Brain metastases in solid tumours: new guidelines for a new era

Imaging Recommendations for Diagnosis, Staging, and Management of Central Nervous System Neoplasms in Adults: CNS Metastases

Brain metastases (BMs) are the most common central nervous system (CNS) neoplasms, with an increasing incidence that is due in part to an overall increase in primary cancers, improved neuroimaging modalities leading to increased detection, better systemic therapies, and longer patient survival.

OBJECTIVE

To identify cancer patients at a higher risk of developing CNS metastases and to evaluate associated prognostic factors.

METHODS

Review of imaging referral guidelines, response criteria, interval imaging assessment, modality of choice, as well as the association of clinical, serological, and imaging findings as per various cancer societies.

RESULTS

Quantitative response assessment of target and non-target brain metastases as well as an interval imaging protocol set up based on primary histological diagnosis and therapy status are discussed as per various cancer societies and imaging programs.

CONCLUSION

Predictive factors in the primary tumor as well as independent variables of brain metastases like size, number, and response to therapy are necessary in management. The location of CNS metastases, symptomatic disease, as well as follow up imaging findings form a skeletal plan to prognosticate the disease, keeping in mind all the available new advanced therapy options of surgery, radiation, and immunotherapy that improve patient outcome significantly.

Heterogeneity in intracranial relapses after complete resection of lung adenocarcinoma: Distinct features of brain-only relapse versus synchronous extracranial relapse

BACKGROUND

Patients with brain oligometastases have better prognosis than those with synchronous extracranial metastases in non-small cell lung cancer (NSCLC). However, studies focusing on intracranial-only recurrence after curative surgery remained scarce. This study aimed to explore distinct features of patients with exclusive brain relapse after resection of lung adenocarcinoma.

METHODS

Records were retrospectively reviewed of 2809 patients who had complete resection and pathologically confirmed stage IB-IIIA NSCLC in our hospital from October 2012 to September 2019. Patients were enrolled if they were adenocarcinoma and developed intracranial recurrence thereafter. They were divided into two groups depending on whether they had synchronous extracranial metastases. Clinical and pathological features of patients enrolled were collected and compared between groups.

RESULTS

Ninety-seven lung adenocarcinoma patients with intracranial recurrences were enrolled. The median follow-up time was 40 months. Fifty patients (51.5%) had brain oligometastases and 47 patients had synchronous extracranial metastases (ECM). Multivariate logistic regression suggested EGFR-sensitive mutation and male sex were positively correlated to brain-only recurrence (OR = 2.59, 95%CI 1.04-6.84 and OR = 2.58, 95% CI 1.05-6.75), while higher clinical stage was associated with synchronous ECM (stage II (OR = 0.33, 95%CI 0.09-1.14) or stage IIIA (OR = 0.54, 95%CI 0.20-1.38) versus stage I). No other pathological feature (lymphovascular invasion, visceral pleural invasion, low tumor differentiation, etc.) or adjuvant chemotherapy was associated with intracranial-only relapse after complete resection of primary tumor.

CONCLUSION

Among patients with brain relapse after resection of lung adenocarcinoma, patients with EGFR mutations might have intracranial relapse only without synchronous extracranial metastases. Further prospective studies are warranted to verify this.

Effect and Tolerability of Immunotherapy in Patients with NSCLC with or without Brain Metastasis

Sparse data exist on immune checkpoint inhibition (ICI) in NSCLC patients with brain metastasis (BM), especially for those with no local therapy (LT) (whole brain radiation therapy (WBRT), stereotactic RT (SRT) or neurosurgery) preceding ICI. Our aims were to investigate the prevalence of BM, rate of intracranial response (ICR), and survival and quality of life (QoL) in real-life patients with advanced NSCLC undergoing palliative ICI. This was a prospective non-randomized study (NCT03870464) with magnetic resonance imaging of the brain (MR-C) performed at baseline resulting in a clinical decision to administer LT or not. ICR evaluation (MR-C) at week 8–9 (mRECIST criteria) for group A (LT) and group B (untreated) was assessed. Change in QoL was assessed using EQ-5D-5L. Of 159 included patients, 45 (28%) had baseline BM. Median follow-up was 23.2 months (IQR 16.4–30.2). Of patients in group A (21) and B (16), 16/37 (43%) had symptomatic BM. ICR was 8/21, 38% (complete or partial response) for group A versus 8/16, 50% for group B. No statistical difference in median overall survival of patients with BM (group A: 12.3 (5.2-NR), group B: 20.5 months (4.9-NR)) and without (22.4 months (95% 16.2–26.3)) was obtained. Baseline QoL was comparable regardless of BM, but an improved QoL (at week 9) was found in those without BM. Patients with NSCLC and BM receiving ICI had long-term survival comparable to those without BM.