case_images: PMC11116670_01
case_images: Sagittal and axial views of MRI images using T1WI enhancement. (A) Preoperative sagittal view in late January 2022 demonstrated a 20 x 19 mm lesion of the left parietal lobe; (B) Preoperative axial view in late January 2022; (C) Sagittal view in early May 2023 after receiving zimberelimab; (D) Axial view in early May 2023 after receiving zimberelimab. (E) The most recent sagittal view (March 2024); (F) The most recent axial view (March 2024).
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case_images: Cooperative Oncology Group performance status score was assessed at 1. Enhanced magnetic resonance imaging (MRI) of the brain exhibited a 20 x 19 mm circular abnormal signal shadow within the medial left parietal lobe ( Figures 1A, B ). Chest computed tomography (CT) revealed a mass in the upper lobe of the right lung, along with multiple satellite lesions ( Figure 2A ). Brain MRI showed no recurrent BM ( Figures 1C, D ). As of the latest follow-up in March 2024, the patient has achieved both progression-free survival (PFS) and intracranial RFS of 24 months ( Figures 1E, F ,  2D-I ).
case_images: Chest CT findings. (A) Chest CT revealed a tumor on admission in January 2022; (B) Chest CT showed persistent abnormalities before initiation of zimberelimab in February 2022; (C) Chest CT demonstrated a significant decrease in lesion size, achieving PR in May 2022; (D-I) Subsequent chest CTs showed sustained PR of the tumor. PR, partial response.
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case_images: Cooperative Oncology Group performance status score was assessed at 1. Enhanced magnetic resonance imaging (MRI) of the brain exhibited a 20 x 19 mm circular abnormal signal shadow within the medial left parietal lobe ( Figures 1A, B ). Chest computed tomography (CT) revealed a mass in the upper lobe of the right lung, along with multiple satellite lesions ( Figure 2A ). BM resection, in late February 2022, the size of the right lung lesion was measured as 47 mm x 45 mm by chest CT. ( Figure 2B ). Because systemic therapies rather than surgical excision are indicated for the treatment of primary lesions in stage IV NSCLC and considering the extremely high TPS of 95%, monotherapy with zimberelimab, a PD-1 inhibitor, was administered intravenously at a dosage of 240 mg every three weeks. In May 2022, after four cycles of therapy, the size of the pulmonary lesion was significantly reduced to 27 x 21 mm ( Figure 2C ), indicating a partial response (PR). As of the latest follow-up in March 2024, the patient has achieved both progression-free survival (PFS) and intracranial RFS of 24 months ( Figures 1E, F ,  2D-I ).
case_images: H&E staining and positive Immunohistochemical staining results for BM (all shown at 400x magnification); (A) H&E staining; (B) TTF-1 (+); (C) NapsinA (+); (D) CK7 (+). BM, brain metastasis; H&E, hematoxylin and eosin.
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case_images: Immunohistochemical staining of the BM lesion revealed positivity for PD-L1 (all shown at 200x magnification); (A) PD-L1 CPS of 98; (B) PD-L1 TPS of 95%. BM, brain metastasis; PD-L1, programmed cell death ligand 1; CPS, Combined Proportion Score; TPS, Tumor Proportion Score.
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case_images: TPS of 95% ( Figure 4 ). The tumor harbored neither EGFR gene mutation nor ALK gene rearrangement. The patient received a diagnosis of metastatic NSCLC (stage IVA) without gene variants.