ABSTRACT
Objective To investigate the correlation between functional lung dose-volume histogram (f-DVH) parameters and radiation-induced lung toxicity (RILT) in patients of locally advanced non-small cell lung cancer (NSCLC) treated with late-course accelerated hyperfractionated radiotherapy and chemotherapy,and to identify the excellent predictors of f-DVH and their reference thresholds.Methods A total of 51 patients of NSCLC at stage Ⅲ underwent PET/CT/SPECT coregistered image guided radiotherapy.Philips Pinnacle3 planning system was used for delineation of the target volume and organs at risk so as to establish the three dimensional conformal radiotherapy or intensity-modulated radiotherapy treatment plans.The version 3.0 of the NCI Common Terminology Criteria for Adverse Events was used to evaluate the grade of RILT,and analyze the correlation of the DVH parameters of the total lung (TL),ipsilateral lung (IL),and functional lung (FL) and RILT,and to identify the excellent predictors.The median follow-up was 15 months.Results During the follow-up,10 cases of RILT (19.6%) ≥grade 2 were observed.Single factor analysis showed that the V5-V40 of TL,V5-V/20 of IL,and V5-V50 of FL were all related to the occurrence of RILT,and multiple factor analysis showed that TL-V15 and FL-V20remained associated with RILT (P = 0.005 and P = 0.016).According to ROC analysis,the V10 (45.38%) of FL was the most sensitive predictor with a sensitivity rate of 90.0% and 1/25 (27.78%) of FL was the most specific predictor with a specificity rate of 90.24%.The sensitivity,specificity and accuracy of V20 of FL were 70.00%,73.17%,and 74.90%,respectively.Conclusions The occurrence of RILT is closely associated with multiple f-DVH parameters of FL,and f-DVH has good sensitivity and specificity for prediction.