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 sites of 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 or having undergone surgical sterilization (bilateral oophorectomy or hysterectomy). 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.