Diagnosis and management of brain metastases

Selecting the Appropriate Radiation Therapy Technique for Extensive Brain Metastases from Tens to Hundreds: Should the Latest Technique Always Be the Best Option?

Brain metastases (BMs) are one of the most common metastatic lesions in adult cancer patients and the most common intracranial neoplasms in adult patients. Especially for multiple BMs, historically, whole-brain radiotherapy (WBRT) has been performed as the mainstay of therapy, which improves neurological symptoms and median survival. However, WBRT could negatively impact the patient's quality of life due to late complications. Owing to these complications, attempts have been made to use the latest radiotherapy (LRT) such as stereotactic radiosurgery (SRS) and intensity-modulated radiotherapy (IMRT) to treat BMs. However, for the extensive BMs (ranging from tens to hundreds), there are currently no prospective studies comparing WBRT with LRT such as IMRT or SRS. For extensive brain metastases, LRT cannot be the best option. Instead, upfront WBRT should be considered given its advantages and disadvantages, rather than LRT. We hope that faster and more reliable LRT for extensive BMs will be applicable for clinical practice without any clinical concerns in the near future.

Effect of perioperative seizures on mortality and recurrence in patients with brain metastases

Objective

To identify the independent risk factors for 30-day perioperative seizures, as well as to evaluate the effect of perioperative seizures on overall mortality and tumor recurrence among patients who underwent surgical resection of brain metastases.

Methods

Patients who underwent surgical resection of brain metastases at our institution between 2011 and 2019 were included. 30-day perioperative seizures were defined as the presence of any preoperative or postoperative seizures diagnosed by a neurosurgeon or neurologist within 30 days of metastases resection. Independent risk factors for 30-day perioperative seizures were evaluated using multivariate logistic regression models. Kaplan-Meier plots and Cox regression models were constructed to evaluate the effects of 30-day perioperative seizures on overall mortality and tumor recurrence. Subgroup analyses were conducted for 30-day preoperative and 30-day postoperative seizures.

Results

A total of 158 patients were included in the analysis. The mean (SD) age was 59.3 (12.0) years, and 20 (12.7%) patients had 30-day perioperative seizures. The presence of 30-day preoperative seizures (OR=41.4; 95% CI=4.76, 924; p=0.002) was an independent risk factor for 30-day postoperative seizures. Multivariate Cox regression revealed that any 30-day perioperative seizure (HR=3.25; 95% CI=1.60, 6.62; p=0.001) was independently and significantly associated with overall mortality but not tumor recurrence (HR=1.95; 95% CI=0.78, 4.91; p=0.154).

Conclusions

Among patients with resected brain metastases, the presence of any 30-day perioperative seizure was independently associated with overall mortality. This suggests that 30-day perioperative seizures may be a prognostic marker of poor outcome. Further research evaluating this association as well as the effect of perioperative antiepileptic drugs in patients with resected brain metastases may be warranted.

Brain metastases: An update on the multi-disciplinary approach of clinical management

IMPORTANCE

Brain metastasis (BM) is the most common malignant intracranial neoplasm in adults with over 100,000 new cases annually in the United States and outnumbering primary brain tumors 10:1.

OBSERVATIONS

The incidence of BM in adult cancer patients ranges from 10-40%, and is increasing with improved surveillance, effective systemic therapy, and an aging population. The overall prognosis of cancer patients is largely dependent on the presence or absence of brain metastasis, and therefore, a timely and accurate diagnosis is crucial for improving long-term outcomes, especially in the current era of significantly improved systemic therapy for many common cancers. BM should be suspected in any cancer patient who develops new neurological deficits or behavioral abnormalities. Gadolinium enhanced MRI is the preferred imaging technique and BM must be distinguished from other pathologies. Large, symptomatic lesion(s) in patients with good functional status are best treated with surgery and stereotactic radiosurgery (SRS). Due to neurocognitive side effects and improved overall survival of cancer patients, whole brain radiotherapy (WBRT) is reserved as salvage therapy for patients with multiple lesions or as palliation. Newer approaches including multi-lesion stereotactic surgery, targeted therapy, and immunotherapy are also being investigated to improve outcomes while preserving quality of life.

CONCLUSION

With the significant advancements in the systemic treatment for cancer patients, addressing BM effectively is critical for overall survival. In addition to patient's performance status, therapeutic approach should be based on the type of primary tumor and associated molecular profile as well as the size, number, and location of metastatic lesion(s).

Brain metastases: increasingly precision medicine-a narrative review

Objective

To broadly review the modern management of brain metastases.

Background

Brain metastases are the commonest neurological manifestation of cancer and a major cause of morbidity in cancer patients. Brain metastases are increasing in frequency, as a result of longer life expectancy of cancer patients, more sensitive methods for brain metastasis detection and an ageing population. The proportional incidence of brain metastases according to cancer of origin, from greatest to least, is lung cancer, melanoma, renal, breast and colorectal cancers. Patients with lung cancer and melanoma are most likely to have brain metastases at diagnosis. Brain metastases cause a variety of symptoms, depending on their size and location, whether they cause mass effect and oedema, compression of the brain parenchyma, or focal neurological deficits. The major differential diagnoses of brain metastases include primary tumours and vascular/inflammatory lesions. Prognosis is dependent on the site, number and volume of lesions, the patients’ performance status, age and the activity and extent of extracranial disease.

Methods

English literature articles in PubMed from 1950 to June 2021 were reviewed. Article bibliographies provided further references.

Conclusions

Treatment of brain metastasis patients has moved from considering them as a homogenous population of patients, to individualised treatment. In those brain metastases patients of satisfactory performance status with a solitary lesion, especially one in a non-eloquent/accessible area causing significant mass effect and/or raised intracranial pressure or for whom the diagnosis is in doubt (histology needed), surgical resection is usually the treatment of choice. For multiple brain metastases, radiotherapy with or without systemic therapies are usually employed. For relatively fit patients with limited numbers of brain metastases (e.g., 4 or less), stereotactic radiosurgery is standard of care. Current clinical trials are testing the efficacy of stereotactic treatment alone for >4 brain metastases (although it is increasingly used for such patients in many centres) as well as integration of local therapies with targeted and immunological therapies in appropriately selected cases. In certain circumstances, cranial irradiation can be omitted.

Seizures Among Patients With Brain Metastases: A Population- and Institutional-Level Analysis

OBJECTIVE

To test the hypothesis that subets of patients with brain metastases (BrM) without seizures at intracranial presentation are at increased risk for developing seizures, we characterized the incidence and risk factors for seizure development among seizure-naive patients with BrMs.

METHODS

We identified 15,863 and 1,453 patients with BrM utilizing Surveillance, Epidemiology, and End Results (SEER)-Medicare data (2008-2016) and Brigham and Women's Hospital/Dana Farber Cancer Institute (2000-2015) institutional data, respectively. Cumulative incidence curves and Fine/Gray competing risks regression were used to characterize seizure incidence and risk factors, respectively.

RESULTS

Among SEER-Medicare and institutional patients, 1,588 (10.0%) and 169 (11.6%) developed seizures, respectively. On multivariable regression of the SEER-Medicare cohort, Black vs White race (hazard ratio [HR] 1.45 [95% confidence interval (CI), 1.22-1.73], p < 0.001), urban vs nonurban residence (HR 1.41 [95% CI, 1.17-1.70], p < 0.001), melanoma vs non-small cell lung cancer (NSCLC) as primary tumor type (HR 1.44 [95% CI, 1.20-1.73], p < 0.001), and receipt of brain-directed stereotactic radiation (HR 1.67 [95% CI, 1.44-1.94], p < 0.001) were associated with greater seizure risk. On multivariable regression of the institutional cohort, melanoma vs NSCLC (HR 1.70 [95% CI, 1.09-2.64], p = 0.02), >4 BrM at diagnosis (HR 1.60 [95% CI, 1.12-2.29], p = 0.01), presence of BrM in a high-risk location (HR 3.62 [95% CI, 1.60-8.18], p = 0.002), and lack of local brain-directed therapy (HR 3.08 [95% CI, 1.45-6.52], p = 0.003) were associated with greater risk of seizure development.

CONCLUSIONS

The role of antiseizure medications among select patients with BrM should be re-explored, particularly for those with melanoma, a greater intracranial disease burden, or BrM in high-risk locations.

Iodine nanoparticle radiotherapy of human breast cancer growing in the brains of athymic mice

About 30% of breast cancers metastasize to the brain; those widely disseminated are fatal typically in 3-4 months, even with the best available treatments, including surgery, drugs, and radiotherapy. To address this dire situation, we have developed iodine nanoparticles (INPs) that target brain tumors after intravenous (IV) injection. The iodine then absorbs X-rays during radiotherapy (RT), creating free radicals and local tumor damage, effectively boosting the local RT dose at the tumor. Efficacy was tested using the very aggressive human triple negative breast cancer (TNBC, MDA-MB-231 cells) growing in the brains of athymic nude mice. With a well-tolerated non-toxic IV dose of the INPs (7 g iodine/kg body weight), tumors showed a heavily iodinated rim surrounding the tumor having an average uptake of 2.9% iodine by weight, with uptake peaks at 4.5%. This is calculated to provide a dose enhancement factor of approximately 5.5 (peaks at 8.0), the highest ever reported for any radiation-enhancing agents. With RT alone (15 Gy, single dose), all animals died by 72 days; INP pretreatment resulted in longer-term remissions with 40% of mice surviving 150 days and 30% surviving > 280 days.

Current approaches to the management of brain metastases

Brain metastases are a very common manifestation of cancer that have historically been approached as a single disease entity given the uniform association with poor clinical outcomes. Fortunately, our understanding of the biology and molecular underpinnings of brain metastases has greatly improved, resulting in more sophisticated prognostic models and multiple patient-related and disease-specific treatment paradigms. In addition, the therapeutic armamentarium has expanded from whole-brain radiotherapy and surgery to include stereotactic radiosurgery, targeted therapies and immunotherapies, which are often used sequentially or in combination. Advances in neuroimaging have provided additional opportunities to accurately screen for intracranial disease at initial cancer diagnosis, target intracranial lesions with precision during treatment and help differentiate the effects of treatment from disease progression by incorporating functional imaging. Given the numerous available treatment options for patients with brain metastases, a multidisciplinary approach is strongly recommended to personalize the treatment of each patient in an effort to improve the therapeutic ratio. Given the ongoing controversies regarding the optimal sequencing of the available and expanding treatment options for patients with brain metastases, enrolment in clinical trials is essential to advance our understanding of this complex and common disease. In this Review, we describe the key features of diagnosis, risk stratification and modern paradigms in the treatment and management of patients with brain metastases and provide speculation on future research directions.

Dosimetric effect of rotational setup errors in stereotactic radiosurgery with HyperArc for single and multiple brain metastases

Purpose

In stereotactic radiosurgery (SRS) with single‐isocentric treatments for brain metastases, rotational setup errors may cause considerable dosimetric effects. We assessed the dosimetric effects on HyperArc plans for single and multiple metastases.

Methods

For 29 patients (1–8 brain metastases), HyperArc plans with a prescription dose of 20–24 Gy for a dose that covers 95% (D_95%) of the planning target volume (PTV) were retrospectively generated (Ref‐plan). Subsequently, the computed tomography (CT) used for the Ref‐plan and cone‐beam CT acquired during treatments (Rot‐CT) were registered. The HyperArc plans involving rotational setup errors (Rot‐plan) were generated by re‐calculating doses based on the Rot‐CT. The dosimetric parameters between the two plans were compared.

Results

The dosimetric parameters [D_99%, D_95%, D_1%, homogeneity index, and conformity index (CI)] for the single‐metastasis cases were comparable (P > 0.05), whereas the D_95% for each PTV of the Rot‐plan decreased 10.8% on average, and the CI of the Rot‐plan was also significantly lower than that of the Ref‐plan (Ref‐plan vs Rot‐plan, 0.93 ± 0.02 vs 0.75 ± 0.14, P < 0.01) for the multiple‐metastases cases. In addition, for the multiple‐metastases cases, the Rot‐plan resulted in significantly higher V_10Gy (P = 0.01), V_12Gy (P = 0.02), V_14Gy (P = 0.02), and V_16Gy (P < 0.01) than those in the Ref‐plan.

Conclusion

The rotational setup errors for multiple brain metastases cases caused non‐negligible underdosage for PTV and significant increases of V_10Gy to V_16Gy in SRS with HyperArc.

Primary Cardiac Sarcoma: A Rare, Aggressive Malignancy with a High Propensity for Brain Metastases

Introduction

Primary cardiac sarcoma (PCS) has a poor prognosis compared to other sarcomas due to late presentation, challenging resection, incidence of metastases, and limited efficacy of systemic therapies.

Methods

A medical record search engine was queried to identify patients diagnosed with PCS from 1992 to 2017 at the University of Michigan.

Results

Thirty-nine patients with PCS had a median age of 41 years (range 2–77). Common histologies were angiosarcoma (AS, 14), high-grade undifferentiated pleomorphic sarcoma (UPS, 10), and leiomyosarcoma (LMS, 5). Sites of origin were left atrium (18), right atrium (16), and pericardium (5). AS was the most common right-sided tumor; UPS was more common on the left. Eighteen patients presented with metastases involving lung (10), bone (7), liver (5), and brain (4). Twenty-five patients underwent resection, achieving 3 R₀ resections. Patients received a median of 2 (1–6) systemic therapies. Median overall survival (OS) was 12.1 months (range 0–79). Median OS was 14.0 months and 8.2 months in patients who did or did not undergo resection, respectively (p=0.018). Brain metastases occurred in 12 (31%) patients, 9 (75%) of whom had left heart tumors, at a median of 8.5 months (range 0–75) from diagnosis. Median OS was 5.6 months (range 0–30) after the diagnosis of brain metastases.

Conclusions

PCS portends a poor prognosis, because of difficulty in obtaining complete resection of sarcoma, advanced stage at diagnosis, and high risk of brain metastases. Providers should be aware of the increased risk of brain metastases and consider brain imaging at diagnosis and follow-up.

Factors influencing the outcome of stereotactic radiosurgery in patients with five or more brain metastases

Background

Stereotactic radiosurgery (srs) for patients with 5 or more brain metastases (bmets) is a matter of debate. We report our results with that approach and the factors influencing outcome.

Methods

In the 103 patients who underwent srs for the treatment of 5 or more bmets, primary histology was non-small-cell lung cancer (57% of patients). All patients were grouped by Karnofsky performance status and recursive partitioning analysis (rpa) classification. In our cohort, 72% of patients had uncontrolled extracranial disease, and 28% had stable or responding systemic disease. Previous irradiation for 1-4 bmets had been given to 56 patients (54%). The mean number of treated bmets was 7 (range: 5-19), and the median cumulative bmets volume was 2 cm³ (range: 0.06-28 cm³).

Results

Multivariate analyses showed that stable extracranial disease (p < 0.001) and rpa (p = 0.022) were independent prognostic factors for overall survival (os). Moreover, a cumulative treated bmets volume of less than 6 cm³ (adjusted hazard ratio: 2.54; p = 0.006; 95% confidence interval: 1.30 to 4.99) was associated with better os. The total number of bmets had no effect on survival (p = 0.206). No variable was found to be predictive of local control. The rpa was significant (p = 0.027) in terms of distant recurrence.

Conclusions

Our study suggests that srs is a reasonable option for the management of patients with 5 or more bmets, especially with a cumulative treatment volume of less than 6 cm³.

Immunotherapy and targeted therapy in brain metastases: emerging options in precision medicine

Brain metastases (BM) continue to represent an unmet clinical need in oncology. Immunotherapy and targeted therapy hold great promise in the treatment of BM. Emerging data are confirming the activity of these agents in patients with BM. Genomic studies have confirmed that clinically actionable mutations are present in BM and they can be used in clinical studies to link targeted therapies with their genetic targets. Furthermore, as molecular signatures associated with sensitivity and resistance to immunotherapies are developed, we will better be able to select BM patients who will most benefit from these therapies. Understanding the genetic and immune evolution within BM should drive the next generation of immunotherapy and target therapy, as well as increase the accuracy of the selection process for these therapies.

Oncologic Mechanical Emergencies

Prevalence of cancer and its various related complications continues to rise. Increasingly these life-threatening complications are initially managed in the emergency department, making a prompt and accurate diagnosis crucial to effectively institute the proper treatment and establish goals of care. The following oncologic emergencies are reviewed in this article: pericardial tamponade, superior vena cava syndrome, brain metastasis, malignant spinal cord compression, and hyperviscosity syndrome.

Impact of CyberKnife Radiosurgery on Overall Survival and Various Parameters of Patients with 1-3 versus ≥ 4 Brain Metastases

Introduction

This study’s objective is to compare the overall survivals (OSs) and various parameters of patients with 1-3 versus ≥ 4 brain metastases post-CyberKnife radiosurgery (CKRS) (Accuray, Sunnyvale, California) alone.

Methods

Charts of 150 patients, from 2009-2014, treated with only CKRS for brain metastases were reviewed retrospectively for overall survival (OS) and patient, tumor, and imaging characteristics. Parameters included demographics, Eastern Cooperative Oncology Group (ECOG) performance scores, number and control of extracranial disease (ECD) sites, cause of death (COD), histology, tumor volume (TV), and post-CKRS whole brain radiotherapy (WBRT). The imaging characteristics assessed were time of complete response (CR), partial response (PR), stable imaging or local failure (LF), and distal brain failure (DBF). Patients and their data were divided into those with 1-3 (group 1) versus ≥ 4 brain metastases (group 2). For each CR and LF patient, absolute neutrophil count (ANC), absolute lymphocyte count (ALC)), and ANC/ALC ratio (NLR) were obtained, when available, at the time of CKRS.

Results

Both group 1 and group 2 had a median OS of 13 months. The patient median age for the 115 group 1 patients versus the 35 group 2 patients was 62 versus 56 years. Group 1 had slightly more males and group 2, females. The predominant ECOG score for each group was 1 and the number of ECD sites was one and two, respectively. Uncontrolled ECD occurred in the majority of both group 1 and group 2 patients. The main COD was ECD in both groups. The prevalent tumor histology for groups 1 and 2 was non-small cell lung carcinoma. Median TVs were 1.08 cc versus 1.42 cc for groups 1 and 2, respectively. The majority of patients in both groups did not undergo post-CKRS WBRT. Imaging outcomes were LC (CR, PR, or stable imaging) in 93 (80.9%) and 26 (74.3%) group 1 and 2 patients, of whom 32 (27.8%) and six (17.1%) had CR; 38 (33.0%) and 18 (51.4%), PR and 23 (20.0%) and two (5.7%), stable imaging; LF was the outcome in 22 (19.1%) and nine (25.7%) patients, and DBF occurred in 62 (53.9%) and 21 (60.0%), respectively. Uni- and multivariable analyses showed the independent parameters of a lower ECOG score, a greater number of ECD sites and uncontrolled ECD were significantly associated with greater mortality risk with and without accounting for other covariates. At CKRS, 19 group 1 and 2 CR patients had a mean ANC of 5.88 K/µL and a mean ALC of 1.31 K/µL and 13 (68%) of 19 had NLRs ≤ five, while 11 with LFs had a mean ANC of 5.22 K/µL and a mean ALC of 0.93 K/µL and seven (64%) had NLRs > five. An NLR ≤ five and high ALC was associated with a CR and an NLR > five and a low ALC with an LF.

Conclusions

Median OS post-CKRS was 13 months for both patients with 1-3 brain metastases and with ≥ 4. This is the only study in the literature to evaluate OS in patients with 1-3 and ≥ 4 brain metastases who were treated with CKRS alone. For groups 1 and 2 patients combined, 119 (79.3%) had LC and 38 (25.3%) had CR. The ANC, ALC, and NLR values are likely predictive of CR and LF outcomes

Radiomic Phenotyping in Brain Cancer to Unravel Hidden Information in Medical Images

Radiomics is a new area of research in the field of imaging with tremendous potential to unravel the hidden information in digital images. The scope of radiology has grown exponentially over the last two decades; since the advent of radiomics, many quantitative imaging features can now be extracted from medical images through high-throughput computing, and these can be converted into mineable data that can help in linking imaging phenotypes with clinical data, genomics, proteomics, and other "omics" information. In cancer, radiomic imaging analysis aims at extracting imaging features embedded in the imaging data, which can act as a guide in the disease or cancer diagnosis, staging and planning interventions for treating patients, monitor patients on therapy, predict treatment response, and determine patient outcomes.

The evolving clinical management of cerebral metastases

Concepts in the management of brain metastases are evolving. Until recently, brain metastases have been considered as a homogenous condition, managed with whole brain radiotherapy, surgical resection for large lesions and stereotactic radiosurgery for smaller lesions. Increasingly, specific systemic medical therapies are being used to treat brain metastases based on the primary site of disease. This disease specific management is causing a change in perspective about brain metastases and has led to improved survival for patients with primary disease subtypes amenable to tailored medical therapies. We review the recent literature to present evidence for the use of subtype specific medical therapies, advances in surgical resection techniques and stereotactic radiosurgery as the primary treatment modalities. The decline in use of whole brain radiotherapy as first line treatment is also discussed. Based on the recent literature, we propose a new management algorithm to reflect the progress in available options for tailoring disease specific treatments and support the change in paradigm to consider brain metastases as separate disease states based on the primary site of cancer rather than as a homogenous entity.

CNS and spinal tumors

Primary CNS tumors consist of a diverse group of neoplasms originating from various cell types in the CNS. Brain tumors are the most common solid malignancy in children under the age of 15 years and the second leading cause of cancer death after leukemia. The most common brain neoplasms in children differ consistently from those in older age groups. Pediatric brain tumors demonstrate distinct patterns of occurrence and biologic behavior according to sex, age, and race. This chapter highlights the imaging features of the most common tumors that affect the child's CNS (brain and spinal cord).

Brain metastases: an overview

So far brain metastases represent a critical stage of a disease course and the frequency is increasing over the years. The treatment of brain metastases should be individualized for each patient: in case of single brain metastasis, surgery or radiosurgery should be considered as first options of treatment; in case of multiple lesions, whole-brain radiotherapy is the standard of care in association with systemic therapy or surgery/radiosurgery. Chemotherapy should be considered when surgery or radiation therapy are not possible. In the last decades, TKIs or monoclonal antibodies have shown increase in overall response rate and overall survival in Phase II-III trials. The aim of this paper is to make an overview of the current approaches in management of patients with brain metastases.

Melanoma cells homing to the brain: an in vitro model

We developed an in vitro contact through-feet blood brain barrier (BBB) model built using type IV collagen, rat astrocytes, and human umbilical vein endothelial cells (HUVECs) cocultured through Transwell porous polycarbonate membrane. The contact between astrocytes and HUVECs was demonstrated by electron microscopy: astrocytes endfeet pass through the 8.0 μm pores inducing HUVECs to assume a cerebral phenotype. Using this model we evaluated transmigration of melanoma cells from two different patients (M1 and M2) selected among seven melanoma primary cultures. M2 cells showed a statistically significant higher capability to pass across the in vitro BBB model, compared to M1. Expression of adhesion molecules was evaluated by flow cytometry: a statistically significant increased expression of MCAM, αvβ3, and CD49b was detected in M1. PCR array data showed that M2 had a higher expression of several matrix metalloproteinase proteins (MMPs) compared to M1. Specifically, data suggest that MMP2 and MMP9 could be directly involved in BBB permeability and that brain invasion by melanoma cells could be related to the overexpression of many MMPs. Future studies will be necessary to deepen the mechanisms of central nervous system invasion.

The pathological spectrum of solid CNS metastases in the pediatric population

OBJECT

Collectively, metastatic tumors are the most common malignancy encountered in the adult central nervous system (CNS), arising most often from lung, breast, skin, and gastrointestinal tract carcinomas. Limited information is available in the literature regarding solid nonhematopoietic CNS metastases in children. The authors carried out a retrospective study of pediatric metastatic neoplasms to the CNS treated in a 30-year period to characterize their frequency, common histological subtypes, and sites of origin.

METHODS

The archival pathology files were searched (1981-2011) for metastatic tumors to the CNS in patients 21 years of age and younger. Pathology material was reviewed, tumors were classified by site of origin and histological subtype, and survival was evaluated.

RESULTS

The authors identified 26 patients with solid nonhematopoietic CNS metastases out of 1135 pediatric CNS tumors diagnosed from 1981 to 2011. Patients ranged in age from 1.5 to 20.3 years and were equally divided between sexes. Most CNS metastases were supratentorial (85%) and solitary (65%). The mean interval from primary malignant diagnosis to CNS metastasis was 27 months. Sites of origin included kidney/adrenal, bone/soft tissue, gonads, head and neck, lung, and liver. Mean survival after CNS involvement was 36.6 months. Overall 1-year and 5-year survival rates were 52% and 16%, respectively.

CONCLUSIONS

In neuropathology practice, nonhematopoietic pediatric CNS metastases are far less common than are nonhematopoietic adult CNS metastases, accounting for approximately 2% of all pediatric CNS tumors. The most common tumors to exhibit CNS metastasis are of kidney/adrenal origin, followed by those from bone/soft tissue. As expected, prognosis is dismal, despite aggressive therapy.

Oncologic mechanical emergencies

Prevalence of cancer and its various related complications continues to rise. Increasingly these life-threatening complications are initially managed in the emergency department, making a prompt and accurate diagnosis crucial to effectively institute the proper treatment and establish goals of care. The following oncologic emergencies are reviewed in this article: pericardial tamponade, superior vena cava syndrome, brain metastasis, malignant spinal cord compression, and hyperviscosity syndrome.

Survival after surgery and stereotactic radiosurgery for patients with multiple intracranial metastases: results of a single-center retrospective study

OBJECTIVES

Patients with systemic cancer and a single brain metastasis who undergo treatment with resection plus radiotherapy live longer and have a better quality of life than those treated with radiotherapy alone. Historically, whole-brain radiotherapy (WBRT) has been the mainstay of radiation therapy; however, it is associated with significant delayed neurocognitive sequelae. In this study, the authors looked at survival in patients with single and multiple intracranial metastases who had undergone surgery and adjuvant stereotactic radiosurgery (SRS) to the tumor bed and synchronous lesions.

METHODS

The authors retrospectively reviewed the records from an 8-year period at a single institution for consecutive patients with brain metastases treated via complete resection of dominant lesions and adjuvant radiosurgery. The cohort was analyzed for time to local progression, synchronous lesion progression, new intracranial lesion development, systemic progression, and overall survival. The Kaplan-Meier method (stratified by age, sex, tumor histology, and number of intracranial lesions prior to surgery) was used to calculate both progression-free and overall survival. A Cox proportional-hazards regression model was also fitted with the number of intracranial lesions as the predictor and survival as the outcome controlling for disease severity, age, sex, and primary histology.

RESULTS

The median overall follow-up among the 150-person cohort eligible for analysis was 17 months. Patients had an average age of 46.2 years (range 16-82 years), and 62.7% were female. The mean (± standard deviation) number of intracranial lesions per patient was 2.5 ± 2.3. The mean time between surgery and stereotactic radiosurgery (SRS) was 3.2 ± 4.1 weeks. Primary cancers included lung cancer (43.3%), breast cancer (21.3%), melanoma (10.0%), renal cell carcinoma (6.7%), and colon cancer (6.7%). The average number of isocenters per treated lesion was 7.6 ± 6.6, and the average treatment dose was 17.8 ± 2.8 Gy. One-year survival for patients in this cohort was 52%, and the 1-year local control rate was 77%. The median (±standard error) overall survival was 13.2 ± 1.9 months. There was no difference in survival between patients with a single lesion and those with multiple lesions (p = 0.319) after controlling for age, sex, and histology of primary tumor. Patients with primary breast histology had the greatest overall median survival (22.9 ± 6.2 months); patients with colorectal cancer had the shortest overall median survival (5.3 ± 1.8 months). The most common cause of death in this series was systemic progression (79%).

CONCLUSIONS

These results confirm that 1-year survival for patients with multiple intracranial metastases treated with resection followed by SRS to both the tumor bed and synchronous lesions is similar to established outcomes for patients with a single intracranial metastasis.

Comparing the cost-effectiveness of two brain metastasis treatment modalities from a payer's perspective: stereotactic radiosurgery versus surgical resection

OBJECTIVES

This study aims to identify the cost-effectiveness of two brain metastatic treatment modalities, stereotactic radiosurgery (SRS) versus surgical resection (SR), from the perspective of Germany's Statutory Health Insurance (SHI) System.

METHODS

Retrospectively reviewing 373 patients with brain metastases (BMs) who underwent SR (n=113) and SRS (n=260). Propensity score matching was used to adjust for selection bias (n=98 each); means of survival time and survival curves were defined by the Kaplan-Meier estimator; and medical costs of follow-up treatment were calculated by the Direct (Lin) method. The bootstrap resampling technique was used to assess the impact of uncertainty.

RESULTS

Survival time means of SR and SRS were 13.0, 18.4 months, respectively (P=0.000). Medians of free brain tumor time were 10.4 months for SR and 13.8 months for SRS (P=0.003). Number of repeated SRS treatments significantly influenced the survival time of SRS (R(2)=0.249; P=0.006). SRS had a lower average cost per patient (€9964 - SD: 1047; Skewness: 7273) than SR (€11647 - SD: 1594; Skewness: 0.465), leading to an incremental cost effectiveness ratio of €-3740 per life year saved (LYS), meaning that using SRS costs €1683 less than SR per targeted patient, but increases LYS by 0.45 years.

CONCLUSION

SRS is more cost-effective than SR in the treatment of brain metastasis (BM) from the SHI perspective. When the clinical conditions allow it, early intervention with SRS in new BM cases and frequent SRS repetition in new BM recurrent cases should be advised.

The role of radiosurgery in patients with brain metastasis from small cell lung carcinoma

OBJECTIVE

The purpose of this retrospective study was to evaluate the outcome of gamma knife radiosurgery (GKRS) and/or whole brain radiation therapy (WBRT) for the treatment of small cell lung carcinoma (SCLC) metastasis to the brain.

METHODS

From 2000 to 2010, 50 patients underwent GKRS for metastatic brain lesions originating from SCLC. Among these patients, 11 received prophylactic cranial irradiation (PCI) before the development of metastatic lesions (PCI group), and GKRS was performed as an initial treatment for newly diagnosed lesions in 12 patients who had not received PCI (primary GKRS group). In addition, GKRS was performed as a salvage treatment for progressive lesions after WBRT in 27 patients (salvage GKRS group). The medical records and imaging data of all patients were retrospectively analyzed.

RESULTS

The overall survival of the 50 patients was 20.8 months (range 1-53) after the diagnosis of primary tumor and 12.0 months (range 1-47) after the development of cerebral metastasis. Median survival after GKRS was 4.8 months (range 1-15) in the PCI group, 4.6 months (range 0-18) in the primary GKRS group, and 7.6 months (range 0-33) in the salvage GKRS group. Further treatment for progressive lesions after GKRS was necessary in 15 patients, after a mean interval of 3.8 months. Causes of death were systemic organ failure in 15 patients, deterioration of neurological state in 13 patients, and unknown or combined causes in 16 patients. The local control rate of the lesions treated with GKRS was 76.4% (decreased in 13 patients and stable in 16 patients at the final imaging follow-up (mean 5.60 months).

CONCLUSION

GKRS is an effective local treatment for brain metastasis from SCLC both as an initial treatment for newly diagnosed lesions after PCI and as a salvage treatment for recurrent or progressive lesions. However, the survival benefit is not significant because most patients die of systemic multi-organ failure with a short life expectancy.

Association of choline levels and tumor perfusion in brain metastases assessed with proton MR spectroscopy and dynamic susceptibility contrast-enhanced perfusion weighted MRI

While malignant brain tumors typically show high choline concentrations and neovascularity, we have anecdotally noted that a substantial number of brain metastases from lung cancer demonstrate only mildly elevated choline resonances on proton MR spectroscopy ((1)H-MRS). The goals of this study were to determine whether lung cancer metastases are more likely to demonstrate low choline than other metastases and, in addition, to assess the relationship between choline and tissue perfusion in brain metastases. We performed a retrospective analysis of 66 patients with untreated brain metastases (40 NSCLC; 17 breast cancer; 9 melanoma) who underwent multivoxel 2D-CSI (1)H-MRS. Cho/Cr was compared between histologies using Mann-Whitney U tests. Lesions were dichotomized into low and high Cho/Cr groups, and differences in relative Cho/Cr between groups were assessed with Fisher's exact tests. 21 patients also underwent dynamic susceptibility MR perfusion weighted imaging (PWI). Normalized relative cerebral blood volume ratios (rCBV(norm)) were calculated, and strength of correlation between Cho/Cr and rCBV(norm) was assessed. Cho/Cr was significantly lower in lung cancer metastases compared to breast cancer metastases. Cho/Cr < 2.0 was observed in 37.5% of lung cancer metastases, 23.5% of breast cancer metastases, and 0% of melanoma metastases. Lung cancer metastases were significantly more likely to demonstrate low Cho/Cr than melanoma metastases (p = 0.04). There was a strong correlation between Cho/Cr and rCBV(norm) (p = 0.847, p < 0.001), and metastases in the high Cho/Cr group showed significantly higher rCBV(norm). These findings suggest that choline metabolism and tumor perfusion in brain metastases are interrelated, and we posit that this relationship may be due to the influence of the transcription factor HIF-1.

Breast cancer subtypes and response to systemic treatment after whole-brain radiotherapy in patients with brain metastases

BACKGROUND

The aim of this study was to assess the role of systemic treatment after whole-brain radiotherapy (WBRT) in immunohistochemically defined biological subsets of breast cancer patients with brain metastases.

METHODS

The group of 420 consecutive breast cancer patients with brain metastases treated at the same institution between the years of 2003 to 2009 was analyzed. Patients were divided into 4 immunohistochemically biological subsets, based on the levels of estrogen, progesterone, and human epidermal growth factor receptor 2 (HER2) receptors, and labeled as luminal A, luminal B, HER2, and triple-negative. Survival from brain metastases with and without systemic treatment after WBRT was calculated in 4 subsets.

RESULTS

In the entire group, the median survival from brain metastases in patients without and with systemic treatment after WBRT was 3 and 10 months, respectively (P < .0001). In the triple-negative subset, the median survival from brain metastases with and without systemic treatment was 4 and 3 months (P = .16), and in the luminal A subset, it was 12 and 3 months, respectively (P = .003). In the luminal B subset, the median survival without further treatment, after chemotherapy and/or hormonal therapy, and after chemotherapy and/or hormonal therapy with targeted therapy was 2 months, 9 months, and 15 months, respectively (P < .0001). In the HER2 subset, the median survival was 4 months, 6 months, and 13 months, respectively (P < .0001). No significant response to systemic treatment was noted in the triple-negative breast cancer population.

CONCLUSIONS

Systemic therapy, ordered after WBRT, appears to improve survival in patients with the luminal A, luminal B, and HER2 breast cancer subtypes. Targeted therapy was found to have an additional positive impact on survival. In patients with triple-negative breast cancer, the role of systemic treatment after WBRT appears to be less clear, and therefore this issue requires further investigation.

Dual phase FDG-PET imaging of brain metastases provides superior assessment of recurrence versus post-treatment necrosis

To study the ability of dual phase FDG-PET/CT imaging to accurately distinguish tumor versus necrosis in patients treated for brain metastases. 32 (22 female, 10 male) consecutive patients with treated brain metastases, lesion size greater than 0.5 cm(3) and suspected recurrence on MRI underwent dual-phase FDG-PET/CT. Clinical outcome was assessed by biopsy or by MRI. SUVmax and SUVmean values of the lesion (L) and gray matter (GM) at the level of the thalamus were measured on early (1) and delayed (2) imaging. L1/GM1 and L2/GM2 and the change of L/GM ratios as a function of time were calculated [(L2/GM2 - L1/GM1)/(L1/GM1)]. Cut-off values were obtained by ROC analysis. P < 0.05 defined statistical significance. Seven patients were excluded due to indeterminate outcomes. 25 patients (16 female, 9 male; 27 lesions; 28 scan sessions) had clear outcomes, proven by either biopsy (n = 16 patients) or serial follow-up MRI (n = 9 patients). Primary subtypes included breast (n = 9), lung (n = 7), melanoma (n = 3), squamous cell cancer of the head and neck (n = 2) and other (n = 4). Twenty-two patients underwent prior radiation (2-113 months) and three received only prior chemotherapy (5 months to 3 years). A change >0.19 of L/GM ratios as a function of time was 95% sensitive, 100% specific, and 96.4% accurate (P = 0.0001; AUC = 0.97) for distinguishing tumor versus radiation necrosis. The ratio of the change of the lesion to WM ratios over time was the second best indicator of outcome when compared to all indices used (ROC cut-off = 0.25, sensitivity 89.5% and specificity 90.9%, and accuracy 89.2%; P = 0.0001; AUC = 0.95), Early or late SUVs of the lesion alone did not differentiate between tumor and necrosis. Regardless of histological type, differentiation of necrosis from metastatic brain lesions was improved by using the change of lesion to gray matter SUVmax ratios as a function of time.

Clinical and pathological characteristics of brain metastasis resected after failed radiosurgery

OBJECTIVE

This study evaluates the tumor histopathology and clinical characteristics of patients who underwent resection of their brain metastasis after failed gamma knife radiosurgery.

METHODS

This study was a retrospective review from a prospective database. A total of 1200 brain metastases in 912 patients were treated by gamma knife radiosurgery during a 7-year period. Fifteen patients (1.6% of patients, 1.2% of all brain metastases) underwent resective surgery for either presumed tumor progression (6 patients) or worsening neurological symptoms associated with increased mass effect (9 patients). Radiographic imaging, radiosurgical and surgical treatment parameters, histopathological findings, and long-term outcomes were reviewed for all patients.

RESULTS

The mean age at the time of radiosurgery was 57 years (age range, 32-65 years). Initial pathological diagnoses included metastatic non-small cell lung carcinoma in 8 patients (53%), melanoma in 4 patients (27%), renal cell carcinoma in 2 patients (13%), and squamous cell carcinoma of the tongue in 1 patient (7%). The mean time interval between radiosurgery and surgical extirpation was 8.5 months (range, 3 weeks to 34 months). The mean treatment volume for the resected lesion at the time of radiosurgery was 4.4 cm(3) (range, 0.6-8.4 cm(3)). The mean dose to the tumor margin was 21Gy (range, 18-24 Gy). In addition to the 15 tumors that were eventually resected, a total of 32 other metastases were treated synchronously, with a 78% control rate. The mean volume immediately before surgery for the 15 resected lesions was 7.5 cm(3) (range, 3.8-10.2 cm(3)). Histological findings after radiosurgery varied from case to case and included viable tumor, necrotic tumor, vascular hyalinization, hemosiderin-laden macrophages, reactive gliosis in surrounding brain tissue, and an elevated MIB-1 proliferation index in cases with viable tumor. The mean survival for patients in whom viable tumor was identified (9.4 months) was significantly lower than that of patients in whom only necrosis was seen (15.1 months; Fisher's exact test, P < 0.05).

CONCLUSION

Radiation necrosis and tumor radioresistance are the most common causes precipitating a need for surgical resection after radiosurgery in patients with brain metastasis.

Short-course whole-brain radiotherapy (WBRT) for brain metastases due to small-cell lung cancer (SCLC)

OBJECTIVE

Many patients with brain metastases due to SCLC have a poor survival prognosis. The most common treatment is whole-brain radiotherapy (WBRT). This retrospective study compares short-course WBRT with 5x4Gy in 1 week to standard WBRT with 10x3Gy in 2 weeks.

METHODS

Forty-four SCLC patients receiving WBRT with 5x4Gy were compared to 102 patients receiving 10x3Gy for survival (OS) and local (intracerebral) control (LC). Seven further potential prognostic factors were investigated: age, gender, Karnofsky Performance Score (KPS), number of brain metastases, extracerebral metastases, interval from tumor diagnosis to WBRT, RPA (Recursive Partitioning Analysis) class.

RESULTS

After 5x4Gy, 12-month OS was 15%, versus 22% after 10x3Gy (p=0.69). On multivariate analysis, improved OS was associated with age <or=60 years (p=0.013), KPS >or=70 (p<0.001), <4 brain metastases (p=0.011), and RPA class 1 (p<0.001). 12-month LC was 34% after 5x4Gy versus 25% after 10x3Gy (p=0.32). On multivariate analysis, improved LC was associated with KPS >or=70 (p<0.001), <4 brain metastases (p=0.027), and RPA class 1 (p<0.001).

CONCLUSION

In patients with brain metastases due to SCLC, short-course WBRT with 5x4Gy provided similar outcomes as 10x3Gy and appears preferable, particularly for patients with poor estimated survival.

Gamma knife radiosurgery after stereotactic aspiration for large cystic brain metastases

OBJECTIVE

Several treatment options have proven effective for metastatic brain tumors, including surgery and stereotactic radiosurgery. Tumors with cystic components, however, are difficult to treat using a single method. We retrospectively assessed the outcome and efficacy of gamma knife radiosurgery (GKRS) for cystic brain metastases after stereotactic aspiration of cystic components to decrease the tumor volume.

METHODS

The study population consisted of 24 patients (13 males, 11 females; mean age, 58.3 years) with cystic metastatic brain tumors treated from January 2002 to August 2008. Non-small cell lung cancer was the most common primary origin. After Leksell stereotactic frame was positioned on each patient, magnetic resonance images (MRI)-guided stereotactic cyst aspiration and GKRS were performed (mean prescription dose : 20.2 Gy). After treatment, patients were evaluated by MRI every 3 or 4 months.

RESULTS

After treatment, 13 patients (54.2%) demonstrated tumor control, 5 patients (20.8%) showed local tumor progression, and 6 patients (25.0%) showed remote progression. Mean follow-up duration was 13.1 months. During this period, 10 patients (41.7%) died, but only 1 patient (4.2%) died from brain metastases. The overall median survival after these procedures was 17.8 months.

CONCLUSION

These results support the usefulness of GKRS after stereotactic cyst aspiration in patients with large cystic brain metastases. This method is especially effective for the patients whose general condition is very poor for general anesthesia and those with metastatic brain tumors located in eloquent areas.

The results of resection after stereotactic radiosurgery for brain metastases

Object

Radiosurgery for brain metastasis fails in some patients, who require further surgical care. In this paper the authors' goal was to evaluate prognostic factors that correlate with the survival of patients who require a resection of a brain metastasis after stereotactic radiosurgery (SRS).

Methods

During the last 14 years when surgical navigation systems were routinely available, the authors identified 58 patients who required resection for various brain metastases after SRS. The median patient age was 54 years. Prior adjuvant treatment included whole-brain radiation therapy alone (17 patients), chemotherapy alone (9 patients), both radiotherapy and chemotherapy (10 patients), and prior resection before SRS (8 patients). The median target volumes at the time of SRS and resection were 7.7 cm3 (range 0.5–24.9 cm3) and 15.5 cm3 (range 1.3–81.2 cm3), respectively.

Results

At a median follow-up of 7.6 months, 8 patients (14%) were living and 50 patients (86%) had died. The survival after surgical removal was 65, 30, and 16% at 6, 12, and 24 months, respectively (median survival after resection 7.7 months). The local tumor control rate after resection was 71, 62, and 43% at 6, 12, and 24 months, respectively. A univariate analysis revealed that patient preoperative recursive partitioning analysis classification, Karnofsky Performance Scale status, systemic disease status, and the interval between SRS and resection were factors associated with patient survival. The mortality and morbidity rates of resection were 1.7 and 6.9%, respectively.

Conclusions

In patients with symptomatic mass effect after radiosurgery, resection may be warranted. Patients who had delayed local progression after SRS (> 3 months) had the best outcomes after resection.

Current therapeutic options for breast cancer central nervous system metastases

OPINION STATEMENT

Breast cancer metastases to the central nervous system (CNS) has devastating consequences for the individual. As treatment options for metastatic breast cancer expand and as quality of life and overall survival improve, researchers are targeting potential treatments for this sanctuary site. Attention is now being focused on defining the phenotype of breast cancer that has a propensity to metastasize to the CNS. Specific therapies that penetrate the blood brain barrier as well as adjuvant therapies that decrease recurrence in the CNS are currently being investigated. We will review current approaches to the diagnosis, evaluation, and treatment of CNS metastases in breast cancer patients.

A boost in addition to whole-brain radiotherapy improves patient outcome after resection of 1 or 2 brain metastases in recursive partitioning analysis class 1 and 2 patients

BACKGROUND

The current study was conducted to compare 2 treatment regimens including surgical resection and whole-brain radiotherapy (WBRT) for patients with 1 to 2 brain metastases.

METHODS

A total of 201 patients with recursive partitioning analysis (RPA) class 1 to 2 disease with 1 to 2 resectable brain metastases were analyzed retrospectively. Patients underwent either resection of the metastases plus WBRT with 10 fractions of 3 grays (Gy) each or 20 fractions of 2 Gy each (99 patients; Group A) or the same treatment plus a WBRT boost to the metastatic site (10 fractions of 3 Gy each plus 5 fractions of 3 Gy each or 20 fractions of 2 Gy each plus 5 fractions of 2 Gy each) (102 patients; Group B). Eight other potential prognostic factors were evaluated with regard to overall survival (OS), brain control (BC), and local control of resected metastases (LC): age, gender, Karnofsky performance status, extent of surgical resection, tumor type, extracranial metastases, RPA class, and interval from tumor diagnosis to WBRT.

RESULTS

Group B patients had better 1-year OS (66% vs 41%; P < .001). On multivariate analysis of OS, treatment regimen (relative risk [RR] of 1.94; P < .001), extent of surgical resection (RR of 1.80; P = .001), and interval from tumor diagnosis to WBRT (RR of 1.62; P = .010) were found to be statistically significant. On multivariate analysis of BC, treatment regimen (RR of 2.15; P = .002), extent of surgical resection (RR of 2.78; P < .001), and interval from tumor diagnosis to WBRT (RR of 1.52; P = .034) were found to be statistically significant. On multivariate analysis of LC, treatment regimen (RR of 2.31; P = .002) and extent of surgical resection (RR of 3.79; P < .001) were found to be statistically significant. On RPA class subgroup analyses, outcome was found to be significantly better with a WBRT boost in both RPA class 1 and class 2 patients. A WBRT boost resulted in better outcome after both complete and incomplete surgical resection. However, the results concerning BC and LC were not found to be statistically significant if surgical resection was incomplete.

CONCLUSIONS

After surgical resection of 1 to 2 brain metastases, a boost of 10 to 15 Gy in addition to WBRT was found to improve outcome. After incomplete surgical resection, further dose escalation to the metastatic site may be considered.

Stereotactic radiosurgery alone versus resection plus whole-brain radiotherapy for 1 or 2 brain metastases in recursive partitioning analysis class 1 and 2 patients

BACKGROUND

The objective of this study was to compare stereotactic radiosurgery (SRS) alone with resection plus whole-brain radiotherapy (WBRT) for the treatment of patients in recursive partitioning analysis (RPA) class 1 and 2 who had 1 or 2 brain metastases.

METHODS

Two hundred six patients in RPA class 1 and 2 who had 1 or 2 brain metastases were analyzed retrospectively. Patients in Group A (n = 94) received from 18 grays (Gy) to 25 Gy SRS, and patients in Group B (n = 112) underwent resection of their metastases and received 10 x 3 Gy/20 x 2 Gy WBRT. Eight other potential prognostic factors were evaluated regarding overall survival (OS), brain control (BC), and local control (LC) of treated metastases: age, sex, performance status, tumor type, number of brain metastases, extracranial metastases, RPA class, and interval from tumor diagnosis to treatment of brain metastases.

RESULTS

A comparison of the 2 treatment groups did not reveal significantly different OS (P = .19), BC (P = .52), or LC (P = .25). In RPA subgroup analyses, outcome also did not differ significantly for either RPA class of patients (P values from .21 to .83). On multivariate analysis, improved OS was associated with age < or =60 years (relative risk [RR], 1.75; P = .002), better performance status (RR, 1.67; P = .015), no extracranial metastases (RR, 2.84; P < .001), interval from tumor diagnosis to treatment >12 months (RR, 1.70; P = .003), and RPA class 1 (RR, 1.51; P = .016). Improved BC was associated with a single metastasis (RR, 1.54; P = .034) and an interval from tumor diagnosis to treatment >12 months (RR, 1.58; P = .019), and improved LC was associated with an interval from tumor diagnosis to treatment >12 months (RR, 1.59; P = .047).

CONCLUSIONS

SRS alone appeared to be as effective as resection plus WBRT in the treatment of 1 or 2 brain metastases for patients in RPA class 1 and 2. Patient outcomes were associated with age, Karnofsky performance status, number of brain metastases, extracranial metastases, RPA class, and interval from tumor diagnosis to treatment.

Surgical Therapies in Brain Metastasis

Brain metastases are the most common intracranial tumors in adults and source of the most common neurological complications of systemic cancer. The treatment approach to brain metastases differs essentially from treatment of systemic metastases due to the unique anatomical and physiological characteristics of the brain. Surgery and radiosurgery are important components in the complex treatment of brain metastases and can prolong survival and improve the quality of life (QOL). Aggressive intervention may be indicated for selected patients with well-controlled systemic cancer and good performance status in whom central nervous system (CNS) disease poses the greatest threat to functionality and survival. In this review the respective roles of surgery and radiosurgery, patient selection, general prognostic factors and tailoring of optimal surgical management strategies for cerebral metastases are discussed.

Retrospective analysis of the efficacy and tolerability of levetiracetam in patients with metastatic brain tumors

Seizures are a common complication of metastatic brain tumors (MBT), affecting approximately 27-50% of all patients during the course of their illness. Treatment of tumor-induced seizures is often inadequate with traditional antiepileptic drugs (AED) due to a variety of factors, including activation of glutamatergic NMDA receptors, alterations of neuronal input pathways, and tumor growth. Levetiracetam (LEV) is a 2nd generation non-enzyme inducing AED with a novel mechanism of action, binding to neuronal synaptic vesicle protein SV2A, that has been previously shown to reduce seizure activity in patients with primary brain tumors. Due to its unique mechanism of action, it has been postulated that LEV may also be effective in controlling seizures from MBT. A retrospective chart review was performed of all Neuro-Oncology Center patients with MBT who had received LEV for seizure control. Thirteen patients were reviewed with a median age of 55.1 years (range: 34-70). Six patients had breast cancer, five had lung cancer, and two had melanoma. LEV was used as an add-on AED in seven patients (54%) and as monotherapy in six patients (46%), with a median dose of 1,000 mg/day (range: 500-3,000). The baseline median seizure frequency was one ictal event every other day. After the addition of LEV, the median seizure frequency was reduced to 0 per week. The seizure frequency was reduced to less than 50% of the pre-LEV baseline in 100% of patients (P=0.0002, Sign test), with 10 patients (77%; confidence interval: 46-95%) noting complete seizure control. The most common adverse event was somnolence and headache, noted in 3 of 13 patients (23%). LEV was very effective and well tolerated in MBT patients with seizures and should be considered for add-on therapy or as a substitute AED for monotherapy.

Molecular events of brain metastasis

The brain is a privileged site of systemic cancer metastasis. The stages of the metastatic journey from the periphery to the brain are driven by molecular events that tie the original site of disease to the distant host tissue. This preference is not arbitrary but rather a directed phenomenon that includes such critical steps as angiogenesis and the preparation of the premetastatic niche. It appears that the connection between naive brain and cancer cells is made in advance of any metastatic breach of the blood-brain barrier. This contributes to the preferential homing of cancer cells to the brain. Delineation of the guidance mechanisms and elements that influence cancer cell motility and dormancy are important for the advancement of treatment modalities aimed at the remediation of this devastating disease.

Optimizing intracranial metastasis detection for stereotactic radiosurgery

BACKGROUND AND PURPOSE

The authors characterize the detection of additional intracranial metastases in cancer patients at the time of stereotactic radiosurgery (SRS) using a specialized high-resolution magnetic resonance imaging (MRI) protocol.

METHODS

A retrospective review of 150 consecutive radiosurgical procedures for patients with < or =5 known metastatic intracranial tumors diagnosed using MRI was undertaken at a single center. On the day of SRS, all patients underwent rigid head fixation in a stereotactic frame followed by a specialized MRI using a 3-dimensional fast spoiled-gradient sequence on a 1.5-tesla magnet with double-dose gadolinium. Axial imaging was performed using 2-mm cuts and no gap.

RESULTS

Additional metastases were detected in 29.3% of patients. The number of known tumors before SRS was predictive of additional metastases being found (p = 0.014). In multivariate analysis, we more frequently found additional metastases at radiosurgery in patients with 3-5 previously known metastases (p = 0.005), in patients with non-small cell lung cancer (p = 0.012) and in patients with a longer time interval between their diagnostic MRI and their stereotactic MRI (p = 0.030). Age, sex and prior fractionated radiation therapy were not predictive factors.

CONCLUSION

Our specialized protocol of high-resolution, double-dose contrast-enhanced MRI is a reliable method to evaluate the extent of intracranial disease in patients with known brain metastasis. Treatment planning for radiosurgery, radiation therapy and open surgical therapy are all impacted by improved metastasis detection.

Current therapeutic approaches in patients with brain metastases

The development of brain metastases is often viewed as the end stage of a disease course and engenders skepticism about the efficacy of treatment. Aggressive management of brain metastases is effective in both symptom palliation and the prolongation of life. The majority of patients with controlled intracranial metastases will expire from systemic disease rather than from recurrence of these metastases. Single brain metastases should be treated with surgical resection or stereotactic radiosurgery, though it is unclear at this time if one modality is more effective than the other. Surgical resection is preferred when a pathologic diagnosis is needed, for tumors larger than 3.5 cm, or when immediate tumor mass decompression is required. Stereotactic radiosurgery (SRS) should be applied for single tumors less than 3.5 cm in surgically inaccessible areas and for patients who are not surgical candidates. Small tumors (ie, < 3.5 cm) that cause minimal edema and are surgically accessible may be treated with either surgery or SRS. There is controversy over whether whole brain radiation therapy (WBRT) can be omitted following surgical resection or SRS. Omission of WBRT increases intracranial tumor recurrence; however, this has not been correlated with decreased survival. Clinicians who choose to omit upfront WBRT are obligated to monitor the patient closely for intracranial recurrence, at which time further salvage therapy in the form of surgery, SRS, or WBRT may be considered. Histology is of particular importance when considering WBRT for patients with radioresistant tumors such as melanoma, renal cell carcinoma, or sarcoma. WBRT may be of less clinical benefit in this setting. Chemotherapy has been demonstrated to improve response rates when used as an adjunct to radiation therapy. These improvements in response rates have not been correlated with an improvement in median survival. Noncytotoxic radiosensitizing agents such as motexafin and efaproxiral show promise. Phase III trials to assess the benefit of motexafin in patients with metastatic lung cancer and efaproxiral in patients with metastatic breast cancer are ongoing. Targeted therapies offer promise in achieving therapeutic efficacy while minimizing side effects. Surgical adjuncts such as BCNU (carmustine) wafers and the GliaSite Radiation System (Cytyc Corporation, Marlborough, MA) may be useful in the future in achieving optimal local tumor control.

Seizures and brain tumors

Seizures commonly occur in people with brain tumors. They may be the presenting symptom of a brain tumor, or develop some time after tumor diagnosis. The risk of seizures is greatest when the tumors have a central location, slow growth rate, and when multiple lesions are present. Interactions between anti-epileptic drugs (AEDs), chemotherapeutic agents, and corticosteroids increase the complexity and challenge in managing seizures, and drugs that do not interfere with the cytochrome P-450 enzyme complex and have low protein binding may be preferable. The comparative efficacy and side effects of the various AEDs are not established in brain tumors, so drug choice relies on both the theoretical advantages of pharmacokinetic properties and clinical judgment. Prophylactic anticonvulsant treatment is not advisable in brain tumor patients who have not experienced seizures.

Current strategies in whole-brain radiation therapy for brain metastases

Whole-brain radiation therapy (WBRT) has been the primary treatment for patients with brain metastases for more than 50 years and provides effective palliative relief in most patients. Although advancements in radiotherapeutic technique continue to improve local and locoregional control, median survival for patients treated with WBRT monotherapy remains fixed at approximately 4 to 6 months. Key issues in the use of WBRT include optimizing its efficacy when it is used in conjunction with surgery, radiosurgery, radiosensitizers, and new chemotherapeutic agents. These multimodal approaches to brain metastases have resulted in significant increases in the median survival time in many patients. Radiosurgery is part of a continuing effort to improve the effects of radiation therapy, especially in brain metastases. The optimal combination of WBRT and radiosurgery remains to be elucidated, including appropriate timing or sequence and use in conjunction with other modalities. Newer radiosensitizing agents (e.g., efaproxiral [RSR-13] and motexafin gadolinium) have shown promise in the treatment of brain tumors, especially in specific patient subsets. Recently developed systemic chemotherapy agents, such as temozolomide, which crosses the blood-brain barrier, have a synergistic effect on brain metastases when used in conjunction with radiation. In addition, the use of interstitial chemotherapy agents provides highly focused local chemotherapy in the brain without increasing systemic toxicity; carmustine polymer wafer, in combination with WBRT, has shown promising results in treating brain metastases.

Modulation of p-glycoprotein transport function at the blood-brain barrier

The central nervous system (CNS) effects of many therapeutic drugs are blunted because of restricted entry into the brain. The basis for this poor permeability is the brain capillary endothelium, which comprises the blood-brain barrier. This tissue exhibits very low paracellular (tight-junctional) permeability and expresses potent, multispecific, drug export pumps. Together, these combine to limit use of pharmacotherapy to treat CNS disorders such as brain cancer and bacterial or viral infections. Of all the xenobiotic efflux pumps highly expressed in brain capillary endothelial cells, p-glycoprotein handles the largest fraction of commonly prescribed drugs and thus is an obvious target for manipulation. Here we review recent studies focused on understanding the mechanisms by which p-glycoprotein activity in the blood-brain barrier can be modulated. These include (i) direct inhibition by specific competitors, (ii) functional modulation, and (iii) transcriptional modulation. Each has the potential to specifically reduce p-glycoprotein function and thus selectively increase brain permeability of p-glycoprotein substrates.

Gamma knife surgery for brain metastases from lung cancer

Object. The authors conducted a study to evaluate the safety and efficacy of gamma knife surgery (GKS) for the treatment of brain metastases from lung cancer.

Methods. Between February 1993 and May 2003 191 patients underwent treatment for 424 brain metastases from non—small (171 cases) and small cell lung carcinoma (20 cases). Imaging and clinical status were monitored every 3 months following the treatment. Kaplan-Meier survival curves, Cox proportional hazards regression for risk factor analysis, and nonparametric methods for evaluating tumor response were used.

There was no difference in median survival following combined whole-brain radiation therapy (WBRT) and gamma knife surgery (14 months) and GKS alone (15 months). There was also no difference between the median survival rates for either tumor type. In the multivariate analysis, age less than 65 years, Karnofsky Performance Scale score greater than 70, normal neurological status, multiple GKS treatments, and pre-GKS craniotomy were related to longer survival.

Tumor control rates varied according to the volume of the metastases and were as follows: 84.4% (< 0.5 cm3), 94% (0.5–2 cm3), 89.1% (2–4 cm3), 93.4% (4–8 cm3), 85.7% (8–14 cm3), and 87.5% (> 14 cm3). Four lesions required post-GKS craniotomy due to swelling or rapid tumor progression. The rate of tumor shrinkage was higher when a volume was 2 cm3, lower in cystic lesions, lower in tumors with previous WBRT, and lower for margin doses less than 14 Gy.

Conclusions. The risk—benefit ratio of GKS in this series was satisfactory. There was no difference in response rates of the two tumor types, and WBRT did not improve the duration of survival.

Analysis of long-term outcomes and prognostic factors in patients with non—small cell lung cancer brain metastases treated by gamma knife radiosurgery

Object.The authors conducted a study to evaluate the long-term outcomes and prognostic factors for survival in a large series of patients treated by gamma knife surgery (GKS) for non—small cell lung cancer (NSCLC) brain metastases.

Methods.The study is based on the retrospective analysis of clinical and radiological records obtained during a 10-year period (1993–2003), concerning 836 lesions in 504 patients. The lesions were primary in 86% and recurrent 14% of the cases; they were solitary in 31%, single in 29%, and multiple in 40%. The mean follow-up period was 16 months (range 4–113 months). The most common histological types were adenocarcinoma (51%) and squamous cell carcinoma (27%). Dose planning parameters were as follows: mean target volume 6.2 cm3(range 0.06–22.5 cm3); mean prescription dose 21.4 Gy (range 15.5–28 Gy); and mean number of isocenters 6.7 (range one–18). Progression-free and actuarial survival curves were calculated using the Kaplan—Meier method. The main factors affecting survival were determined by unimultivariate analysis (log-rank test and Cox proportional hazard models).

Analysis of long-term outcomes seemed to confirm that GKS is a primary therapeutic option in these patients. The 1-year local tumor control rate was 94%. The overall median survival was 14.5 months, with extremely rewarding quality of life indices. The recursive partitioning analysis classification was the dominant prognostic factor.

Conclusions.Gamma knife surgery is a useful treatment for brain metastases from NSCLC.

Gamma knife surgery for brain metastases from lung cancer

OBJECT

The authors conducted a study to evaluate the safety and efficacy of gamma knife surgery (GKS) for the treatment of brain metastases from lung cancer.

METHODS

Between February 1993 and May 2003 191 patients underwent treatment for 424 brain metastases from non-small (171 cases) and small cell lung carcinoma (20 cases). Imaging and clinical status were monitored every 3 months following the treatment. Kaplan-Meier survival curves, Cox proportional hazards regression for risk factor analysis, and nonparametric methods for evaluating tumor response were used. There was no difference in median survival following combined whole-brain radiation therapy (WBRT) and gamma knife surgery (14 months) and GKS alone (15 months). There was also no difference between the median survival rates for either tumor type. In the multivariate analysis, age less than 65 years, Karnofsky Performance Scale score greater than 70, normal neurological status, multiple GKS treatments, and pre-GKS craniotomy were related to longer survival. Tumor control rates varied according to the volume of the metastases and were as follows: 84.4% (< 0.5 cm3), 94% (0.5-2 cm3), 89.1% (2-4 cm3), 93.4% (4-8 cm3), 85.7% (8-14 cm3), and 87.5% (> 14 cm3). Four lesions required post-GKS craniotomy due to swelling or rapid tumor progression. The rate of tumor shrinkage was higher when a volume was 2 cm3, lower in cystic lesions, lower in tumors with previous WBRT, and lower for margin doses less than 14 Gy.

CONCLUSIONS

The risk-benefit ratio of GKS in this series was satisfactory. There was no difference in response rates of the two tumor types, and WBRT did not improve the duration of survival.

Analysis of long-term outcomes and prognostic factors in patients with non—small cell lung cancer brain metastases treated by gamma knife radiosurgery

Object. The authors conducted a study to evaluate the long-term outcomes and prognostic factors for survival in a large series of patients treated by gamma knife surgery (GKS) for non—small cell lung cancer (NSCLC) brain metastases.

Methods. The study is based on the retrospective analysis of clinical and radiological records obtained during a 10-year period (1993–2003), concerning 836 lesions in 504 patients. The lesions were primary in 86% and recurrent 14% of the cases; they were solitary in 31%, single in 29%, and multiple in 40%. The mean follow-up period was 16 months (range 4–113 months). The most common histological types were adenocarcinoma (51%) and squamous cell carcinoma (27%). Dose planning parameters were as follows: mean target volume 6.2 cm3 (range 0.06–22.5 cm3); mean prescription dose 21.4 Gy (range 15.5–28 Gy); and mean number of isocenters 6.7 (range one–18). Progression-free and actuarial survival curves were calculated using the Kaplan—Meier method. The main factors affecting survival were determined by unimultivariate analysis (log-rank test and Cox proportional hazard models).

Analysis of long-term outcomes seemed to confirm that GKS is a primary therapeutic option in these patients. The 1-year local tumor control rate was 94%. The overall median survival was 14.5 months, with extremely rewarding quality of life indices. The recursive partitioning analysis classification was the dominant prognostic factor.

Conclusions. Gamma knife surgery is a useful treatment for brain metastases from NSCLC.

The pathogenesis and treatment of brain metastases: a comprehensive review

Brain metastases are the most common intracranial tumors and their incidence is increasing. Untreated brain metastases are associated with a poor prognosis and a poor performance status. The role of surgery in the management of multiple brain metastases is still controversial. As more than 70% of patients have multiple metastases at the time of diagnosis, whole brain radiotherapy is the treatment of choice in most cases. Brain metastases are an ideal target for stereotactic radiosurgery, as they are better circumscribed than primary brain tumors. Currently, chemotherapy has a limited role in the treatment of most brain metastases. Several new therapies, with a good penetration through the blood brain barrier, such as temozolomide, have been used in brain metastases with different results depending on the histology of the primary tumor. A better understanding of the complex processes underlying the development of brain metastasis will enable us to develop more satisfactory targeted treatments.