DISEASE CHARACTERISTICS: Histologically or cytologically confirmed small cell carcinoma of the lung Limited disease (stage I-IIIb but excluding T4 tumor based on malignant pleural effusion or N3 disease based on contralateral hilar or contralateral supraclavicular involvement) No pericardial or pleural effusion on chest x-ray regardless of cytology Measurable or evaluable disease Tumor must be encompassed by limited radiation therapy fields without causing severe symptomatic pulmonary dysfunction

PATIENT CHARACTERISTICS: Age: 18 to 80 Performance status: Karnofsky 70-100% Life expectancy: Greater than 6 months Hematopoietic: Absolute granulocyte count at least 1,500/mm3 Platelet count at least 150,000/mm3 Hepatic: Bilirubin no greater than 1.5 mg/dL Renal: Creatinine no greater than 1.5 mg/dL Cardiovascular: No symptomatic heart disease At least 6 months since prior myocardial infarction Pulmonary: See Disease Characteristics Forced expiratory volume at one second (FEV1) greater than 0.8 L No uncontrolled bronchospasm in unaffected lung Other: No other serious concurrent illness No prior or concurrent malignancy within the past 2 years except curatively treated basal cell or squamous cell skin cancer or carcinoma in situ of the cervix No other concurrent malignancy No history of uncontrolled psychiatric illness, severe head injury, chronic alcohol or drug abuse, or central nervous system disease Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: No prior chemotherapy Endocrine therapy: Not specified Radiotherapy: No prior radiotherapy Surgery: No prior complete tumor resection