Dosimetric study of volumetric modulated arc therapy and cyberknife six-dimensional skull tracking in spatially fractionated lattice radiotherapy for head and neck tumors
YUAN Ke
LIAO Xiongfei
WANG Xianliang
LANG Jinyi
YING Wei
Abstract：Objective To compare the dosimetric and treatment efficiency differences between volumetric modulated arc therapy(VMAT)and cyberknife six-dimensional(CK-6D)skull tracking technology in lattice radiotherapy(LRT)for head and neck tumors and analyze their respective advantages.Methods This retrospective study selected seven patients with head and neck tumor who received LRT based on the VMAT technique(VMAT plan).The patients'CT images and related radiotherapy structure sets were imported into the CK-6D planning system(CK-6D plan),and treatment plans were designed using a variable(Iris)collimator.Both plans employed the same prescription dose.The tumor target area(GTV)and lattice tumor target area(GTV-Lattice)were compared for 90％volume irradiation dose(D90),mean dose(Dmean),peak-to-valley dose ratio(PVDR),and ablation dose ratio(ADR).Dosimetric parameters for organs at risk were measured,including the maximum dose(Dmax)to the brainstem,spinal cord,and optic chiasm;Dmean to the parotid glands;and the doses received by 0.05-1cm3 of skin(D005 mL-D1 mL)and their Dmean.Paired t-tests were used to compare treatment time,Gamma passing rate,PVDR,ADR,and monitor units(MU)between the two plans.Results Compared to the VMAT plan,the CK-6D plan showed a reduced Dmean for the GTV and increased D90 and Dmean for the GTV-Lattice(all P＜0.05).Other dosimetric parameters showed no statistically significant differences between the two plans(all P＞0.05).The CK-6D plan required longer treatment time,higher PVDR,and more MUs than the VMAT plan(all P＜0.05).The Gamma passing rate and ADR showed no significant differences between the two plans(both P＞0.05).Conclusion For LRT in head and neck tumors,CK-6D achieves higher PVDR and greater dose gradients within the tumor target area compared with VMAT.However,considering treatment time,it is essential to balance the choice of technique to optimize therapeutic outcomes and efficiency.
Keywords：Intensity modulated radiotherapyCyberknifeSpatially fractionated radiation therapyLattice radiation therapyPeak-to-valley dose ratioHead and neck tumors
Publication Date：2025-01-14
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 53-58 )