This pilot phase I/II trial studies how well a continuous positive airway pressure device or deep inspiration breath hold works in reducing tumor movement in patients undergoing stereotactic body radiation therapy (SBRT) for lung cancer. The continuous positive airway pressure device works by blowing air into the lungs while patients wear a face mask or nozzle to help expand their airways and lungs. Deep inspiration breath hold is a standard technique that uses active breath-holding to restrict movement of the body. Using a continuous positive airway pressure device may work better than deep inspiration breath hold in lowering the amount of tumor movement during stereotactic radiation body therapy.

PRIMARY OBJECTIVES:

I. To compare the two methods of tumor motion management, continuous positive airway pressure (CPAP) and deep inspiration breath hold (DIBH) and to estimate the decrease in tumor motion from free breathing for CPAP and DIBH.

SECONDARY OBJECTIVES:

I. To determine if CPAP is a more time-efficient option for tumor motion management than is DIBH.

Ia. Determine if CPAP is better tolerated by patients than is DIBH. Ib. Determine the reproducibility of lung expansion and tumor motion reduction by CPAP.

Ic. Determine if the dosimetric coverage of the tumor and the sparing of the normal tissues with CPAP is comparable to that with DIBH.

Id. Measure treatment time differences between CPAP and breath hold (DIBH) treatments.

OUTLINE:

Patients undergo free-breathing, DIBH, and CPAP CT simulation scans. If patient has difficulty exhaling on CPAP, then patient undergo biphasic positive airway pressure (BiPAP) CT simulation. The attending physician then compares all 3 simulation treatment plans (free-breathing, DIBH, and CPAP/BiPAP) and determines which method to use during SBRT. If CPAP/BiPAP is chosen as preferred method, patients wear CPAP/BiPAP over 1 hour prior to SBRT, then again during SBRT over 30-60 minutes. All other patients complete free-breathing or DIBH during SBRT over 30-60 minutes.

Inclusion Criteria:

• The patient will receive stereotactic body radiotherapy in the Thoracic Radiation Oncolcogy Service at MD Anderson.

Exclusion Criteria:

• The patient has a contra-indication for using a CPAP device.
• The patient has not signed a study-specific informed consent for this study.
• The patient is uncooperative.
• The patient has reduced consciousness.
• The patient has sustained trauma or burns to the face.
• The patient has undergone any facial, esophageal, gastric or sinus surgery within the last 3 months.
• The patient has idiopathic pulmonary fibrosis (IPF) as documented in their medical history.
• Adults who are unable to consent, individuals who are not yet adults, pregnant women and prisoners will be excluded from this study.