Stereotactic fractionated radiotherapy for multiple brain metastasis treated with single isocenter multitargeted approach: a case report

Introduction: Adult patients with solid cancers frequently develop brain metastases. Whole brain radiotherapy (WBRT) alone or Stereotactic radiosurgery/radiotherapy (SRS/SRT) alone or in combination can be considered in Brain metastasis. Stereotactic radiosurgery has been effective in brain metastasis. Linac-based stereotactic radiosurgery has made use of volumetric modulated arc therapy (VMAT), which enables the simultaneous treatment of many targets with a single plan and isocenter. Case presentation: A 62-year-old Asian presented to us with complaints of headache and blurring of vision. Disease mapping with positron emission tomography (PET) revealed Lung primary. Magnetic resonance imaging (MRI) of brain revealed multiple brain metastasis. He was planned with fractionated stereotactic radiotherapy. Plan involved volumetric arc therapy - Stereotactic radiosurgery (VMAT-SRS) treatment with single isocenter multiple target stereotactic fractionated radiotherapy, which was delivered post stringent quality assurance. Discussion: SRS immobilization System has become more patient specific. Multiple challenges are encountered with single isocenter multiple target stereotactic fractionated radiotherapy. Essential yet challenging aspect of SRS is dosimetry. It requires a comprehensive Quality assurance to treatment planning to its delivery. Conclusion: LINAC based VMAT SRS plans are more conformal with prescribed isodose line up to 75%. Hence, optimization strategies should be applied for better plan outcome. Our patient completed treatment without any major side effects. Planned imaging with the CEMRI brain showed complete response with no new findings.