Klinge Thomas, Modat Marc, McClelland Jamie R, Dimitriadis Alexis, Paddick Ian, Hopewell John W, Walton Lee, Rowe Jeremy, Kitchen Neil, Ourselin Sébastien
Wellcome/EPSRC Centre for Interventional and Surgical Sciences (WEISS), Dept. Medical Physics and Biomedical Engineering, University College London, London, UK.
Centre for Medical Image Computing, Dept. Medical Physics and Biomedical Engineering, University College London, London, UK.
J Radiosurg SBRT. 2021;7(3):213-221.
Establish the impact of iso-centre sequencing and unscheduled gaps in Gamma Knife® (GK) radiosurgery on the biologically effective dose (BED).
A BED model was used to study BED values on the prescription iso-surface of patients treated with GK Perfexion™ (Vestibular Schwannoma). The effect of a 15 min gap, simulated at varying points in the treatment delivery, and adjustments to the sequencing of iso-centre delivery, based on average dose-rate, was quantified in terms of the impact on BED.
Depending on the position of the gap and the average dose-rate profiles, the mean BED values were decreased by 0.1% to 9.9% of the value in the original plan. A heuristic approach to iso-centre sequencing showed variations in BED of up to 14.2%, relative to the mean BED of the original sequence.
The treatment variables, like the iso-centre sequence and unscheduled gaps, should be considered during GK radiosurgery treatments.
确定伽玛刀（GK）放射外科治疗中，等中心序列和非计划间隙对生物等效剂量（BED）的影响。
使用BED模型研究接受GK Perfexion™（前庭神经鞘瘤）治疗的患者处方等剂量面上的BED值。在治疗过程中的不同时间点模拟15分钟的间隙，并根据平均剂量率对等中心照射序列进行调整，通过对BED的影响进行量化。
根据间隙位置和平均剂量率分布，平均BED值比原计划降低了0.1%至9.9%。一种启发式的等中心序列方法显示，相对于原序列的平均BED，BED变化高达14.2%。
在GK放射外科治疗过程中，应考虑等中心序列和非计划间隙等治疗变量。
