Table 3.

Potential clinical applications of liquid biopsy in the management of CNS metastases

• Diagnosis of LM when CSF cytology is negative or inconclusive

• Diagnosis of brain metastasis from unknown primary tumor or multiple lesions

• Quantification of residual tumor following surgical resection

• Differential diagnosis between pseudoprogression/radionecrosis and tumor progression

• Early indication of tumor response following cytotoxic or targeted agents

• Early diagnosis of tumor relapse

• Prediction of resistance to targeted agents

• Monitoring of treatment of resistance mutations with specific targeted agents

• Evaluation of prognosis (based on number of cells and molecular features)

• Screening in patients at high risk for brain or leptomeningeal metastases.