Hyperpolarized Xenon-129 Magnetic Resonance Imaging in Lung Cancer Patients Receiving Radiation Therapy for Investigating Radiation-response and Toxicity

Inclusion Criteria: 1. Healthy control cohort: 1. Able to consistently hold breath for 10-12 seconds 2. No history of any pulmonary disorders (i.e., asthma, COPD, lung cancer, etc.) 3. Able to undergo MRI examination 4. At least 18 years of age 2. Lung cancer patient cohort: 1. Biopsy proven diagnosis of lung cancer 2. Receiving photon- or proton-based external beam radiotherapy as a part of treatment 3. Able to undergo MRI examination 4. Will receive follow-up at University of Texas MD Anderson Cancer Center (UTMDACC) 5. Able to consistently hold breath for 10-12 seconds 6. Women and men with child-bearing potential agree to use adequate contraception prior to study entry and during the duration of study participation. 7. Able to understand and willing to sign a written informed consent document 8. At least 18 years of age The effects of HP 129Xe MRI on the developing human fetus are unknown. For this reason and because radiotherapy is known to be teratogenic, women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation. (Refer to Pregnancy Assessment Policy MD Anderson Institutional Policy # CLN1114). This includes all female patients, between the onset of menses (as early as 8 years of age) and 55 years unless the patient presents with an applicable exclusionary factor which may be one of the following: * Postmenopausal (no menses in greater than or equal to 12 consecutive months). * History of hysterectomy or bilateral salpingo-oophorectomy. * Ovarian failure (Follicle Stimulating Hormone and Estradiol in menopausal range, who have received Whole Pelvic Radiation Therapy). * History of bilateral tubal ligation or another surgical sterilization procedure. * Approved methods of birth control are as follows: Hormonal contraception (i.e. birth control pills, injection, implant, transdermal patch, vaginal ring), Intrauterine device (IUD), Tubal Ligation or hysterectomy, Subject/Partner post vasectomy, Implantable or injectable contraceptives, and condoms plus spermicide. Not engaging in sexual activity for the total duration of the trial and the drug washout period is an acceptable practice; however periodic abstinence, the rhythm method, and the withdrawal method are not acceptable methods of birth control. Should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she should inform her treating physician immediately. Additionally, if female partners of male study participants become pregnant during study participation, the treating physician should be informed immediately. * Ability to understand and the willingness to sign a written informed consent document. Exclusion Criteria: 1. Patients unable to follow up at MD Anderson for routine clinical care 2. Inability or unwillingness to give informed consent 3. Relapsed disease or life expectancy less than 6 months at time of enrollment 4. Severe claustrophobia precluding MRI imaging active pulmonary infection 5. Pregnant women 6. Under 18 years of age