Survival of patients with melanoma brain metastasis treated with stereotactic radiosurgery and active systemic drug therapies

The Safety and Efficacy of Concurrent Immune Checkpoint Blockade and Stereotactic Radiosurgery Therapy with Practitioner and Researcher Recommendations

BACKGROUND

Immune checkpoint inhibitors (ICIs) have shown growing promise in the treatment of brain metastases, especially combined with stereotactic radiosurgery (SRS). The combination of ICIs with SRS has been studied for efficacy as well as increasing radiation necrosis risks. In this review, we compare clinical outcomes of radiation necrosis, intracranial control, and overall survival between patients with brain metastases treated with either SRS alone or SRS-ICI combination therapy.

METHODS

A literature search of PubMed, Scopus, Embase, Web of Science, and Cochrane was performed in May 2023 for articles comparing the safety and efficacy of SRS/ICI versus SRS-alone for treating brain metastases.

RESULTS

The search criteria identified 1961 articles, of which 48 met inclusion criteria. Combination therapy with SRS and ICI does not lead to significant increases in incidence of radiation necrosis either radiographically or symptomatically. Overall, no difference was found in intracranial control between SRS-alone and SRS-ICI combination therapy. Combination therapy is associated with increased median overall survival. Notably, some comparative studies observed decreased neurologic deaths, challenging presumptions that improved survival is due to greater systemic control. The literature supports SRS-ICI administration within 4 weeks of another for survival but remains inconclusive, requiring further study for other outcome measures.

CONCLUSIONS

Combination SRS-ICI therapy is associated with significant overall survival benefit for patients with brain metastases without significantly increasing radiation necrosis risks compared to SRS alone. Although intracranial control rates appear to be similar between the 2 groups, timing of treatment delivery may improve control rates and demands further study attention.

Stereotactic radiosurgery with immune checkpoint inhibitors for brain metastases: a meta-analysis study

BACKGROUND

Immune checkpoint inhibitors (ICIs) are an emerging tool in the treatment of brain metastases (BMs), Stereotactic radiosurgery (SRS), traditionally used for BMs, elicits an immune brain response and can act synergistically with ICIs. We aim to investigate the efficacy of ICI administered with SRS and determine the impact of timing on BM response.

METHODS

A systematical search was performed to identify potential studies concerning BMs managed with SRS alone or with SRS + ICI with relative timing administration (ICI concurrent with SRS, ICI nonconcurrent with SRS, SRS before ICI, SRS after ICI). The overall survival (OS), 12-month OS, local progression-free survival (LPFS), 12-month local brain control (LBC), distant progression-free survival (DPFS), 12-month distant brain control (DBC), and adverse events (intracranial hemorrhage, radionecrosis) were analyzed using the random-effects model.

RESULTS

A total of 16 retrospective studies with 1356 BM patients were included. Compared to nonconcurrent therapy, concurrent therapy revealed a significantly longer OS (HR= 1.43; p = 0.008) and 12-months LBC (HR = 1.91; p = 0.04), a similar 12-months DBC (HR = 1.12; p = 0.547) and higher complication rate (R = 0.77; p = 0.346). Concurrent therapy leads to a significantly higher OS compared to ICI before SRS (HR = 2.55; p = 0.0003).

CONCLUSION

The combination of SRS with ICI improves patients' clinical and radiological outcomes. The effectiveness of the combination is subject to the identification of an optimal therapeutic window.

Estimating survival in patients with melanoma brain metastases: prognostic value of lactate dehydrogenase

Patients with melanoma brain metastases (MBM) have poor prognosis, albeit advances in locoregional and systemic treatments. The melanoma-specific Graded Prognostic Assessment (GPA) effectively stratifies survival for patients with MBM. Nevertheless, lactate dehydrogenase (LDH), a well known prognostic factor for patients with melanoma, is not represented in the GPA scores and might add prognostic information for patients with MBM. In this study, 150 consecutive patients with MBM were retrospectively analyzed with the aim of evaluating independent prognostic factors for MBM patients, including LDH. Furthermore, we implemented a disease-specific prognostic score and estimated survival according to treatment modalities. On the basis of multivariable Cox regression analyses, six prognostic factors (age, BRAF status, number of MBM, number of extracranial metastatic sites, performance status, and LDH level) resulted statistically significant in terms of survival and were combined in a prognostic score to stratify patients in distinct prognostic groups ( P  < 0.0001). Among treatment modalities, a multimodal approach with stereotactic radiosurgery or neurosurgery associated with systemic therapy showed the best outcome (median overall survival: 12.32 months, 95% confidence interval, 7.92-25.30). This is the first study to demonstrate that LDH has independent prognostic value for patients with MBM and might be used to improve prognostic stratification, albeit external validation is mandatory. Survival of patients with MBM is affected by both disease-specific risk factors and treatment modalities, with locoregional treatments associated with better outcomes.

Optimizing the synergy between stereotactic radiosurgery and immunotherapy for brain metastases

Solid tumors metastasizing to the brain are a frequent occurrence with an estimated incidence of approximately 30% of all cases. The longstanding conventional standard of care comprises surgical resection and whole-brain radiotherapy (WBRT); however, this approach is associated with limited long-term survival and local control outcomes. Consequently, stereotactic radiosurgery (SRS) has emerged as a potential alternative approach. The primary aim of SRS has been to improve long-term control rates. Nevertheless, rare observations of abscopal or out-of-field effects have sparked interest in the potential to elicit antitumor immunity via the administration of high-dose radiation. The blood-brain barrier (BBB) has traditionally posed a significant challenge to the efficacy of systemic therapy in managing intracranial metastasis. However, recent insights into the immune-brain interface and the development of immunotherapeutic agents have shown promise in preclinical and early-phase clinical trials. Researchers have investigated combining immunotherapy with SRS to enhance treatment outcomes in patients with brain metastasis. The combination approach aims to optimize long-term control and overall survival (OS) outcomes by leveraging the synergistic effects of both therapies. Initial findings have been encouraging in the management of various intracranial metastases, while further studies are required to determine the optimal order of administration, radiation doses, and fractionation regimens that have the potential for the best tumor response. Currently, several clinical trials are underway to assess the safety and efficacy of administering immunotherapeutic agents concurrently or consecutively with SRS. In this review, we conduct a comprehensive analysis of the advantages and drawbacks of integrating immunotherapy into conventional SRS protocols for the treatment of intracranial metastasis.

Long duration of immunotherapy before radiosurgery might improve intracranial control of melanoma brain metastases

PURPOSE

Despite significant advances that have been made in management of metastatic melanoma with immune checkpoint therapy, optimal timing of combination immune checkpoint therapy and stereotactic radiosurgery is unknown. We have reported toxicity and efficiency outcomes of patients treated with concurrent immune checkpoint therapy and stereotactic radiosurgery.

PATIENTS AND METHODS

From January 2014 to December 2016, we analyzed 62 consecutive patients presenting 296 melanoma brain metastases, treated with gamma-knife and receiving concurrent immune checkpoint therapy with anti-CTLA4 or anti-PD1 within the 12 weeks of SRS procedure. Median follow-up time was 18 months (mo) (13-22). Minimal median dose delivered was 18 gray (Gy), with a median volume per lesion of 0.219 cm³.

RESULTS

The 1-year control rate per irradiated lesion was 89% (CI 95%: 80.41-98.97). Twenty-seven patients (43.5%) developed distant brain metastases after a median time of 7.6 months (CI 95% 1.8-13.3) after gamma-knife. In multivariate analysis, positive predictive factors for intracranial tumor control were: delay since the initiation of immunotherapy exceeding 2 months before gamma-knife procedure (P=0.003) and use of anti-PD1 (P=0.006). Median overall survival (OS) was 14 months (CI 95%: 11-NR). Total irradiated tumor volume<2.1 cm³ was a positive predictive factor for overall survival (P=0.003). Ten patients (16.13%) had adverse events following irradiation, with four grade≥3. Predictive factors of all grade toxicity were: female gender (P=0.001) and previous treatment with MAPK (P=0.05).

CONCLUSION

A long duration of immune checkpoint therapy before stereotactic radiosurgery might improve intracranial tumor control, but this relationship and its ideal timing need to be assessed in prospective trials.

Optimal timing and sequence of combining stereotactic radiosurgery with immune checkpoint inhibitors in treating brain metastases: clinical evidence and mechanistic basis

Recent evidence has shown that immune checkpoint inhibitors (ICIs) are efficacious for treating brain metastases of various primary tumors. However, the immunosuppressive tumor microenvironment and the blood-brain barrier (BBB) or blood-tumor barrier (BTB) essentially restrict the efficacy of ICIs. Stereotactic radiosurgery (SRS) can be a powerful ally to ICIs due to its trait of disrupting the BBB/BTB and increasing the immunogenicity of brain metastases. The combination of SRS + ICI has shown synergy in brain metastases in several retrospective studies. Nevertheless, the optimal schedule for the combination of SRS and ICI in brain metastases is yet to be determined. In this review, we summarized the current clinical and preclinical evidence on the timing and sequence of SRS + ICI to provide insight into the current state of knowledge about this important area in patient care.

Time interval from diagnosis to treatment of brain metastases with stereotactic radiosurgery is not associated with radionecrosis or local failure

Introduction

Brain metastases are the most common intracranial tumor diagnosed in adults. In patients treated with stereotactic radiosurgery, the incidence of post-treatment radionecrosis appears to be rising, which has been attributed to improved patient survival as well as novel systemic treatments. The impacts of concomitant immunotherapy and the interval between diagnosis and treatment on patient outcomes are unclear.

Methods

This single institution, retrospective study consisted of patients who received single or multi-fraction stereotactic radiosurgery for intact brain metastases. Exclusion criteria included neurosurgical resection prior to treatment and treatment of non-malignant histologies or primary central nervous system malignancies. A univariate screen was implemented to determine which factors were associated with radionecrosis. The chi-square test or Fisher’s exact test was used to compare the two groups for categorical variables, and the two-sample t-test or Mann-Whitney test was used for continuous data. Those factors that appeared to be associated with radionecrosis on univariate analyses were included in a multivariable model. Univariable and multivariable Cox proportional hazards models were used to assess potential predictors of time to local failure and time to regional failure.

Results

A total of 107 evaluable patients with a total of 256 individual brain metastases were identified. The majority of metastases were non-small cell lung cancer (58.98%), followed by breast cancer (16.02%). Multivariable analyses demonstrated increased risk of radionecrosis with increasing MRI maximum axial dimension (OR 1.10, p=0.0123) and a history of previous whole brain radiation therapy (OR 3.48, p=0.0243). Receipt of stereotactic radiosurgery with concurrent immunotherapy was associated with a decreased risk of local failure (HR 0.31, p=0.0159). Time interval between diagnostic MRI and first treatment, time interval between CT simulation and first treatment, and concurrent immunotherapy had no impact on incidence of radionecrosis or regional failure.

Discussion

An optimal time interval between diagnosis and treatment for intact brain metastases that minimizes radionecrosis and maximizes local and regional control could not be identified. Concurrent immunotherapy does not appear to increase the risk of radionecrosis and may improve local control. These data further support the safety and synergistic efficacy of stereotactic radiosurgery with concurrent immunotherapy.

Immune-related adverse events are associated with therapeutic efficacy of immunotherapy in patients with melanoma brain metastases

Immunotherapy with T-cell checkpoint inhibitors have changed the treatment landscape for patients with melanoma brain metastases (MBMs), offering increased survival compared with historical outcomes. We sought to identify clinical features associated with intracranial tumour responses or progression-free survival (PFS) in patients with MBMs treated with immunotherapy. Patients with MBMs treated with immunotherapy from August 2013 to March 2020 were identified through local databases. Melanoma disease burdens and immune-related adverse events (irAEs) were assessed retrospectively by review of patient medical records. Efficacy was evaluated by determining objective response rates (ORRs) in brain metastases using immune-Response Evaluation Criteria in Solid Tumours criteria, MBM-specific survival and overall PFS. Twenty-six patients were identified as eligible for this study. The presence and volume of extracranial metastases (ECM) were associated with a non-significant trend of reduced intracranial ORRs and PFS. Patients with irAEs, on the other hand, had significantly increased intracranial ORRs and PFS compared to those without irAEs. Severe, grade ≥3 irAEs and co-occurrence of ≥2 irAEs were also significantly associated with longer PFS. The presence and volume of ECM correlated inversely with development and severity of irAEs. We report a strong association between the development of irAEs and favourable melanoma-specific outcomes in patients with MBMs receiving immunotherapy. Contrary to previous studies, we found that co-occurrence of ECM in these patients was associated with fewer irAEs and reduced treatment efficacy.

Comparison of immunotherapy combined with stereotactic radiotherapy and targeted therapy for patients with brain metastases: A systemic review and meta-analysis

Advances in brain imaging have led to a higher incidence of brain metastases (BM) being diagnosed. Stereotactic radiotherapy (SRS), systemic immunotherapy, and targeted drug therapy are commonly used for treating BM. In this study, we summarized the differences in overall survival (OS) between several treatments alone and in combination. We carried out a systematic literature search on Pubmed, EMBASE, and Cochrane Library. Differences in OS associated with Immune checkpoint inhibitors (ICI) alone versus targeted therapy alone and SRS + ICI or ICI alone were evaluated. This analysis was conducted on 11 studies involving 4,154 patients. The comprehensive results of fixed effect model showed that the OS of SRS + ICI group was longer than that of the ICI group (hazard ratio, 1.72; 95% CI: 1.41-2.11; P = 0.22; I ² = 30%). The combined fixed-effect model showed that the OS time of ICI was longer than that of targeted therapy (hazard ratio, 2.09; 95% CI: 1.37-3.20; P = 0.21; I ² = 35%). The study had a low risk of bias. In conclusion, our analysis confirmed that immunotherapy alone showed a higher OS benefit in BM patients than targeted therapy alone. The total survival time of patients with SRS combined with ICI was higher than that of patients with single ICI.

Systematic literature review and meta-analysis of clinical outcomes and prognostic factors for melanoma brain metastases

Background

More than 60% of all stage IV melanoma patients develop brain metastases, while melanoma brain metastases (MBM) is historically difficult to treat with poor prognosis.

Objectives

To summarize clinical outcomes and prognostic factors in MBM patients.

Methods

A systematic review with meta-analysis was conducted, and a literature search for relevant studies was performed on November 1, 2020. Weighted average of median overall survival (OS) was calculated by treatments. The random-effects model in conducting meta-analyses was applied.

Results

A total of 41 observational studies and 12 clinical trials with our clinical outcomes of interest, and 31 observational studies addressing prognostic factors were selected. The most common treatments for MBM were immunotherapy (IO), MAP kinase inhibitor (MAPKi), stereotactic radiosurgery (SRS), SRS+MAPKi, and SRS+IO, with median OS from treatment start of 7.2, 8.6, 7.3, 7.3, and 14.1 months, respectively. Improved OS was observed for IO and SRS with the addition of IO and/or MAPKi, compared to no IO and SRS alone, respectively. Several prognostic factors were found to be significantly associated with OS in MBM.

Conclusion

This study summarizes pertinent information regarding clinical outcomes and the association between patient characteristics and MBM prognosis.

Stereotactic radiosurgery combined with immune checkpoint inhibitors for brain metastasis: A systematic review and meta-analysis

Many studies have reported the combination of radiosurgery and immune checkpoint inhibitors (ICI) in the treatment of brain metastasis, but these studies have not reached a consistent conclusion. Therefore, we conducted this systematic review and meta-analysis to evaluate the effect of combination therapy compared with radiosurgery alone on the prognosis of patients with brain metastasis. The Pubmed-MEDLINE and Ovid-EMBASE databases were comprehensively searched to identify relevant articles until May 5, 2022. The search results were filtered by the inclusion and exclusion criteria described in this paper. The pooled hazard ratios (HR) with 95% confidence intervals (CI) were presented as estimates effect to reflect the effect of combined therapy on each outcome. A total of 17 eligible studies covering 2079 patients were included in this meta-analysis. The pooled results showed that the use of targeted drugs could significantly improve the overall survival (HR = 0.62, 95%CI: 0.51-0.76; P<0.01), reduce the risk of local recurrence (HR = 0.48, 95%CI: 0.38-0.62; P<0.01) and distant brain recurrence (HR = 0.70, 95%CI: 0.50-0.97; P<0.05). Overall, SRS combined with ICIs could significantly improve overall survival, local control, and distant brain control of patients with brain metastasis compared to SRS alone, but the effect varies for different pathological types. Our results verified the rationality of the current treatment strategy for brain metastasis which emphasizes the combination of local and systematic therapy.

Impact of radiotherapy and sequencing of systemic therapy on survival outcomes in melanoma patients with previously untreated brain metastasis: a multicenter DeCOG study on 450 patients from the prospective skin cancer registry ADOREG

BACKGROUND

Despite of various therapeutic strategies, treatment of patients with melanoma brain metastasis (MBM) still is a major challenge. This study aimed at investigating the impact of type and sequence of immune checkpoint blockade (ICB) and targeted therapy (TT), radiotherapy, and surgery on the survival outcome of patients with MBM.

METHOD

We assessed data of 450 patients collected within the prospective multicenter real-world skin cancer registry ADOREG who were diagnosed with MBM before start of the first non-adjuvant systemic therapy. Study endpoints were progression-free survival (PFS) and overall survival (OS).

RESULTS

Of 450 MBM patients, 175 (38.9%) received CTLA-4+PD-1 ICB, 161 (35.8%) PD-1 ICB, and 114 (25.3%) BRAF+MEK TT as first-line treatment. Additional to systemic therapy, 67.3% of the patients received radiotherapy (stereotactic radiosurgery (SRS); conventional radiotherapy (CRT)) and 24.4% had surgery of MBM. 199 patients (42.2%) received a second-line systemic therapy. Multivariate Cox regression analysis revealed the application of radiotherapy (HR for SRS: 0.213, 95% CI 0.094 to 0.485, p<0.001; HR for CRT: 0.424, 95% CI 0.210 to 0.855, p=0.016), maximal size of brain metastases (HR for MBM >1 cm: 1.977, 95% CI 1.117 to 3.500, p=0.019), age (HR for age >65 years: 1.802, 95% CI 1.016 to 3.197, p=0.044), and ECOG performance status (HR for ECOG ≥2: HR: 2.615, 95% CI 1.024 to 6.676, p=0.044) as independent prognostic factors of OS on first-line therapy. The type of first-line therapy (ICB vs TT) was not independently prognostic. As second-line therapy BRAF+MEK showed the best survival outcome compared with ICB and other therapies (HR for CTLA-4+PD-1 compared with BRAF+MEK: 13.964, 95% CI 3.6 to 54.4, p<0.001; for PD-1 vs BRAF+MEK: 4.587 95% CI 1.3 to 16.8, p=0.022 for OS). Regarding therapy sequencing, patients treated with ICB as first-line therapy and BRAF+MEK as second-line therapy showed an improved OS (HR for CTLA-4+PD-1 followed by BRAF+MEK: 0.370, 95% CI 0.157 to 0.934, p=0.035; HR for PD-1 followed by BRAF+MEK: 0.290, 95% CI 0.092 to 0.918, p=0.035) compared with patients starting with BRAF+MEK in first-line therapy. There was no significant survival difference when comparing first-line therapy with CTLA-4+PD-1 ICB with PD-1 ICB.

CONCLUSIONS

In patients with MBM, the addition of radiotherapy resulted in a favorable OS on systemic therapy. In BRAF-mutated MBM patients, ICB as first-line therapy and BRAF+MEK as second-line therapy were associated with a significantly prolonged OS.

Immunotherapy and radiotherapy in melanoma: a multidisciplinary comprehensive review

Melanoma is an extremely aggressive tumor and is considered to be an extremely immunogenic tumor because compared to other cancers it usually presents a well-expressed lymphoid infiltration. The aim of this paper is to perform a multidisciplinary comprehensive review of the evidence available about the combination of radiotherapy and immunotherapy for melanoma. Radiation, in fact, can increase tumor antigens visibility and promote priming of T cells but can also exert immunosuppressive action on tumor microenvironment. Combining radiotherapy with immunotherapy provides an opportunity to increase immunostimulatory potential of radiation. We therefore provide the latest clinical evidence about radiobiological rationale, radiotherapy techniques, timing, and role both in advanced and systemic disease (with a special focus on ocular melanoma and brain, liver, and bone metastases) with a particular attention also in geriatric patients. The combination of immunotherapy and radiotherapy seems to be a safe therapeutic option, supported by a clear biological rationale, even though the available data confirm that radiotherapy is employed more for metastatic than for non-metastatic disease. Such a combination shows promising results in terms of survival outcomes; however, further studies, hopefully prospective, are needed to confirm such evidence.

State of the Art in Combination Immuno/Radiotherapy for Brain Metastases: Systematic Review and Meta-Analysis

Objectives: Common origins for brain metastases (BMs) are melanoma, lung, breast, and renal cell cancers. BMs account for a large share of morbidity and mortality caused by these cancers. The advent of new immunotherapeutic treatments has made a revolution in the treatment of cancer patients and particularly, as a new concept, if it is combined with radiotherapy, may lead to considerably longer survival. This systematic review and meta-analysis aimed to evaluate the survival rate and toxicities of such a combination in brain metastases. Methods: To perform a systematic review of the literature until January 2021 using electronic databases such as PubMed, Cochrane Library, and Embase; the Newcastle–Ottawa Scale was used to evaluate the quality of cohort studies. For data extraction, two reviewers extracted the data blindly and independently. Hazard ratio with 95% confidence interval (CI), fixed-effect model, and inverse-variance method was calculated. The meta-analysis has been evaluated with the statistical software Stata/MP v.16 (The fastest version of Stata). Results: In the first step, 494 studies were selected to review the abstracts, in the second step, the full texts of 86 studies were reviewed. Finally, 28 studies were selected consisting of 1465 patients. The addition of IT to RT in the treatment of brain metastasis from melanoma and non-small-cell lung carcinoma was associated with a 39% reduction in mortality rate and has prolonged overall survival, with an acceptable toxicity profile. The addition of IT to RT compared with RT alone has a hazard ratio of 0.39(95% CI 0.34–0.44). Conclusions: A combination of immuno/radiotherapy (IR) for the treatment of patients with BMs from melanoma and non-small-cell lung carcinoma has prolonged overall survival and reduced mortality rate, with acceptable toxicity. In terms of timing, RT seems to have the best effect on the result when performed before or simultaneously with immunotherapy.

Stereotactic radiosurgery for melanoma brain metastases: Concurrent immune checkpoint inhibitor therapy associated with superior clinicoradiological response outcomes

INTRODUCTION/PURPOSE

This study assessed long-term clinical and radiological outcomes following treatment with combination stereotactic radiosurgery (SRS) and immunotherapy (IT) for melanoma brain metastases (BM).

METHODS

A retrospective review was performed in a contemporary cohort of patients with melanoma BM at a single tertiary institution receiving Gamma Knife^® SRS for melanoma BM. Multivariate Cox proportional-hazards modelling was performed with a P <0.05 for significance.

RESULTS

101 patients (435 melanoma BM) were treated with SRS between January-2015 and June-2019. 68.3% of patients received IT within 4 weeks of SRS (concurrent) and 31.7% received SRS alone or non-concurrently with IT. Overall, BM local control rate was 87.1% after SRS. Median progression free survival was 8.7 months. Median follow-up was 29.2 months. On multivariate analysis (MVA), patients receiving concurrent SRS-IT maintained a higher chance of achieving a complete (CR) or partial response (PR) [HR 2.6 (95% CI: 1.2-5.5, P = 0.012)] and a reduced likelihood of progression of disease (PD) [HR 0.52 (95% CI: 0.16-0.60), P = 0.048]. Any increase in BM volume on the initial MRI 3 months after SRS predicted a lower likelihood of achieving long-term CR or PR on MVA accounting for concurrent IT, BRAF status and dexamethasone use [HR = 0.048 (95% CI: 0.007-0.345, P = 0.0026)]. Stratified volumetric change demonstrated a sequential relationship with outcomes on Kaplan-Meier analysis.

CONCLUSION

Concurrent SRS-IT has favourable clinical and radiological outcomes with respect to CR, PR and a reduced likelihood of PD. Changes in BM volume on the initial MRI 3 months after SRS were predictive of long-term outcomes for treatment response.

Leptomeningeal disease and brain control after postoperative stereotactic radiosurgery with or without immunotherapy for resected brain metastases

Purpose

Immunotherapy has shown activity in patients with brain metastases (BM) and leptomeningeal disease (LMD). We have evaluated LMD and intraparenchymal control rates for patients with resected BM receiving postoperative stereotactic radiosurgery (SRS) and immunotherapy or postoperative SRS alone. We hypothesize that postoperative SRS and immunotherapy will result in a lower rate of LMD with acceptable toxicity compared with postoperative SRS.

Patients and methods

One hundred and twenty-nine patients with non-small-cell lung cancer (NSCLC) and melanoma BM who received postoperative fractionated SRS (fSRS; 3×9 Gy) in combination with immunotherapy or postoperative fSRS alone for completely resected BM were retrospectively evaluated. The primary endpoint of the study was the rate of LMD after treatments. The secondary endpoints were local failure, distant brain parenchymal failure (DBF), overall survival (OS), and treatment-related toxicity.

Results

Sixty-three patients received postoperative SRS and immunotherapy, either nivolumab or pembrolizumab, and 66 patients received postoperative SRS alone to the resection cavity. With a median follow-up of 15 months, LMD occurred in 19 patients: fSRS group, 14; fSRS and immunotherapy, 5. The 12-month LMD cumulative rates were 22% (95% CI 14% to 37%) in the fSRS group and 6% (95% CI 2% to 17%) in the combined treatment group (p=0.007). Resection cavity control was similar between the groups, whereas DBF and OS were significantly different; the 1-year DBF rates were 31% (95% CI 20% to 46%) in the fSRS and immunotherapy group and 52% (95% CI 39% to 68%) in the fSRS group; respective OS rates were 78% (95% CI 67% to 88%) and 58.7% (95% CI 47% to 70%). Twenty-two patients undergoing postoperative fSRS and immunotherapy and nine subjected to postoperative fSRS experienced treatment-related imaging changes suggestive of radiation-induced brain necrosis (p=0.02).

Conclusions

Postoperative fSRS in combination with immunotherapy decreases the incidence of LMD and DBF in patients with resected BM from NSCLC and melanoma as compared with fSRS alone, reducing the rate of neurological death and prolonging survival.

Treatment patterns and clinical outcomes for patients with melanoma and central nervous system metastases: A real-world study

Background

Patients with melanoma and central nervous system (CNS) metastases have poor survival outcomes. We investigated real‐world treatment patterns and overall survival (OS) of patients with melanoma and CNS metastases.

Methods

A retrospective analysis utilizing a nationwide de‐identified electronic health record‐derived database was undertaken in patients diagnosed with advanced melanoma between January 2011 and September 2018. Patients with any visit ≤90 days of metastatic diagnosis and with confirmed CNS metastases were included.

Results

Of 3473 patients diagnosed with advanced melanoma, 791 patients with confirmed CNS metastases were identified and included in this analysis. Synchronous CNS metastasis (≤30 days of metastatic diagnosis) was associated with longer median OS than metachronous CNS metastasis (>30 days after metastatic diagnosis, 0.58 vs 0.42 years). Stereotactic radiosurgery (SRS) was the most common treatment (40.5%) alone or in combination with other local or systemic therapies, being more frequent in patients diagnosed in 2015+ versus 2011–2014 (44.1% vs 35.5%, respectively). The most common systemic treatment was immune checkpoint inhibitors (ICIs; 30.5%), predominantly anti‐cytotoxic T‐lymphocyte antigen 4 (CTLA‐4) alone (2011–2014) and anti‐programmed death‐1 alone or in combination with anti–CTLA‐4 (2015+). Median OS was longest in SRS‐treated patients (1.17 years) regardless of number of CNS metastases. Median OS for SRS‐treated patients increased from 0.83 years (2011–2014) to 1.75 years (2015+). In multivariable analysis, the effect of SRS remained significant after adjustment for sex, race, intracranial and extracranial disease burden, and timing of CNS metastases. Interaction testing to examine potential synergy between SRS/whole‐brain radiation therapy and ICIs found no significant interaction.

Conclusions

Despite advances in treatment, patients with melanoma and CNS metastases have poor survival outcomes. Prevalence of SRS increased over time and was associated with improved outcomes.

Radiotherapy and immunotherapy in melanoma brain metastases

BACKGROUND AND OBJECTIVE

Melanoma brain metastasis (MBM) generally portends a dismal prognosis. Simultaneous use of radiotherapy (RT) and immune checkpoint inhibitor (ICI) therapy demonstrated tremendous promise and emerged as the new standard. This meta-analysis was conducted to evaluate survival outcomes and toxicities of this combination in patients with MBM. Data analyses were performed using Comprehensive Meta-Analysis software (version 2) and IBM SPSS software (version 27).

METHODS

A systematic literature search of PubMed, EMBASE, and the Cochrane Library (via Wiley) was conducted using PICOS/PRISMA selection protocol and included studies to evaluate survival and safety-associated outcomes of ICI + RT for the treatment of MBM.

RESULTS

A total 44 studies involving 2498 patients were reviewed. The pooled effect size (ES) for overall survival (OS) to compare the ICI + RT arm and ICI alone arm (HR: 0.693 [0.526-0.913, p = .001]), and compare the ICI + RT arm and brain RT alone (HR: 0.595 [0.489-0.723, p < .001)] indicated better survival outcomes in ICI + RT versus RT alone and ICI alone arms. Comparing central nervous system toxicity in the ICI + RT arm and RT alone arm, the pooled ES Grade ≥ 3 neurologic adverse events (NAEs) risk ratio ([RR] = 1.425; 95% confidence interval [CI]: 0.485-4.183; p = .519) indicated that ICI + RT nonsignificantly increased Grade 3-4 NAEs. Comparing Grade ≥ 3 radiation necrosis in the ICI + RT arm and RT alone arm, the pooled ES RR (RR = 2.73; 95% CI: 0.59-12.59; p = .199) indicated that ICI + RT nonsignificantly increased Grade ≥ 3 radiation necrosis.

CONCLUSION

Concurrent administration of RT and ICI evinced favorable OS outcomes and acceptable safety profile in MBM patients. Planned prospective trials are required to demonstrate the issue.

Immune Checkpoints Inhibitors and SRS/SBRT Synergy in Metastatic Non-Small-Cell Lung Cancer and Melanoma: A Systematic Review

Background: Several immunotherapy (IT) agents are FDA approved for treatment of melanoma and non-small-cell lung cancer (NSCLC). The addition of stereotactic radiosurgery (SRS) or stereotactic body radiation therapy (SBRT) to immunotherapy looks promising. A systematic review was conducted to evaluate the possible synergistic effects of immune checkpoints inhibitors (ICIs) and stereotactic radiation therapy in melanoma and NSCLC. Materials and methods: Pubmed databases from January 2010 to December 2020 were reviewed to identify English language studies reporting control of local and abscopal effect of the combination of ICI-SBRT/SRS in metastatic NSCLC and melanoma cancer. The inclusion criteria were followed according to PICO criteria. Results: Thirty-nine articles were included of the 2141 initial results. The reported rates for local control were 16.5–100% and 40–94% in brain and extracerebral metastases, respectively. Distant/abscopal response rates were 1–45% in extracerebral metastases. Abscopal effect could not be evaluated in brain metastases because it was not reported in studies. Treatments were well tolerated with few grade 4 toxicities and no grade 5. Conclusions: The combined treatment of ICI-SBRT/SRS achieves high local control and non-negligible abscopal response in patients with extracerebral metastases, with its benefit in cerebral metastases being more controversial. Clinical trials are needed to better characterize the potential synergism.

Combination of radiotherapy and targeted therapy for melanoma brain metastases: a systematic review

Radiotherapy is a mainstay of efficient treatment of brain metastases from solid tumors. Immunotherapy has improved the survival of metastatic cancer patients across many tumor types. However, targeted therapy is a feasible alternative for patients unable to continue immunotherapy or with poor outcomes of immunotherapy. The combination of radiotherapy and targeted therapy for the treatment of brain metastases has a strong theoretical underpinning, but data on the efficacy and safety of this combination is still limited. A systematic search of PubMed, Embase, Web of Science and the Cochrane library database was conducted. Eleven studies were included for a total of 316 patients. Median OS was about 6.2-17.8 months from radiotherapy. Weighted survival and local control at 1 and 2 years were correlated (50.1 and 17.8%, 90.7 and 14.7% at 1 and 2 year, respectively). Radiotherapy given before or concurrently to targeted therapy provided the best effect on the outcome. For patients with brain metastases from cutaneous melanoma, the addition of concurrent targeted therapy to brain radiotherapy can increase survival and provide long-term control.

Toxicity of combined targeted therapy and concurrent radiotherapy in metastatic melanoma patients: a single-center retrospective analysis

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The Eastern Cooperative Oncology Group consensus guidelines from 2016 recommend interruption of targeted therapy with BRAF- and MEK-inhibitors during radiotherapy with data being based mostly on BRAF monotherapy. The aim of this study is to provide data on the safety of concurrent radiotherapy and combination targeted therapy with BRAF- and MEK-inhibitors. A total of 32 patients with 51 sessions of radiotherapy from one center receiving concurrent radiotherapy and BRAF- and MEK- inhibitors were included. Radiotherapy-associated toxicities were retrospectively collected. Incidence was compared between three groups: (A) targeted therapy during radiotherapy with and, (B) without interruption, and (C) radiotherapy before the start of targeted therapy. Survival and local disease control were examined. Targeted therapy was interrupted during radiotherapy in 16, not interrupted in 14, and only started after radiotherapy in 21 sessions. Stereotactic radiotherapy was applied in 28 sessions, conventionally fractionated radiotherapy in 23. The brain was the most common site of irradiation (n = 36). Radiotherapy-associated toxicities occurred in 41.2% (n = 21) of sessions and did not differ significantly among the groups. Overall survival was 11.7 months and progression-free survival was 8.4 months. No increase in radiotherapy-associated toxicity was seen where combination targeted therapy was not interrupted during radiotherapy. Prospective clinical trials are warranted to support our findings.

Integration of Systemic Therapy and Stereotactic Radiosurgery for Brain Metastases

Simple Summary

In the multi-modal treatment of brain metastasis (BM), the role of systemic therapy has undergone a recent revolution. Due to the development of multiple agents with modest central nervous system penetration of the blood-brain barrier, targeted therapies and immune checkpoint inhibitors are increasingly being utilized alone or in combination with radiation therapy. However, the adoption of sequential or concurrent strategies varies considerably, and treatment strategies employed in clinical practice have rapidly outpaced evidence development. Therefore, this review critically analyzes the data regarding combinatorial approaches for a variety of systemic therapeutics with stereotactic radiosurgery and provides an overview of ongoing clinical trials.

Abstract

Brain metastasis (BM) represents a common complication of cancer, and in the modern era requires multi-modal management approaches and multi-disciplinary care. Traditionally, due to the limited efficacy of cytotoxic chemotherapy, treatment strategies are focused on local treatments alone, such as whole-brain radiotherapy (WBRT), stereotactic radiosurgery (SRS), and resection. However, the increased availability of molecular-based therapies with central nervous system (CNS) penetration now permits the individualized selection of tailored systemic therapies to be used alongside local treatments. Moreover, the introduction of immune checkpoint inhibitors (ICIs), with demonstrated CNS activity has further revolutionized the management of BM patients. The rapid introduction of these cancer therapeutics into clinical practice, however, has led to a significant dearth in the published literature about the optimal timing, sequencing, and combination of these systemic therapies along with SRS. This manuscript reviews the impact of tumor biology and molecular profiles on the management paradigm for BM patients and critically analyzes the current landscape of SRS, with a specific focus on integration with systemic therapy. We also discuss emerging treatment strategies combining SRS and ICIs, the impact of timing and the sequencing of these therapies around SRS, the effect of corticosteroids, and review post-treatment imaging findings, including pseudo-progression and radiation necrosis.

Combined immunotherapy with nivolumab and ipilimumab with and without local therapy in patients with melanoma brain metastasis: a DeCOG* study in 380 patients

Background

Nivolumab combined with ipilimumab have shown activity in melanoma brain metastasis (MBM). However, in most of the clinical trials investigating immunotherapy in this subgroup, patients with symptomatic MBM and/or prior local brain radiotherapy were excluded. We studied the efficacy of nivolumab plus ipilimumab alone or in combination with local therapies regardless of treatment line in patients with asymptomatic and symptomatic MBM.

Methods

Patients with MBM treated with nivolumab plus ipilimumab in 23 German Skin Cancer Centers between April 2015 and October 2018 were investigated. Overall survival (OS) was evaluated by Kaplan-Meier estimator and univariate and multivariate Cox proportional hazard analyses were performed to determine prognostic factors associated with OS.

Results

Three hundred and eighty patients were included in this study and 31% had symptomatic MBM (60/193 with data available) at the time of start nivolumab plus ipilimumab. The median follow-up was 18 months and the 2 years and 3 years OS rates were 41% and 30%, respectively. We identified the following independently significant prognostic factors for OS: elevated serum lactate dehydrogenase and protein S100B levels, number of MBM and Eastern Cooperative Oncology Group performance status. In these patients treated with checkpoint inhibition first-line or later, in the subgroup of patients with BRAFV600-mutated melanoma we found no differences in terms of OS when receiving first-line either BRAF and MEK inhibitors or nivolumab plus ipilimumab (p=0.085). In BRAF wild-type patients treated with nivolumab plus ipilimumab in first-line or later there was also no difference in OS (p=0.996). Local therapy with stereotactic radiosurgery or surgery led to an improvement in OS compared with not receiving local therapy (p=0.009), regardless of the timepoint of the local therapy. Receiving combined immunotherapy for MBM in first-line or at a later time point made no difference in terms of OS in this study population (p=0.119).

Conclusion

Immunotherapy with nivolumab plus ipilimumab, particularly in combination with stereotactic radiosurgery or surgery improves OS in asymptomatic and symptomatic MBM.

Emerging principles of brain immunology and immune checkpoint blockade in brain metastases

Brain metastases are the most common type of brain tumours, harbouring an immune microenvironment that can in principle be targeted via immunotherapy. Elucidating some of the immunological intricacies of brain metastases has opened a therapeutic window to explore the potential of immune checkpoint inhibitors in this globally lethal disease. Multiple lines of evidence suggest that tumour cells hijack the immune regulatory mechanisms in the brain for the benefit of their own survival and progression. Nonetheless, the role of the immune checkpoint in the complex interplays between cancers cells and T cells and in conferring resistance to therapy remains under investigation. Meanwhile, early phase trials with immune checkpoint inhibitors have reported clinical benefit in patients with brain metastases from melanoma and non-small cell lung cancer. In this review, we explore the workings of the immune system in the brain, the immunology of brain metastases, and the current status of immune checkpoint inhibitors in the treatment of brain metastases.

Surgical and Peri-Operative Considerations for Brain Metastases

Introduction

Brain metastases are the most common brain tumors in adults, whose management remains nuanced. Improved understanding of risk factors for surgical complications and mortality may guide treatment decisions.

Methods

A nationwide, multicenter analysis was conducted with a retrospective cohort. Adult patients in the 2012-2015 American College of Surgeons National Surgical Quality Improvement Project (ACS NSQIP) databases who received a craniotomy for resection of brain metastasis were included.

Results

3500 cases were analyzed, of which 17% were considered frail and 24% were infratentorial. The most common 30-day medical complications were venous thromboembolism (3%, median time-to-event [TTE] 4.5 days), pneumonia (4%, median TTE 6 days), and urinary tract infections (2%, median TTE 5 days). Reoperation and unplanned readmission occurred in 5% and 12% of patients, respectively. Infratentorial approach and frailty were associated with reoperation before discharge (OR 2.0 for both; p=0.01 and p=0.03 respectively), but not after discharge. Infratentorial approaches conferred heightened risk for readmission for hydrocephalus (OR 5.1, p=0.02) and reoperation for cerebrospinal fluid diversion (OR 7.1, p<0.001).Overall 30-day mortality was 4%, with nearly three-quarters occurring after discharge. Pre-frailty and frailty were associated with increased odds for post-discharge mortality (OR 1.7 and 2.7, p<0.05), but not pre-discharge mortality. We developed a model to identify pre-/peri-operative variables associated with death, including frailty, thrombocytopenia, and high American Society of Anesthesiologists score (AUROC 0.75).

Conclusions

Optimization of metrics contributing to patient frailty and heightened surveillance in patients with infratentorial metastases may be considered in the peri-operative period.

Toxicity and time lapse between immunotherapy and stereotactic radiotherapy of brain metastases

PURPOSE

Stereotactic radiotherapy (SRT) is the standard treatment for brain metastases of non-small-cell lung cancer (NSCLC) and melanoma, mostly in combination with immunotherapy. The objective was to retrospectively evaluate the influence of the time-lapse between immunotherapy and stereotactic radiotherapy on toxicity.

PATIENTS AND METHODS

From 2016 to 2019, 59 patients treated with SRT for 103 brain metastases of NSCLC (60%) and melanoma (40%) in combination with concomitant immunotherapy (≤30 days) were included. The prescribed dose was 20Gy/1f or 33Gy/3f at the isocentre and 14Gy or 23.1Gy (70%) respectively at the PTV envelope (PTV=GTV+2mm). The mean tumour diameter was 14mm (4-52mm). The immunotherapies used were anti-PD1 and anti-PDL1. The 103 metastases were classified into 3 groups according to the time-lapse between instatement of immunotherapy and instatement of SRT for the patient concerned: 7 (7%) in group A (≤7 days), 38 (37%) in group B (7 to 14 days) and 58 (56%) in group C (14 to 30 days).

RESULTS

The mean follow-up was 10.1 months. The median overall survival was 11.5 months for NSCLC and 12.5 months for melanoma. The percentage of local control (LC) at one year was 65.1% (93.6% for NSCLC and 26.5% for melanoma). The time-lapse between immunotherapy and SRT was not a significant predictor of LC (P=0.86), while the histology was (P<0.001). The proportion of grade≥3 toxicities was 5.1%, and that of radionecrosis was 9.7% (among these patients, 80% were non-symptomatic): 0%, 13.1% and 8.6% for groups A, B and C respectively. The time-lapse between immunotherapy and SRT was not a significant predictor of toxicity. Only tumour volume was a significant predictive factor (P=0.03).

CONCLUSION

The time lapse between immunotherapy and SRT does not influence brain toxicity. The tumour volume remains the main factor.

Survival Benefits of Anti-PD-1 Therapy in Combination With Radiotherapy in Chinese Melanoma Patients With Brain Metastasis

Limited data reported the synergistic anti-tumor effect of anti-PD-1 (programmed death 1) therapy and radiotherapy on melanoma BM (brain metastasis). And the efficacy in the Chinese population is unclear. This study aimed to evaluate the efficacy of anti-PD-1 therapy and radiotherapy in Chinese melanoma patients with BM. We retrospectively reviewed 96 consecutive melanoma patients with BM treated at Sun Yat-Sen University Cancer Center. Patient demographics, BM characteristics and treatment details were carefully collected. The intracranial PFS (progression free survival) and OS (overall survival) were estimated using the Kaplan-Meier method. Twenty-five patients were treated with anti-PD-1 therapy and radiotherapy. Eighteen (72.0%) patients had SBRT (stereotactic body radiation therapy) or SRS (stereotactic radiosurgery) for BM, 1 (4.0%) patient had WBRT (whole brain radiation therapy), 6 (24.0%) patients had SBRT/SRS and WBRT. The median treatment period of anti-PD-1 therapy was 10.77 months. Objective intracranial response was observed in 15 (60%) patients, and 5 (20%) patients achieved CR (complete response). After a median follow-up of 16 months, 11 (44%) patients experienced intracranial PD (progressive disease), and 15 (60%) patients died. The median intracranial PFS and OS were 10.73 months (range, 1.67–38.83 months) and 15.87 months (range, 2.47–41.50 months), respectively. The 1-year intracranial PFS and OS were 61.9% (95% CI, 44.1–86.9%) and 62.5% (95%CI, 45.8–85.2%), respectively. Patients with BM can benefit from a combination of anti-PD-1 therapy and radiotherapy. It merits further investigation in melanoma patients with BM.

Efficacy of BRAF Inhibitors in Combination With Stereotactic Radiosurgery for the Treatment of Melanoma Brain Metastases: A Systematic Review and Meta-Analysis

Background

BRAF inhibitors have improved the outcome for patients with BRAF mutant metastatic melanoma and have shown intracranial responses in melanoma brain metastases. Stereotactic radiosurgery (SRS) is being used as a local treatment for melanoma brain metastasis (MBM) with better local control and survival. We searched for studies comparing the combination of two treatments with SRS alone to detect any clinical evidence of synergism.

Materials and Methods

PubMed, EMBASE, Medline, and Cochrane library were searched until May 2020 for studies with desired comparative outcomes. Outcomes of interest that were obtained for meta-analysis included survival as the primary, and local control as the secondary outcome.

Results

A total of eight studies involving 976 patients with MBM were selected. Survival was significantly improved for patients receiving BRAF inhibitor plus SRS in comparison to SRS alone as assessed from the time of SRS induction (SRS survival: hazard ratio [HR] 0.67 [0.58–0.79], p <0.00001), from the time of brain metastasis diagnosis (BM survival: HR 0.65 [0.54, 0.78], p < 0.00001), or from the time of primary diagnosis (PD survival: HR 0.74 [0.57–0.95], p = 0.02). Dual therapy was also associated with improved local control, indicating an additive effect of the two treatments (HR 0.53 [0.31–0.93], p=0.03). Intracranial hemorrhage was higher in patients receiving BRAF inhibitors plus SRS than in those receiving SRS alone (OR, 3.16 [1.43–6.96], p = 0.004).

Conclusions

BRAF inhibitors in conjunction with SRS as local treatment appear to be efficacious. Local brain control and survival improved in patients with MBM receiving dual therapy. Safety assessment would need to be elucidated further as the incidence of intracranial hemorrhage was increased.

Tumor DNA Mutations From Intraparenchymal Brain Metastases Are Detectable in CSF

Discordant responses between brain metastases and extracranial tumors can arise from branched tumor evolution, underscoring the importance of profiling mutations to optimize therapy. However, the morbidity of brain biopsies limits their use. We investigated whether cell-free DNA (cfDNA) in CSF could serve as an effective surrogate marker for genomic profiling of intraparenchymal (IP) brain metastases.

METHODS

CSF and blood were collected simultaneously from patients with progressive brain metastases undergoing a craniotomy or lumbar puncture. Mutations in both biofluids were measured using an error-suppressed deep sequencing method previously published by our group. Forty-three regions of 24 cancer-associated genes were assayed.

RESULTS

This study enrolled 14 patients with either IP brain metastases (n = 12) or cytology-positive leptomeningeal disease (LMD, n = 2) and two controls with normal pressure hydrocephalus. Primary cancer types were lung, melanoma, renal cell, and colorectal. cfDNA was measurable in all sixteen samples of CSF. Cancer-associated mutations were found in the CSF of ten patients (eight with IP [67%] and two with LMD [100%]) and plasma of five patients (five with IP [42%] and none with LMD). All patients with plasma cfDNA had extracranial tumors. Among the five patients in the cohort who also had mutation data from time-matched brain metastasis tissue, four patients (80%) had matching mutations detected in CSF and brain, whereas only one patient (20%) had matching mutations detected in plasma and brain.

CONCLUSION

The detection of mutational DNA in CSF is not restricted to LMD and was found in two thirds of patients with IP brain metastases in our cohort. Analysis of CSF can be a viable alternative to biopsy for detection of somatic mutations in brain metastases.

Safety of radiosurgery concurrent with systemic therapy (chemotherapy, targeted therapy, and/or immunotherapy) in brain metastases: a systematic review

Stereotactic radiosurgery (SRS) is a standard option for brain metastases (BM). There is lack of consensus when patients have a systemic treatment, if a washout is necessary. The aim of this review is to analyze the toxicity of SRS when it is concurrent with chemotherapies, immunotherapy, and/or targeted therapies. From Medline and Embase databases, we searched for English literature published up to April 2020 according to the PRISMA guidelines, using for key words the list of the main systemic therapies currently in use And "radiosurgery," "SRS," "GKRS," "Gamma Knife," "toxicity," "ARE," "radiation necrosis," "safety," "brain metastases." Studies reporting safety or toxicity with SRS concurrent with systemic treatment for BM were included. Of 852 abstracts recorded, 77 were included. The main cancers were melanoma, lung, breast, and renal carcinoma. These studies cumulate 6384 patients. The median SRS dose prescription was 20 Gy [12-30] .For some, they compared a concurrent arm with a non-concurrent or a SRS-alone arm. There were no skin toxicities, no clearly increased rate of bleeding, or radiation necrosis with significant clinical impact. SRS combined with systemic therapy appears to be safe, allowing the continuation of treatment when brain SRS is considered.

Radiotherapy in combination with systemic therapies for brain metastases: current status and progress

Brain metastases (BMs) are the most common cause of intracranial neoplasms in adults with poor prognosis. Most BMs originate from lung cancer, breast cancer, or melanoma. Radiotherapy (RT), including whole brain radiotherapy (WBRT) and stereotactic radiation surgery (SRS), has been widely explored and is considered a mainstay anticancer treatment for BMs. Over the past decade, the advent of novel systemic therapies has revolutionized the treatment of BMs. In this context, there is a strong rationale for using a combination of treatments based on RT, with the aim of achieving both local disease control and extracranial disease control. This review focuses on describing the latest progress in RT as well as the synergistic effects of the optimal combinations of RT and systemic treatment modalities for BMs, to provide perspectives on current treatments.

An open-label, single-arm, phase II trial of buparlisib in patients with melanoma brain metastases not eligible for surgery or radiosurgery-the BUMPER study

Background

Patients with melanoma brain metastasis (MBM) still carry a dismal prognosis. Preclinical data originated in xenograft models showed that buparlisib therapy was highly effective in therapy-naïve MBM.

Patients and Methods

In this open-label, phase II trial, we investigate the safety and efficacy of monotherapy with buparlisib, a PI3K inhibitor, in patients with asymptomatic MBM who were not candidates for local therapy. These patients had also progressed under immunotherapy if BRAF wild-type or under targeted therapy with BRAF/MEK inhibitors if carrying a BRAFV600E/K mutation. The primary endpoint was the intracranial disease control rate assessed by the investigators. The secondary endpoints were overall response rate, duration of response (DOR) of intracranial disease, overall response, progression-free survival (PFS), overall survival (OS), safety, and tolerability of buparlisib.

Results

A total of 20 patients were screened and 17 patients were treated with buparlisib. Twelve patients had progressed under more than 2 systemic therapy lines and 17 had received at least 1 previous local therapy. There were no intracranial responses. Three patients achieved intracranial stable disease; the median DOR was 117 days. The median PFS was 42 days (95% confidence interval [CI]: 23–61 days) and the median OS was 5.0 months (95% CI: 2.24–7.76 months). No new safety signs were observed.

Conclusions

Buparlisib was well tolerated but no intracranial responses were observed. These results might be explained in part by the inclusion of only heavily pretreated patients. However, preclinical data strongly support the rationale to explore PI3K inhibitor-based combinations in patients with MBM displaying hyperactivation of the PI3K–AKT pathway.

Impact of concomitant systemic treatments on toxicity and intracerebral response after stereotactic radiotherapy for brain metastases

Background

The aim of this study was to determine the safety and efficacy of fractionated stereotactic radiotherapy (SRT) in combination with systemic therapies (ST) for brain metastases (BM).

Methods

Ninety-nine patients (171 BM) received SRT and concurrent ST (group 1) and 95 patients (131 BM) received SRT alone without concurrent ST (group 2). SRT was planned on a linear accelerator, using volumetric modulated arc therapy. All ST were allowed including chemotherapy (CT), immunotherapy (IT), targeted therapy (TT) and hormonotherapy (HT). Treatment was considered to be concurrent if the timing between the drug administration and SRT did not exceed 1 month. Local control (LC), freedom for distant brain metastases (FFDBM), overall survival (OS) and radionecrosis (RN) were evaluated.

Results

After a median follow-up of 11.9 months (range 0.7–29.7), there was no significant difference between the two groups. However, patients who received concurrent IT (n = 30) had better 1-year LC, OS, FFDBM but a higher RN rate compared to patients who did not: 96% versus 78% (p = 0.02), 89% versus 77% (p = 0.02), 76% versus 53% (p = 0.004) and 80% versus 90% (p = 0.03), respectively. In multivariate analysis, concurrent IT (p = 0.022) and tumor volume < 2.07 cc (p = 0.039) were significantly correlated with improvement of LC. The addition of IT to SRT compared to SRT alone was associated with an increased risk of RN (p = 0.03).

Conclusion

SRT delivered concurrently with IT seems to be associated with improved LC, FFDBM and OS as well as with a higher rate of RN.

Quantification of Scheduling Impact on Safety and Efficacy Outcomes of Brain Metastasis Radio- and Immuno-Therapies: A Systematic Review and Meta-Analysis

Objectives: The goal of this quantitative research was to evaluate the impact of various factors (e.g., scheduling or radiotherapy (RT) type) on outcomes for RT vs. RT in combination with immune checkpoint inhibitors (ICI), in the treatment of brain metastases, via a meta-analysis. Methods: Clinical studies with at least one ICI+RT treatment combination arm with brain metastasis patients were identified via a systematic literature search. Data on 1-year overall survival (OS), 1-year local control (LC) and radionecrosis rate (RNR) were extracted; for combination studies which included an RT monotherapy arm, odds ratios (OR) for the aforementioned endpoints were additionally calculated and analyzed. Mixed-effects meta-analysis models were tested to evaluate impact on outcome, for different factors such as combination treatment scheduling and the type of ICI or RT used. Results: 40 studies representing a total of 4,359 patients were identified. Higher 1-year OS was observed in ICI and RT combination vs. RT alone, with corresponding incidence rates of 59% [95% CI: 54-63%] vs. 32% [95% CI: 25-39%] (P < 0.001). Concurrent ICI and RT treatment was associated with significantly higher 1-year OS vs. sequential combinations: 68% [95% CI: 60-75%] vs. 54% [95% CI: 47-61%]. No statistically significant differences were observed in 1-year LC and RNR, when comparing combinations vs. RT monotherapies, with 1-year LC rates of 68% [95% CI: 40-90%] vs. 72% [95% CI: 63-80%] (P = 0.73) and RNR rates of 6% [95% CI: 2-13%] vs. 9% [95% CI: 5-14%] (P = 0.37). Conclusions: A comprehensive, study-level meta-analysis of brain metastasis disease treatments suggest that combinations of RT and ICI result in higher OS, yet comparable neurotoxicity profiles vs. RT alone, with a superiority of concurrent vs. sequential combination regimens. A similar meta-analysis using patient-level data from past trials, as well as future prospective randomized trials would help confirming these findings.

Changing Therapeutic Landscape for Melanoma With Multiple Brain Metastases

Over 90 000 people are expected to be diagnosed with melanoma in the United States this year. The development of brain metastases is particularly difficult to manage. Over the past few years, melanoma patients with multiple unresectable brain metastases for which stereotactic surgery might also not be a viable option have fortunately experienced a dramatic expansion in available management options given improvements made to targeted agents, immunotherapy, and radiotherapy. Whole-brain radiation therapy (WBRT) is a long-standing radiation technique that has become increasingly sophisticated. In this review, we summarize retrospective and prospective studies on individual advances in targeted agents, immunotherapy, and WBRT, highlighting important variables such as overall survival, intracranial progression-free survival, control and response rates, and toxicities. We also discuss the recent integration of these therapies into a multimodality approach, which has shown promise in the clinical setting although toxicities have not been insignificant. Finally, we describe ongoing prospective trials relevant to melanoma with brain metastases, and we conclude with our own thoughts on the optimal approach for these patients.

Impact of Tyrosine Kinase Inhibitors (TKIs) Combined With Radiation Therapy for the Management of Brain Metastases From Renal Cell Carcinoma

Background: Targeted therapy has transformed the outcome for patients with metastatic renal cell carcinoma. Their efficacy and safety have also been demonstrated in brain metastatic RCC. Preclinical evidence suggests synergism of radiation and tyrosine kinase inhibitors. Consequently, several studies have compared their efficacy in the treatment of RCC brain metastases to the era of brain management with surgery/radiation only.

Objectives: We seek to systematically review and meta-analyze the results of those studies that involved comparative intervention groups of brain management; TKIs, and never used TKIs.

Methods and Materials: Online databases (PubMed, EMBASE, Cochrane library, and ClinicalTrials.gov) were searched for comparative studies. Overall survival as the primary outcome of interest, and local brain control, distant control, and adverse events as secondary outcomes of interest were recorded for meta-analysis. Hazard ratios were pooled together using Review Manager 5.3. Fixed effects or random effects model were adopted according to the level of heterogeneity. Subgroup analysis included studies that involved SRS as the local treatment of management.

Results: Overall 7 studies (n = 897) were included for meta-analysis. TKI use was associated with better survival (HR 0.60 [0.52, 0.69], p < 0.00001) and local brain control (HR 0.34 [0.11, 0.98], p = 0.05). SRS subgroup also revealed significantly better survival (HR 0.61 [0.44, 0.83], p = 0.002) and local brain control (HR 0.19 [0.08, 0.45], p = 0.0002). Distant brain control (HR 0.95 [0.67, 1.35], p = 0.79) and brain progression free survival were unaffected (HR 0.94 [0.56, 1.56], p = 0.80). Only one study (n = 376) reported significantly greater 12-months cumulative incidence of radiation necrosis with TKI use within 30 days of SRS (10.9 vs. 6.4%, p = 0.04).

Conclusions: TKIs use in combination with SRS is safe and effective for treating RCC brain metastases. Larger randomized controlled trials are warranted to validate the results.

Acute neurological adverse events during immune checkpoint inhibition therapy in patients with melanoma brain metastases

The common adverse effects of immune checkpoint blockade therapy are well recognised. However, neurological adverse effects of checkpoint inhibitor therapy are less widely appreciated, and their clinical management remains challenging. Therefore, we report our experience of managing acute, life-threatening neurological toxicity during immune checkpoint inhibitor therapy. Five male patients with stage IV melanoma underwent anti-programmed cell death protein 1 therapy (monotherapy or combination therapy with anti-cytotoxic T-lymphocyte antigen-4 antibodies) and developed severe neurological symptoms and signs including headache, hemiparesis and dysarthria. The initial diagnosis of brain metastases actually occurred after initiation of checkpoint inhibitor therapy in three of the patients, whereas two patients had pre-existing central nervous metastases and developed cerebral oedema and haemorrhage during immunotherapy. A rapidly fatal outcome occurred in two patients treated with immunotherapy following the development of BRAF-inhibitor and MEK-inhibitor resistance. Four of the patients died owing to neurological complications, and one achieved a complete cerebral response. Immunotherapy and tumour progression can both result in the development of neurological symptoms and signs, making it difficult to determine causality. However, the temporal relationship between the development of neurological symptoms and the first administration of therapy means that patients should be closely monitored for the development of neurological sequelae, which may even herald the presence of occult brain metastases. The decision on whether to continue immunotherapy must balance the risks of symptom - versus disease progression. However, in our case series, it is encouraging to note that the initial acute neurological symptoms were often transient. Nevertheless, pretherapeutic brain imaging to exclude occult brain metastases and stratify the risk of intracerebral oedema and haemorrhage should be considered.

Tumor Primary Site and Histology Subtypes Role in Radiotherapeutic Management of Brain Metastases

Randomized controlled trials have failed to report any survival advantage for WBRT combined with SRS in the management of brain metastases, despite the enhanced local and distant control in comparison to each treatment alone. Literature review have revealed important role of primary histology of the tumor when dealing with brain metastases. NSCLC responds better to combined approach even when there was only single brain metastasis present while breast cancer has registered better survival with SRS alone probably due to better response of primary tumor to advancement in surgical and chemotherapeutic agents. Furthermore, mutation status (EGFR/ALK) in lung cancer and receptor status (ER/PR/HER2) in breast cancer also exhibit diversity in their response to radiotherapy. Radioresistant tumors like renal cell carcinoma and melanoma brain metastases have achieved better results when treated with SRS alone. Secondly, single brain metastasis may benefit from local and distant brain control achieved with combined treatment. These diverse outcomes suggest a primary histology-based analysis of the radiotherapy regimens (WBRT, SRS, or their combination) would more ideally establish the role of radiotherapy in the management of brain metastases. Molecularly targeted therapeutic and immunotherapeutic agents have revealed synergism with radiation therapy particularly SRS in treating cancer patients with brain metastases. Clinical updates in this regard have also been reviewed.

Stereotactic radiosurgery combined with anti-PD1 for the management of melanoma brain metastases: A retrospective study of safety and efficacy

BACKGROUND

Brain metastases can be effectively treated with stereotactic radiosurgery (SRS). Immune checkpoint inhibitors are now pivotal in metastatic melanoma care, but some concerns have emerged regarding the safety of their combination with radiation therapy.

METHODS

We present a retrospective analysis of a cohort of patients treated by anti-PD1 and SRS as a sole modality of radiation therapy (no whole brain radiation therapy at any time) in a single institution. We included patients on anti-PD1 at the time of SRS or patients who started anti-PD1 within a maximum period of 3 months following SRS and were treated at least one year before the analysis. Clinical and serial imaging data were reviewed to determine the efficacy and the rate of adverse radiation effectss of the combination.

RESULTS

A total of 50 patients were included. SRS targeted 1, 2 to 3 and >3 brain metastases in 17, 16 and 17 patients, respectively. Two patients died before the first evaluation. Nine patients presented with an increase in peritumoral oedema, three with intracranial haemorrhage and one patient with both oedema and haemorrhage. Median follow-up was 38.89 months (interquartile range 24.43; 45.28). Median overall survival from SRS was 16.62 months with 1-, 2- and 3-year rates of 60%, 40% and 35%, respectively. Median brain-Progression Free Survival was 13.2 months with 1, 2 and 3-year rates of 62.1%, 49.7% and 49.7%, respectively.

CONCLUSIONS

This real-world cohort of patients treated with a homogeneous strategy combining upfront stereotactic radiosurgery and anti-PD1 shows remarkable survival rates and does not reveal unexpected toxicity.

Upregulation of cell surface GD3 ganglioside phenotype is associated with human melanoma brain metastasis

Melanoma metastasis to the brain is one of the most frequent extracranial brain tumors. Cell surface gangliosides are elevated in melanoma metastasis; however, the metabolic regulatory mechanisms that govern these specific changes are poorly understood in melanoma particularly brain metastases (MBM) development. We found ganglioside GD3 levels significantly upregulated in MBM compared to lymph node metastasis (LNM) but not for other melanoma gangliosides. Moreover, we demonstrated an upregulation of ST8SIA1 (GD3 synthase) as melanoma progresses from melanocytes to MBM cells. Using RNA‐ISH on FFPE specimens, we evaluated ST8SIA1 expression in primary melanomas (PRM) (n = 23), LNM and visceral metastasis (n = 45), and MBM (n = 39). ST8SIA1 was significantly enhanced in MBM compared to all other specimens. ST8SIA1 expression was assessed in clinically well‐annotated melanoma patients from multicenters with AJCC stage III B‐D LNM (n = 58) with 14‐year follow‐up. High ST8SIA1 expression was significantly associated with poor overall survival (HR = 3.24; 95% CI, 1.19–8.86, P = 0.02). In a nude mouse human xenograft melanoma brain metastasis model, MBM variants had higher ST8SIA1 expression than their respective cutaneous melanoma variants. Elevated ST8SIA1 expression enhances levels of cell surface GD3, a phenotype that favors MBM development, hence associated with very poor prognosis. Functional assays demonstrated that ST8SIA1 overexpression enhanced cell proliferation and colony formation, whereby ST8SIA1 knockdown had opposite effects. Icaritin a plant‐derived phytoestrogen treatment significantly inhibited cell growth in high GD3‐positive MBM cells through targeting the canonical NFκB pathway. The study demonstrates GD3 phenotype associates with melanoma progression and poor outcome.

Predicting survival in melanoma patients treated with concurrent targeted- or immunotherapy and stereotactic radiotherapy : Melanoma brain metastases prognostic score

Background

Melanoma patients frequently develop brain metastases. The most widely used score to predict survival is the molGPA based on a mixed treatment of stereotactic radiotherapy (SRT) and whole brain radiotherapy (WBRT). In addition, systemic therapy was not considered. We therefore aimed to evaluate the performance of the molGPA score in patients homogeneously treated with SRT and concurrent targeted therapy or immunotherapy (TT/IT).

Methods

This retrospective analysis is based on an international multicenter database (TOaSTT) of melanoma patients treated with TT/IT and concurrent (≤30 days) SRT for brain metastases between May 2011 and May 2018. Overall survival (OS) was studied using Kaplan-Meier survival curves and log-rank testing. Uni- and multivariate analysis was performed to analyze prognostic factors for OS.

Results

One hundred ten patients were analyzed. 61, 31 and 8% were treated with IT, TT and with a simultaneous combination, respectively. A median of two brain metastases were treated per patient. After a median follow-up of 8 months, median OS was 8.4 months (0–40 months). The molGPA score was not associated with OS. Instead, cumulative brain metastases volume, timing of metastases (syn- vs. metachronous) and systemic therapy with concurrent IT vs. TT influenced OS significantly. Based on these parameters, the VTS score (volume-timing-systemic therapy) was established that stratified patients into three groups with a median OS of 5.1, 18.9 and 34.5 months, respectively (p = 0.001 and 0.03).

Conclusion

The molGPA score was not useful for this cohort of melanoma patients undergoing local therapy for brain metastases taking into account systemic TT/IT. For these patients, we propose a prognostic VTS score, which needs to be validated prospectively.

Severe Radiation Necrosis Refractory to Surgical Resection in Patients with Melanoma and Brain Metastases Managed with Ipilimumab/Nivolumab and Brain-Directed Stereotactic Radiation Therapy

BACKGROUND

The use of targeted therapies and immune checkpoint inhibitors has drastically changed the management of patients with melanoma and brain metastases. Specifically, combination therapy with ipilimumab, a cytotoxic T-lymphocyte antigen 4 inhibitor, and nivolumab, a programmed cell death protein 1 inhibitor, has become a preferred systemic therapy option for patients with melanoma and asymptomatic brain metastases. However, the efficacy and toxicity profile of these agents in combination with brain-directed radiation therapy is not well described.

CASE DESCRIPTION

In this case series, we highlight a series of patients with melanoma demonstrating severe radiation necrosis immediately refractory to surgical resection following brain-directed stereotactic radiation therapy with concurrent ipilimumab and nivolumab. Three patients described in this series each received stereotactic radiation therapy to a dose of 30 Gy in 5 fractions to a melanoma brain metastasis. These areas developed radiographic evidence of necrosis, which was managed surgically and progressed immediately and rapidly after resection. Re-resection, bevacizumab, steroids, and/or discontinuation of nivolumab was used to mitigate further necrosis with varying efficacy.

CONCLUSIONS

Patients with metastatic melanoma receiving brain-directed radiation therapy with concurrent ipilimumab and nivolumab are at risk for developing severe, surgically refractory radiation necrosis and should be closely followed clinically and with imaging. The exact mechanism for such severe necrosis is unknown, and future studies are needed to better understand this pathophysiology and identify optimal treatment strategies.

Stereotactic radiosurgery combined with targeted/ immunotherapy in patients with melanoma brain metastasis

BACKGROUND

There is limited data on the use of targeted or immunotherapy (TT/IT) in combination with single fraction stereotactic radiosurgery (SRS) in patients with melanoma brain metastasis (MBM). Therefore, we analyzed the outcome and toxicity of SRS alone compared to SRS in combination with TT/IT.

METHODS

Patients with MBM treated with single session SRS at our department between 2014 and 2017 with a minimum follow-up of 3 months after first SRS were included. The primary endpoint of this study was local control (LC). Secondary endpoints were distant intracranial control, radiation necrosis-free survival (RNFS), and overall survival (OS). The local/ distant intracranial control rates, RNFS and OS were analyzed using the Kaplan-Meier method. The log-rank test was used to test differences between groups. Cox proportional hazard model was performed for univariate continuous variables and multivariate analyses.

RESULTS

Twenty-eight patients (17 male and 11 female) with 52 SRS-lesions were included. The median follow-up was 19 months (range 14-24 months) after first SRS. Thirty-six lesions (69.2%) were treated with TT/IT simultaneously (4 weeks before and 4 weeks after SRS), while 16 lesions (30.8%) were treated with SRS alone or with sequential TT/IT. The 1-year local control rate was 100 and 83.3% for SRS with TT/IT and SRS alone (p = 0.023), respectively. The estimated 1-year RNFS was 90.0 and 82.1% for SRS in combination with TT/IT and SRS alone (p = 0.935). The distant intracranial control rate after 1 year was 47.7 and 50% for SRS in combination with TT/IT and SRS alone (p = 0.933). On univariate analysis, the diagnosis-specific Graded Prognostic Assessment including the BRAF status (Melanoma-molGPA) was associated with a significantly improved LC. Neither gender nor SRS-PTV margin had a prognostic impact on LC. V10 and V12 were significantly associated with RNFS (p < 0.001 and p = 0.004).

CONCLUSION

SRS with simultaneous TT/IT significantly improved LC with no significant difference in radiation necrosis rate. The therapy combination appears to be effective and safe. However, prospective studies on SRS with simultaneous TT/IT are necessary and ongoing.

TRIAL REGISTRATION

The institutional review board approved this analysis on 10th of February 2015 and all patients signed informed consent (UE nr. 128-14).

Hypofractionated radiation therapy with versus without immune checkpoint inhibitors in patients with brain metastases: A meta-analysis

INTRODUCTION

The efficacy and safety of hypofractionated radiation therapy (HFRT) combined with immune checkpoint inhibitors (ICIs) in patients with brain metastases (BM) remain controversial. This meta-analysis was performed to compare the efficacy and safety of HFRT with and without ICIs in BM patients.

MATERIALS AND METHODS

PubMed, Embase, and Cochrane Library were searched up to 25 December 2018 for studies that compared the efficacy and safety of HFRT with and without ICIs in BM patients.

RESULTS

Twenty-four studies involving 2,365 patients were included in this analysis. Compared with those of HFRT without ICIs, the 6-month locoregional recurrence-free survival (LRFS) rate (P = 0.002), 6-month overall survival (OS) rate (P = 0.001), 1-year OS rate (P = 0.001), 2-year OS rate (P = 0.007), and median OS (mOS) (P < 0.001) were significantly improved in combined HFRT and ICI treatment. A trend toward improved 1-year LRFS rate (P = 0.392) and 3-year OS rate (P = 0.266) for the ICI arm was observed compared with the non-ICI arm, although there was no statistically significant difference between the two arms. No significant difference in toxicity was found between the two arms (radionecrosis: P = 0.361; BM hemorrhage: P = 0.738).

CONCLUSIONS

Compared with HFRT without ICIs, the combination of these two therapies improved efficacy but did not increase toxicity in patients with BM.