Positron Emission Tomography in Predicting Response in Patients Who Are Undergoing Treatment With Pemetrexed Disodium and Cisplatin With or Without Surgery for Stage I, Stage II, or Stage III Non-Small Cell Lung Cancer

RATIONALE: Diagnostic procedures, such as positron emission tomography (PET), (done before, during, and after chemotherapy) may help doctors predict a patient's response to treatment and help plan the best treatment. Drugs used in chemotherapy, such as pemetrexed disodium and cisplatin, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Giving combination chemotherapy after surgery may kill any tumor cells that remain after surgery. PURPOSE: This phase II trial is studying how well PET works in predicting response in patients who are undergoing treatment with pemetrexed disodium and cisplatin with or without surgery for stage I, stage II, or stage III non-small cell lung cancer.