DISEASE CHARACTERISTICS: Histologically or cytologically confirmed non-small cell lung cancer, including:

Squamous cell carcinoma Adenocarcinoma (including bronchoalveolar cell) Large cell anaplastic carcinoma (including giant and clear cell carcinomas) Inoperable or unresectable stage IIIA or IIIB disease of the following stage groupings: T1 N2 M0 or T2 N2 M0 T3 N2 M0 and T4 N0-2 M0 eligible if staging is based on closeness to the carina or invasion of the mediastinum or chest wall Patients with contralateral mediastinal disease (N3) or tumors adjacent to but not invading a vertebral body are eligible if all gross disease can be encompassed in the study radiation boost field Patients with a transudate, cytologically negative, nonbloody pleural effusion are eligible if the tumor can be encompassed within a reasonable field of radiotherapy Measurable or evaluable disease

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: CALBG 0-1 Life expectancy: Not specified

Hematopoietic: Platelet count at least 100,000/mm3 Absolute granulocyte count at least 1,500/mm3 Hepatic:

Bilirubin less than 1.5 mg/dL AST less than 2 times upper limit of normal Renal: Creatinine clearance at least 20 mL/min Other: Not pregnant or nursing Effective contraception required of fertile patients No active second malignancy except nonmelanomatous skin cancer

PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: No prior chemotherapy No other concurrent chemotherapy Endocrine therapy: No concurrent hormones except for steroids administered for adrenal failure or septic shock, or hormones administered for non-disease-related conditions (e.g., insulin for diabetes) Glucocorticosteroids permitted as antiemetics Radiotherapy: No prior radiotherapy Surgery: At least 2 weeks since exploratory thoracotomy