Positron Emission Tomography and Computed Tomography in Guiding Radiation Therapy for Stage III Non-small Cell Lung Cancer

Inclusion Criteria:

* Patients must have FDG-avid (maximum SUV \>= 4.0) (from PET scan of any date, any scanner) and histologically or cytologically proven non-small cell lung cancer
* Patients must be clinical American Joint Committee on Cancer (AJCC) stage IIIA or IIIB (AJCC, 7th ed.) with non-operable disease; non-operable disease will be determined by a multi-disciplinary treatment team, involving evaluation by at least 1 thoracic surgeon within 8 weeks prior to registration; Note: For patients who are clearly nonresectable, the case can be determined by the treating radiation oncologist and a medical oncologist, or pulmonologist
* Patients with multiple, ipsilateral pulmonary nodules (T3 or T4) are eligible if a definitive course of daily fractionated radiation therapy (RT) is planned
* History/physical examination, including documentation of weight, within 2 weeks prior to registration
* FDG-PET/CT scan for staging and RT plan within 4 weeks prior to registration
* CT scan or sim CT of chest and upper abdomen (IV contrast is recommended unless medically contraindicated) within 6 weeks prior to registration
* CT scan of the brain (contrast is recommended unless medically contraindicated) or MRI of the brain within 6 weeks prior to registration
* Pulmonary function tests, including diffusion capacity of carbon monoxide (DLCO), within 6 weeks prior to registration; patients must have forced expiratory volume in 1 second (FEV1) \>= 1.2 Liter or \>= 50% predicted without bronchodilator
* Zubrod performance status 0-1
* Able to tolerate PET/CT imaging required to be performed at an American College of Radiology (ACR) Imaging Core Laboratory (Lab) qualified facility
* Absolute neutrophil count (ANC) \>= 1,500 cells/mm\^3 (within 2 weeks prior to registration on study)
* Platelets \>= 100,000 cells/mm\^3 (within 2 weeks prior to registration on study)
* Hemoglobin (Hgb) \>= 10.0 g/dL (note: the use of transfusion or other intervention to achieve Hgb \>= 10.0 g/dL is acceptable) (within 2 weeks prior to registration on study)
* Serum creatinine within normal institutional limits or a creatinine clearance \>= 60 ml/min within 2 weeks prior to registration
* Negative serum or urine pregnancy test within 3 days prior to registration for women of childbearing potential
* Women of childbearing potential and male participants must agree to use a medically effective means of birth control throughout their participation in the treatment phase of the study
* The patient must provide study-specific informed consent prior to study entry

Exclusion Criteria:

* Patients with any component of small cell lung carcinoma are excluded
* Patients with evidence of a malignant pleural or pericardial effusion are excluded
* Prior invasive malignancy (except non-melanomatous skin cancer) unless disease free for a minimum of 3 years (for example, carcinoma in situ of the breast, oral cavity, or cervix are all permissible)
* Prior systemic chemotherapy for the study cancer; note that prior chemotherapy for a different cancer is allowable
* Prior radiotherapy to the region of the study cancer that would result in overlap of radiation therapy fields
* Severe, active co-morbidity, defined as follows:

  * Unstable angina and/or congestive heart failure requiring hospitalization within the last 6 months
  * Transmural myocardial infarction within the last 6 months
  * Acute bacterial or fungal infection requiring intravenous antibiotics at the time of registration
  * Chronic obstructive pulmonary disease exacerbation or other respiratory illness requiring hospitalization or precluding study therapy at the time of registration
  * Hepatic insufficiency resulting in clinical jaundice and/or coagulation defects; note, however, that laboratory tests for liver function and coagulation parameters are not required for entry into this protocol
  * Acquired immune deficiency syndrome (AIDS) based upon current Centers for Disease Control (CDC) definition; note, however, that human immunodeficiency virus (HIV) testing is not required for entry into this protocol
* Pregnancy or women of childbearing potential and men who are sexually active and not willing/able to use medically acceptable forms of contraception
* Poorly controlled diabetes (defined as fasting glucose level \> 200 mg/dL) despite attempts to improve glucose control by fasting duration and adjustment of medications; patients with diabetes will preferably be scheduled in the morning and instructions for fasting and use of medications will be provided in consultation with the patients' primary physicians
* Patients with T4 disease with radiographic evidence of massive invasion of a large pulmonary artery and tumor causing significant narrowing and destruction of that artery are excluded