Analysis of relationship between severe radiation pneumonitis and dose-volume histogram parameters for non-small cell lung cancer treated with three-dimensional conformal radiation therapy / 中国医师进修杂志

ABSTRACT

Objective To explore the relationship between severe(≥grade 3 ) radiation pneumonitis (RP) and dose-volume histogram (DVH) parameters for non-small cell lung cancer (NSCLC) treated with three-dimensional conformal radiation therapy (3-DCRT). Methods Ninety-four patients with NSCLC treated with 3-DCRT were retrospectively analyzed. Clinical parameters were analyzed. DVH parameters analyzed were V20, V30, V40,mean lung dose (MLD),normal tissue complication probability(NTCP) ,and total dose. Results Age,sex, Karnofsky scored, performance status, forced expiratory volume in 1 second,presence of weight loss, preexisting lung disease, history of thoracic surgery, and history of chemotherapy were not associated with the risk of severe RP(P>0.05). However,in univariate analyses, V20, V30, V40, MID and NTCP were associated with severe RP(P<0.01). In multivariate analysis, MID and V30 were variable associated with severe RP(P<0.01). The severe RP was 0 when MLD < 10 Gy and 21%(8/39) when MLD between 10 Gy and 20 Gy but 35%(7/20) when MLD > 20 Gy,it was 0 when V30 < 25% and 12%(4/33) when V30 between 25% and 35% but 38%(11/29) when V30 >35%. Conclusion MLD and V30 are significant predictive factors for severe RP and they should be limited to ≤20 Gy and ≤ 35% in order to reduce severe RP.