Inclusion Criteria

* • Presence of parenchymal lung nodule, without pathological diagnosis, highly suspicious for NSCLC as defined by at least one of the criteria below. Validated clinical prediction model estimates probability of malignancy is ≥ 85% or

* Multidisciplinary tumor board determines patient's history, clinical findings, and radiographic findings are consistent with high probability of malignancy.

Medically-inoperable patient due to one of the criteria below

* Poor pulmonary function for resection including baseline Forced Expiratory Volume in 1 second (FEV1), FEV1 \<50%, post-operative predicted FEV1\<30% predicted, diffusion capacity \<50%, baseline hypoxemia and/or hypercapnia. Patients with severe obstructive or restrictive lung disease will be eligible for inclusion.
* Pulmonary hypertension
* Cerebral, cardiac, or peripheral vascular disease
* Chronic heart disease
* Diabetes mellitus with end organ damage
* Age ≥75
* Patient declines surgery

Absence of pathological diagnosis due to one of the criteria below

* High risk of complications from transbronchial or transthoracic biopsy
* Biopsy was performed or attempted but with complications requiring abortion of procedure
* Biopsy was performed and non-diagnostic for malignancy but without other diagnosis to explain the clinical and radiographic findings
* Patient declines biopsy Stage T1-3, N0, M0 (AJCC Staging, 7th Ed.) based upon the following diagnostic workup
* History/Physical examination by an experienced thoracic cancer clinician (thoracic surgeon, interventional pulmonologist, medical oncologist, or radiation oncologist) within 4 weeks prior to registration
* Diagnostic imaging (CT and/or PET/CT) Serial computed tomography and/or positron emission tomography imaging clinically consistent with lung malignancy.
* CT scan with contrast (unless medically contraindicated) within 6 weeks of registration. The tumor dimensions will be measured on CT with greatest dimension ≤5cm.
* Whole body Positron Emission Tomography / Computerized Tomography (PET/CT) within 12 weeks of registration. Standard uptake value (SUV) must be available but no minimum SUV is required for inclusion.

No clinical or radiographic evidence of nodal disease or distant metastases No previous local therapy such as external beam radiotherapy, lobectomy, or sublobar resection.

Women of child-bearing potential must undergo pregnancy testing prior to enrollment on study. Should a woman become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately.

* A female of child-bearing potential is any woman (regardless of sexual orientation, having undergone a tubal ligation, or remaining celibate by choice) who meets the following criteria:
* Has not undergone a hysterectomy or bilateral oophorectomy; or
* Has not been naturally postmenopausal for at least 12 consecutive months.

Patients with prior history of malignancy are permitted registration but must not be undergoing active cytotoxic or biologically-targeted therapy, must be disease-free from any malignancy for the previous three years, and must not have any history of brain metastases with the following exceptions:

* Patients with history of basal cell carcinoma and/or squamous cell carcinoma may be permitted access within 3 years of being disease-free and is up to the discretion of the treating physicians
* Patients with any prior history of lung cancer may not participate in this study.

Age ≥ 18 years. Ability to understand and willingness to sign a written informed consent document.

Exclusion Criteria:

* • Prior history of lung cancer.

* Prior local therapy (surgery or radiotherapy) for the current, clinically-diagnosed NSCLC.
* Patients receiving any other investigational agents.
* Patients with a known history of malignancy with a disease-free interval \<3 years prior to enrollment or a history of brain metastases
* Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, severely symptomatic congestive heart failure, cardiac arrhythmia, or psychiatric illness/social situations that could limit compliance with study requirements.
* Patients who are currently pregnant or nursing due to the potential for congenital abnormalities and potential harm to nursing infants.
* Patients enrolled on a competing investigational study.