DISEASE CHARACTERISTICS: Histologically confirmed unresectable stage II, IIIA, or IIIB non-small cell lung cancer No distant metastases No prior complete (or gross subtotal) tumor resection No post-resection intrathoracic tumor recurrence Pleural effusion seen on a chest x-ray allowed only if appearing after thoracotomy or other invasive thoracic procedure (pleural effusion acceptable if seen only on CT scan, not on chest x-ray) Must be ineligible or refused participation in protocol RTOG-9309