Users Manual Part 2

IBA | 20-2 | Clinical User’s Guide
Volume 1 - Treatment Session
|Part III - The Pencil Beam Scanning (PBS) Suite Pencil Beam Scanning Principles |
Beam delivery in the treatment volume is achieved:
 Longitudinally, by varying the proton beam energy
 Transversally, by magnetic scanning
Figure 20-1. Pencil Beam Scanning (PBS) Delivery Technique
Clinical Advantages
Clinical advantages of PBS over other techniques are:
 Better dose conformity
 Better sparing of organs at risk and healthy tissues
 Allow dose escalation for better local tumor control
 No need for patient specific devices (i.e., no block nor range compensator)
 Reduce costs
 Increase patient throughput
 Easier operation
 Allow more flexibility in plan evolution
 Less neutron dose
Proton
beam
Scanning
magnets Yg
Scanning beam
Scanning
magnets Xg
Bragg peak
layers already
treated
2-D dose
distribution on
the actually
scanned layer