DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed non-small cell lung cancer (NSCLC), including any of the following:

  • Squamous cell carcinoma
  • Adenocarcinoma (including bronchoalveolar cell)
  • Large cell anaplastic carcinoma (including giant and clear cell carcinomas)

• Stage IIIA/B disease

  • Unresectable disease

  • Tumors adjacent to a vertebral body allowed

    • No demonstrable bone invasion
    • All gross disease must be able to be encompassed in the radiation boost field in accordance with the homogeneity criteria

  • Contralateral mediastinal disease (N3) allowed if all gross disease can be encompassed in the radiation boost field in accordance with the homogeneity criteria

    • No scalene, supraclavicular, or contralateral hilar node involvement

  • Pleural effusion allowed if it is transudate, cytologically negative, and non-bloody AND tumor can be encompassed within a reasonable field of radiotherapy

    • No exudative, bloody, or cytologically malignant effusions
    • Pleural effusion seen on chest CT scan but not on chest x-ray and too small to tap allowed

• Measurable disease, defined as lesions that can be accurately measured in ≥ 1 dimension (longest diameter to be recorded) as ≥ 20 mm with conventional techniques or as ≥ 10 mm with spiral CT scan

  • No nonmeasurable disease, including any of the following:

    • Bone lesions
    • Leptomeningeal disease
    • Ascites
    • Pleural/pericardial effusion
    • Abdominal masses that are not confirmed and followed by imaging techniques
    • Cystic lesions
    • Tumor lesions situated in a previously irradiated area

PATIENT CHARACTERISTICS:

• ECOG performance status 0-1
• Granulocyte count ≥ 1,500/mm^3
• Hemoglobin > 8.0 g/dL
• Platelet count ≥ 100,000/mm^3
• Bilirubin < 1.5 mg/dL
• Creatinine < 1.5 times upper limit of normal (ULN)

• Meets 1 of the following criteria:

  • AST and ALT < 2 times ULN
  • AST and ALT ≤ 2.5 times ULN AND alkaline phosphatase (AP) normal
  • AST and ALT normal AND AP ≤ 4 times ULN
• FEV_1 ≥ 1.2 L

• No other currently active malignancy except nonmelanoma skin cancers

  • Patients are not considered to have another currently active malignancy if they have completed therapy for the other malignancy and are considered by their physician to be at < 30% risk of relapse (i.e., after treatment for early-stage prostate cancer)
• Not pregnant or nursing
• Fertile patients must use effective contraception during and for 3 months after completing treatment
• No history of severe hypersensitivity reaction to docetaxel or other drugs formulated with polysorbate 80
• No known severe hypersensitivity to gefitinib or any of the excipients of this product
• No evidence of severe or uncontrolled systemic disease (e.g., unstable or uncompensated respiratory, cardiac, hepatic, or renal disease)
• No evidence of any other significant clinical disorder or laboratory finding that would limit compliance with study requirements
• No evidence of clinically active interstitial lung disease (asymptomatic, chronic stable radiographic changes allowed)
• No peripheral neuropathy ≥ grade 1

PRIOR CONCURRENT THERAPY:

• At least 2 weeks since prior formal exploratory thoracotomy
• No prior chemotherapy or radiotherapy for NSCLC
• No prior epidermal growth factor-targeting drugs (i.e., gefitinib, erlotinib, or cetuximab)
• No other investigational agent within 30 days of study entry
• No concurrent phenytoin, carbamazepine, rifampicin, barbiturates, or Hypericum perforatum (St John's wort)

• No other concurrent hormonal therapy or chemotherapy except for the following:

  • Steroids for adrenal failure, allergic reactions, or septic shock
  • Hormones for nondisease-related conditions (e.g., insulin for diabetes)
  • Glucocorticosteroids as anti-emetics