Imaging Features for the Risks for Recurrence After Stereotactic Radiosurgery in Brain Metastasis

PRIMARY OBJECTIVE:

I. To develop an imaging risk score for recurrence after stereotactic radiosurgery (SRS) in brain metastasis using multiparametric MRI.

II. To validate the imaging risk score in retrospective external validation and prospective internal validation test set.

SECONDARY OBJECTIVE:

I. To predict radiation necrosis using imaging risk score.

OUTLINE:

Participants undergo multi-parametric MRI including 3D pre- and contrast-enhanced T1 weighted image, T2 weighted image, diffusion-weighted image, dynamic susceptibility contrast MRI, and arterial spin labeling image before receiving SRS, and every 3 months after SRS.

Inclusion criteria

• Patients who underwent stereotactic radiosurgery (SRS, gamma-knife radiosurgery or cyberknife radiosurgery) for brain metastases
• Patients with lesions eligible for SRS :

• One to ten newly diagnosed brain metastases
• Patients without acute neurological symptom
• Patients with a Karnofsky performance status score of 70 or higher
• Patients who underwent brain MRI within 1 month of enrollment
• Patients with measurable enhancing lesions on MRI.
• Patients who have available reference standard (second-look surgery for recurrence) or available follow up imaging for clinic-radiologic reference standard.
• A longest diameter > 1.5 cm for tumor habitat analysis.

Exclusion criteria

• Patients who have undergone prior brain surgery, SRS, or whole-brain radiation therapy.
• Patients who are diagnosed with leukemia, lymphoma, germ-cell tumor, small-cell lung cancer, leptomeningeal disease, or unknown primary tumor.
• Patients with age < 18 years.
• Patients without baseline MRI.
• Patients with nonmeasurable enhancing lesions on MRI : all other lesions, including lesions with longest dimension < 10 mm, lesions with borders that cannot be reproducibly measured, dural metastases, bony skull metastases, and leptomeningeal disease.