case_images: PMC9396254_01
case_images: NGS panel results showed EGFR mutation L747P (2239-2240 TT>CC) in exon 19.
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case_images: ALK, BRAF, EGFR, ERBB2, KRAS, MET, NTRK, RET, and ROS1), and PD-L1 (Ventana SP263) expression detection in tumor tissue paraffin section (30% neoplastic cell) found EGFR exon 19 L747P mutation (EGFR NM_005228.3 Exon19 c.2239_2240del TTinsCC p.L747P) ( Figure 1 ) with a mutation abundance of 14.21% and PD-L1 expression was greater than 10% in tumor cells (TCs). After the operation, the patient did not receive any antitumor therapy due to personal refusal.
case_images: Craniocerebral CT about clinical response to afatinib therapy at different times. (A) Baseline before afatinib treatment. (B) Brain metastases progressive disease (PD) after 4 months.
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case_images: Subsequently, the patient started oral afatinib 40 mg daily as first-line therapy on 4 August 2020 ( Figure 2A ), and achieved stable disease for 7 months until January 2021 ( Figure 2B ).
case_images: Craniocerebral MRI about clinical response to dacomitinib therapy at different times. (A) Baseline before dacomitinib treatment. (B) Brain metastases partial response (PR) after 2 months. (C) Brain metastases PR after 4 months. (D) Brain metastases PR after 6 months.
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case_images: After experiencing dizziness and headache, the patient was reexamined by brain MRI on 19 January 2021, which revealed a new brain metastasis in the left occipital lobe ( Figure 3A ). The patient underwent MRI 2 months later, and found that the lesion was significantly reduced, the efficacy achieved partial response (PR) ( Figure 3B ), and follow-up MRI at 4 and 6 months showed that the lesion continued to shrink and almost disappeared ( Figures 3C, D ).
case_images: Craniocerebral MRI about clinical response to dacomitinib therapy at different times. (A) Brain metastases still PR after 12 months. (B) Brain metastases PD after 17 months.
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case_images: The patient continued to receive dacomitinib until new right parietal lobe brain metastases were identified on 23 June 2022 (the cutoff day,  Figures 4A, B ), and the progression-free survival (PFS) was 17 months ( Figure 5 ).
case_images: Treatment history and genomic results during the patient's clinical course.
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case_images: The patient continued to receive dacomitinib until new right parietal lobe brain metastases were identified on 23 June 2022 (the cutoff day,  Figures 4A, B ), and the progression-free survival (PFS) was 17 months ( Figure 5 ).