The goal of this study is to provide proof that patients can be treated with simulation-free, single-fraction palliative radiation therapy with a single in-person visit.

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.