Early Radiotherapy Versus Observation for High-risk Asymptomatic or Minimally Symptomatic Bone Metastases

Inclusion Criteria: * I1: Histologically confirmed solid tumor malignancy (with polymetastastic spread (≥ 3 metastases)) * I2: High-risk bone metastasis(es) that is (are) asymptomatic or minimally symptomatic: \*Asymptomatic or minimally symptomatic is defined as follows: O Numeric Pain Rating Scale (NRS) score ≤2 for the specific lesion(s) \*High-risk is defined as follows (i.e. at least one of the following points must be applicable): O Bulky site of disease in bone (diameter ≥ 2 cm) O Disease involving the hip (acetabulum, femoral head, femoral neck), shoulder (acromion, glenoid, humeral head), or sacroiliac joints O Disease in long bones with cortical involvement of \>1/3 in proportion to the diameter of the bone (humerus, radius, ulna, clavicle, femur, tibia, fibula, metacarpals, phalanges) O Disease in vertebrae of the junctional spine (C1-2, C7- T1, T12-L1, L5-S1) and/or disease with posterior element involvement or epidural extension (Bilsky epidural compression score 1a-3) \[Bilsky et al\]. The posterior elements of the spine consist of the pedicles, laminae, facets (articular processes), transverse processes, and the spinous process. * I3: Number of Risk Factors (NRF) prognostic score 0-2 * I4: Age ≥ 18 years * I5: Ability to provide informed consent (either by the patient or by a legally authorized representative) * I6: A female participant is eligible to participate if she confirms not to be pregnant at screening, and one of the following conditions applies: Is not a woman of child bearing potential or A woman of child bearing potential must confirm that she is not pregnant at screening and must agree to use a very effective method of birth control Exclusion Criteria: * E1: Previous RT to the target treatment site(s) * E2: NRF prognostic score 3 * E3: Serious medical co-morbidities that preclude radiotherapy * E4: Bone lesion complicated with a pathological fracture or impending pathologic fracture for which prophylactic stabilization is recommended, characterized by Mirels score of ≥9 \[Mirels et al\]. * E5: Spinal metastasis with SINS score \>13 requiring upfront neurosurgical stabilization \[Fourney et al\]. * E6: More than 5 high-risk asymptomatic or minimally symptomatic metastatic bone locations * E7: Patient already included in another clinical trial that would interfere with the HERMES clinical trial, as assessed by the Investigator.

Reproduced word-for-word from the public registry record — the study team can answer questions about it.