Cisplatin, Pemetrexed Disodium, and Radiation Therapy Followed by Docetaxel in Treating Patients With Stage III Non-Small Cell Lung Cancer

DISEASE CHARACTERISTICS: Histologic or cytologic diagnosis of non-small cell lung cancer (NSCLC), meeting 1 of the following staging criteria: Stage IIIA disease, meeting all of the following criteria: Mediastinal lymph node involvement Greater than one mediastinal lymph node enlarged on CT scan, confirmed by positron emission tomography (PET) scan Paralyzed left vocal cord with separate lung primary distinct from the aorto-pulmonary lymph nodes on the CT scan Stage IIIB disease, meeting all of the following criteria: N3 lymph node involvement Enlarged N3 lymph nodes on CT scan confirmed by PET scan Lymph node involvement may not extend to cervical lymph nodes other than supraclavicular lymph nodes Right-sided primary tumor with left vocal cord paralysis Evidence of tumor extension into the mediastinum and/or mediastinal structures by mediastinoscopy, bronchoscopy, or CT scan No evidence of malignant pleural effusion unless effusion is only evident on CT scan No more than 1 parenchymal lesions on the same or opposite sides of the lung No brain metastases by CT scan or MRI PATIENT CHARACTERISTICS: SWOG performance status 0 or 1 Platelet count ≥ 100,000/mm³ Absolute neutrophil count ≥ 1,500/mm³ Creatinine ≤ 1.5 times upper limit of normal (ULN) Creatinine clearance ≥ 45 mL/min Bilirubin normal Transaminases (SGOT and/or SGPT) ≤ 1.5 times ULN Alkaline phosphatase ≤ 2.5 times ULN Total lung volume (i.e., right and left lung minus the gross tumor volume) receiving greater than 20 Gy of radiation ≤ 40% FEV_1 ≥ 70% of predicted DLCO ≥ 50 mL/min No other concurrent malignancy Prior malignancy allowed provided it is in clinical control and is not likely to impact clinical outcome in the opinion of the treating physician No peripheral neuropathy ≥ grade 2 No serious medical illness, including, but not limited to, any of the following: Uncontrolled congestive heart failure Uncontrolled angina Myocardial infarction Cerebrovascular event within the past 6 months History of chronic active hepatitis History of HIV infection Active bacterial infection Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception Must be willing and able to take folic acid, cyanocobalamin (vitamin B12), or dexamethasone PRIOR CONCURRENT THERAPY: No prior chemotherapy or radiotherapy for NSCLC No concurrent participation in another therapeutic investigational study Concurrent ibuprofen (400 mg four times daily) allowed during pemetrexed disodium administration provided the patient has normal renal function No concurrent aspirin or other nonsteroidal antiinflammatory drugs (NSAIDs) 2 days before, during, and for 2 days after pemetrexed disodium administration Patients on long-acting NSAIDs (e.g. naproxen sodium, diflunisal, nabumetone, or celecoxib) must be willing or able to discontinue usage 5 days prior to, during, and for 2 days after pemetrexed disodium administration