BACKGROUND: 10%-30% of patients with lung adenocarcinoma (LUAD) and leptomeningeal metastasis (LM) respond poorly to conventional and targeted therapy. The relationship between genetic subtypes and both MRI features and survival outcomes remains poorly understood in this patient population. PURPOSE: To explore the genetic phenotypes among LUAD-LM patients who respond poorly to conventional and targeted therapy, and to compare the MRI characteristics and survival outcomes among these genetic phenotypes: STUDY TYPE: Retrospective. POPULATION: 110 LUAD-LM patients (LU confirmed by histology, LM by cytology) treated with intrathecal chemotherapy, comprising 43 with epidermal growth factor receptor exon 21 L858R mutations (EGFR 21), 29 with EGFR exon 19 deletions (EGFR 19), and 38 with Non-Classic and Other Mutations (NCOM). FIELD STRENGTH/SEQUENCE: 3.0T; axial T ASSESSMENT: MRI morphologic features (including LM presence, presentation subtype, and lesion distribution) were independently reviewed by three radiologists (Y. J., W. S., and M. Y., with 5, 5, and 15 years of experience, respectively), following standardized criteria. Intracranial progression-free survival (iPFS) and overall survival (OS) were analyzed from the date of LM diagnosis based on clinical follow-up. STATISTICAL TESTS: Chi-square or Fisher's exact tests for imaging features; Kaplan-Meier method with log-rank tests for survival analysis; Cox proportional hazards regression for multivariable analysis. A two-sided p < 0.05 was considered significant. RESULTS: MRI-negative LM was significantly more frequent in EGFR 19 (65.5%). However, these patients showed no survival advantage (iPFS: p = 0.10, OS: p = 0.64) over other groups. Among MRI-positive LM patients, EGFR 21 affected significantly fewer lobes (< 4 lobes: 85.7%) compared to NCOM (< 4 lobes: 45.5%). Median iPFS in EGFR 21 was significantly longer than in NCOM (12.0 vs. 6.5 months; 95% CI: 5.16-7.84), and OS was also significantly longer (18.0 vs. 10.2 months; 95% CI: 4.79-15.61) DATA CONCLUSION: This radiogenomics study showed that EGFR mutation subtypes are associated with MRI features and survival outcomes in LUAD-LM patients with poor response to conventional and targeted therapies. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY STAGE: 4. Leptomeningeal metastasis is a serious complication of lung cancer and is difficult to diagnose and treat. This study examined whether different genetic types of lung cancer are linked to brain MRI findings and patient survival. Researchers reviewed MRI scans, genetic test results, and outcomes from 110 patients treated with intrathecal chemotherapy via an Ommaya reservoir. Patients with one common genetic change showed more limited disease on MRI and lived longer, while another group often had MRI‐negative disease without survival benefit. These findings suggest that genetics influence how disease spreads and appears on imaging, which may help improve diagnosis and treatment. Leptomeningeal metastasis is a serious complication of lung cancer and is difficult to diagnose and treat. This study examined whether different genetic types of lung cancer are linked to distinct brain MRI findings and patient survival. Researchers reviewed MRI scans, genetic test results, and outcomes from 110 patients treated with intrathecal chemotherapy via an Ommaya reservoir. Patients with one common genetic change showed more limited disease on MRI and lived longer, while another group often had MRI‐negative disease without survival benefit. These findings suggest that genetics influence how the disease spreads and appears on imaging, which may help improve diagnosis and treatment.
Jia et al. (Fri,) studied this question.