Image-Guided, Intensity-Modulated Photon or Proton Beam Radiation Therapy in Treating Patients With Stage II-IIIB Non-small Cell Lung Cancer

This partially randomized phase I/II trial studies the side effects and best dose of image-guided, intensity-modulated photon or proton beam radiation therapy and to see how well they work in treating patients with stage II-IIIB non-small cell lung cancer. This trial is testing a new way of delivering radiation dose when only the tumor receives dose escalation while the surrounding normal structure is kept at standard level. Photon beam radiation therapy is a type of radiation therapy that uses x-rays or gamma rays that come from a special machine called a linear accelerator (linac). The radiation dose is delivered at the surface of the body and goes into the tumor and through the body. Proton beam radiation therapy is a type of radiation therapy that uses streams of protons (tiny particles with a positive charge) to kill tumor cells. Both methods are designed to give a higher than standard dose of treatment to the tumor and may reduce the amount of radiation damage to healthy tissue near a tumor.

Inclusion Criteria: * Pathologically proven diagnosis of unresected stage II-IIIB, or recurrent after surgical resection or stereotactic body radiation therapy (SBRT) non-small cell lung cancer * Suitability for concurrent chemoradiation therapy per treating physician's assessment * Karnofsky performance status (KPS) score \>= 70 * Weight loss \< 15% in the 3 months before diagnosis * Prior receipt of induction chemotherapy followed by referral for concurrent chemoradiation is allowed * Adequate lung function indicated by forced expiratory volume at 1 second (FEV1) \>= 1 L is required * The primary tumor and/or regional lymph nodes must be evaluable radiographically * The gross target volume (GTV) is suitable for motion management using 4 dimensional computed tomography (4D CT), internal target volume (ITV), or respiratory gating; in addition, the target coverage and normal tissue constraints must be met as specified in protocol accounting for the respiratory motion of anatomy as a whole (not just the tumor) * No prior radiation to the mediastinal structures * Hemoglobin \>= 9.0 g/dL * Absolute neutrophil count (ANC) \>= 1,500/mm\^3 * Platelet count \>= 100,000/mm\^3 * Total bilirubin =\< 1.5 times the upper limit of normal (ULN) * Alanine and aspartate transaminases (ALT and AST) =\< 2.5 times the ULN (=\< 5 x ULN for patients with liver involvement) * Creatinine =\< 1.5 times ULN * Patients must sign an informed consent indicating that they are aware of the investigational nature of the study in keeping with the policy of MD Anderson Cancer Center (MDACC) Exclusion Criteria: * Prior radiotherapy to any anatomic regions that would result in overlap of radiation dose distribution to critical structures (esophagus, heart, spinal cord, brachial plexus) * T4 tumor with direct invasion of esophagus, spinal cord, major blood vessel, or heart * Pregnancy * Patients of childbearing potential must practice appropriate contraception * Patient refusal