Pulmonary Function Following Three-dimensional Confromal Radiation Therapy Of Lung Cancer

ObjectiveTo assess the pulmonary function after three-dimensional conformal radiation treatment of lung cancer in relation to radiation pneumonitis.Methods54 patients with inoperable lung cancer (male 35, female 19, median age 63, Kps>75) were evaluated by pulmonary function tests and blood gas analysis before and after three-dimensional conformal radiotherapy respectively. In 3~4 months of follow-up time, we reviewed the appearance and degree of radiation pneumonitis. Then we got V20, V30, MLD and NTCP.ResultAll patients completed radiotherapy, dose was 56~70Gy and time of therapy was 30-45 days. Before radiotherapy, FVC (L), FEV1.0 (L), DLCO (mL/min/mmHg) and pH, PO2(mmHg), PCO2(mmHg) were respectively 2.59±0.62, 1.91±0.58, 15.25±4,53 and 7.424±0.023, 80.65±7.48, 37.29±4.45; in 1st month after radiotherapy, 2.84±0.75, 2.04±0.64, 14.48±3.70 and 7.434±0.022, 79.93±7.32, 35.07±3.35; in 3rd month after radiotherapy, 2.56±0.55, 1.89±0.57, 13.58±2.47 and 7.444±0.023, 79.74±7.12, 35.06±4.03. The accidence of radiation pneumonitis was 44.4 %, moderate and severe radiation pneumonitis was 24.0%. V20,V30,MLD and NTCP was respectively 34±13%,22±10%, 1701±596cGy and 52±39%.