Presenter of 1 Presentation
CAN UHDR VHEE DEVICES WITH ONLY A FEW FIXED BEAMS PROVIDE COMPETITIVE TREATMENT PLANS COMPARED TO VMAT ?
Abstract
Background and Aims
Future RT devices using very-high energy electrons (VHEE) (50-250MeV) may produce suitable beams to treat deep-seated tumours conformally and at ultra-high dose rates (UHDR) capable of triggering the FLASH effect. The FLASH effect has been observed for large doses delivered with overall treatment times less than 200ms. Such treatment durations do not allow the use of a movable gantry and multiple fixed beam lines (FBL) become mandatory. This treatment planning study evaluates VHEE dose distributions in patients using a varying number of FBL with different energies and source-axis-distances (SAD). The minimum requirements for delivering conformal VHEE RT comparable to conventional VMAT plans and trade-offs between plan quality and number of beam lines are assessed.
Methods
We performed VHEE and VMAT treatment planning for multiple indications (glioblastoma, mediastinum, lung, prostate) using RayStation (research version) and compared the dosimetric quality of VHEE plans to VMAT while assessing the impact of arrangement and number of FBL, beam energies, and SAD.
Results
Most substantial coverage and conformity improvement is achieved when increasing the beam energy from 50 to 100MeV. Further improvement is obtained specifically for deep-seated targets (>10-15cm) when increasing energies further to 200MeV. While VHEE plans using 16 coplanar beams outperform VMAT plans, we found that VHEE plans using only 3-5 beams have DVH metrics that are comparable to VMAT plans. Beams with SAD>1m are preferable for treatments using few beams.
Conclusions
UHDR VHEE devices with only a few FBL may provide competitive dosimetric conformity that may be additionally enhanced by the FLASH effect.
Author Of 1 Presentation
CAN UHDR VHEE DEVICES WITH ONLY A FEW FIXED BEAMS PROVIDE COMPETITIVE TREATMENT PLANS COMPARED TO VMAT ?
Abstract
Background and Aims
Future RT devices using very-high energy electrons (VHEE) (50-250MeV) may produce suitable beams to treat deep-seated tumours conformally and at ultra-high dose rates (UHDR) capable of triggering the FLASH effect. The FLASH effect has been observed for large doses delivered with overall treatment times less than 200ms. Such treatment durations do not allow the use of a movable gantry and multiple fixed beam lines (FBL) become mandatory. This treatment planning study evaluates VHEE dose distributions in patients using a varying number of FBL with different energies and source-axis-distances (SAD). The minimum requirements for delivering conformal VHEE RT comparable to conventional VMAT plans and trade-offs between plan quality and number of beam lines are assessed.
Methods
We performed VHEE and VMAT treatment planning for multiple indications (glioblastoma, mediastinum, lung, prostate) using RayStation (research version) and compared the dosimetric quality of VHEE plans to VMAT while assessing the impact of arrangement and number of FBL, beam energies, and SAD.
Results
Most substantial coverage and conformity improvement is achieved when increasing the beam energy from 50 to 100MeV. Further improvement is obtained specifically for deep-seated targets (>10-15cm) when increasing energies further to 200MeV. While VHEE plans using 16 coplanar beams outperform VMAT plans, we found that VHEE plans using only 3-5 beams have DVH metrics that are comparable to VMAT plans. Beams with SAD>1m are preferable for treatments using few beams.
Conclusions
UHDR VHEE devices with only a few FBL may provide competitive dosimetric conformity that may be additionally enhanced by the FLASH effect.