State-of-the-Art IGRT

Transcription

1 in partnership with State-of-the-Art IGRT Exploring the Potential of High-Precision Dose Delivery and Real-Time Knowledge of the Target Volume Location Antje-Christin Knopf IOP Medical Physics Group Scientific Meeting 7/12/15 Making the discoveries that defeat cancer

2 What is IGRT? 2 What if something changes? 1.week 2.week 3.week 4.week 5.week image plan treat treat identify target volume identify organs at risk anatomical changes treatment response setup errors

3 What is IGRT? 3 Anatomical changes *Francesca Albertini, PSI planning CT Treatment response first treatment day fourth treatment day *Grootjans et al, Nature Reviews Clinical Oncology 2015 pre-treatment in-treatment end-of-treatment

4 What is IGRT? 4 What if something changes? 1.week 2.week 3.week 4.week 5.week image plan treat treat treat identify target volume identify organs at risk anatomical changes treatment response setup errors image image verify the planning situation

5 What is state-of-the-art IGRT? 5 What if something changes? image plan treat treat treat motion

6 What is state-of-the-art IGRT? 6 What if something changes? image plan treat treat treat motion

7 What is state-of-the-art IGRT? 7 The motion challenge: target miss conventional RT proton RT ribs lung target radiation field

8 What is state-of-the-art IGRT? 8 The motion challenge: target miss conventional RT proton RT ribs lung ribs lung target target radiation field proton field

9 rel. dose What is state-of-the-art IGRT? 9 The motion challenge: dose blurring / interplay effects conventional RT proton RT 100% target position

10 rel. dose rel. dose What is state-of-the-art IGRT? 10 The motion challenge: dose blurring / interplay effects conventional RT proton RT 100% 100% target target position position

11 What is state-of-the-art IGRT? 11 What if something changes? image plan treat treat treat motion monitor monitor monitor

12 What is state-of-the-art IGRT? 12 image high-precision dose delivery calls for high-precision imaging treat

13 What is state-of-the-art IGRT? 12 image high-precision dose delivery calls for high-precision imaging treat

14 What is state-of-the-art IGRT? 12 image high-precision dose delivery calls for high-precision imaging treat

15 What is state-of-the-art IGRT? 13 To deliver high-precision radiotherapy to moving targets realtime knowledge of the target is required! The following techniques help to mitigate motion effects: margins rescanning breath hold gating tracking

16 Two modern IGRT delivery machines 14 hybrid MR-Linac scanning proton gantry 3D online imaging 2D MLC tracking 3D tracking

17 MR-Linac 15 Online imaging T 2 w MR imaging of axillary lymph nodes Stereotactic boost to individual lymph nodes 4D MR imaging tumor tracking *Marielle Philippens, UMCU Challenge: real-time MR imaging? compromise between FOV, spatial resolution, temporal resolution

18 MR-Linac 16 2D MLC tracking MLC to shape the treatment field MLC to track motion 1cm x-motion / 2cm y-motion *Andreas Krauss, DKFZ

19 MR-Linac 16 2D MLC tracking MLC to shape the treatment field MLC to track motion step-and-shoot IMRT / real breathing trace Challenge: real-time tracking? system latency motion modeling / prediction *Andreas Krauss, DKFZ

20 MR-Linac 17 Online adaptive radiotherapy necessity: imaging delivery

21 MR-Linac 18 Currently different combined MR-radiotherapy machines finding their way into the clinic. U Utrecht, Elekta / Philips U Alberta Australian MR-Linac Viewray, MRI-Cobalt Their capability to perform state-of-the-art IGRT will be shown in coming years.

22 Two modern IGRT delivery machines 19 hybrid MR-Linac scanning proton gantry 3D online imaging 2D MLC tracking but low dose bath 3D tracking

23 Scanning proton gantry 20 3D tracking magnetic scanner

24 Scanning proton gantry 20 3D tracking magnetic scanner

25 Scanning proton gantry 20 3D tracking magnetic scanner

26 Scanning proton gantry 20 3D tracking magnetic scanner Challenge: real-time 3D motion information?

27 Scanning proton gantry 21 possible tracking workflow Imaging Motion Modeling Treatment Delivery Online Motion Monitoring

28 Scanning proton gantry 22 possible tracking workflow liver MRI motion information without imaging dose 4DMRI motion library Imaging lung MRI patient specific 4DCT MRI library comprising information of several breathing cycles generation of 4DCT MRI transfer of motion information to 3DCT von Siebenthal et al. 4D MR imaging of respiratory organ motion and its variability (2007) Phys Med Biol Boye et al. Population based modeling of respiratory lung motion and prediction from partial information (2013) Proc. SPIE

29 Scanning proton gantry 23 possible tracking workflow Imaging Motion Modeling v t X [dx [v, v 1 1,dy 2 1,dz,..., v t 1,...,dx k ](t T),dy patient specific motion model k,dz k ] T (k K) magnitude regularity consistency deformability Principle Component Analysis [PCA] input for 4D dose calculation reference for online motion monitoring Zhang et al. Deformable motion reconstruction for scanned proton beam therapy using on-line X-ray imaging (2013) Phys Med Biol

30 Scanning proton gantry 24 possible tracking workflow Imaging Beams-Eye-View (BEV) imaging field II field III Motion Modeling field I BEV field III BEV field I BEV field II Online Motion Monitoring Pedroni et al. The PSI Gantry 2: a second generation proton scanning gantry (2004) Z Med Phys Zhang et al. Deformable motion reconstruction for scanned proton beam therapy using on-line x-ray imaging (2013) Phys Med Biol Zhang et al. Online image guided tumour tracking with scanned proton beams: A comprehensive simulation study (2015) Phys Med Biol

31 Scanning proton gantry 25 possible tracking workflow Imaging Beams-Eye-View (BEV) imaging Motion Modeling VisionRT RPM CBCT implanted markers Online Motion Monitoring Pedroni et al. The PSI Gantry 2: a second generation proton scanning gantry (2004) Z Med Phys Zhang et al. Deformable motion reconstruction for scanned proton beam therapy using on-line x-ray imaging (2013) Phys Med Biol Zhang et al. Online image guided tumour tracking with scanned proton beams: A comprehensive simulation study (2015) Phys Med Biol

32 Scanning proton gantry 26 possible tracking workflow Imaging Beams-Eye-View (BEV) imaging online motion monitoring motion model based on 4DMRI library Motion Modeling tracking considering deformations Treatment Delivery Online Motion Monitoring Pedroni et al. The PSI Gantry 2: a second generation proton scanning gantry (2004) Z Med Phys Zhang et al. Deformable motion reconstruction for scanned proton beam therapy using on-line x-ray imaging (2013) Phys Med Biol Zhang et al. Online image guided tumour tracking with scanned proton beams: A comprehensive simulation study (2015) Phys Med Biol

33 Scanning proton gantry 27 possible tracking workflow Imaging patient specific 4DCT MRI Motion Modeling patient specific motion model Treatment Delivery combining online information with the established motion model enables tracking 1D or 2D surogate motion Online Motion Monitoring Pedroni et al. The PSI Gantry 2: a second generation proton scanning gantry (2004) Z Med Phys Zhang et al. Deformable motion reconstruction for scanned proton beam therapy using on-line x-ray imaging (2013) Phys Med Biol Zhang et al. Online image guided tumour tracking with scanned proton beams: A comprehensive simulation study (2015) Phys Med Biol

34 Two modern IGRT delivery machines 28 hybrid MR-Linac scanning proton gantry 3D online imaging 2D MLC tracking but low dose bath 3D tracking but no 3D online imaging How about a MR-proton solution?

35 MR-proton solution? dosimetric effect? 0T 0.5T 3T cost? MR + Linac < MR-Linac MR + proton < MR-proton MR-proton will be very expensive! 29 predictable and less pronounced than for photons Bas Raaymakers, UMCU: "We should go for a MRproton hybrid system. It's simply too cool not to do it." patent application by Johan Overweg, Philips Hamburg, Germany Real-time knowledge of the target volume location in combination with high-precision dose delivery will make a real difference! Raaijmakers et al. Integrating a MRI scanner with a 6 MV radiotherapy accelerator dose increase at tissue air (2005) Phys Med Biol

36 Summary 30 Imaging has always been the basis for radiotherapy treatments. Technology has evolved from pre-treatment imaging via interfractional imaging towards online imaging. The MR-Linac and scanning proton gantries are two state-ofthe-art radiotherapy approaches that illustrate the potential of real-time imaging and high-precision dose delivery. Eventually, a MR-proton hybrid machine will combine real-time imaging and high-precision dose delivery to enable optimal IGRT treatments.

37 in partnership with Thank you very much to my colleagues at PSI: ICR: Toni Lomax Uwe Oelfke Francesca Albertini Simeon Nill Monika Zakova Martin Fast Dirk Boye Peter Ziegenhein Ye Zhang Filipa Costa Kinga Bernatowicz... and many many more students UMCU: Bas Raaymakers Sjoerd Crijns for helping preparing these slides. Thank you very much for your attention!