Inclusion Criteria:

- Histologically confirmed primary lung cancer, lung metastasis from another primary,
or recurrent tumors in the setting of prior RFA or cryotherapy

- Tumors < 2 cm from trachea or zone of proximal bronchial tree (central tumors)

- Each tumor < 5 cm in size prior to treatment

- Medically inoperable patients as determined at the multidisciplinary thoracic tumor
board, or medically operable patients who refuse surgery

- Criterion for medical inoperability include:

- Overall clinical assessment at the UCLA thoracic tumor board

- Reduced Pulmonary Function (FEV1, DLCO, etc) based on one major or two minor
criterion as described below:

- Modified ACOSOG Criteria for medical inoperability:

- Major Criteria: FEV1% < 50% or < 1L and DLCO < 50%

- Minor Criteria: Age > 75, FEV1 51-60% predicted, or FEV1 1-1.2L, DLCO 51%-60%
predicted, pulmonary hypertension, poor left ventricular function (EF < 40% or
less), resting or exercise arterial pO2 < 55 mmHg, and pCO2 > 45 mmHg

- Age > 18 years old

- KPS > 70

- If a woman is of childbearing potential, a negative urine or serum pregnancy test
must be documented.

- Ability to understand and the willingness to sign a written informed consent

Exclusion Criteria:

- Prior thoracic radiation near the targets of interest

- More than 2 central tumor targets per patient

- Active infections requiring systemic antibiotics