Study of Hypofractionated Radiotherapy Alone in Locally Advanced Nonsmall Cell Lung Cancer Patients

Inclusion Criteria: * Histological confirmation of non-small cell lung cancer by either biopsy or cytology * American Joint Committee on Cancer (AJCC) 8th Edition Stage II-III or ultracentral Stage IB disease as determined by PET/CT and MRI Brain * Ultracentral disease will be defined as edge of gross visible tumor within 1.0 cm of the proximal bronchial tree. * Eastern Cooperative Oncology Group (ECOG) Performance Status of 0-3 * Participant is not eligible for or has declined surgical resection or stereotactic body radiotherapy as determined by the treating physician * Participant is not eligible for or has declined concurrent chemotherapy as determined by the treating physician * While investigators expect it to be an uncommon event, sequential use of systemic therapy after completion of radiation therapy is permissible if the participant's status improves such that they become eligible for such therapies, per the discretion of a multidisciplinary tumor board. * Negative serum or urine pregnancy test within 2 weeks of the date of enrollment for women of child-bearing potential. * Ability to understand and the willingness to sign an IRB-approved informed consent document (either directly or via a legally authorized representative). Exclusion Criteria: * History of previous thoracic radiotherapy with the exception of prior radiotherapy for breast cancer without overlap of the fields with the cancer to be treated. * Prior systemic therapy or surgery for the study cancer. * Prior malignancy within the past two years except for non-melanoma skin cancer, prostate cancer, or any in-situ malignancy. * Receipt of anti-angiogenic therapy, such as bevacizumab, within 6 months of enrollment. * Pregnant women are excluded from this study because radiation therapy has known potential for teratogenic or abortifacient effects.