FDG-PET/CT Scans in Patients With Stage IIIB or Stage IV NSCLC Undergoing Chemotherapy

DISEASE CHARACTERISTICS: * Histologically or cytologically confirmed non-small cell lung cancer * Newly diagnosed stage IIIB (with malignant pleural effusion) or stage IV disease (Group I and II), or newly diagnosed stage IIIA, IIIB, or IV (Group III) determined by all of the following: * CT scan or MRI of the chest and upper abdomen (including liver and adrenal glands) within the past 4 weeks * History/physical examination within the past 6 weeks * CT scan or MRI of the brain within the past 4 weeks, if there is headache, mental/physical impairment, or other signs or symptoms suggesting brain metastases within the past 2 months * No small cell carcinoma * No pure bronchioloalveolar carcinoma * Patients with recurrent or metastatic disease are eligible provided they meet 1 of the following criteria: * Received surgery or radiotherapy for treatment of the primary tumor and locoregional disease ≥ 3 months prior to study entry AND have a measurable lesion in the chest * Received chemotherapy in the adjuvant setting or as part of combined modality therapy for locoregional disease ≥ 3 months prior to recurrent or metastatic disease diagnosis AND have a measurable lesion in the chest * Measurable disease, defined as at least 1 measurable primary tumor or other intrathoracic/supraclavicular lesion ≥ 2 cm * Scheduled to be treated with a platinum-based dual-agent chemotherapy regimen administered at 3-week intervals with or without bevacizumab or cetuximab (Group I and II) * Scheduled to be treated with standard chemotherapy in the current protocol, other standard chemotherapy, experimental chemotherapy, or other treatment including no treatment (Group III) * No symptomatic brain metastases (Groups I and II only) PATIENT CHARACTERISTICS: * ECOG performance status 0-2 (Groups I and II only) * Group III may include potential participants regardless of ECOG performance status score * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * Able to tolerate positron emission tomography (PET)/CT scanning * No contraindication to chemotherapy and PET/CT scanning, as demonstrated by laboratory testing * No poorly controlled diabetes (i.e., fasting glucose level \> 150 mg/dL) despite attempts to improve glucose control by fasting duration and adjustment of medications * No prior malignancy other than basal cell or squamous cell carcinoma of the skin, carcinoma in situ, or other cancer from which the patient has been disease free for ≥ 3 years (Groups I and II) * Prior malignancy is not an exclusion factor for Group III * No clinical or radiographic signs of post-obstructive pneumonia PRIOR CONCURRENT THERAPY: * See Disease Characteristics * More than 3 months since prior thoracic radiotherapy, lung surgery, or chemotherapy * Prior chemotherapy in the adjuvant setting or as part of a combined modality regimen for locoregional disease that was given ≥ 3 months prior to diagnosis of recurrent or metastatic disease allowed * No planned treatment with any targeted biologic therapy including gefitinib or erlotinib hydrochloride (Group I and II) * No concurrent chemoradiotherapy * No concurrent bevacizumab