 Cancer-specific survival 57 % at 3 years Fritz et al., Lung Cancer 2008

32 Required dose: > 1 x 30 Gy PTV-including Timmerman et al., J Thorac Surg 2007

33 Fractionated SBRT

34 Importance of dose Local control rate 1 TTLP=1.6 +/- 1.4 y BED > 100 Gy (n=228) 5-y LC :84.3% p< BED < 100 Gy (n=72) 5-y LC : 57.1% Time (years) H Onishi et al. 2007

35 Mean results at 5 years worldwide Overall survival 47 % Cancer-specific survival 57 % Local control 86 % 35 studies between Median follow-up months 1000 patients BED > 100 Gy for T1 BED > 140 Gy for T2 Chi et al. Radiother Oncol 2010 Zimmermann et al. Sem RT 2010

36 RTOG Data Amerikanische Ergebnisse Necessary dose: 3 x Gy in including 80 %-isodose Timmerman et al., J Thorac Surg 2007

37 Most results with normal linac

38 Side effects (%) Type RT 4 W 8 W 4 M 12 M Fatigue ,1 3,4 3,4 Shivering 5,7 1, Nausea 3,4 6, Dysphagia 1, Dermatitis 3,4 3,4 3,4 3,4 0

39 Pneumonitis ( % ) Grade RT 4 W 8 W 4 M 6 M > 12 M I 1,1 22,0 16,3 12,8 12,0 15,0 II 0 6,8 16,3 35,8 16,6 19,2 III ,6 2,8 3,0

40 More technique? More money! Improvement by more technique not documented (for the patient) VOLUME PERCENT VOLUME PERCENT DOSE DOSE PERCENT Images from Elekta, BrainLab, Cyberknife, Internet

41 With very simple technique Immobilization free to usual local custom! Dose escalation by hypofractionation: Local control > 85 % Bogart et al. JCO 2010

42 Follow-up with FDG-PET-CT CR vs. PR? (follow-up o.k.) (follow-up, repeated biopsies, 2. FDG-PET-CT negative)

43 Follow-up concept FDG-PET-CT-scan if Persistent tumor > 12 months New tumor (vs. pneumonitis) Suspicious LN in CT-scan With SUV < 3,0 = CR With SUV > 4,05 = PD (27 pats.: ROC-Analysis; sensitivity / specifity 100 % each)

44 Conclusion High local control Few side effects Immoblization reasonable More complex techniques not proven better

45 Randomised trial in pancreatic cacner RCT vs. supportive therapy Author Year Pats. Therapy M-OS (months) OS (1 year) p Sinchi RT (50,4 Gy) + 5-FU 13,2 53,3 0, ,4 0 RCT > BSC in inoperable/unresectable cancer

46 RCT vs. CTx RCT for local pain and dominant local problems Otherwise systemic chemotherapy

47 Studies on SBRT Phase I-study, 15 patients (Koong et al. 2004): - 1 x 15, 1 x 20, 1 x 25 Gy escalation: Distant metastases only problem, 0 % CTC III tox. Phase II-study, 19 patients (Koong et al. 2005): - 45 Gy IMRT and 1 x 25 Gy: 15 % 1-OS, > 90 % local control, 10 % CTC III tox. Phase II-study, 22 patients (Hoyer et al. 2005): - 3 x 15 Gy: 5 % 1-JÜL, < 50 % local control, 23 % CTC III-IV tox.

48 Concept of IMRT-SBRT Fractionation 5 x 5,0 Gy margin of target volume 5 x 7,0 Gy in tumor center / at large vessels Target volume Tumor in soft tissue window margin of 5 mm axial margin of 5-15 mm cc

49 Dose distribution of IMRT-SBRT Dose escalation retroperitoneal paravascular

50 Definitive RCT Palliation: improvement of - local control (40 % LRR) - OS (plus ca. 4 Monate) - Pain (in 70 % of patients) Low toxicity, but long treatment Best combined concept? - Radiotherapy: Hypofractionation? - 5-FU / Gemcitabine / Platinum? Development of SBRT?