Radiotherapy and chemotherapy of brain metastases

Predicting voxel-level dose distributions of single-isocenter volumetric modulated arc therapy treatment plan for multiple brain metastases

Purpose

Brain metastasis is a common, life-threatening neurological problem for patients with cancer. Single-isocenter volumetric modulated arc therapy (VMAT) has been popularly used due to its highly conformal dose and short treatment time. Accurate prediction of its dose distribution can provide a general standard for evaluating the quality of treatment plan. In this study, a deep learning model is applied to the dose prediction of a single-isocenter VMAT treatment plan for radiotherapy of multiple brain metastases.

Method

A U-net with residual networks (U-ResNet) is employed for the task of dose prediction. The deep learning model is first trained from a database consisting of hundreds of historical treatment plans. The 3D dose distribution is then predicted with the input of the CT image and contours of regions of interest (ROIs). A total of 150 single-isocenter VMAT plans for multiple brain metastases are used for training and testing. The model performance is evaluated based on mean absolute error (MAE) and mean absolute differences of multiple dosimetric indexes (DIs), including (D max and D mean) for OARs, (D 98, D 95, D 50, and D 2) for PTVs, homogeneity index, and conformity index. The similarity between the predicted and clinically approved plan dose distribution is also evaluated.

Result

For 20 tested patients, the largest and smallest MAEs are 3.3% ± 3.6% and 1.3% ± 1.5%, respectively. The mean MAE for the 20 tested patients is 2.2% ± 0.7%. The mean absolute differences of D 98, D 95, D 50, and D2 for PTV60, PTV52, PTV50, and PTV40 are less than 2.5%, 3.0%, 2.0%, and 3.0%, respectively. The prediction accuracy of OARs for D max and D mean is within 3.2% and 1.2%, respectively. The average DSC ranges from 0.86 to 1 for all tested patients.

Conclusion

U-ResNet is viable to produce accurate dose distribution that is comparable to those of the clinically approved treatment plans. The predicted results can be used to improve current treatment planning design, plan quality, efficiency, etc.

Neurotoxicity-sparing radiotherapy for brain metastases in breast cancer: a narrative review

Breast cancer brain metastasis (BCBM) has a devastating impact on patient survival, cognitive function and quality of life. Radiotherapy remains the standard management of BM but may result in considerable neurotoxicity. Herein, we describe the current knowledge on methods for reducing radiation-induced cognitive dysfunction in patients with BCBM. A better understanding of the biology and molecular underpinnings of BCBM, as well as more sophisticated prognostic models and individualized treatment approaches, have appeared to enable more effective neuroprotection. The therapeutic armamentarium has expanded from surgery and whole-brain radiotherapy to stereotactic radiosurgery, targeted therapies and immunotherapies, used sequentially or in combination. Advances in neuroimaging have allowed more accurate screening for intracranial metastases, precise targeting of intracranial lesions and the differentiation of the effects of treatment from disease progression. The availability of numerous treatment options for patients with BCBM and multidisciplinary approaches have led to personalized treatment and improved therapeutic outcomes. Ongoing studies may define the optimal sequencing of available and emerging treatment options for patients with BCBM.

Identifying Topics and Evolutionary Trends of Literature on Brain Metastases Using Latent Dirichlet Allocation

Research on brain metastases kept innovating. We aimed to illustrate what topics the research focused on and how it varied in different periods of all the studies on brain metastases with topic modelling. We used the latent Dirichlet allocation model to analyse the titles and abstracts of 50,176 articles on brain metastases retrieved from Web of Science, Embase and MEDLINE. We further stratified the articles to find out the topic trends of different periods. Our study identified that a rising number of studies on brain metastases were published in recent decades at a higher rate than all cancer articles. Overall, the major themes focused on treatment and histopathology. Radiotherapy took over the first and third places in the top 20 topics. Since the 2010’s, increasing attention concerned about gene mutations. Targeted therapy was a popular topic of brain metastases research after 2020.

Consensus recommendations for a standardized brain tumor imaging protocol for clinical trials in brain metastases

A recent meeting was held on March 22, 2019, among the FDA, clinical scientists, pharmaceutical and biotech companies, clinical trials cooperative groups, and patient advocacy groups to discuss challenges and potential solutions for increasing development of therapeutics for central nervous system metastases. A key issue identified at this meeting was the need for consistent tumor measurement for reliable tumor response assessment, including the first step of standardized image acquisition with an MRI protocol that could be implemented in multicenter studies aimed at testing new therapeutics. This document builds upon previous consensus recommendations for a standardized brain tumor imaging protocol (BTIP) in high-grade gliomas and defines a protocol for brain metastases (BTIP-BM) that addresses unique challenges associated with assessment of CNS metastases. The "minimum standard" recommended pulse sequences include: (i) parameter matched pre- and post-contrast inversion recovery (IR)-prepared, isotropic 3D T1-weighted gradient echo (IR-GRE); (ii) axial 2D T2-weighted turbo spin echo acquired after injection of gadolinium-based contrast agent and before post-contrast 3D T1-weighted images; (iii) axial 2D or 3D T2-weighted fluid attenuated inversion recovery; (iv) axial 2D, 3-directional diffusion-weighted images; and (v) post-contrast 2D T1-weighted spin echo images for increased lesion conspicuity. Recommended sequence parameters are provided for both 1.5T and 3T MR systems. An "ideal" protocol is also provided, which replaces IR-GRE with 3D TSE T1-weighted imaging pre- and post-gadolinium, and is best performed at 3T, for which dynamic susceptibility contrast perfusion is included. Recommended perfusion parameters are given.

Lung cancer-associated brain metastasis: Molecular mechanisms and therapeutic options

BACKGROUND

Lung cancer is the most common cause of cancer-related mortality in humans. There are several reasons for this high rate of mortality, including metastasis to several organs, especially the brain. In fact, lung cancer is responsible for approximately 50% of all brain metastases, which are very difficult to manage. Understanding the cellular and molecular mechanisms underlying lung cancer-associated brain metastasis brings up novel therapeutic promises with the hope to ameliorate the severity of the disease. Here, we provide an overview of the molecular mechanisms underlying the pathogenesis of lung cancer dissemination and metastasis to the brain, as well as promising horizons for impeding lung cancer brain metastasis, including the role of cancer stem cells, the blood-brain barrier, interactions of lung cancer cells with the brain microenvironment and lung cancer-driven systemic processes, as well as the role of growth factor/receptor tyrosine kinases, cell adhesion molecules and non-coding RNAs. In addition, we provide an overview of current and novel therapeutic approaches, including radiotherapy, surgery and stereotactic radiosurgery, chemotherapy, as also targeted cancer stem cell and epithelial-mesenchymal transition (EMT)-based therapies, micro-RNA-based therapies and other small molecule or antibody-based therapies. We will also discuss the daunting potential of some combined therapies.

CONCLUSIONS

The identification of molecular mechanisms underlying lung cancer metastasis has opened up new avenues towards their eradication and provides interesting opportunities for future research aimed at the development of novel targeted therapies.

Icotinib versus whole-brain irradiation in patients with EGFR-mutant non-small-cell lung cancer and multiple brain metastases (BRAIN): a multicentre, phase 3, open-label, parallel, randomised controlled trial

BACKGROUND

For patients with non-small-cell lung cancer (NSCLC) and multiple brain metastases, whole-brain irradiation (WBI) is a standard-of-care treatment, but its effects on neurocognition are complex and concerning. We compared the efficacy of an epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI), icotinib, versus WBI with or without chemotherapy in a phase 3 trial of patients with EGFR-mutant NSCLC and multiple brain metastases.

METHODS

We did a multicentre, open-label, parallel randomised controlled trial (BRAIN) at 17 hospitals in China. Eligible participants were patients with NSCLC with EGFR mutations, who were naive to treatment with EGFR-TKIs or radiotherapy, and had at least three metastatic brain lesions. We randomly assigned participants (1:1) to either icotinib 125 mg orally (three times per day) or WBI (30 Gy in ten fractions of 3 Gy) plus concurrent or sequential chemotherapy for 4-6 cycles, until unacceptable adverse events or intracranial disease progression occurred. The randomisation was done by the Chinese Thoracic Oncology Group with a web-based allocation system applying the Pocock and Simon minimisation method; groups were stratified by EGFR gene mutation status, treatment line (first line or second line), brain metastases only versus both intracranial and extracranial metastases, and presence or absence of symptoms of intracranial hypertension. Clinicians and patients were not masked to treatment assignment, but individuals involved in the data analysis did not participate in the treatments and were thus masked to allocation. Patients receiving icotinib who had intracranial progression only were switched to WBI plus either icotinib or chemotherapy until further progression; those receiving icotinib who had extracranial progression only were switched to icotinib plus chemotherapy. Patients receiving WBI who progressed were switched to icotinib until further progression. Icotinib could be continued beyond progression if a clinical benefit was observed by the investigators (eg, an improvement in cognition or intracranial pressure). The primary endpoint was intracranial progression-free survival (PFS), defined as the time from randomisation to either intracranial disease progression or death from any cause. We assessed efficacy and safety in the intention-to-treat population (all participants who received at least one dose of study treatment), hypothesising that intracranial PFS would be 40% longer (hazard ratio [HR] 0·60) with icotinib compared with WBI. This trial is registered with ClinicalTrials.gov, number NCT01724801.

FINDINGS

Between Dec 10, 2012, and June 30, 2015, we assigned 176 participants to treatment: 85 to icotinib and 91 to WBI. 18 withdrew from the WBI group before treatment, leaving 73 for assessment. Median follow-up was 16·5 months (IQR 11·5-21·5). Median intracranial PFS was 10·0 months (95% CI 5·6-14·4) with icotinib versus 4·8 months (2·4-7·2) with WBI (equating to a 44% risk reduction with icotinib for an event of intracranial disease progression or death; HR 0·56, 95% CI 0·36-0·90; p=0·014). Adverse events of grade 3 or worse were reported in seven (8%) of 85 patients in the icotinib group and 28 (38%) of 73 patients in the WBI group. Raised concentrations of alanine aminotransferase and rash were the most common adverse events of any grade in both groups, occurring in around 20-30% of each group. At the time of final analysis, 42 (49%) patients in the icotinib group and 37 (51%) in the WBI group had died. 78 of these patients died from disease progression, and one patient in the WBI group died from thrombogenesis related to chemotherapy.

INTERPRETATION

In patients with EGFR-mutant NSCLC and multiple brain metastases, icotinib was associated with significantly longer intracranial PFS than WBI plus chemotherapy, indicating that icotinib might be a better first-line therapeutic option for this patient population.

FUNDING

Guangdong Provincial Key Laboratory of Lung Cancer Translational Medicine, National Health and Family Planning Commission of China, Guangzhou Science and Technology Bureau, Betta Pharmaceuticals, and the Chinese Thoracic Oncology Group.

Apoptosis of Lewis Lung Carcinoma Cells Induced by Microwave via p53 and Proapoptotic Proteins In vivo

Background:

Microwave therapy is a minimal invasive procedure and has been employed in clinical practice for the treatment of various types of cancers. However, its therapeutic application in non-small-cell lung cancer and the underlying mechanism remains to be investigated. This study aimed to investigate its effect on Lewis lung carcinoma (LLC) tumor in vivo.

Methods:

Fifty LLC tumor-bearing C57BL/6 mice were adopted to assess the effect of microwave radiation on the growth and apoptosis of LLC tumor in vivo. These mice were randomly assigned to 10 groups with 5 mice in each group. Five groups were treated by single pulse microwave at different doses for different time, and the other five groups were radiated by multiple-pulse treatment of a single dose. Apoptosis of cancer cells was determined by terminal deoxynucleotidyl transferase dUTP nick-end labeling assay. Western blotting was applied to detect the expression of proteins.

Results:

Single pulse of microwave radiation for 5 min had little effect on the mice. Only 15-min microwave radiation at 30 mW/cm² significantly increased the mice body temperature (2.20 ± 0.82)°C as compared with the other groups (0.78 ± 0.29 °C, 1.24 ± 0.52 °C, 0.78 ± 0.42 °C, respectively), but it did not affect the apoptosis of LLC tumor cells significantly. Continous microwave radiation exposure, single dose microwave radiation once per day for up to seven days, inhibited cell division and induced apoptosis of LLC tumor cells in a dose- and duration-dependent manner. It upregulated the protein levels of p53, Caspase 3, Bax and downregulated Bcl-2 protein.

Conclusions:

Multiple exposures of LLC-bearing mice to microwave radiation effectively induced tumor cell apoptosis at least partly by upregulating proapoptotic proteins and downregulating antiapoptotic proteins. Continuous radiation at low microwave intensity for a short time per day is promising in treating non-small-cell lung cancer.

National Perspectives on the Training of Neurosurgery Residents in Stereotactic Radiosurgery

BACKGROUND

Despite the critical role played by neurosurgeons in performing radiosurgery, neurosurgery residents in Canada have limited exposure to radiosurgery during their training. A survey of neurosurgery residents and faculty along with radiation oncology faculty was conducted to analyze perspectives regarding incorporating formal radiosurgery training into the neurosurgery residency curriculum Methods: An online survey platform was employed. Descriptive statistics were used to summarize center and respondent characteristics. Categorical variables were compared using odds ratios and corresponding 95% confidence intervals. The chi-squared test was utilized to assess statistical significance. A value of p<0.05 was considered significant Results: The response rate was 31% (119/381); 87% (102/119) of respondents were from the neurosurgical specialty and 13% (17/119) from radiation oncology. Some 46% of residents (18/40) were "very uncomfortable" with radiosurgery techniques, and 57% of faculty (42/73) believed that dedicated radiosurgery training would be beneficial though impractical. No respondents felt that "no training" would be beneficial. A total of 46% of residents (19/41) felt that this training would be beneficial and that time should be taken away from other rotations, if needed, while 58% of faculty (42/73) and 75% (28/41) of residents believed that either 1 or 1-3 months of time dedicated to training in radiosurgery would suffice Conclusions: Canadian neurosurgeons are actively involved in radiosurgery. Despite residents anticipating a greater role for radiosurgery in their future, they are uncomfortable with the practice. With the indications for radiosurgery expanding, this training gap can have serious adverse consequences for patients. Considerations regarding the incorporation and optimal duration of dedicated radiosurgery training into the Canadian neurosurgery residency curriculum are necessary.

Dexamethasone and supportive care with or without whole brain radiotherapy in treating patients with non-small cell lung cancer with brain metastases unsuitable for resection or stereotactic radiotherapy (QUARTZ): results from a phase 3, non-inferiority, randomised trial

BACKGROUND

Whole brain radiotherapy (WBRT) and dexamethasone are widely used to treat brain metastases from non-small cell lung cancer (NSCLC), although there have been no randomised clinical trials showing that WBRT improves either quality of life or overall survival. Even after treatment with WBRT, the prognosis of this patient group is poor. We aimed to establish whether WBRT could be omitted without a significant effect on survival or quality of life.

METHODS

The Quality of Life after Treatment for Brain Metastases (QUARTZ) study is a non-inferiority, phase 3 randomised trial done at 69 UK and three Australian centres. NSCLC patients with brain metastases unsuitable for surgical resection or stereotactic radiotherapy were randomly assigned (1:1) to optimal supportive care (OSC) including dexamethasone plus WBRT (20 Gy in five daily fractions) or OSC alone (including dexamethasone). The dose of dexamethasone was determined by the patients' symptoms and titrated downwards if symptoms improved. Allocation to treatment group was done by a phone call from the hospital to the Medical Research Council Clinical Trials Unit at University College London using a minimisation programme with a random element and stratification by centre, Karnofsky Performance Status (KPS), gender, status of brain metastases, and the status of primary lung cancer. The primary outcome measure was quality-adjusted life-years (QALYs). QALYs were generated from overall survival and patients' weekly completion of the EQ-5D questionnaire. Treatment with OSC alone was considered non-inferior if it was no more than 7 QALY days worse than treatment with WBRT plus OSC, which required 534 patients (80% power, 5% [one-sided] significance level). Analysis was done by intention to treat for all randomly assigned patients. The trial is registered with ISRCTN, number ISRCTN3826061.

FINDINGS

Between March 2, 2007, and Aug 29, 2014, 538 patients were recruited from 69 UK and three Australian centres, and were randomly assigned to receive either OSC plus WBRT (269) or OSC alone (269). Baseline characteristics were balanced between groups, and the median age of participants was 66 years (range 38-85). Significantly more episodes of drowsiness, hair loss, nausea, and dry or itchy scalp were reported while patients were receiving WBRT, although there was no evidence of a difference in the rate of serious adverse events between the two groups. There was no evidence of a difference in overall survival (hazard ratio 1·06, 95% CI 0·90-1·26), overall quality of life, or dexamethasone use between the two groups. The difference between the mean QALYs was 4·7 days (46·4 QALY days for the OSC plus WBRT group vs 41·7 QALY days for the OSC group), with two-sided 90% CI of -12·7 to 3·3.

INTERPRETATION

Although the primary outcome measure result includes the prespecified non-inferiority margin, the combination of the small difference in QALYs and the absence of a difference in survival and quality of life between the two groups suggests that WBRT provides little additional clinically significant benefit for this patient group.

FUNDING

Cancer Research UK, Medical Research Council Clinical Trials Unit at University College London, and the National Health and Medical Research Council in Australia.

Treatment of single or multiple brain metastases by hypofractionated stereotactic radiotherapy using helical tomotherapy

This study investigated the clinical outcomes of a 4-fraction stereotactic radiotherapy (SRT) study using helical tomotherapy for brain metastases. Between August 2009 and June 2013, 54 patients with a total of 128 brain metastases underwent SRT using tomotherapy. A total dose of 28 or 28.8 Gy at 80% isodose was administered in 4 fractions for all tumors. The mean gross tumor volume (GTV) was 1.9 cc. Local control (LC) rates at 6, 12, and 18 months were 96%, 91%, and 88%, respectively. The 12-month LC rates for tumors with GTV ≤0.25, >0.25 and ≤1, and >1 cc were 98%, 82%, and 93%, respectively; the rates were 92% for tumors >3 cc and 100% for >10 cc. The 6-month rates for freedom from distant brain failure were 57%, 71%, and 55% for patients with 1, 2, and >3 brain metastases, respectively. No differences were significant. No major complications were observed. The 4-fraction SRT protocol provided excellent tumor control with minimal toxicity. Distant brain failure was not so frequent, even in patients with multiple tumors. The results of the current study warrant a prospective randomized study comparing single-fraction stereotactic radiosurgery (SRS) with SRT in this patient population.

Chemotherapy for brain metastases from small cell lung cancer

BACKGROUND

Small cell lung cancer (SCLC) accounts for approximately 20% of all cases of lung cancer. It tends to disseminate early in the course of its natural history and to grow quickly. Approximately 10% to 18% of patients present with brain metastases (BM) at the time of initial diagnosis, and an additional 40% to 50% will develop BM some time during the course of their disease.

OBJECTIVES

The aim of this review was to evaluate the effectiveness and toxicity of systemic chemotherapy for the treatment of BM from SCLC.

SEARCH METHODS

We searched the Cochrane Lung Cancer Review Group Specialised Register (July 2011), CENTRAL (2011, Issue 5), PubMed (1966 to July 2011), EMBASE (2005 to July 2011), LILACS (1982 to July 2011) and the International Clinical Trial Registry Platform (ICTRP).

SELECTION CRITERIA

Randomized controlled trials (RCTs) comparing systemic chemotherapy (single agent or combination chemotherapy) with another chemotherapy regimen, palliative care, whole brain radiotherapy or any combination of these interventions for the treatment of BM as the only site of progression.

DATA COLLECTION AND ANALYSIS

Data extraction and 'Risk of bias' assessment were carried out independently by two review authors. As the included studies evaluated three different treatment modalities meta-analysis was not possible.

MAIN RESULTS

Three RCTs, involving 192 participants, met inclusion criteria for this review. No significant differences for overall survival (OS) were reported in any of the trials: in the first trial, 33 patients received whole brain radiation therapy and no significant difference was found between patients treated with topotecan and those not treated with topotecan. In a second trial, in which 120 patients were randomized to receive teniposide with or without brain radiation therapy, the authors reported that the median progression-free survival (brain-specific progression-free survival (PFS)) was 3.5 months in the combined modality arm and 3.2 in the teniposide alone arm. In a third trial, comparing sequential and concomitant chemoradiotherapy (teniposide plus cisplatin) in 39 participants, the survival difference between the two groups was not statistically significant. While the first trial reported no significant difference in PFS, the second RCT found a significant difference favoring combined therapy group. The second trial also found that patients receiving chemoradiotherapy (teniposide plus whole brain radiotherapy) had a higher complete response rate than those receiving only the topoisomerase inhibitor.

AUTHORS' CONCLUSIONS

Given the paucity of robust studies assessing the clinical effects of treatments, available evidence is insufficient to judge the effectiveness and safety of chemotherapy for the treatment of BM from SCLC. Published studies are insufficient to address the objectives of this review. According to the available evidence included in this review, chemotherapy does not improve specific brain PFS and OS in patients with SCLC. The combined treatment of teniposide and brain radiation therapy contributed to outcome in terms of increased complete remission and shorter time to progression (though not OS).

Predicting compliance and survival in palliative whole-brain radiotherapy for brain metastases

OBJECTIVE

Brain radiotherapy is the main treatment for patients with brain metastases but its goal is just symptom control. Our aim was to study if different performance tools, used in geriatric practice, could improve patient selection for decision-making in the palliative brain radiotherapy setting.

PATIENTS AND METHODS

Data from 61 consecutive patients were analysed. In addition to Karnofsky Performance Status (KPS) their physical activity was assessed by means of the activity of daily living (ADL) and instrumental ADL (IADL) scales. A neurocognitive evaluation was performed with the Pfeiffer Short Portable Mental Status Questionnaire (SPMSQ) and with the Mini-Mental Status Exam (MMSE). Radiotherapy compliance and short survival were the endpoints of the study.

RESULTS

High rates of cognitive impairment were found by both neurocognitive tools (Pfeiffer: 19.7% of patients; MMSE: 30%). Dependence was also highly prevalent, either measured by the ADL (50.8%) or by the IADL (43.3%). Nearly one third (27.9%) of patients died soon after radiotherapy evaluation. Longer survival was related to female, younger than 60 years, breast cancer primary tumour, steroid response, RPA class, and higher performance and neurocognitive score tools. A premature death was associated with neurocognitive tools, IADL and longer interval from brain metastatic diagnosis to radiotherapy. Twenty-three percent of patients were not able to finish the WBRT course due to clinical deterioration. The only variable related to compliance was a low MMSE score.

CONCLUSIONS

Results suggest that the geriatric tools analysed could offer information on brain palliative radiotherapy complementary to that offered by the more usual tools. It will be interesting to study if our data could be extrapolated to the general palliative oncological field.

Surgical brain metastases: management and outcome related to prognostic indexes: a critical review of a ten-year series

Brain metastasis are the most common neoplastic lesions of the nervous system. Many cancer patients are diagnosed on the basis of a first clinical presentation of cancer on the basis of a single or multiple brain lesions. Brain metastases are manifestations of primary disease progression and often determine a poor prognosis. Not all patients with a brain metastases undergo surgery: many are submitted to alternative or palliative treatments. Management of patients with brain metastases is still controversial, and many studies have been developed to determine which is the best therapy. Furthermore, management of patients operated for a brain metastasis is often difficult. Chemotherapy, stereotactic radiosurgery, panencephalic radiation therapy, and surgery, in combination or alone, are the means most commonly used. We report our experience in the management of a ten-year series of surgical brain metastasis and discuss our results in the preoperative and postoperative management of this complex condition.

Increases in the number of brain metastases detected at frame-fixed, thin-slice MRI for gamma knife surgery planning

For gamma knife planning, 2.4-mm-slice MRIs are taken under rigid frame fixation, so tiny tumors become visible. This study evaluated differences in the numbers of brain metastases between conventional contrast-enhanced MRI (6 ± 1 mm slice thickness) taken before patient referral and contrast-enhanced MRI for gamma knife planning. The numbers of metastases on the 2 images were counted by at least 2 oncologists. For gamma knife planning, spoiled gradient-recalled echo images were obtained after 0.1 mmol/kg gadolinium administration using a 1.5-T system. Images from 1045 patients with an interval between the 2 MRI studies of 6 weeks or less were analyzed. Increases in the number of metastases were found in 33.7% of the 1045 patients, whereas the number was identical in 62.3%. In 4.0%, the number decreased, indicating overdiagnosis at conventional MRI. These proportions did not differ significantly by the interval before gamma knife. An increase from single to multiple metastases was found in 16.0%. Meningeal dissemination was newly diagnosed in 2.3%. On planning images, the proportions of patients with 1, 2, 3, and 4 or more lesions were 37.6%, 19.3%, 9.3%, and 33.8%, respectively. In cases of colorectal cancer and hepatoma, the proportions of patients with a single metastasis (32 of 61 [52%] and 5 of 6 [83%], respectively) were higher than that of patients with other malignancies. In about one-third of the patients, an increased number of metastases were found on the thin-slice images. This should be kept in mind when deciding the treatment strategy for brain metastases.

Clinical analysis of patients who survived for less than 3 months after brain metastatectomy

In the patients with brain metastasis (BM), it is impossible to determine who will benefit from surgery because of limited survival. In an attempt to identify optimal candidates for brain metastatectomy, we analyzed patients who survived for <3 months after craniotomy for a single BM lesion. Between January 1st, 1997 and July 31st, 2007, 83 patients with a single BM underwent craniotomy. Of these patients, 25 patients (30.1%) died within 3 months of craniotomy. The primary lesions were non-small call lung cancer in 15, colon cancer in 6, and breast cancer, renal cell carcinoma, ovarian cancer, or esophageal cancer in one apiece. Of the 25 patients, 19 (79%) were of tumor stage IV and had extra-cranial metastasis. Eleven (44%) of the 25 primary cancers had a well-controlled status. Twelve patients (48%) had a Karnofsky Performance Scale (KPS) score of <70, and 13 (52%) were of Recursive Partitioning Analysis (RPA) class 3. Primary cancer status, RPA class, and functional status were found to be critical factors for consideration when selecting surgical candidates. In addition, adjuvant therapy was found to have an important role on survival.

Reduced local recurrence of a single brain metastasis through microscopic total resection

OBJECT

The goal of this study was to evaluate the therapeutic impact of the resection of metastatic brain tumor cells infiltrating adjacent brain parenchyma.

METHODS

Between July 2001 and February 2007, 94 patients (67 males and 27 females, with a mean age of 55.0 +/-12.0 years) underwent resection of a single brain metastasis, followed by systemic chemotherapy with or without radiotherapy. In 43 patients with tumors located in noneloquent areas, the authors performed microscopic total resections (MTRs) that included tumor cells infiltrating adjacent brain parenchyma, and they pathologically confirmed during surgery that the resection margins were free of tumor cells (MTR group). In 51 patients with lesions in eloquent locations, gross-total resections (GTRs) were performed without the removal of neighboring brain parenchyma (GTR group). The 2 groups were then compared for local recurrence and survival.

RESULTS

The MTR group had better local control of the tumor than did the GTR group; 10 (23.3%) of 43 patients in the MTR group and 22 (43.1%) of 51 patients in the GTR group had a local recurrence (p = 0.04). The median time to tumor progression in the MTR group could not be calculated using the Kaplan-Meier method, whereas it was 11.4 months in the GTR group. The 1- and 2-year respective local recurrence rates were 29.1 and 29.1% in the MTR group and 58.6 and 63.2% in the GTR group (p = 0.01). Multivariate analysis showed that the MTR procedure was associated with a decreased risk of local recurrence (p = 0.003). A Cox regression analysis revealed that the hazard ratio for a local recurrence in the MTR group versus the GTR group was 3.14 (95% CI 1.47-6.72, p = 0.003). There was no significant difference in the local recurrence rate between the MTR group without radiotherapy (10 [30.3%] of 33) and the GTR group with postoperative radiotherapy (5 [26.3%] of 19).

CONCLUSIONS

The results in this study suggest that MTRs including tumor cells infiltrating adjacent brain parenchyma for a single brain metastasis provide better local tumor control.

Brain metastases: current management and new developments

PURPOSE OF REVIEW

To review the state-of-the-art and new developments in the management of patients with brain metastases.

RECENT FINDINGS

Treatment decisions are based on prognostic factors to maximize neurologic function and survival, while avoiding unnecessary therapies. Whole-brain radiotherapy (WBRT) is the treatment of choice for patients with unfavorable prognostic factors. Stereotactic radiosurgery (SRS) or surgery is indicated for patients with favorable prognostic factors and limited brain disease. In single brain metastasis, the addition of either stereotactic radiosurgery or surgery to WBRT improves survival. The omission of WBRT after surgery or radiosurgery results in a worse local and distant control, though it does not affect survival. The incidence of neurocognitive deficits in long-term survivors after WBRT remains to be defined. New approaches to avoid cognitive deficits following WBRT are being investigated. The role of chemotherapy is limited. Molecularly targeted therapies are increasingly employed. Prophylaxis with WBRT is the standard in small-cell lung cancer.

SUMMARY

Many questions need future trials: the usefulness of new radiosensitizers; the role of local treatments after surgery; and the impact of molecularly targeted therapies on subgroups of patients with specific molecular profiles. Quality of life and cognitive functions are recognized as major endpoints in clinical trials.

Detection of brain metastases from small cell lung cancer: consequences of changing imaging techniques (CT versus MRI)

BACKGROUND

The aims of this study were to show 1) the effect of changing from computed tomography (CT) to magnetic resonance imaging (MRI) on the prevalence of detected brain metastases (BM) in patients with newly diagnosed small cell lung cancer (SCLC); 2) the difference in survival between patients with single and multiple BM; and 3) the effect of the change in patient labeling on eligibility for prophylactic brain irradiation.

METHODS

From 1980 to 2004, 481 consecutive patients with SCLC were enrolled. Brain imaging was routinely performed after diagnosis of SCLC. At the start of 1991, MRI replaced CT in almost all patients. All patients were regularly examined by a neurologist.

RESULTS

The prevalence of detected BM was 10% in the CT era and 24% in the MRI era. In the CT era, all detected BM were symptomatic, whereas in the MRI era, 11% were asymptomatic. In both periods, patients labeled as single BM survived longer than those labeled as multiple BM. For patients labeled as single BM or multiple BM, survival was longer in the MRI era than in the CT era. The proportion of patients who were eligible for prophylactic cranial irradiation was lower in the MRI era.

CONCLUSIONS

The estimated prevalence of BM increases when MRI is used instead of CT. Patients with a detected single BM survive longer than patients with multiple BM. The apparently increased survival in the MRI era can be attributed to the "Will Rogers phenomenon". The use of MRI makes fewer patients eligible for prophylactic cranial irradiation.

Chemotherapy and targeted molecular therapies for brain metastases

As therapy for systemic cancers improves, an increasing number of patients are developing brain metastases. Although conventional therapy with surgery, radiation therapy and radiosurgery has improved the outcome of a significant number of patients, many develop multiple lesions that are not amenable to standard treatments. In this review, the current role of chemotherapy and targeted molecular agents for brain metastases is summarized and future directions are discussed.

EFNS Guidelines on diagnosis and treatment of brain metastases: report of an EFNS Task Force

The objectives have been to establish evidence-based guidelines and identify controversies regarding the management of patients with brain metastases. The collection of scientific data was obtained by consulting the Cochrane Library, bibliographic databases, overview papers and previous guidelines from scientific societies and organizations. A tissue diagnosis is necessary when the primary tumor is unknown or the aspect on computed tomography/magnetic resonance imaging is atypical. Dexamethasone is the corticosteroid of choice for cerebral edema. Anticonvulsants should not be prescribed prophylactically. Surgery should be considered in patients with up to three brain metastases, being effective in prolonging survival when the systemic disease is absent/controlled and the performance status is high. Stereotactic radiosurgery should be considered in patients with metastases of 3-3.5 cm of maximum diameter. Whole-brain radiotherapy (WBRT) after surgery or radiosurgery is debated: in case of absent/controlled systemic cancer and Karnofsky Performance score of 70 or more, one can either withhold initial WBRT or deliver early WBRT with conventional fractionation to avoid late neurotoxicity. WBRT alone is the treatment of choice for patients with single or multiple brain metastases not amenable to surgery or radiosurgery. Chemotherapy may be the initial treatment for patients with brain metastases from chemosensitive tumors.