Clinical Research on Three-Dimensional Conformal Radiotherapy of Non-Small Cell Lung Cancer

OBJECTIVE To investigate the clinical efficacy and toxic effect of the 3-dimensional conformal radiation therapy(3DCRT)for non- small cell lung cancer(NSCLC). METHODS Fifty-two patients with the Stage-I and IV NSCLC were treated with 3DCRT.Cross analysis of the clinical data was conducted in the comparison between the 52 cases with 3DCRT and the other 50 cases with the conventional radiation therapy (CRT).In the 3DCRT group,only the primary tumor and positive lymph-node draining area were included in the clinical target area,setting 4 to 6 coplanar or non-coplanar irradiation fields,with 2 Gy or 3 Gy/fraction,1 fraction a day and 5 fractions per week. The total dose ranged from a test dose(DT)of 66 Gy to 72 Gy.In the CRT group,the field area contained the primary tumor plus the homolateral hilum of the lung,the mediastinum superior or hol-mediastinum,and opposed anteroposterior irradiation.When the dosage reached DT 36～40 Gy,an oblique portal administered radiation was conducted in order to avoid injuring the spinal cord. The DT was 1.8～2.0 Gy/fraction,1 fraction a day,5 fractions per week,with a total dose of 60 Gy to 70 Gy. RESULTS The therapeutic effect(CR+PR)was 90.4% in the 3DCRT group,and was 72% in the CRT group.There was statistically significant difference between the two groups,P<0.01. There was a clinical symptom improvement attained by 96.5% and 86.4% respectively in the two groups,and there was a statistically significant difference between the groups,P<0.01.The 6-month, 1 and 2-year overall survival rates were 92.3%,75.0% and 42.3% in the 3DCRT group,and 76%,60% and 30% in the CRT group, respectively.There was a significant difference in the 6-month overall survival rate between the groups,P<0.05.There was no obvious significant difference in the 1 and 2-year overall survival rates between the two groups,P>0.05.The toxic reaction was 12.5% and 23.7% respectively in the 3DCRT and CRT groups. Acute radioactive esophagitis and leucopenia were markedly lower in the 3DCRT group than in the CRT group.There was a statistically significant difference between the groups,P<0.05.No toxic reaction of Stage-Ⅲand over was found in the 3DCRT group during radiation therapy. CONCLUSION The 3DCRT method has a satisfactory short- term efficacy and improvement of clinical symptoms in treating NSCLC,with a mild toxic reaction and good tolerance in patients. It can be used for enhancing the tumor-control rate and bettering the quality of life.