Durable Intracranial Control Beyond Five Years in EGFR Wild-Type Non-Small Cell Lung Cancer with Sequential Brain Metastases Managed with Multimodal Therapy: A Case Report

Background and Clinical Significance: Brain metastases in non-small cell lung cancer (NSCLC) carry a poor prognosis, particularly in patients lacking targetable driver mutations or significant programmed death-ligand 1 (PD-L1) expression. Durable intracranial control exceeding five years is uncommon in this population and the factors that determine exceptional therapeutic response remain incompletely understood; Case Presentation: We report a 59-year-old male with pathological stage pT3N1 solid-type pulmonary adenocarcinoma (EGFR wild-type, ALK wild-type, PD-L1 <1%) who developed two sequential brain metastases following right upper lobectomy and adjuvant pembrolizumab plus pemetrexed-carboplatin. The first lesion was treated with single-fraction stereotactic radiosurgery (SRS, 10 Gy); a second metastasis identified 18 months later was managed with focal radiotherapy (8 Gy, single fraction) followed by whole-brain radiotherapy (24 Gy in 12 fractions). Local progression of the second metastasis in 2024 prompted successful surgical resection via right occipital craniotomy. Over a follow-up exceeding five years, the patient achieved sustained intracranial disease control, preserved neurological function, and maintained quality of life. Notably, no clinically apparent neurocognitive deterioration was documented on routine clinical follow-up, despite whole-brain irradiation without hippocampal sparing; formal neuropsychological testing was not performed; Conclusions: This case demonstrates that durable intracranial control may be achievable through carefully sequenced multimodal therapy—including stereotactic radiosurgery, whole-brain radiotherapy, and neurosurgical resection—even in biologically unfavorable NSCLC. The absence of clinically apparent neurocognitive deterioration on routine follow-up after WBRT raises hypothesis-generating questions regarding interindividual variability in radiation tolerance; this observation must be interpreted in the absence of formal neuropsychological testing and prospective hippocampal dosimetry. A multidisciplinary, individualized approach integrating radiotherapy, systemic therapy, and neurosurgery remains essential in this setting.