Surgical Resection of Cerebral Metastases Leads to Faster Resolution of Peritumoral Edema than Stereotactic Radiosurgery: A Volumetric Analysis

Management Paradigm of Central Nervous System Metastases in NSCLC: An Australian Perspective

Life-prolonging central nervous system active systemic therapies for metastatic NSCLC have increased the complexity of managing brain metastases (BMs). Australian medical oncologists, radiation oncologists, and neurosurgeons discussed the evidence guiding the diverse clinical approaches to the management of BM in NSCLC. The Australian context is broadly applicable to other jurisdictions; therefore, we have documented these discussions as principles with broader applications. Patient management was stratified according to clinical and radiologic factors under two broad classifications of newly diagnosed BMs: symptomatic and asymptomatic. Other important considerations include the number and location of metastases, tumor histotypes, molecular subtype, and treatment purpose. Careful consideration of the pace and burden of symptoms, risk of worsening neurologic function at a short interval, and extracranial disease burden should determine whether central nervous system active systemic therapies are used alone or in combination with local therapies (surgery with or without radiation therapy). Most clinical trial evidence currently focuses on historical treatment options or a single treatment modality rather than the optimal sequencing of multiple modern therapies; therefore, an individualized approach is key in a rapidly changing therapeutic landscape.

Revisiting the Role of Surgical Resection for Brain Metastasis

Brain metastasis (BM) is the most common type of brain tumor in adults. The contemporary management of BM remains challenging. Advancements in systemic cancer treatment have increased the survival of patients with cancer. Although the treatment of BM is still complicated, advances in radiotherapy, including stereotactic radiosurgery and chemotherapy, have improved treatment outcomes. Surgical resection is the traditional treatment for BM and its role in the surgical resection of BM has been well established. However, refinement of the surgical resection technique and strategy for BM is needed. Herein, we discuss the evolving role of surgery in patients with BM and the future of BM treatment.

Clinical Outcomes and Prognostic Factors of Fractionated Stereotactic Radiosurgery for Brain Metastases ≥20 mm as a Potential Alternative to Surgery

BACKGROUND

This study investigated the outcomes and prognostic factors of fractionated stereotactic radiosurgery (FSRS) for the treatment of brain metastases ≥20 mm, and determined whether FSRS could replace surgery-the primary treatment for large brain metastases.

METHODS

Patients with brain metastases ≥20 mm treated with FSRS were retrospectively examined. Patients who underwent FSRS postoperatively were excluded. Local failure, intracranial failure, and adverse events were evaluated.

RESULTS

Overall, 116 lesions in 105 patients were evaluated. The performance status was 0-1, 2-4, and unknown for 86, 28, and two patients, respectively. The median maximum tumor diameter was 25 mm, and the median prescribed dose was 35 Gy in 3 fractions. The median follow-up period after FSRS was 8 months. The 1-year local failure, intracranial failure, and overall survival rates were 12.5%, 56.6%, and 49.0%, respectively. A maximum dose of ≥135 Gy (biological equivalent dose [α/β = 10 Gy]) and good performance status were independent favorable prognostic factors for local control. Twenty-one (20%) patients were treated with whole-brain radiotherapy after FSRS because of multiple intracranial recurrences, while four (3.4%) patients underwent surgery because of local recurrence.

CONCLUSIONS

FSRS for brain metastases ≥20 mm achieved good local control. Only 3.4% of patients required surgery after FSRS, suggesting that FSRS is a potential alternative to surgery. For FSRS, a higher maximum tumor dose was useful for local control.

Role of Laser Interstitial Thermal Therapy in the Management of Primary and Metastatic Brain Tumors

OPINION STATEMENT

Laser interstitial thermal therapy (LITT) is a minimally invasive treatment option for brain tumors including glioblastoma, other primary central nervous system (CNS) neoplasms, metastases, and radiation necrosis. LITT employs a fiber optic coupled laser delivery probe stabilized via stereotaxis to deliver thermal energy that induces coagulative necrosis in tumors to achieve effective cytoreduction. LITT complements surgical resection, radiation treatment, tumor treating fields, and systemic therapy, especially in patients who are high risk for surgical resection due to tumor location in eloquent regions or poor functional status. These factors must be balanced with the increased rate of cerebral edema post LITT compared to surgical resection. LITT has also been shown to induce transient disruption of the blood-brain barrier (BBB), especially in the peritumoral region, which allows for enhanced CNS delivery of anti-neoplastic agents, thus greatly expanding the armamentarium against brain tumors to include highly effective anti-neoplastic agents that have poor BBB penetration. In addition, hyperthermia-induced immunogenic cell death is another secondary side effect of LITT that opens up immunotherapy as an attractive adjuvant treatment for brain tumors. Numerous large studies have demonstrated the safety and efficacy of LITT against various CNS tumors and as the literature continues to grow on this novel technique so will its indications.

Peri-radiosurgical administration of bevacizumab improves radiographic response to single and fractionated stereotactic radiosurgery for large brain metastasis

INTRODUCTION

Stereotactic radiosurgery (SRS) is a standard of care for brain metastases (BM) patients, yet large BM are at a greater risk for radionecrosis and local progression (LP). Concomitant bevacizumab and radiotherapy has been shown to improve outcomes in primary and metastatic brain tumors. This retrospective study investigated the efficacy and safety of concurrent bevacizumab and SRS for large BM.

METHODS

From 2015 to 2019, patients with a BM diameter ≥ 2 cm who received either combination therapy (n = 49, SRS + BVZ group), or SRS alone (n = 73, SRS group) were enrolled. Bevacizumab was given peri-radiosurgically with a 2-week interval. Radiographic response was assessed using the RECIST version 1.1. Competing risk and logistic regression analysis were performed to evaluate prognostic factors.

RESULTS

Radiographic response was achieved in 41 patients (84%) in the SRS + BVZ group and 37 patients (51%) in the SRS group (p = 0.001). In the multivariate regression analysis, concurrent bevacizumab was independently associated with a better radiographic response (p = 0.003). The cumulative incidences of LP and ≥ grade 2 radionecrosis at 12 months between the SRS + BVZ group and SRS group were 2% versus 6.8%, and 14.3% versus 14.6%, respectively. For patients with BM size ≥ 3 cm, the cumulative incidence of LP was significantly lower in the SRS + BVZ group (p = 0.03). No ≥ grade 4 toxicity was observed in either group.

CONCLUSIONS

Concurrent bevacizumab and SRS for large BM is highly effective, with a better radiographic response and minimal excessive treatment-related toxicities. Peri-radiosurgical bevacizumab preferentially reduced the risk of LP, especially for BM size ≥ 3 cm.

Retrospective study of 229 surgically treated patients with brain metastases: Prognostic factors, outcome and comparison of recursive partitioning analysis and diagnosis-specific graded prognostic assessment

Background:

Metastases are the most frequent tumors in the brain. Most often used scoring systems to predict the outcome are the RPA (Recursive Partitioning Analysis) classification and the DS-GPA (Diagnosis-Specific Graded Prognostic Assessment) score. The goal of our study was to determine prognostic factors which influence outcome in patients who undergo surgery for brain metastases and to compare different outcome scores.

Methods:

Two hundred and twenty-nine patients who underwent surgery for brain metastases in our institution between January 2005 and December 2014 were included in the study. Patient data were evaluated retrospectively.

Results:

The mean survival time was 19.2 months (median survival time, MST: 8 months), for patients with a single metastasis (n = 149) 17.6 months (MST: 8 months), and for patients with multiple metastases (n = 80) 17.9 months (MST: 6 months). Significant influence on MST had age <65 years (9 vs. 5 months, P = 0.002), female sex (10 vs. 6 months, P < 0.001), RPA Class I and II (11 vs. 4 months, P < 0.001), Karnofsky score >70% (11 vs. 4 months, P < 0.001), and postoperative radiotherapy (8 vs. 5 months, P < 0.002). To evaluate the diagnostic power of DS-GPA and RPA score in respect of survival, two Cox regressions were modeled, where the RPA classification showed a better predictive power.

Conclusion:

Favorable factors for prolonged survival were KPS >70%, RPA Class I and II, age <65 years, female sex, a DS-GPA Score of 2.5–3 and 3.5–4, and adjuvant radiotherapy. The RPA Classification was more accurate in predicting the outcome than the DS-GPA score.