Inclusion Criteria:

• * Plan for fractionated (≥15 treatments) proton beam thoracic radiotherapy with curative intent for lung cancer
• * Non-small cell lung cancer (NSCLC) or small cell lung cancer (SCLC) histology is permitted.
• * Concurrent chemotherapy is permitted but not required..
• * Previous thoracic radiotherapy is allowed.
• * Ability to complete study surveys in English or Spanish
• * Age \>/= 18
• * Concurrent enrollment on other trials is permitted
• * Patients who already use wearable devices and/or smartphones that monitor physical activity are eligible for this trial, provided they agree to utilize the devices provided by the study team during the study period
• * All patients must sign study-specific informed consent prior to study entry

Exclusion Criteria:

• * Ongoing treatment for another cancer that is expected to affect the toxicity profile of thoracic radiotherapy
• * Pregnancy or women of childbearing potential and men who are sexually active and not willing/able to use medically acceptable forms of contraception; this exclusion is necessary because the treatment involved in this study may be significantly teratogenic