Résumé
Objective To observe the changes of lung function before and after radiotherapy with the lung perfusion of single-photon emission computed tomography and compare the difference between radiotherapy plans conducted by functional imagines and anatomical imagines in radiotherapy of patients with non-small-cell lung cancer.Methods A total of 36 patients (26 males and 10 females,aged 36-80 years) with lung cancer diagnosed as stage Ⅰ to stage Ⅲ non-small cell lung cancer confirmed by histological proof were selected.The lung perfusion image was delivered to radiotherapy planning system and the two plan (plan1 and plan 2) were made by lung perfusion image fusion.Plan 1 was only based on the anatomical informations and no lung perfusion images of SPECT considering.Plan 2 was optimized based on the lung perfusion image to reduce the irradiation dose of the normal tissues.The differences of protecting lung function between plan 1 and plan 2 were compared.Results 36 patients were stratified for clinical stage.FV10,fV20,fV30,MLD and PTV90/fV20 were decreased significantly after optimized with IMRT (all P =0.000).FV20,fMLD were decreased by (4.89±2.0) ％,(1.74 ±0.9)％.The IMRT plan based on the lung perfusion fusion images of SPECT could reduce the irradiation dose of normal lung tissues and the incidence of radiation pneumonitis.Conclusions Radionuclide pulmonary perfusion imaging can assess effectively the effect of tumor to regional pulmonary artery perfusion function before radiotherapy and reduce the irradiation dose of normal lung tissue in lung cancer patients undergoing IMRT.