Dosimetric evaluation of different IMRT treatment plans for non-small cell lung cancer / 中华放射医学与防护杂志

ABSTRACT

Objective To investigate the optimal treatment planning of intensity modulated radiotherapy (IMRT) for non-small cell lung cancer (NSCLC) .Methods Two types of treatment plans were designed for 11 patients with inoperable NSCLC disease.In the first plan(PTV60 plan) ,60 Gy was prescribed to the planning target volume(PTV) which was created using CTV(GTV +6-8 mm) plus the margin for organ motion and setup uncertainties.In the second plan(PTV70 plan) ,70 Gy was prescribed to the PTV which was created using GTV plus the margin for organ motion and setup uncertainties.The dose-volume histogram,the planning target volume coverage,and other dosimetric parameters of normal structures were compared between the two plans.Results These two plans were not significantly different in the dose heterogeneity,but commpared with the PTV60 plan,the PTV70 plan significantly improved 60 Gy volume with regard to PTV coverage.The values of V_(20) and V_5 of lung were reduced in average by (1.69 ±0.42) % ,and (1.29 ±1.09) % (t ＝ 0.047,0.264,P ＝ 0.002) ,respectively.Conclusions The planning of 70 Gy to the PTV using GTV plus the margin for organ motion and setup uncertainties might be better than that of 60 Gy to the PTV using CTV(GTV +6-8 mm) plus the margin for organ motion and setup uncertainties.