Brain metastasis and treatment

Assessment of Radiation Dosage to the Hippocampi during Treatment of Multiple Brain Metastases Using Gamma Knife Therapy

Background and Objectives: Brain metastases (BMs) pose significant clinical challenges in systemic cancer patients. They often cause symptoms related to brain compression and are typically managed with multimodal therapies, such as surgery, chemotherapy, whole brain radiotherapy (WBRT), and stereotactic radiosurgery (SRS). With modern oncology treatments prolonging survival, concerns about the neurocognitive side effects of BM treatments are growing. WBRT, though widely used for multiple BMs, has recognized neurocognitive toxicity. SRS, particularly Gamma Knife (GK) therapy, offers a minimally invasive alternative with fewer side effects, suitable for patients with a quantifiable number of metastases and better prognoses. Materials and Methods: A retrospective analysis was conducted on 94 patients with multiple BMs treated exclusively with GK at an academic medical center. Patients with prior WBRT were excluded. This study focused on the mean radiation dose received by the hippocampal area, estimated according to the 'Hippocampal Contouring: A Contouring Atlas for RTOG 0933' guidelines. Results: The precision of GK equipment results in mean doses of radiation that are lower than those suggested by RTOG 0933 and observed in other studies. This precision may help mitigate cognitive dysfunction and other side effects of hippocampal irradiation. Conclusions: GK therapy facilitates the administration of smaller, safer radiation doses to the hippocampi, which is advantageous even for lesions in the temporal lobe. It is feasible to treat multiple metastases, including cases with more than 10, but it is typically reserved for patients with fewer metastases, with an average of 3 in this study. This underlines GK's potential for reducing adverse effects while managing BMs effectively.

Efficacy of memantine in preventing neurocognitive dysfunction induced by radiation therapy in patients with brain metastases: A systematic review of clinical trials

PURPOSE

About 50%-90% of patients with brain metastases who receive radiation therapy experience cognitive impairment. This systematic review aims to gather credible sources of comprehensive information on the efficacy of memantine in preventing cognitive dysfunction.

METHODS

A comprehensive review conducted in compliance with the PRISMA statement and systematic search was performed across five databases included PubMedⓇ, EmbaseⓇ, ScopusⓇ, Cochrane LibraryⓇ, and ClinicalTrial.gov.in from inception until November 2021.

RESULTS

A total of four eligible studies were selected in this review that included 1,444 patients with brain metastases who received radiation therapy (Intervention group [n = 729] and control group [n = 715]). Overall, three of the four studies reported some improvement in neurocognitive function in at least one or more parameters such as recall and recognition (P = .39, P = .10 and P = .05), verbal fluency (P = .03 and P < .0001), complex attention (P = .59) executive function (P = .92) and normal appearing white matter (P = .01) following memantine therapy compared to control group. Further, two of the four studies reported an improvement in the patients' quality of life following memantine therapy compared to the control group, and there was no significant difference in the toxicity profile of the interventional compared to the control group as reported from two studies.

CONCLUSION

This review embraces the comprehensive evidence that the use of memantine therapy in patients with brain metastases to prevent radiation-induced neurocognitive dysfunction has a modest and statistically significant beneficial impact in improving quality of life and preserving some neurocognitive function without any complications. Pending the completion of additional ongoing studies, one can argue that memantine is a reasonable treatment to consider in patients with brain metastases while they receive whole brain radiation therapy.

Direct Evaluation of Treatment Response in Brain Metastatic Disease with Deep Neuroevolution

Cancer centers have an urgent and unmet clinical and research need for AI that can guide patient management. A core component of advancing cancer treatment research is assessing response to therapy. Doing so by hand, for example, as per RECIST or RANO criteria, is tedious and time-consuming, and can miss important tumor response information. Most notably, the prevalent response criteria often exclude lesions, the non-target lesions, altogether. We wish to assess change in a holistic fashion that includes all lesions, obtaining simple, informative, and automated assessments of tumor progression or regression. Because genetic sub-types of cancer can be fairly specific and patient enrollment in therapy trials is often limited in number and accrual rate, we wish to make response assessments with small training sets. Deep neuroevolution (DNE) is a novel radiology artificial intelligence (AI) optimization approach that performs well on small training sets. Here, we use a DNE parameter search to optimize a convolutional neural network (CNN) that predicts progression versus regression of metastatic brain disease. We analyzed 50 pairs of MRI contrast-enhanced images as our training set. Half of these pairs, separated in time, qualified as disease progression, while the other 25 image pairs constituted regression. We trained the parameters of a CNN via "mutations" that consisted of random CNN weight adjustments and evaluated mutation "fitness" as summed training set accuracy. We then incorporated the best mutations into the next generation's CNN, repeating this process for approximately 50,000 generations. We applied the CNNs to our training set, as well as a separate testing set with the same class balance of 25 progression and 25 regression cases. DNE achieved monotonic convergence to 100% training set accuracy. DNE also converged monotonically to 100% testing set accuracy. We have thus shown that DNE can accurately classify brain metastatic disease progression versus regression. Future work will extend the input from 2D image slices to full 3D volumes, and include the category of "no change." We believe that an approach such as ours can ultimately provide a useful and informative complement to RANO/RECIST assessment and volumetric AI analysis.

Breakouts-A Radiological Sign of Poor Prognosis in Patients With Brain Metastases

Purpose

Brain metastases (BM) can present a displacing or infiltrating growth pattern, independent of the primary tumor type. Previous studies have shown that tumor cell infiltration at the macro-metastasis/brain parenchyma interface (MMPI) is correlated with poor outcome. Therefore, a pre-therapeutic, non-invasive detection tool for potential metastatic cell infiltration at the MMPI would be desirable to help identify patients who may benefit from a more aggressive local treatment strategy. The aim of this study was to identify specific magnetic resonance imaging (MRI) patterns at the MMPI in patients with BM and to correlate these patterns with patient outcome.

Patients and Methods

In this retrospective analysis of a prospective BM registry, we categorized preoperative MR images of 261 patients with BM according to a prespecified analysis system, which consisted of four MRI contrast enhancement (CE) patterns: two with apparently regularly shaped borders (termed “rim-enhancing” and “spherical”) and two with irregular delineation (termed “breakout” and “diffuse”). The primary outcome parameter was overall survival (OS). Additionally analyzed prognostic parameters were the Karnofsky Performance Index, tumor size, edema formation, extent of resection, and RPA class.

Results

OS of patients with a breakout pattern was significantly worse than OS of all other groups.

Conclusion

Our data show that BM with a breakout pattern have a highly aggressive clinical course. Patients with such a pattern potentially require a more aggressive local and systemic treatment strategy.

The structure of blood-tumor barrier and distribution of chemotherapeutic drugs in non-small cell lung cancer brain metastases

Background

Brain metastasis is an important cause of increased mortality in patients with non-small cell lung cancer (NSCLC). In brain metastasis, the blood–brain barrier (BBB) is frequently impaired, forming blood–tumor barrier (BTB). The efficacy of chemotherapy is usually very poor. However, the characteristics of BTB and the impacts of BTB on chemotherapeutic drug delivery remain unclear. The present study investigated the structure of BTB, as well as the distribution of routine clinical chemotherapeutic drugs in both brain and peripheral tumors.

Methods

Bioluminescent image was used to monitor the tumor load after intracranial injection of lung cancer Lewis cells in mice. The permeability of BBB and BTB was measured by fluorescent tracers of evans blue and fluorescein sodium. Transmission electron microscopy (TEM), immunohistochemistry and immunofluorescence were performed to analyze structural differences between BBB and BTB. The concentrations of chemotherapeutic drugs (gemcitabine, paclitaxel and pemetrexed) in tissues were assayed by liquid chromatography with tandem mass spectrometry (LC-MS/MS).

Results

Brain metastases exhibited increased BTB permeability compared with normal BBB detected by fluorescence tracers. TEM showed abnormal blood vessels, damaged endothelial cells, thick basement membranes, impaired intercellular endothelial tight junctions, as well as increased fenestrae and pinocytotic vesicles in metastatic lesions. Immunohistochemistry and immunofluorescence revealed that astrocytes were distributed surrounded the blood vessels both in normal brain and the tumor border, but no astrocytes were found in the inner metastatic lesions. By LC-MS/MS analysis, gemcitabine showed higher permeability in brain metastases.

Conclusions

Brain metastases of lung cancer disrupted the structure of BBB, and this disruption was heterogeneous. Chemotherapeutic drugs can cross the BTB of brain metastases of lung cancer but have difficulty crossing the normal BBB. Among the three commonly used chemotherapy drugs, gemcitabine has the highest distribution in brain metastases. The permeability of chemotherapeutic agents is related to their molecular weight and liposolubility.

Health-related quality of life after Gamma Knife radiosurgery in patients with 1-10 brain metastases

PURPOSE

Increasingly more patients with multiple (> 4) brain metastases (BM) are being treated with stereotactic radiosurgery (SRS). Preserving patients' health-related quality of life (HRQoL) is an important treatment goal. The aim of this study was to assess (individual) changes in HRQoL in patients with 1-10 BM over time.

METHODS

A total of 92 patients were assessed before (n = 92) and at 3 (n = 66), 6 (n = 53), and 9 (n = 41) months after Gamma Knife radiosurgery (GKRS), using the Functional Assessment of Cancer Therapy-Brain (FACT-Br). The course of HRQoL was analyzed using linear mixed models. Clinical minimally important differences were used to evaluate individual changes.

RESULTS

At group level, patients' physical well-being worsened, whereas emotional well-being improved over 9 months. Scores on other HRQoL subscales did not change significantly. Number (1-3 versus 4-10) and volume (small, medium, and large) of BM did not influence HRQoL over time, except for the subscale additional concerns; medium intracranial tumor volume was associated with less additional concerns. On the individual level as well, physical well-being declined while emotional well-being improved in most patients over 9 months after GKRS. At patient level, however, most patients had both declines as well as improvements in the different HRQoL aspects.

CONCLUSION

Our results indicate that even in patients with up to 10 BM, both at group and individual subscale level, aspects of HRQoL remained stable over nine months after GKRS, except for an improvement in emotional well-being and a decline in physical well-being. Nevertheless, HRQoL scores varied considerably at the individual patient level.

TRAIL REGISTRATION NUMBER

ClinicalTrials.gov Identifier: NCT02953756, November 3, 2016.

Survival benefit from immunocheckpoint inhibitors in stage IV non-small cell lung cancer patients with brain metastases: A National Cancer Database propensity-matched analysis

Immunocheckpoint inhibitors (ICIs) have become a standard pharmacological therapy in non‐small cell lung cancer (NSCLC). Because brain metastases (BMs) have historically been listed as exclusion criteria in previous clinical trials involving ICIs in advanced NSCLC, the survival benefit from ICI in NSCLC patients with BMs remains unclear. The National Cancer Database was queried for stage IV NSCLC patients with or without BMs between 2014 and 2015. Overall survival (OS) of stage IV NSCLC patients who received immunotherapy and that of stage IV NSCLC patients who did not receive immunotherapy were compared according to the presence or absence of BMs. Multivariable logistic analyses identified the clinical characteristics predictive of overall survival. A propensity score analysis was conducted with the aim of adjusting the potential biases arising from the clinical characteristics. This study included 42,512 patients with stage IV NSCLC; 11,810 patients with BMs and 30,702 patients without BMs. In univariate analysis, stage IV NSCLC patients with BMs treated with immunotherapy had a significantly longer OS than those without immunotherapy after propensity score matching (median OS: 12.8 vs 10.1 months, hazard ratio [HR]: 0.80, 95% confidence interval [CI]: 0.72–0.89, p < 0.0001). Multivariable Cox modeling after propensity score matching confirmed the survival benefit from ICI for stage IV NSCLC patients with BMs (HR: 0.75, 95% CI: 0.67–0.83, p < 0.0001). The HR in NSCLC patients without BMs treated with ICI compared with those without ICI was 0.77 (95% CI: 0.73–0.82, p < 0.0001). Survival in stage IV NSCLC patients with BMs was significantly improved by ICI treatment at levels comparable to those without BMs using a retrospective database. ICI may be one of the promising treatment options for stage IV NSCLC patients with BMs. These findings should be validated in future prospective studies.

Identification of the origin of brain metastases based on the relative methylation orderings of CpG sites

Accurate diagnosis of the origin of brain metastases (BMs) is crucial for tailoring an effective therapy to improve patients' prognosis. BMs of unknown origin account for approximately 2-14% of patients with BMs. Hence, the aim of this study was to identify the original cancer type of BMs based on their DNA methylation profiles. The DNA methylation profiles of glioma (GM), BM, and seven other types of primary cancers were collected. In comparison with GM, the reversal CpG site pairs were identified for each of the seven other types of primary cancers based on the within-sample relative methylation orderings (RMOs) of the CpG sites. Then, using the reversal CpG site pairs, GMs were distinguished from BMs and the seven other types of primary cancers. All 61 of the GM samples were correctly identified as GM. The cancer type was also identified for the non-GM samples. For the seven other types of primary cancers, greater than 93% of samples of each cancer type were correctly identified as their corresponding cancer type, except for breast cancer, which had an 88% accuracy. For 133 BM samples, 132 BM samples were identified as non-GM, and 95% of the 133 BM samples were correctly classified into their corresponding original cancer types. The RMO-based method can accurately identify the origin of BMs, which is important for precision treatment.

Association of Immunotherapy With Survival Among Patients With Brain Metastases Whose Cancer Was Managed With Definitive Surgery of the Primary Tumor

IMPORTANCE

Immunotherapy has shown significant control of intracranial metastases in patients with melanoma. However, the association of immunotherapy combined with other cancer treatments and overall survival (OS) of patients with brain metastases, regardless of primary tumor site, is unknown.

OBJECTIVE

To explore the association of immunotherapy with OS in patients with cancer and brain metastases who received definitive surgery of the primary site.

DESIGN, SETTING, AND PARTICIPANTS

This comparative effectiveness study included 3112 adult patients in the National Cancer Database from 2010 to 2016 with non-small cell lung cancer, breast cancer, melanoma, colorectal cancer, or kidney cancer and brain metastases at the time of diagnosis and who received definitive surgery of the primary site. Data analysis was conducted from March to April 2020.

EXPOSURES

Treatment groups were stratified as follows: (1) any treatment with or without immunotherapy, (2) chemotherapy with or without immunotherapy, (3) radiotherapy (RT) with or without immunotherapy, and (4) chemoradiation with or without immunotherapy.

MAIN OUTCOMES AND MEASURES

The association of immunotherapy with OS was assessed with Cox proportional hazards regression, adjusted for age at diagnosis, race, sex, place of living, income, education, treatment facility type, primary tumor type, and year of diagnosis.

RESULTS

Of 3112 patients, 1436 (46.14%) were men, 2714 (87.72%) were White individuals, 257 (8.31%) were Black individuals, and 123 (3.98%) belonged to other racial and ethnic groups. The median (range) age at diagnosis was 61 (19-90) years. Overall, 183 (5.88%) received immunotherapy, 318 (10.22%) received chemotherapy alone, 788 (25.32%) received RT alone, and 1393 (44.76%) received chemoradiation alone; 22 (6.47%) received chemotherapy plus immunotherapy, 72 (8.37%) received RT plus immunotherapy, and 76 (5.17%) received chemoradiation plus immunotherapy. In the multivariable analysis, patients who received immunotherapy had significantly improved OS compared with no immunotherapy (hazard ratio, 0.62; 95% CI, 0.51-0.76; P < .001). Treatment with RT plus immunotherapy was associated with significantly improved OS compared with RT alone (hazard ratio, 0.59; 95% CI, 0.42-0.84; P = .003). Chemotherapy plus immunotherapy or chemoradiation plus immunotherapy were not associated with improved OS in the multivariable analysis.

CONCLUSIONS AND RELEVANCE

In this study, the addition of immunotherapy to RT was associated with improved OS compared with radiotherapy alone in patients with brain metastases who received definitive surgery of the primary tumor site.

The primary sites leading to brain metastases: Shifting trends at a tertiary care center

While the majority of brain metastases arise from lung cancer, breast cancer, or melanoma, new treatments and improved prognoses have altered the profile of primary cancers that metastasize to the brain. We sought to determine the proportion of brain metastases from less common primary sites and conduct trend analyses. We reviewed the charts of 3585 patients with brain metastases seen at our institution from 2008 to 2018. We determined the primary site for each of these patients, and the Mann-Kendall test was used to evaluate temporal trends in the yearly proportion of brain metastases originating from each primary cancer. The five most common primary sites were lung (43.0%), breast (19.9%), melanoma (8.2%), renal (5.0%), and colorectal (3.8%). The proportion of yearly brain metastases originating from breast cancer (p = 0.029) and melanoma (p = 0.013) decreased by 23.8% and 46.7%, respectively, from 2008 (0.21 breast, 0.15 melanoma) to 2018 (0.16 breast, 0.08 melanoma), while no change was found in the proportion of brain metastases from lung, renal, and colorectal cancers. Brain metastases arising from rare primary sites, defined as those comprising at most 2% of all brain metastases, increased by 34.4% (p = 0.005). Limited sample size prohibited trend analysis of other individual primary sites. We report a decrease over 11 years in the proportion of brain metastases originating from breast cancer and melanoma at our institution, and an increase in brain metastases from rare primary sites. Further work with larger, multi-center databases will enable additional evaluation of brain metastases from rare primary sites.

Impact of Immunotherapy on the Survival of Patients With Cancer and Brain Metastases

Background: Immunotherapy has shown excellent efficacy in various cancers. However, there is a lack of knowledge regarding the significant role of immunotherapy in patients with brain metastases (BMs). The objective of this study was to investigate, using the National Cancer Database, the impact of immunotherapy on the overall survival (OS) of patients with BMs who did not receive definitive surgery of the primary tumor. Patients and Methods: Patients diagnosed with the primary cancer of non–small cell lung cancer, small cell lung cancer, other types of lung cancer, breast cancer, melanoma, colorectal cancer, or renal cancer who had BMs at the time of diagnosis were identified from the National Cancer Database. We assessed OS using a Cox proportional hazards model adjusted for age at diagnosis, sex, race, education level, income level, residential area, treatment facility type, insurance status, Charlson-Deyo comorbidity status, year of diagnosis, primary tumor type, and receipt of chemotherapy, radiation therapy (RT), and/or immunotherapy, because these factors were significantly associated with OS in the univariable analysis. Results: Of 94,215 patients who were analyzed, 3,097 (3.29%) received immunotherapy. In the multivariable analysis, immunotherapy was associated with significantly improved OS (hazard ratio [HR], 0.694; 95% CI, 0.664–0.726; P<.0001) compared with no immunotherapy. Treatment using chemotherapy plus immunotherapy was significantly associated with improved OS (HR, 0.643; 95% CI, 0.560–0.738; P<.0001) compared with chemotherapy without immunotherapy. RT plus immunotherapy was also associated with significantly improved OS (HR, 0.389; 95% CI, 0.352–0.429; P<.0001) compared with RT alone. Furthermore, chemoradiation (CRT) plus immunotherapy was associated with significantly improved OS (HR, 0.793; 95% CI, 0.752–0.836; P<.0001) compared with CRT alone. Conclusions: In this comprehensive analysis, the addition of immunotherapy to chemotherapy, RT, and CRT was associated with significantly improved OS in patients with BMs. The study warrants future clinical trials of immunotherapy in patients with BMs, who have historically been excluded from these trials.

Evaluating Magnetic Resonance Spectroscopy as a Tool for Monitoring Therapeutic Response of Whole Brain Radiotherapy in a Mouse Model for Breast-to-Brain Metastasis

Brain metastases are the most common intracranial tumor in adults and are associated with poor patient prognosis and median survival of only a few months. Treatment options for brain metastasis patients remain limited and largely depend on surgical resection, radio- and/or chemotherapy. The development and pre-clinical testing of novel therapeutic strategies require reliable experimental models and diagnostic tools that closely mimic technologies that are used in the clinic and reflect histopathological and biochemical changes that distinguish tumor progression from therapeutic response. In this study, we sought to test the applicability of magnetic resonance (MR) spectroscopy in combination with MR imaging to closely monitor therapeutic efficacy in a breast-to-brain metastasis model. Given the importance of radiotherapy as the standard of care for the majority of brain metastases patients, we chose to monitor the post-irradiation response by magnetic resonance spectroscopy (MRS) in combination with MR imaging (MRI) using a 7 Tesla small animal scanner. Radiation was applied as whole brain radiotherapy (WBRT) using the image-guided Small Animal Radiation Research Platform (SARRP). Here we describe alterations in different metabolites, including creatine and N-acetylaspartate, that are characteristic for brain metastases progression and lactate, which indicates hypoxia, while choline levels remained stable. Radiotherapy resulted in normalization of metabolite levels indicating tumor stasis or regression in response to treatment. Our data indicate that the use of MR spectroscopy in addition to MRI represents a valuable tool to closely monitor not only volumetrical but also metabolic changes during tumor progression and to evaluate therapeutic efficacy of intervention strategies. Adapting the analytical technology in brain metastasis models to those used in clinical settings will increase the translational significance of experimental evaluation and thus contribute to the advancement of pre-clinical assessment of novel therapeutic strategies to improve treatment options for brain metastases patients.

Significance of BRCA1 expression in breast and ovarian cancer patients with brain metastasis - A multicentre study

PURPOSE

Cerebral metastases develop in 10-30% of patients with breast cancer (BC) and in around 3.3 to 4% of patients with ovarian cancer (OC). The aim of the multicenter study is to investigate the correlation between the expression of estrogen alpha receptors (ERα), progesterone receptors (PR), human epidermal growth factor receptor 2 (HER2), stromal cell-derived factor 1 (SDF1) and its receptor C-X-C chemokine receptor type 4 (CXCR4), breast cancer metastasis suppressor 1 (BRMS1), astrocyte elevated gene 1 (AEG1), depending on the status of BRCA1 protein, in patients suffering from OC and BC with brain metastases.

PATIENTS AND METHODS

The analysis included 51 patients: 29 with BC and 22 with OC, in whom brain metastases were disclosed.

RESULTS

In most patients (65.5% of BC patients and 68.2% of patients with OC tumors) BRCA1 protein loss was found. No correlation was disclosed between the levels of ERα, PR receptors, HER2, SDF1, CXCR4, AEG1, BRMS1 and BRCA1 status, patient age, stage of disease advancement, grade of histological maturity of the cells, presence of metastases to lymph nodes. A statistically significant correlation was disclosed between the negative expression of PR receptors and a high expression of CXCR4 in patients with BC. High values of the AEG1 protein (linked to metastases) were detected alongside a high expression of BRMS1 (a suppressor of metastases).

CONCLUSIONS

Patients with BC and OC and brain metastases have a frequent loss of BRCA1 expression. The role of ERα, PR, HER2, SDF1, CXCR4, AEG1, BRMS1 in metastatic process needs further studies.

Turning "Cold" Into "Hot" Tumors-Opportunities and Challenges for Radio-Immunotherapy Against Primary and Metastatic Brain Cancers

The development of immunotherapies has revolutionized intervention strategies for a variety of primary cancers. Despite this promising progress, treatment options for primary brain cancer and brain metastasis remain limited and still largely depend on surgical resection, radio- and/or chemotherapy. The paucity in the successful development of immunotherapies for brain cancers can in part be attributed to the traditional view of the brain as an immunologically privileged site. The presence of the blood-brain barrier and the absence of lymphatic drainage were believed to restrict the entry of blood-borne immune and inflammatory cells into the central nervous system (CNS), leading to an exclusion of the brain from systemic immune surveillance. However, recent insight from pre-clinical and clinical studies on the immune landscape of brain cancers challenged this dogma. Recruitment of blood-borne immune cells into the CNS provides unprecedented opportunities for the development of tumor microenvironment (TME)-targeted or immunotherapies against primary and metastatic cancers. Moreover, it is increasingly recognized that in addition to genotoxic effects, ionizing radiation represents a critical modulator of tumor-associated inflammation and synergizes with immunotherapies in adjuvant settings. This review summarizes current knowledge on the cellular and molecular identity of tumor-associated immune cells in primary and metastatic brain cancers and discusses underlying mechanisms by which ionizing radiation modulates the immune response. Detailed mechanistic insight into the effects of radiation on the unique immune landscape of brain cancers is essential for the development of multimodality intervention strategies in which immune-modulatory effects of radiotherapy are exploited to sensitize brain cancers to immunotherapies by converting immunologically “cold” into “hot” environments.

Prognostic models for patients with brain metastases after stereotactic radiosurgery with or without whole brain radiotherapy: a validation study

PURPOSE/OBJECTIVE(S)

To compare the performance of five prognostic models [RTOG recursive partitioning analysis (RPA), Score Index for Radiosurgery in Brain Metastases (SIR), Barnholtz-Sloan-Kattan nomogram (BSKN), diagnosis-specific Graded Prognostic Assessment (dsGPA), and Graded Prognostic Assessment for Lung Cancer Using Molecular Markers (Lung-molGPA)] against actual survival in patients with brain metastases treated with SRS +/- WBRT.

MATERIALS/METHODS

100 consecutive patients treated with SRS +/- WBRT between January 2006 and July 2012 were retrospectively analyzed. Patients were binned according to 33 percentiles of the predicted survival distribution for the BSKN and dsGPA models to compare with LungmolGPA, RPA and SIR. Pearson's correlation coefficients between predicted and observed survival were estimated to quantify the proportion of variance in observed survival.

RESULTS

Median survival for the entire cohort was 13.5 months, with predicted vs actual MS by BSKN, SIR, dsGPA, RPA, adenocarcinoma Lung-molGPA, and nonadenocarcinoma Lung-molGPA was 3.8 vs 15.6 months, 7 vs 13.5 months, 9.4 vs 13.5 months, 10.3 vs 13.5 months, 13.7 vs 13.7 months, and 9.8 vs 9.7 months, respectively. The BSKN model and adenocarcinoma LungmolGPA created three groups with a statistically significantly different MS (p = 0.002 and p = 0.01, respectively).

CONCLUSION

All models under-predicted MS and only the BSKN and Lung-molGPA model stratified patients into three risk groups with statistically significant actual MS. The prognostic groupings of the adenocarcinoma Lung-molGPA group was the best predictor of MS, and showed that we are making improvements in our prognostic ability by utilizing molecular information that is much more widely available in the current treatment era.

Management of Leptomeningeal Metastases in Non-oncogene Addicted Non-small Cell Lung Cancer

Brain metastases in non-small cell lung cancer (NSCLC) patients are more often detected due to imaging modalities improvements but also emerge because of improved treatments of the primary tumor which lead to a longer survival. In this context, development of leptomeningeal metastases (LM) is a devastating complication and its prognosis remains poor despite advances in systemic and local approaches. Histology characterization of NSCLC and molecular expression influence LM management. For those with “oncogene addiction,” new generation epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors (TKIs) were developed to strongly penetrate the blood-brain barrier (BBB) with the aim to prevent central nervous system cancer dissemination, eventually impacting on LM appearance and its subsequent management. Systemic chemotherapy, often combined with intrathecal chemotherapy (when possible), was one of common indications for lung cancer patients affected by LM, without driver mutations and a good performance status but currently, with the advent of innovative systemic approaches treatment solutions in this subgroup of patients are rapidly evolving. Whole brain radiation therapy (WBRT) is the conventional treatment for patients with brain metastases. Furthermore, modern radiation techniques, as stereotactic radiotherapy (SRT), improve outcomes in those cases with a limited number of lesions. However, LM represent a minority of CNS metastases and few literature data are available to drive the radiotherapy approach. Considering all relevant progress made in this setting, after a literature review, the aim of this paper is to discuss about recent developments and therapeutic options in LM management of non-oncogene addicted NSCLC.

Local control and possibility of tailored salvage after hypofractionated stereotactic radiotherapy of the cavity after brain metastases resection

In patients undergoing surgical resection of brain metastases, the risk of local recurrence remains high. Adjuvant whole brain radiation therapy (WBRT) can reduce the risk of local relapse but fails to improve overall survival. At two tertiary care centers in Germany, a retrospective study was performed to evaluate the role of hypofractionated stereotactic radiotherapy (HFSRT) in patients with brain metastases after surgical resection. In particular, need for salvage treatment, for example, WBRT, surgery, or stereotactic radiosurgery (SRS), was evaluated. Both intracranial local (LF) and locoregional (LRF) failures were analyzed. A total of 181 patients were treated with HFSRT of the surgical cavity. In addition to the assessment of local control and distant intracranial control, we analyzed treatment modalities for tumor recurrence including surgical strategies and reirradiation. Imaging follow-up for the evaluation of LF and LRF was available in 159 of 181 (88%) patients. A total of 100 of 159 (63%) patients showed intracranial progression after HFSRT. A total of 81 of 100 (81%) patients received salvage therapy. Fourteen of 81 patients underwent repeat surgery, and 78 of 81 patients received radiotherapy as a salvage treatment (53% WBRT). Patients with single or few metastases distant from the initial site or with WBRT in the past were retreated by HFSRT (14%) or SRS, 33%. Some patients developed up to four metachronous recurrences, which could be salvaged successfully. Eight (4%) patients experienced radionecrosis. No other severe side effects (CTCAE≥3) were observed. Postoperative HFSRT to the resection cavity resulted in a crude rate for local control of 80.5%. Salvage therapy for intracranial progression was commonly needed, typically at distant sites. Salvage therapy was performed with WBRT, SRS, and surgery or repeated HFSRT of the resection cavity depending on the tumor spread and underlying histology. Prospective studies are warranted to clarify whether or not the sequence of these therapies is important in terms of quality of life, risk of radiation necrosis, and likelihood of neurological cause of death.

Foe or friend? Janus-faces of the neurovascular unit in the formation of brain metastases

Despite the potential obstacle represented by the blood-brain barrier for extravasating malignant cells, metastases are more frequent than primary tumors in the central nervous system. Not only tightly interconnected endothelial cells can hinder metastasis formation, other cells of the brain microenvironment (like astrocytes and microglia) can also be very hostile, destroying the large majority of metastatic cells. However, malignant cells that are able to overcome these harmful mechanisms may benefit from the shielding and even support provided by cerebral endothelial cells, astrocytes and microglia, rendering the brain a sanctuary site against anti-tumor strategies. Thus, cells of the neurovascular unit have a Janus-faced attitude towards brain metastatic cells, being both destructive and protective. In this review, we present the main mechanisms of brain metastasis formation, including those involved in extravasation through the brain vasculature and survival in the cerebral environment.

Dosimetric Study and Neurocognitive Function of Hippocampal-Sparing Whole-Brain Radiotherapy

Objective:

To investigate the feasibility of hippocampal-sparing whole-brain radiotherapy and reduction in neurocognitive function impairment after radiotherapy.

Methods:

Forty-three patients with brain metastases were selected. Whole-brain radiotherapy was performed in 22 patients, with 3-dimensional conformal radiotherapy in parallel opposed fields. Twenty-one patients had significant difference. Planning parameter values and neurocognitive function scores in 2 groups were statistically analyzed.

Results:

Homogeneity index in the 3-dimensional conformal radiotherapy group and tomotherapy group was 0.12 ± 0.02 and 0.36 ± 0.03, respectively, with a significant difference (P < .05). The homogeneity of target doses was better in the tomotherapy group than in the 3-dimensional conformal radiotherapy group. There was a statistical significance in D_mean and D_max between the 2 groups (P < .05). The dose in hippocampal was less in the tomotherapy group than in the other group. D_mean and D_max of the left hippocampus declined to 20.14% and 35.39% of prescription dose, respectively, and D_mean and D_max of the right hippocampus declined to 19.92% and 35.14% of prescription dose, respectively. Neurocognitive function score between the 2 groups before treatment and 1 month after treatment had no significant difference (P > .05), while there was a significant difference in 3 and 6 months after treatment (P < .05). Neurocognitive function score was higher in the tomotherapy group than in the other group. No level III or above adverse reactions were observed.

Conclusions:

Hippocampal-sparing whole-brain radiotherapy in brain metastases treatment is feasible. Homogeneity index value is higher in the tomotherapy group than in the 3-dimensional conformal radiotherapy group. All V_95% in the 2 groups meet the requirements. Hippocampal sparing could avoid neurocognitive function impairment to some extent.

Intercellular transfer of small RNAs from astrocytes to lung tumor cells induces resistance to chemotherapy

Brain metastases are resistant to chemotherapy and carry a poor prognosis. Studies have shown that tumor cells are surrounded by activated astrocytes, whose cytoprotective properties they exploit for protection from chemotherapy-induced apoptosis. The mechanism of such astrocytic protection is poorly understood. A non-mutational mechanism of resistance to chemotherapy that is receiving increased attention is the regulation of gene translation mediated by small noncoding RNAs (sRNAs), and particularly microRNAs (miRNAs). With the aim of examining the role of astrocytic sRNAs in promoting resistance of human lung tumor PC14 cells to chemotherapy-induced apoptosis, here we used a miRNA microarray to compare sRNA profiles of human lung tumor cells cultured with and without astrocytes. We found that sRNAs are transferred from astrocytes to PC14 cells in a contact-dependent manner. Transfer was rapid, reaching a plateau after only 6 hours in culture. The sRNA transfer was inhibited by the broad-spectrum gap-junction antagonist carbenoxolone, indicating that transfer occurs via gap junctions. Among the transferred sRNAs were several that are implicated in survival pathways. Enforced expression of these sRNAs in PC14 cells increased their resistance to the chemotherapeutic agent paclitaxel. These novel findings might be of clinical relevance for the treatment of patients with brain metastases.

Local control and overall survival after frameless radiosurgery: A single center experience

Introduction

Stereotactic radiosurgery (SRS) has been increasingly advocated for 1-3 small brain metastases. The goal of this study was to evaluate the clinical results in patients with brain metastases treated with LINAC-based SRS using a thermoplastic mask (non-invasive fixation system) and Image-Guided Radiotherapy (IGRT).

Material and Methods

In this single-institution study 48 patients with 77 brain metastases were treated between February 2012 and January 2014. The prescribed dose was 20 Gy or 18 Gy as a single fraction. SRS was performed with a True Beam STX Novalis Radiosurgery LINAC (Varian Medical Systems). The verification of positioning was done using the BrainLAB ExacTrac ® X-ray 6D system and cone-beam CT.

Results

In 69 of 77 treated brain metastases (90%) the follow-up was documented on MR imaging performed every 3 months. Mean follow-up time was 10.86 months. Estimated 1-year local control was 83%, using the Kaplan-Meier method. In 7/69 brain metastases (10%) local failure (LF) was diagnosed. Median progression free survival (PFS) was 3.73 months, largely due to distant brain relapse. A GTV of ≤2.0 cm³ was significantly associated with a better PFS than a GTV >2.0 cm³. Extracranial stable disease and GTV ≤2.5 cm³ were significant predictors of OS.We observed 2 cases of radiation necrosis diagnosed by histology after surgical resection. No other cases of severe side effects (CTACE ≥ 3) were observed.

Conclusion

LINAC-based frameless SRS with the BrainLAB Mask using the BrainLAB ExacTrac ® X-ray 6D system for patient positioning is well tolerated, safe and leads to favorable crude local control of 90%. In our experience, local control after frameless (ringless) SRS is as good as ring-based SRS reported in literature. Without invasive head fixation, radiotherapy is more comfortable for patients.

Preclinical Modeling and Therapeutic Avenues for Cancer Metastasis to the Central Nervous System

Metastasis is the dissemination of cells from the primary tumor to other locations within the body, and continues to be the predominant cause of death among cancer patients. Metastatic progression within the adult central nervous system is 10 times more frequent than primary brain tumors. Metastases affecting the brain parenchyma and leptomeninges are associated with grave prognosis, and even after successful control of the primary tumor the median survival is a dismal 2-3 months with treatment options typically limited to palliative care. Current treatment options for brain metastases (BM) and disseminated brain tumors are scarce, and the improvement of novel targeted therapies requires a broader understanding of the biological complexity that characterizes metastatic progression. In this review, we provide insight into patterns of BM progression and leptomeningeal spread, outlining the development of clinically relevant in vivo models and their contribution to the discovery of innovative cancer therapies. In vivo models paired with manipulation of in vitro methods have expanded the tools available for investigators to develop agents that can be used to prevent or treat metastatic disease. The knowledge gained from the use of such models can ultimately lead to the prevention of metastatic dissemination and can extend patient survival by transforming a uniformly fatal systemic disease into a locally controlled and eminently more treatable one.

Brain metastases from hepatocellular carcinoma: recent advances and future avenues

The incidence of brain metastases from hepatocellular carcinoma (BMHCC) is becoming more frequent than that of the past as a result of prolonged survival of patients with HCC. Compared with brain metastases from other types of cancer, BMHCC tends to exhibit a high incidence of intracerebral hemorrhage (ICH) and poor liver function. Unfortunately, the prognosis is extremely poor for patients with BMHCC owing to the limited treatment selection. Currently, optimal treatment requires multidisciplinary approaches including surgery, whole-brain radiation therapy and stereotactic radiosurgery. Besides these traditional approaches, novel treatments such as target therapy and immunotherapy provide an opportunity to improve the survival of these patients. This review provides an overview of the incidence, characteristics, prognosis, and current and potential future management strategies for BMHCC.

A Randomized Controlled Open-Label Pilot Study of Simvastatin Addition to Whole-Brain Radiation Therapy in Patients With Brain Metastases

Statins have been reported to have a potential radiosensitizing effect that has not been evaluated in clinical trials. The aim of this study was to evaluate the efficacy and safety of simvastatin in addition to whole-brain radiation therapy (WBRT) in patients with brain metastases (BM). A prospective randomized, controlled, open-label pilot study was conducted on 50 Egyptian patients with BM who were randomly assigned to receive 30-Gy WBRT (control group: 25 patients) or 30 Gy WBRT + simvastatin 80 mg/day for the WBRT period (simvastatin group: 25 patients). The primary outcome was radiological response at 4 weeks after WBRT. Secondary outcomes were 1-year progression-free survival (PFS), 1-year overall survival (OS), and health-related quality of life (HRQL) that was assessed using the European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire C30 (EORTC QLQ-C30) and its brain module (BN-20), at baseline, after WBRT, and 4 weeks after WBRT. The addition of simvastatin was tolerated. Twenty-one patients were not evaluated for radiological response because of death (n = 16), noncompliance to follow-up (n = 4), and clinical deterioration (n = 1). Response rates were 60% and 78.6% (p = 0.427), 1-year PFS rates were 5.2% and 17.7% (p = 0.392), and 1-year OS rates were 12% and 8% (p = 0.880) for the control group and simvastatin group, respectively. Nonsignificant differences were found between the two arms regarding HRQL scales. The addition of simvastatin 80 mg/day did not improve the clinical outcomes of patients with BM receiving WBRT.

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

BACKGROUND

Surgical resection and stereotactic radiosurgery (SRS) are well-established treatment options for selected patients with oligo-brain metastases (BMs). The dynamics of edema resolution with each treatment method have not been well characterized.

METHODS

Of 389 patients treated for BMs between 2012 and 2014, this study retrospectively identified 107 patients (150 metastases) who underwent either surgery or SRS as a single treatment method for BMs. The two groups of patients were matched for clinical parameters. Volumetric assessments of the tumor and associated edema were performed before treatment and then 2-3 months after treatment.

RESULTS

In this study, 76 surgical cases were compared with 74 cases treated with SRS. The volume of the tumor and surrounding edema was significantly greater in the surgery group than in the SRS group. However, resolution of edema was significantly more rapid in the surgical group (p < 0.0001), accompanied by faster weaning from steroids. After a matching process based on the propensity of a patient to receive SRS, a subgroup cohort was analyzed (mean maximal diameter: 21 mm in the surgical group vs 20.8 mm in the SRS group; p = 0.9). At diagnosis, edema volume, but not tumor volume, was significantly greater in the surgical group. The resolution of edema 2-3 months after treatment was better in the surgical group than in the SRS group (89.6% vs 71.1% of baseline, respectively; p = 0.09), although this difference did not reach the level of significance.

CONCLUSIONS

Resolution of tumor-associated edema in BMs suitable for either surgery or SRS was significantly faster after surgical resection than after SRS. Accordingly, when both treatment options are suitable, surgery appears to induce faster resolution of the edema.

Brain Metastases: Surgical Treatment and Overall Survival

BACKGROUND

Brain metastases occur in 10%-40% of patients with cancer and are more common than primary brain tumors (30%-40%); their incidence is growing because of improvements in control of systemic disease, better radiologic detection, and prolonged survival. Modern treatment of brain metastases has dramatically changed the expected prognosis. Traditionally, the prognosis has been considered very poor, and patients were referred to palliative treatment because of their terminal stage; however, new prognostic indexes have been proposed to evaluate these patients. The aim of our study was to determine the long-term effect of surgery on overall survival (OS) in patients with brain metastases from dissimilar primary tumors and to identify prognostic variables associated with prolonged survival.

METHODS

We retrospectively reviewed a consecutive series of patients who underwent surgery between January 2010 and October 2014 for cerebral metastases from lung, kidney, breast, and gastrointestinal cancers and melanoma. Variables included age; sex; histology; location of lesions; and specific treatments patients had undergone including chemotherapy, radiotherapy, and surgery, individually or combined.

RESULTS

No patients deteriorated after surgery. At discharge, 19 patients (26.76%) had an unchanged postoperative neurologic examination, whereas 52 patients (73.23%) showed improvement (χ² = 34.84, P < 0.0001). Expected OS, considering all tumor subtypes, was 372.24 months; the patients in our series had an OS of 787 months, more than twice the expected OS; specifically, average expected survival of each patient was 5.24 months, whereas actual survival was 11.08 months (P = 0.000008).

CONCLUSIONS

Surgery is a safe and effective procedure for cerebral metastases and should not be considered an aggressive treatment in such disease. In our series, 55% of patients had a survival >6 months and a significant improvement in terms of actual versus expected survival. Surgical resection should be considered the primary option for patients with brain metastases.

Surgical management of posterior fossa metastases

The diagnosis of brain metastases is associated with a poor prognosis reflecting uncontrolled primary disease that has spread to the relative sanctuary of the central nervous system. 20 % of brain metastases occur in the posterior fossa and are associated with significant morbidity. The risk of acute hydrocephalus and potential for sudden death means these metastases are often dealt with as emergency cases. This approach means a full pre-operative assessment and staging of underlying disease may be neglected and a proportion of patients undergo comparatively high risk surgery with little or no survival benefit. This study aimed to assess outcomes in patients to identify factors that may assist in case selection. We report a retrospective case series of 92 consecutive patients operated for posterior fossa metastases between 2007 and 2012. Routine demographic data was collected plus data on performance status, primary cancer site, details of surgery, adjuvant treatment and survival. The only independent positive prognostic factors identified on multivariate analysis were good performance status (if Karnofsky performance score >70, hazard ratio (HR) for death 0.36, 95 % confidence interval (CI) 0.18–0.69), adjuvant whole brain radiotherapy (HR 0.37, 95 % CI 0.21–0.65) and adjuvant chemotherapy where there was extracranial disease and non-synchronous presentation (HR 0.51, 95 % CI 0.31–0.82). Patients presenting with posterior fossa metastases may not be investigated as thoroughly as those with supratentorial tumours. Staging and assessment is essential however, and in the meantime emergencies related to tumour mass effect should be managed with steroids and cerebrospinal fluid diversion as required.

Stereotactic fractionated radiotherapy of the resection cavity in patients with one to three brain metastases

OBJECTIVES

The goal of this study is to evaluate the role of stereotactic fractionated radiotherapy (SFRT) in patients with one to three brain metastases after surgical resection.

METHODS AND MATERIALS

We performed a retrospective single-institutional study in patients undergoing SFRT of surgical cavity after resection of ≤3 brain metastases. 60 patients with newly diagnosed brain metastases treated with SFRT following resection were included. The total irradiation dose was 30 Gy (5 Gy/d, BED 45 Gy) after complete macroscopical resection and 35 Gy (5 Gy/d, BED 52.5 Gy) in patients with macroscopic residual tumour after surgery. Macroscopic residual tumour was defined as contrast enhancement next to the resection cavity on the postoperative T1-MRI. The gross tumour volume (GTV) encompassing the residual tumour was delineated on the T1-MRI, the clinical target volume (CTV) encompassed the surgical cavity plus 1mm and the planning target volume (PTV) the CTV plus 2mm.

RESULTS

Eight of 60 patients had no imaging follow-up due to morbidity/mortality. Two of 52 (3.8%) patients experienced local failures only, 25 of 52 (48.1%) patients experienced distant intracranial failures only and 4 (7.7%) patients experienced both local and distant intracranial failures. In summary, there were 6 (11.5%) local failures and 29 (55.8%) distant failures. Age was significant for local control in the Cox regression test (p=0.046). Thirty-seven of 60 (61.7%) patients died during follow-up. Median follow-up was 8 months. Median overall survival was 15 months. Cox regression for survival was significant for KPS score ≤70% and size of PTV. No severe side effects were seen. Patients undergoing whole brain radiation therapy (WBRT) as salvage therapy in case of progression had no severe side effects either.

CONCLUSION

In the light of encouraging local control rates, SFRT could be an alternative to WBRT after surgical resection of ≤3 brain metastases. Due to the high rate of distant intracranial failure regular follow-up with MRI is mandatory.