Symptomatic Brain Radiation Necrosis in an Anaplastic Lymphoma Kinase (ALK)-Positive Non-small Cell Lung Cancer (NSCLC) Patient After Fractionated Stereotactic Radiotherapy While on Alectinib

Anaplastic lymphoma kinase (ALK)-positive non-small cell lung cancer (NSCLC) has a higher incidence of brain metastasis. Despite having a favorable prognosis and relatively long survival with second-generation ALK tyrosine kinase inhibitors (TKI), patients can have substantial morbidity, negatively affecting functional progression-free and symptom-free survival. Studies have shown that ALK-rearranged NSCLC is a risk factor for developing radiation necrosis (RN). Recently, second-generation TKI, especially lorlatinib, alectinib, and brigatinib, have demonstrated good central nervous system (CNS) penetration and overall response rates in patients with brain metastasis. However, to improve overall outcomes in symptomatic or limited brain metastases, stereotactic radiosurgery (SRS) is increasingly preferred over whole brain radiotherapy (WBRT) prior to systemic therapy to avoid significant cognitive deterioration. To improve the therapeutic ratio, fractionated stereotactic radiotherapy (FSRT) has been explored for brain metastasis. Herein, we report on one ALK-rearranged NSCLC patient who developed RN despite FSRT, one year after the completion of radiotherapy while on alectinib.