Simulation-Free, Single-Fraction Palliative Radiation Therapy for Treatment of Bone Metastases

Inclusion Criteria: * Participant aged ≥ 18 years. * Diagnosis of any cancer with one to two painful and treatable metastatic bone lesions. * Bone metastases are causing pain or instability in the opinion of the treating investigator. * Amenable to single fraction radiation therapy per the discretion of the treating physician. * CT collected within 60 days of registration with adequate visualization of target site as determined by the treating investigator. * ECOG Performance Status ≤ 2. * Participants must adhere to the following sex and contraceptive/barrier requirements: * If participant is of childbearing potential, they must have a negative pregnancy test ≤ 14 days before the planned date of radiation therapy. This may be completed on the day of radiation if results from the pregnancy test are available for review before treatment. * For participants of non-child bearing potential: The post-menopausal status will be defined as having been amenorrheic for 12 months without an alternative medical cause. The following age-specific requirements apply: * \< 50 years of age: * Amenorrheic for ≥ 12 months following cessation of exogenous hormonal treatments; and * Luteinizing hormone and follicle-stimulating hormone levels in the post-menopausal range for the institution ---≥ 50 years of age: * Amenorrheic for 12 months or more following cessation of all exogenous hormonal treatments; or * Had radiation-induced menopause with last menses \>1 year ago; or * Had chemotherapy-induced menopause with last menses \>1 year ago * Participants of childbearing potential and participants with a sexual partner of childbearing potential must agree to use a highly effective method of contraception. * Able to provide informed consent and willing to sign an approved consent form that conforms to federal and institutional guidelines. Exclusion Criteria: * Evidence of spinal cord compression caused by the bone metastases to be treated. * Any other condition that would, in the Investigator's judgment, contraindicate the participant's participation in the clinical study due to safety concerns or compliance with clinical study procedures. * Medical, psychiatric, cognitive, or other conditions that may compromise the participant's ability to understand the participant information, give informed consent, comply with the study protocol or complete the study. * Participants taking prohibited medications as described in Section 6.7.1.