Radiation Pneumonitis After Volumetric Modulated Arc Therapy for Non-small Cell Lung Cancer.

ABSTRACT

BACKGROUND/AIM: To evaluate the incidence and grade of radiation pneumonitis after volumetric modulated arc therapy (VMAT) performed for the treatment of non-small cell cancer (NSCLC). PATIENTS AND METHODS: Fifty consecutive non-surgical candidates with NSCLC underwent VMAT. Thirty-five patients had stage-III tumors and 15 had recurrent tumors. The prescribed radiation dose for the gross tumor and the elective nodal area was 69 Gy in 30 fractions and 51 Gy in 30 fractions, respectively. RESULTS: Radiation pneumonitis developed in 38 patients (76%, 38/50), and grade ≥2 radiation pneumonitis developed in 11 patients (22%, 11/50). The percentage of lung volume that received a dose in excess of 5 Gy (V5), V10, V20, V30, and the mean lung dose (MLD) in the bilateral and ipsilateral lung were significantly associated with the development of grade ≥2 radiation pneumonitis. CONCLUSION: The incidence and degree of radiation pneumonitis are acceptable following treatment of NSCLC with VMAT.