Conventional treatment planning system is based on static image series supposed to reflect the patient's anatomy all over the treatment process. But the patient anatomy changes as the target and surrounding OARs move and deform, because of soft tissues deformation or tumor regression and internal motion can happen during treatment delivery,mainly due to breathing. New imaging devices such as Cone Beam CT or 4D CT give the opportunity to finer deal with these anatomy changes. The challenge for treatment planning systems manufacturers is to introduce the 4th dimension in their software and handle the temporal aspects in a secured and intuitive way based on robust deformation models. Today, DOSIsoft’s 4D & Adaptative Radiotherapy tools offer the opportunity to account for these anatomical elastic deformations and to handle the temporal issues in a unique secured and intuitive way.
Adaptive radiotherapy capabilities implemented in ISOgray4D™, include elastic registration, patient model deformation, IMRT re-planning and dose distribution deformation for cumulative dose evaluation.
Easy evaluation in 3 steps
1/ Import newly acquired (replanning) image series onto the previous (original) 3D conformal or IMRT plan, and compute the deformable registration that maps the original planning CT on replanning image series
2/ Apply elastic transformation on original planning patient model which now fits the replanning image series
3/ Apply same deformation on the original dose distribution that now matches the replanning images
Easy decisions in 3 steps
1/ Compare dose distributions between original and replanning patient model
2/ Decide if replanning is necessary
3/ Evaluate cumulative dose distribution
4D CT image series allow finer modeling of free breathing treatments. ISOgray4D provides all the necessary tools to take advantage of the 4D information. At the heart of the process is our efficient GPU based elastic registration algorithm which performs the computations for ten phases within minutes.
The resulting elastic transforms can be used to propagate anatomical structures definitions from phase to phase and reduce drastically contouring time:
1/ Compute the bounding hull of dynamic structures
2/ Set up beams geometry with fully dynamic displays, including DRR and beam projection on skin
3/ Evaluate dose distribution on each phase or display the weighted cumulative 4D dose computed from deformed 3D dose distributions
Dosisoft has strongly focused on robust architecture, user friendly interface and efficient deformable registration in order to offer a complete set of features deeply and naturally integrated in the TPS for both adaptive and 4D planning:
- Accurate dose at the right location, throughout the entire treatment - Propagation of structures, reducing contouring time with efficient and fast deformable registration - Tumor change of shape, shrinkage or movement management - Efficient and fast deformable registration (demons and superbaloo) - IMRT re-planning - Dose distribution deformation and cumulative dose evaluation - All necessary tools to take advantage of 4D information (CBCT, 4DCT) - Computations for 10 breathing phases within minutes - Strong and robust architecture with user friendly interface - Powerful GPU based algorithms
DOSIsoft 45/47 avenue Carnot, 94230 Cachan - France Tel: +33 (0)1 41 24 26 26 Fax: +33 (0)1 41 24 26 28