Prophylactic Proton Pump Inhibition for Esophageal Protection in Lung Radiation Therapy

Inclusion Criteria: * Age 18 years or older * Willing to provide informed consent * Eastern Cooperative Oncology Group (ECOG) performance status 0-3 * Life expectancy of at least 3 months * Primary lung malignancy of any stage (including NSCLC and small cell lung cancer). Histologic/pathologic diagnosis is preferred, but not required. * Receiving a prescribed dose of at least 40 Gy in 15 fractions (or equivalent). Eligible fractionations include, but are not limited to, 60 Gy in 30 fractions, 55 Gy in 20 fractions, and 40-45 Gy in 15 fractions. * On radiation planning, at least 5 cc of esophagus is receiving at least 95% of prescription dose Exclusion Criteria: * • Serious medical comorbidities precluding radiotherapy * Use of PPI within 3 months prior to enrollment * Allergy to PPI * Odynophagia (painful swallowing) prior to enrollment * Pregnant or lactating women Note: previous radiation to the thorax is allowed, as long as the composite plan of current and prior radiation doses meet standard institutional dose constraints, in the opinion of the treating radiation oncologist.