Related Experiment Video
Updated: Dec 20, 2025
Stereotactic Radiosurgery for Gynecologic Cancer
Published on: April 17, 2012
Multi-institutional dosimetric delivery assessment of intracranial stereotactic radiosurgery on different treatment
Alexis Dimitriadis1, Yatman Tsang2, Russell A S Thomas3
1Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, UK; Radiation Dosimetry Group, National Physical Laboratory, Teddington, UK; Department of Medical Physics, Royal Surrey County Hospital NHS Foundation Trust, Guildford, UK.
Background And Purpose:
Assessment of dosimetric accuracy of radiosurgery on different treatment platforms.
Material And Methods:
Thirty-three single fraction treatment plans were assessed at thirty centres using an anthropomorphic head phantom with target and brainstem structures. The target being a single irregular shaped target, ~8 cc, 10 mm from the brainstem. The phantom was "immobilised", scanned, planned and treated following the local protocols. EBT-XD films and alanine pellets were used to measure absolute dose, inside both the target and the brainstem, and compared with TPS predicted dose distributions.
Results:
PTV alanine measurements from gantry-based linacs showed a median percentage difference to the TPS of 0.65%. Cyberknife (CK) had the highest median difference of 2.3% in comparison to the other platforms. GammaKnife (GK) showed the smallest median of 0.3%. Similar trends were observed in the OAR with alanine measurements showing median percentage differences of1.1%, 2.0% and 0.4%, for gantry-based linacs, CK and GK respectively. All platforms showed comparable gamma passing rates between axial and sagittal films.
Conclusions:
This comparison has highlighted the dosimetric variation between measured and TPS calculated dose for each delivery platform. The results suggest that clinically acceptable agreement with the predicted dose distributions is achievable by all treatment delivery systems.
