Use of robots to improve patients' treatment and throughput
Reporter: Arpi Thukral, MD MPH
The Abramson Cancer Center of the University of Pennsylvania
Last Modified: May 12, 2011
Presenter: Regis Ferrand
Presenter's Affiliation: Institut Curie-Centre de Protontherapie d'Orsay
- The purpose of this presentation was to provide an overview of the 15-20 year history of the use of robotic couches at Institut Curie-Centre de Protontherapie d'Orsay (CPO).
- In the past 15 years, use of robotic positioning has developed tremendously in radiation therapy, particularly in particle therapy.
- The challenge of robotic positioning is that it must be fast and precise.
- Need 6 degrees of freedom, long range motion <0.5 mm, with smooth trajectories
- Need high repeatibility for QA checks and calibration
- Short range of motion: 0.2 mm
- Ability to load/unload patient
- Need to use a combination of fields
- Fast detection of unexpected motion
- Collision avoidance/back to safe position
- History of robots
- Before 1990: prototypes: MGH/HCL chair or eye chairs (CPO, PSI, MGH, Nice)
- 1995-2003 – 6 axis robot based (ex. MPRI)
- 2003-2009 – Scara-based, hexapode based
- 2010 – new hybrid designs (Poros PPS, Toshiba PPS)
- Extended use of robots besides patient postioning:
- Robotic CBCT
- MPRI snouth changer
- Trolleys (PSI, automated in Essen)
- Use of robots to calibrate devices inside the treatment room
- Chair and couch
- The CPO modest experience of 20 years:
- The CPO has been working on 4 different robots since 1990. These include:
- Hexapodes (original in 1991 and new version in 2006)
- accuracy <0.2 mm with limited range through +/- 10 degrees
- 2006 version has 360 degree vertical rotation
- not ideal for long range motion
- 6 axis based (1995)
- accuracy approx 3 mm
- The biggest advantage of this type is repeatibility.
- Scara based (Forte/Procure)
- Approx 0.5 mm precision
- New pit free prototype
- Developed within the frame of a research project.
- Specific architecture
- Intrinisic high precision (+/- 0.5 mm accuracy over long range movements)
- Ability to align patient inside and outside room
- Water tank permanently ready to use
- Lessons learned from 20 year experience at CPO:
- Except for hexapode, the intrinsic precision is NOT sufficient
- Calibration is mandatory and takes time.
- Robot has high potential and is designed for guidance.
- Has incredible robustness (only 3 problems in 15 years at CPO, likely due to neutrons)
- Future directions/concepts:
- New robotic concepts: (ex. Poros prototype, patented):
- Increased working envelope
- Intrinsic precision enhanced
- Reduced cycle (20 ms) – dynamic motion
- Hardware redundant saftely systems
- Fluid process
- Natural ability for: alignment inside/outside and adaptive therapy
- Simultaneous multi-PAS guidance
- Definition of true postioning strategy at the OIS level.
- To compare proton and proton treatment, we need to dramatically improve the treatment process for protons (and not only the beam).
- Robotic patient positioners have proven their potential to play a key role in this process.
- However, there are still many advances that need to be made in this field for proton therapy.
- The author of this presentation clearly highlighted the history and advances made in the last 2 decades regarding the use of robotic technology to improve patient treatment and throughput in the proton arena.
- Robots play a key role in patient positioning, which in turn translates to greater efficiency in patient throughput.
- From this overview, we are able to assess the value and limitations of robotic patient positioning. This will help guide the development of future robotic technology for particle therapy.
- Future studies may focus not only on improving this technology, but also advancing it in terms of image guidance, safety and dynamic motion.
- Furthermore, efforts to adapt a global positioning process to specific clinical protocols are underway.