Surgical and anatomic factors predict development of leptomeningeal disease in patients with melanoma brain metastases

Patterns of Recurrence After Postoperative Stereotactic Radiotherapy for Brain Metastases

BACKGROUND/OBJECTIVES

Neurosurgical resection is the standard treatment for large brain metastases (BMs). Postoperative stereotactic radiotherapy (SRT) is used to reduce local recurrence (LR) but does not always prevent leptomeningeal disease (LMD). This study aims to analyze patterns of tumor recurrence and to identify opportunities for the further improvement of treatment efficacy.

METHODS

We included 147 patients who underwent resection and SRT for BMs. The distance between the resection cavity target volume and the new tumor growth was calculated. Cox regression analyses were used to assess associations of LMD with various patient characteristics.

RESULTS

Median survival after postoperative SRT was 14 months (IQR 6-30) with a 3-year actuarial survival rate of 21%. LR occurred in 20/147 patients (14%). After total resection, LR occurred in 21% of patients after 3 years of follow-up compared to 36% after subtotal resection. Marginal LR occurred in 5/147 patients (3%). LMD was found in 21/147 patients (14%; 3-year actuarial rate, 26%), and it was found more commonly in patients with resected cerebellar metastases (23%; 3-year actuarial rate, 46%) compared to those with cerebral metastases (11%; 3-year actuarial rate 17%) (HR 2.54, 95% CI 1.07-6.04, p = 0.034).

CONCLUSIONS

This study examined patterns of recurrence after postoperative radiotherapy and its implications for radiation dose, radiation field size, and treatment sequence. Local control was high after total resection. Radiation field size appeared adequate given the low incidence of marginal recurrences. Patients with cerebellar metastases showed an increased risk of LMD, underscoring the need for preventive measures, particularly preoperative SRT.

Cerebral spinal fluid analyses and therapeutic implications for leptomeningeal metastatic disease

PURPOSE

To review applications of cerebral spinal fluid (CSF) biomarkers for the diagnosis, monitoring and treatment of leptomeningeal metastatic disease (LMD) among patients with metastatic solid tumors.

METHODS

A narrative review identified original research related to CSF biomarkers among patients with metastatic solid tumors and LMD. Pre-clinical research (e.g. studies conducted in animal models) was not included. A descriptive analysis of literature was undertaken, with a focus on clinical applications related to the diagnosis, monitoring and treatment of LMD.

RESULTS

The low cellularity of CSF in comparison to plasma is an advantage for liquid biopsy, given that circulating tumor DNA (ctDNA) is not significantly diluted by genomic DNA from non-cancer cells. This results in higher variant allelic frequencies and increased sensitivity in detecting ctDNA compared to plasma. However, the clinical significance of positive ctDNA and/or circulating tumor cells (CTCs) in the CSF, particularly in the absence of other signs of LMD (either clinical and/or radiological), remains unclear. While the use of CSF liquid biopsy to monitor treatment response is promising, this approach requires prospective validation using larger sample sizes prior to adoption in routine clinical care. Discovery efforts involving proteomics and metabolomics have potential to identify proteins involved in the regulation of energy metabolism, vasculature, and inflammation in LMD, which in turn, may offer insights into novel treatment approaches.

CONCLUSION

CSF liquid biopsy should be incorporated in prospective studies for patients with LMD to validate promising diagnostic and/or predictive biomarkers of treatment response, as well as new therapeutic targets.

The research progress on meningeal metastasis in solid tumors

Meningeal metastasis (MM), particularly Leptomeningeal metastases (LM), represents the advanced stage of solid tumors and poses a significant threat to patients' lives. Moreover, it imposes a substantial burden on society. LM represents the ultimate and most fatal stage of solid tumors, inflicting devastating consequences on patients and imposing a substantial burden on society. The incidence of LM continues to rise annually, emphasizing the urgent need for early recognition and treatment initiation in individuals with LM to significantly extend overall patient survival. Despite rapid advancements in current LM detection and treatment methods, the diagnosis of LM remains constrained by several limitations such as low diagnostic efficiency, the therapeutic outcomes remain suboptimal. Furthermore, there is currently no universally recognized industry standard for LM treatment, further underscoring its status as an unresolved challenge in tumor management. Additionally, progress towards elucidating the mechanisms underlying MM has stagnated. Therefore, this review aims to comprehensively summarize recent research advances pertaining to MM in solid tumors by elucidating its underlying mechanisms, exploring diagnostic and prognostic biomarkers while addressing existing research challenges.

Leptomeningeal metastases at recurrence in IDH-wildtype glioblastomas: incidence, risk factors, and prognosis based on postcontrast FLAIR imaging

OBJECTIVES

To comprehensively investigate the incidence, risk factors, and prognosis of leptomeningeal metastases (LM) diagnosed at recurrence in IDH-wildtype glioblastoma patients.

MATERIALS AND METHODS

A total of 734 IDH-wildtype glioblastoma patients were enrolled between 2005 and 2022. LM at recurrence was diagnosed with MRI including postcontrast FLAIR. Logistic analysis for development of LM at recurrence was performed with clinical, molecular, imaging (including tumor volume and distance to subventricular zone via automatic segmentation), and surgical data including extent of resection and ventricular entry. The overall survival (OS) was compared between patients with and without LM at recurrence.

RESULTS

The incidence of LM at recurrence based on postcontrast FLAIR was 10.8% (79 patients). On multivariable analysis, younger age at diagnosis (odds ratio (OR) = 0.98, p = 0.011) and ventricular entry (OR = 3.15, p < 0.001) were independent predictors of LM at recurrence. However, patients with LM at recurrence showed no significant difference in OS from patients without LM (log-rank test; p = 0.461), with median OS of 18.0 (95% confidence interval (CI) 16.2-19.8) and 18.5 (95% CI 16.4-20.7) months in patients with and without LM at recurrence, respectively.

CONCLUSION

The incidence of LM at recurrence is relatively high in IDH-wildtype glioblastoma patients. Younger age and ventricular entry during surgery warrant imaging surveillance for LM at recurrence. As LM at recurrence showed no significant OS compromise and larger extent of resection (EOR) is associated with survival benefits, ventricular entry during maximal safe resection may be acceptable.

KEY POINTS

Question The incidence, risk factors, and prognosis of leptomeningeal metastases (LM) diagnosed at recurrence in IDH-wildtype glioblastoma patients are currently unknown. Findings LM at recurrence occurred in 10.8% of cases, with younger age and ventricular entry as risk factors, but no significant difference in survival outcomes between groups. Clinical relevance The incidence, risk factors, and prognosis of LM at recurrence were investigated in IDH-wildtype glioblastoma patients with postcontrast FLAIR. Younger age and ventricular entry warrant surveillance of LM at recurrence, while the overall survival is not as discouraging as expected.

Conformal Partial Brain Irradiation Versus Stereotactic Radiation Therapy in the Management of Resected Brain Metastases: A Retrospective Study

INTRODUCTION

The standard of care after resection of a single brain metastasis is to treat the cavity with stereotactic radiation therapy (SRT) to minimize the risk of recurrence. However, a prospective randomized trial of SRT demonstrated higher than expected rates of local recurrence, possibly due to geographic miss. Conformal partial brain (CPB) irradiation using conventional fractionation is an alternate technique that allows a larger margin of healthy tissue to be safely irradiated, potentially decreasing the risk of tumor recurrence. We performed a retrospective chart review to compare the results between CPB and SRT treatments.

METHODS AND MATERIALS

Patients receiving postoperative cranial radiotherapy within two months of a brain metastasis resection from 2015 to 2022 were eligible for this retrospective single-institution analysis. Fifty-seven patients met the eligibility criteria (SRT: n=32; CPB: n=25). SRT patients were treated using a robotic linear accelerator with a median dose of 24 Gy in 3 fractions. The median prescribed dose for the CPB group was 33 Gy in 11 fractions.

RESULTS

The mean follow-up was 19.9 months. The crude rate of local recurrence rate was 21.9% (SRT) versus 0% (CPB) (p<0.013). The crude rate of radiation necrosis (RN) was 21.9% (SRT) versus 0% (CPB) (p<0.013). The mean cavity volume was 13 cc (SRT) versus 73 cc (CPB) (p<0.001). Most cases of RN were asymptomatic, although one patient suffered grade 4 status epilepticus.

CONCLUSION

In this single-institution cohort, CPB radiation therapy was statistically associated with a lower risk of both local failure and radiation necrosis as compared to SRT. Despite the cavity being much larger, none of the CPB patients suffered either local failure or radiation necrosis. Postoperative CPB irradiation may be beneficial for large cavity sizes or when it is difficult to delineate the tumor bed.

Postoperative Air in the Cisterns or Ventricles Predicts Early Leptomeningeal Disease of Brain Metastases: A Retrospective Study

OBJECTIVE

We investigated whether air in the cisterns or ventricles on postoperative computed tomography (CT) (reflecting the opening of the cerebrospinal fluid spaces during surgery) is a predictor of classical or nodular leptomeningeal disease (LMD) after resection of brain metastases.

METHODS

We retrospectively analyzed 73 patients who underwent gross total resection of brain metastases between 2012 and 2020. Patients with air in the cisterns or ventricles on postoperative day 1 CT were categorized into the air-positive group, whereas those without air in the cisterns or ventricles on postoperative day 1 CT were categorized into the air-negative group. The primary outcome was the occurrence of classical or nodular LMD (nLMD), which was assessed using survival analysis.

RESULTS

There were 15 (21%) patients in the air-positive group and 58 (79%) in the air-negative group. The air-positive group exhibited significantly more cerebellar and ventricular contact lesions than the air-negative group. The 4-year rate of classical or nLMD was significantly higher in the air-positive group than in the air-negative group (67% vs. 33%, P < 0.001). Multivariate analysis identified air in the cisterns or ventricles on postoperative CT as the only significant predictor of classical or nLMD (P < 0.001).

CONCLUSIONS

Postoperative air in the cisterns or ventricles can predict early classical or nodular leptomeningeal disease.

The anatomic basis of leptomeningeal metastasis

Leptomeningeal metastasis (LM), or spread of cancer to the cerebrospinal fluid (CSF)-filled space surrounding the central nervous system, is a fatal complication of cancer. Entry into this space poses an anatomical challenge for cancer cells; movement of cells between the blood and CSF is tightly regulated by the blood-CSF barriers. Anatomical understanding of the leptomeninges provides a roadmap of corridors for cancer entry. This Review describes the anatomy of the leptomeninges and routes of cancer spread to the CSF. Granular understanding of LM by route of entry may inform strategies for novel diagnostic and preventive strategies as well as therapies.

Anatomical and surgical characteristics correlate with pachymeningeal failure in patients with brain metastases after neurosurgical resection and adjuvant stereotactic radiosurgery

PURPOSE

Neurosurgery (NS) is an essential modality for large brain metastases (BM). Postoperative stereotactic radiosurgery (SRS) is the standard of care adjuvant treatment. Pachymeningeal failure (PMF) is a newly described entity, distinct from classical leptomeningeal failure (LMF), that is uniquely observed in postoperative patients treated with adjuvant SRS. We sought to identify risk factors for PMF in patients treated with NS + SRS.

METHODS

From a prospective registry (2009 to 2021), we identified all patients treated with NS + SRS. Clinical, imaging, pathological, and treatment factors were analyzed. PMF incidence was evaluated using a competing risks model.

RESULTS

144 Patients were identified. The median age was 62 (23-90). PMF occurred in 21.5% (31/144). Female gender [Hazard Ratio (HR) 2.65, p = 0.013], higher Graded Prognostic Assessment (GPA) index (HR 2.4, p < 0.001), absence of prior radiation therapy (HR N/A, p = 0.018), controlled extracranial disease (CED) (HR 3.46, p = 0.0038), and pia/dura contact (PDC) (HR 3.30, p = 0.0053) were associated with increased risk for PMF on univariate analysis. In patients with PDC, wider target volumes correlated with reduced risk of PMF. Multivariate analysis indicated PDC (HR 3.51, p = 0.0053), piecemeal resection (HR 2.38, p = 0.027), and CED (HR 3.97, p = 0.0016) independently correlated with PMF risk. PMF correlated with reduced OS (HR 2.90, p < 0.001) at a lower rate compared to LMF (HR 10.15, p < 0.001).

CONCLUSION

PMF correlates with tumor PDC and piecemeal resection in patients treated with NS + SRS. For unclear reasons, it is also associated with CED. In tumors with PDC, wider dural radiotherapy coverage was associated with a lower risk of PMF.

Stereotactic Radiosurgery for Intraventricular Metastases: A Multicenter Study

BACKGROUND

Intraventricular metastases (IVMs) are uncommon, and their optimal management remains debatable.

OBJECTIVE

To define the safety and efficacy of stereotactic radiosurgery (SRS) in the treatment of IVMs.

METHODS

This retrospective, multicenter study included patients managed with SRS for IVMs. SRS-induced adverse events, local tumor or intracranial progression, and the frequency of new-onset hydrocephalus or leptomeningeal spread were documented. Analyses of variables related to patient neuroimaging or clinical outcomes were also performed.

RESULTS

The cohort included 160 patients from 11 centers who underwent SRS for treatment of 1045 intracranial metastases, of which 196 were IVMs. The median survival from SRS was 10 months. Of the 154 patients and 190 IVMs with imaging follow-up, 94 patients (61%) experienced distant intracranial disease progression and 16 IVMs (8.4%) progressed locally. The 12- and 24-month local IVM control rates were 91.4% and 86.1%, respectively. Sixteen (10%) and 27 (17.5%) patients developed hydrocephalus and leptomeningeal dissemination post-SRS, respectively. Adverse radiation effects were documented in 24 patients (15%). Eleven patients (6.9%) died because of intracranial disease progression.

CONCLUSION

SRS is an effective treatment option for IVMs, with a local IVM control rate comparable with SRS for parenchymal brain metastases. Leptomeningeal spread and hydrocephalus in patients with IVM occur in a minority of patients, but these patients warrant careful follow-up to detect these changes.