[Reduced irradiation target volume of mediastinal lymph node drainage in conformal radiotherapy for patients with non-small cell lung cancer after thoracic surgery].

Objective: To decrease lung and esophageal radiation injuries by reducing irradiation target volume of mediastinal lymph mode drainage in conformal radiotherapy (CRT) for patients with non-small cell lung cancer (NSCLC) after thoracic surgery.
Methods: Fifty-three patients with NSCLC were randomized into groups A and B to receive 3D-CRT after thoracic surgery. Patients in group A, according to conventional therapy, received preventive nodal irradiation (PNI) of the mediastinal lymph node drainage, and those in group B, according to pathological nodal staging after operation, did not have PNI of the metastasis-free area to reduce the clinical target volume (CTV). Patients in both groups were treated with conventional fractionated radiotherapy (CFRT) at 2 Gy in each fraction, and 5 fractions each week. All patients were followed up for two years to record their 2-year survival rate, local relapse of lymph node drainage and lung and esophageal radiation injuries.
Results: The total 2-year survival rate was 58.5%in these patients and comparable between the two groups. The rates of local regional relapse and recurrence out of the CTV were 13.8% and 3.4% in group A and 16.7% and 8.3% in group B, respectively (P=1 and P=0.571). The incidence of radiation pneumonia and lung fibrosis were 6.9% and 62.1% in group A and 0% and 58.3% in group B (P=0.459 and P=0.782), and that of radiation esogphagitis and esophagus stricture rates were 27.6% and 6.9% in group A and 12.5% and 4.2% in group B, respectively (P=0.039 and P=1).
Conclusion: Reduced CTV does not warrant decrease in the local control but may lower the incidence of acute esophageal radiation injury in postoperative patients with NSCLC.