Stereotactic radiosurgery and ipilimumab for patients with melanoma brain metastases: clinical outcomes and toxicity

'Immunotherapeutic Strategies for Intra-cranial Metastatic Melanoma - a Meta-analysis and Systematic Review'

Immune-activating anti-CTLA4 and anti-PD1 monoclonal antibodies (alone or in combination) are being used to treat advanced melanoma patients and can lead to durable remissions, and long-term overall survival may be achieved in between 50-60% of patients. Although intracranial metastases are very common in melanoma (about 50-75% of all patients with advanced disease), most of the pivotal prospective clinical trials exclude patients with intra-cranial metastases, certainly if their lesions are symptomatic and steroid-requiring and the degree of sensitivity of intra-cranial melanoma to immunotherapy remains uncertain, and requires further investigation especially in view of the demonstrable activity of RAF-MEK inhibitors in this clinical setting and the emergence of stereotactic radiotherapy. Our study aimed to evaluate the efficacy and toxicity of immunotherapy against advanced melanoma patients with brain metastases. In terms of comparative studies, only retrospective analyses could be identified. Based on 3 retrospective studies, treatment of patients with melanoma brain metastases with immunotherapeutic approaches improves overall survival substantially compared with supportive measures alone (no active anticancer treatment). The efficacy of targeted therapy appeared to be comparable to that of immune therapy in terms of overall survival, based on a small number of patients. The combination of concurrent radiation therapy to the brain and systemic immunotherapy led to improved overall survival compared to radiotherapy alone, suggesting potential synergism between the approaches, and combination treatment could be delivered safely. Our review supports the use of immunotherapeutic strategies for these patients although treatment efficacy appears to be lower for symptomatic lesions. In view of the extremely high efficacy of stereotactic radiotherapy approaches in the brain, understanding the interaction between radiotherapy and immunotherapy is vital and should be an area of active investigation.

Role of radiotherapy in the management of brain oligometastases

The management of patients with brain oligometastases is complex and relies on specific reasoning compared to extracranial oligometastases. The levels of evidence are still low because patients with brain oligometastases are frequently excluded from randomized clinical trials. Stereotactic radiotherapy should be preferred in this indication over whole brain irradiation, both for patients with metastases in place and for those who have undergone surgery. The decision of local treatment and its timing must be a multidisciplinary reflection taking into account the histological and molecular characteristics of the tumor as well as the intracranial efficacy of the prescribed systemic treatments. Great caution must be observed when using stereotactic radiotherapy and concomitant systemic treatments because interactions are still poorly documented. We present the recommendations of the French society of radiation oncology on the management of brain oligometastatic patients with radiotherapy.

Which is the best treatment for melanoma brain metastases? A Bayesian network meta-analysis and systematic review

OBJECTIVE

Melanoma has a high degree of central nervous system tropism, and there are many treatment modalities for melanoma brain metastases (MBM). The efficacy and toxicity of various treatments are still controversial. Therefore, they were evaluated by direct and indirect comparison to assist clinical decision-making in this study.

METHOD

A total of 7 therapeutic modalities for MBM were studied. Retrieval was conducted through Embase, PubMed, Cochrane Library and Web of science databases and the quality of the included literature was evaluated. Meta-analysis and Bayesian network meta-analysis were performed using Review Manager and R language.

RESULTS

A total of 10 articles were included with 836 MBM patients. Direct comparison showed that stereotactic radiotherapy combined with immunotherapy (SRS + IT) was superior to IT (HR = 0.66, 95%CI = 0.52-0.84) or SRS (HR = 0.81, 95%CI = 0.63-1.03) alone in improving intracranial progression-free survival (PFS). In terms of overall survival (OS), SRS + IT was superior to SRS alone (HR = 0.64, 95%CI = 0.49-0.83), or IT (HR = 0.59, 95%CI = 0.29-1.21). Rank probability and surface under the cumulative ranking curve (SUCRA) by indirect comparison showed that SRS + IT had the best effect on improving intracranial PFS (0.88) and OS (0.98). Additionally, various combination therapies, especially SRS + IT (0.72), increased the incidence of radiation necrosis (RN). In direct comparisons, SRS + IT (RR = 0.93, 95%CI = 0.47-1.83) and SRS + TT (targeted therapy) (RR = 0.24, 95%CI = 0.10-0.56) did not increase intracranial hemorrhage (ICH) compared with SRS.

CONCLUSIONS

SRS + IT treatment was the best choice for MBM patients in both intracranial PFS and OS, even though it also led to an increased probability of RN.

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.

Whole brain radiation therapy resulting in radionecrosis: a possible link with radiosensitising chemoimmunotherapy

Radionecrosis describes a rare but serious complication of radiation therapy. In clinical practice, stereotactic radiosurgery (SRS) is increasingly used in combination with systemic therapy, including chemotherapy, immune checkpoint inhibitor and targeted therapy, either concurrently or sequentially. There is a paucity of literature regarding radionecrosis in patients receiving whole brain radiation therapy (WBRT) alone (without additional SRS) in combination with immunotherapy or targeted therapies. It is observed that certain combinations increase the overall radiosensitivity of the tumorous lesions. We present a rare case of symptomatic radionecrosis almost 1 year after WBRT in a patient with non-squamous non-small cell lung cancer on third-line chemoimmunotherapy. We discuss available research regarding factors that may lead to radionecrosis in these patients, including molecular and genetic profiles, specific drug therapy combinations and their timing or increased overall survival.

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.

The Role of Radiotherapy in the Management of Vaginal Melanoma: A Literature Review with a Focus on the Potential Synergistic Role of Immunotherapy

Among the mucosal melanomas, vaginal melanomas are very rare tumors, accounting for less than 20% of melanomas arising from the female genital tract. They occur most frequently in women in post-menopausal age, but younger patients may also experience this neoplasm, mainly located in the lower third of the vagina or the anterior wall. The optimal management of this tumor remains controversial, with surgery reported as the most frequently adopted approach. However, a clear benefit of surgical treatment in terms of survival has not yet been demonstrated. Conversely, radiotherapy may represent an attractive non-invasive alternative, and there are several favorable reports of the role of radiation therapy, either delivered with photons, brachytherapy, or hadrontherapy. A wide range of techniques and fractionation regimens are reported with substantially good tolerance to the treatment, and acute G3 or higher toxicities are reported only in the case of concurrent immunotherapy. Of note, due to the rarity of the disease, there is a lack of high-level evidence for the optimal therapeutic option. In this scenario, recent studies theorize the possibility of developing combinatorial approaches of radiotherapy with immunotherapy based on cutaneous melanomas reports. In this review, we aim to summarize the evidence available in the literature supporting the role of definitive radiotherapy for vaginal melanomas, with a focus on the combination of RT with immunotherapy, in terms of optimal timing and biological rationale.

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.

Stereotactic radiosurgery and combined immune checkpoint therapy with ipilimumab and nivolumab in patients with melanoma brain metastases: A retrospective monocentric toxicity analysis

Purpose and objective

Adding stereotactic radiosurgery (SRS) to combined immune checkpoint therapy with ipilimumab and nivolumab (IPI + NIVO) has led to promising results for patients with melanoma brain metastases (MBM). This study retrospectively analyzes the toxicity profile depending on the timing of SRS with regard to IPI + NIVO.

Materials and methods

For this study, the clinical database was searched for all patients with MBM who were treated with SRS and IPI + NIVO. The patients were separated into three groups: group A completed IPI + NIVO (usually up to four cycles) >14 days before SRS, in group B IPI + NIVO was initiated>14 days after SRS, and group C received SRS concurrently to IPI + NIVO. Treatment related toxicity was obtained from clinical and neuroradiological records. Analyses were performed using the Fisher-Yates-test.

Results

31 patients were assessed including six (19.4 %), seven (22.6 %) and 18 (58.1 %) patients, in groups A, B and C, respectively. Baseline prognostic markers between groups were balanced. In total, five (16.1 %) patients experienced neurological grade 3 toxicities related to SRS. All of these five patients were in group C, which was near-significantly correlated with a risk for grade 3 toxicities (p = 0.058). Post-hoc analyses showed that a maximum time period of seven days between SRS and IPI + NIVO was significantly correlated with grade 3 toxicity (p = 0.048).

Conclusion

Application of SRS to IPI + NIVO within a seven-day span was related to higher toxicity rates in this retrospective analysis. After previous studies focused on immune checkpoint monotherapies with SRS and declared it as safe, this study indicates that concomitant application of IPI + NIVO and SRS might increase side effects. Prospective validation is warranted to corroborate these findings.

Efficacy and safety of combined immunotherapy and stereotactic radiosurgery in NSCLCBM patients and a novel prognostic nomogram: A real-world study

Objective

To explore the effectiveness of combined immunotherapy (IT) and stereotactic radiosurgery (SRS) and address the gap between evidence-based clinical practice and academic knowledge of optimal timing of IT relative to SRS. In addition, to meet the unmet need for an up-to-date prognostic assessment model in the era of IT.

Methods

The data of 86 non-small cell lung cancer brain metastasis (NSCLCBM) patients treated with SRS to 268 brain metastases (BMs) were retrospectively extracted from our hospital database. The Kaplan-Meier analysis was employed for overall survival (OS) and a log-rank test for comparison between groups. Cox proportional hazards regression models were used to identify the significant prognostic factors. The prognostic nomogram was established utilizing the rms package of R software.

Results

IT was found to be associated with improved OS (from BM diagnosis: HR 0.363, 95% CI 0.199 - 0.661, P < 0.001; from SRS: HR 0.472, 95% CI 0.260 - 0.857, P = 0.014). Individuals who received IT in combination with SRS had better OS than those who didn't (from the day of BM diagnosis: 16.8 vs. 8.4 months, P = 0.006; from the day of SRS: 12 vs. 7 months, P = 0.037). Peri-SRS timing of IT administration was a significant prognostic factor for OS (from BM diagnosis: HR 0.132, 95% CI 0.034 - 0.517, P = 0.004; from SRS: HR 0.14, 95% CI 0.044 - 0.450, P = 0.001). Initiating IT after SRS led to superior OS than concurrent or before (from BM diagnosis: 26.5 vs. 14.1 vs. 7.1 months; from SRS: 21.4 vs. 9.9 vs. 4.1 months, respectively). Additionally, we build a nomogram incorporating IT, cumulative intracranial tumor volume (CITV), and recursive partitioning analysis (RPA), demonstrating a remarkable prognosis prediction performance for SRS-treated NSCLCBM patients.

Conclusion

Peri-SRS IT is a promising approach in treating NSCLCBM, as improved OS was observed without significantly increasing adverse events. Receipt of IT post-SRS was associated with superior OS than those who received IT concurrently or before. Incorporating IT and CITV into the RPA index could augment its prognosis assessment value for SRS-treated NSCLCBM patients, predominantly in the wild-type.

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.

Radiation therapy for melanoma brain metastases: a systematic review

BACKGROUND

Radiation therapy (RT) for melanoma brain metastases, delivered either as whole brain radiation therapy (WBRT) or as stereotactic radiosurgery (SRS), is an established component of treatment for this condition. However, evidence allowing comparison of the outcomes, advantages and disadvantages of the two RT modalities is scant, with very few randomised controlled trials having been conducted. This has led to considerable uncertainty and inconsistent guideline recommendations. The present systematic review identified 112 studies reporting outcomes for patients with melanoma brain metastases treated with RT. Three were randomised controlled trials but only one was of sufficient size to be considered informative. Most of the evidence was from non-randomised studies, either specific treatment series or disease cohorts. Criteria for determining treatment choice were reported in only 32 studies and the quality of these studies was variable. From the time of diagnosis of brain metastasis, the median survival after WBRT alone was 3.5 months (IQR 2.4-4.0 months) and for SRS alone it was 7.5 months (IQR 6.7-9.0 months). Overall patient survival increased over time (pre-1989 to 2015) but this was not apparent within specific treatment groups.

CONCLUSIONS

These survival estimates provide a baseline for determining the incremental benefits of recently introduced systemic treatments using targeted therapy or immunotherapy for melanoma brain metastases.

Narrative Review of Synergistics Effects of Combining Immunotherapy and Stereotactic Radiation Therapy

Stereotactic radiotherapy (SRT) has become an attractive treatment modality in full bloom in recent years by presenting itself as a safe, noninvasive alternative to surgery to control primary or secondary malignancies. Although the focus has been on local tumor control as the therapeutic goal of stereotactic radiotherapy, rare but intriguing observations of abscopal (or out-of-field) effects have highlighted the exciting possibility of activating antitumor immunity using high-dose radiation. Furthermore, immunotherapy has revolutionized the treatment of several types of cancers in recent years. However, resistance to immunotherapy often develops. These observations have led researchers to combine immunotherapy with SRT in an attempt to improve outcomes. The benefits of this combination would come from the stimulation and suppression of various immune pathways. Thus, in this review, we will first discuss the immunomodulation induced by SRT with the promising results of preclinical studies on the changes in the immune balance observed after SRT. Then, we will discuss the opportunities and risks of the combination of SRT and immunotherapy with the preclinical and clinical data available in the literature. Furthermore, we will see that many perspectives are conceivable to potentiate the synergistic effects of this combination with the need for prospective studies to confirm the encouraging data.

Stereotactic Body Radiation Therapy (SBRT) for Oligorecurrent/Oligoprogressive Mediastinal and Hilar Lymph Node Metastasis: A Systematic Review

Simple Summary

This paper is a review of the literature on oligorecurrent/oligoprogressive mediastinal and hilar lymph node metastasis treated with SBRT. The use of mediastinal SBRT had historically been not feasible in view of the expected toxicity due to the proximity of critical structures such as the airways and esophagus. Despite the heterogeneity and lack of some data in the studies analyzed, this literature review is the first published and can be a valid guide for the radiotherapist in the management of oligometastatic/oligoprogressive patients, with particular regard to the radiotherapy doses, dose constraints for organs at risk, and clinical outcomes.

Abstract

Introduction: Mediastinal or hilar lymph node metastases are a challenging condition in patients affected by solid tumors. Stereotactic body radiation therapy (SBRT) could play a crucial role in the therapeutic management and in the so-called “no-fly zone”, delivering high doses of radiation in relatively few treatment fractions with excellent sparing of healthy surrounding tissues and low toxicity. The aim of this systematic review is to evaluate the feasibility and tolerability of SBRT in the treatment of mediastinal and hilar lesions with particular regard to the radiotherapy doses, dose constraints for organs at risk, and clinical outcomes. Materials and methods: Two blinded investigators performed a critical review of the Medline, Web of Knowledge, Google Scholar, Scopus, and Cochrane databases according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement (PRISMA), starting from a specific question: What is the clinical impact of SBRT for the treatment of oligorecurrent/oligoprogressive mediastinal and hilar metastasis? All retrospective and prospective clinical trials published in English up to February 2022 were analyzed. Results: A total of 552 articles were identified and 12 of them were selected with a total number of 478 patients treated with SBRT for mediastinal or hilar node recurrence. All the studies are retrospective, published between 2015 and 2021 with a median follow-up ranging from 12 to 42.2 months. Studies following SBRT for lung lesions or retreatments after thorax radiotherapy for stage III lung cancer were also included. The studies showed extensive heterogeneity in terms of patient and treatment characteristics. Non-small cell lung cancer was the most frequently reported histology. Different dose schemes were used, with a higher prevalence of 4–8 Gy in 5 or 6 fractions, but dose escalation was also used up to 52 Gy in 4 fractions with dose constraints mainly derived from RTOG 0813 trial. The radiotherapy technique most frequently used was volumetric modulated arc therapy (VMAT) with a median PTV volume ranging from 7 to 25.7 cc. The clinical outcome seems to be very encouraging with 1-year local control (LC), overall survival (OS) and progression-free survival (PFS) rates ranging from 84 to 94%, 53 to 88% and 23 to 53.9%, respectively. Half of the studies did not report toxicity greater than G3 and only five cases of fatal toxicity were reported. CONCLUSIONS: From the present review, it is not possible to draw definitive conclusions because of the heterogeneity of the studies analyzed. However, SBRT appears to be a safe and effective option in the treatment of mediastinal and hilar lymph node recurrence, with a good toxicity profile. Its use in clinical practice is still limited, and there is extensive heterogeneity in patient selection and fractionation schedules. Good performance status, small PTV volume, absence of previous thoracic irradiation, and administration of a high biologically effective dose (BED) seem to be factors that correlate with greater local control and better survival rates. In the presence of symptoms related to the thoracic lymph nodes, SBRT determines a rapid control that lasts over time. We look forward to the prospective studies that are underway for definitive conclusions.

[Expert Consensus on the Treatment of Antiangiogenic Agents for Radiation Brain Necrosis]

Vascular damage is followed by vascular endothelial growth factor (VEGF) expression at high levels, which is an important mechanism for cerebral radiation necrosis (CRN) development. Antiangiogenic agents (Bevacizumab) alleviates brain edema symptoms caused by CRN through inhibiting VEGF and acting on vascular tissue around the brain necrosis area. Many studies have confirmed that Bevacizumab effectively relieves symptoms caused by brain necrosis, improves patients' performance status and brain necrosis imaging. Considering that the efficacy of antiangiogenic therapy is mainly related to the duration of drug action, low-dose antiangiogenic agents can achieve favorable efficacy. Prevention is the best treatment. The occurrence of CRN is associated with tumor-related factors and treatment-related factors. By controlling these factors, CRN can be effectively prevented.
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Melanoma Brain Metastases: An Update on the Use of Immune Checkpoint Inhibitors and Molecularly Targeted Agents

Brain metastases from melanoma are no longer uniformly associated with dismal outcomes. Impressive tumor tissue-based (craniotomy) translational research has consistently shown that distinct patient subgroups may have a favorable prognosis. This review provides a historical overview of the standard-of-care treatments until the early 2010s. It subsequently summarizes more recent advances in understanding the biology of melanoma brain metastases (MBMs) and treating patients with MBMs, mainly focusing upon prospective clinical trials of BRAF/MEK and PD-1/CTLA-4 inhibitors in patients with previously untreated MBMs. These additional systemic treatments have provided effective complementary treatment approaches and/or alternatives to radiation and craniotomy. The current role of radiation therapy, especially in conjunction with systemic therapies, is also discussed through the lens of various retrospective studies. The combined efficacy of systemic treatments with radiation has improved overall survival over the last 10 years and has sparked considerable research interest regarding optimal dosing and sequencing of radiation treatments with systemic treatments. Finally, the review describes ongoing clinical trials in patients with MBMs.

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.

Luteolin binds Src, promotes STAT3 protein ubiquitination and exerts anti-melanoma effects in cell and mouse models

Signal transducer and activator of transcription 3 (STAT3) has been proposed as a target for melanoma prevention. Luteolin, a bioactive flavonoid abundant inmedicinal herbs, has been reported to have anti-melanoma activity in vitro. However, its in vivo anti-melanoma effects and underlying mechanisms have not been fully elucidated. In this study, ten cell lines and two mouse models (B16F10 allograft and A375 xenograft models) were used for assessing the in vitro and in vivo anti-melanoma effects of luteolin. A STAT3 over-activated stable A375 cell line was used to determine the contribution of STAT3 signaling in luteolin's anti-melanoma effects. Results showed that luteolin dose-dependently reduced viability of melanoma cells. Luteolin also induced apoptosis in, and suppressed migration and invasion of, A375 and B16F10 melanoma cells. Mechanistically, luteolin inhibited phosphorylation of STAT3 and Src (an upstream kinase of STAT3), accelerated ubiquitin-proteasome pathway-mediated STAT3 degradation, and downregulated the expression of STAT3-targeted genes involved in cell survival and invasion in melanoma cells. Molecular modelling and surface plasmon resonance imaging showed that luteolin stably bound to the protein kinase domain of Src. Animal studies demonstrated that prophylactic administration of luteolin restrained melanoma growth and Src/STAT3 signaling in both A375 and B16F10 melanoma-bearing mice. Moreover, luteolin's anti-melanoma effects were diminished by STAT3 over-activation in A375 cells. Our findings indicate that luteolin inhibits STAT3 signaling by suppressing STAT3 activation and promoting STAT3 protein degradation in melanoma cells, thereby exhibiting anti-melanoma effects. This study provides further pharmacological groundwork for developing luteolin as a chemopreventive agent against melanoma.

Focal Radiotherapy of Brain Metastases in Combination With Immunotherapy and Targeted Drug Therapy

BACKGROUND

Advances in systemic treatment and in brain imaging have led to a higher incidence of diagnosed brain metastases. In the treatment of brain metastases, stereotactic radiotherapy and radiosurgery, systemic immunotherapy, and targeted drug therapy are important evidence-based options. In this review, we summarize the available evidence on the treatment of brain metastases of the three main types of cancer that give rise to them: non-small-cell lung cancer, breast cancer, and malignant melanoma.

METHODS

This narrative review is based on pertinent original articles, meta-analyses, and systematic reviews that were retrieved by a selective search in PubMed. These publications were evaluated and discussed by an expert panel including radiation oncologists, neurosurgeons, and oncologists.

RESULTS

There have not yet been any prospective randomized trials concerning the optimal combination of local stereotactic radiotherapy/radiosurgery and systemic immunotherapy or targeted therapy. Retrospective studies have consistently shown a benefit from early combined treatment with systemic therapy and (in particular) focal radiotherapy, compared to sequential treatment. Two metaanalyses of retrospective data from cohorts consisting mainly of patients with non-small-cell lung cancer and melanoma revealed longer overall survival after combined treatment with focal radiotherapy and checkpoint inhibitor therapy (rate of 12-month overall survival for combined versus non-combined treatment: 64.6% vs. 51.6%, p <0.001). In selected patients with small, asymptomatic brain metastases in non-critical locations, systemic therapy without focal radiotherapy can be considered, as long as follow-up with cranial magnetic resonance imaging can be performed at close intervals.

CONCLUSION

Brain metastases should be treated by a multidisciplinary team, so that the optimal sequence of local and systemic therapies can be determined for each individual patient.

Stereotactic body ablative radiotherapy for reirradiation of small volume head and neck cancers is associated with prolonged survival: Large, single-institution, modern cohort study

BACKGROUND

Recurrent head and neck cancer has poor prognosis. Stereotactic body radiotherapy (SBRT) may improve outcomes by delivering ablative radiation doses.

METHODS

We reviewed patients who received definitive-intent SBRT reirradiation at our institution from 2013 to 2020. Patterns of failure, overall survival (OS), and toxicities were analyzed.

RESULTS

One hundred and thirty-seven patients were evaluated. The median OS was 44.3 months. The median SBRT dose was 45 Gy and median target volume 16.9 cc. The 1-year local, regional, and distant control was 78%, 66%, and 83%, respectively. Systemic therapy improved regional (p = 0.004) and distant control (p = 0.04) in nonmetastatic patients. Grade 3+ toxicities were more common at mucosal sites (p = 0.001) and with concurrent systemic therapy (p = 0.02).

CONCLUSIONS

In a large cohort of SBRT reirradiation for recurrent, small volume head and neck cancers, a median OS of 44.3 months was observed. Systemic therapy improved regional and distant control. Toxicities were modulated by anatomic site and systemic therapy.

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.

Intermittent radiotherapy as alternative treatment for recurrent high grade glioma: a modeling study based on longitudinal tumor measurements

Recurrent high grade glioma patients face a poor prognosis for which no curative treatment option currently exists. In contrast to prescribing high dose hypofractionated stereotactic radiotherapy (HFSRT, [Formula: see text] Gy [Formula: see text] 5 in daily fractions) with debulking intent, we suggest a personalized treatment strategy to improve tumor control by delivering high dose intermittent radiation treatment (iRT, [Formula: see text] Gy [Formula: see text] 1 every 6 weeks). We performed a simulation analysis to compare HFSRT, iRT and iRT plus boost ([Formula: see text] Gy [Formula: see text] 3 in daily fractions at time of progression) based on a mathematical model of tumor growth, radiation response and patient-specific evolution of resistance to additional treatments (pembrolizumab and bevacizumab). Model parameters were fitted from tumor growth curves of 16 patients enrolled in the phase 1 NCT02313272 trial that combined HFSRT with bevacizumab and pembrolizumab. Then, iRT +/- boost treatments were simulated and compared to HFSRT based on time to tumor regrowth. The modeling results demonstrated that iRT + boost(- boost) treatment was equal or superior to HFSRT in 15(11) out of 16 cases and that patients that remained responsive to pembrolizumab and bevacizumab would benefit most from iRT. Time to progression could be prolonged through the application of additional, intermittently delivered fractions. iRT hence provides a promising treatment option for recurrent high grade glioma patients for prospective clinical evaluation.

VEGF and Immune Checkpoint Inhibition for Prevention of Brain Metastases: Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVES

We conducted a systematic review and meta-analysis to investigate the role of vascular endothelial growth factor (VEGF) inhibitors and immune checkpoint inhibitors (ICIs) in preventing the development of brain metastases (BMs).

METHODS

We searched MEDLINE, Embase, Cochrane Database, and Google Scholar between January 1, 2000, and June 1, 2020. Included studies were randomized controlled trials (RCTs) of adults with systemic cancer that reported the incidence of BMs treated with and without VEGF inhibitors, as well as observational studies of adults with systemic cancer that reported the incidence of BMs treated with and without ICIs (no RCTs addressed the ICI question). Pooled relative risks (RR) were computed with a binary random-effects model.

RESULTS

A search for VEGF and incidence of new BMs revealed 7 studies (6,212 patients with breast, colon, and non-small-cell lung cancer). Meta-analysis showed a lower incidence of new BMs compared to control (RR 0.71, 95% confidence interval [CI] 0.56-0.89, p = 0.003). A search for ICIs and incidence of new BMs yielded 8 studies (732 patients with non-small-cell lung cancer or metastatic melanoma) in which ICIs were used as an adjunct to radiosurgery. Meta-analysis showed a lower incidence of out-of-treatment-field BMs with ICIs compared to controls at 1 year (RR 0.65, 95% CI 0.49-0.88, p = 0.005). The overall Grading of Recommendations, Assessment, Development and Evaluations score for the evidence evaluating the role of bevacizumab and ICIs was high and moderate, respectively.

DISCUSSION

VEGF and ICIs may have a role in prophylaxis against BM in patients with solid tumors.

Iron oxide nanoparticles for immune cell labeling and cancer immunotherapy

Cancer immunotherapy is a novel approach to cancer treatment that leverages components of the immune system as opposed to chemotherapeutics or radiation. Cell migration is an integral process in a therapeutic immune response, and the ability to track and image the migration of immune cells in vivo allows for better characterization of the disease and monitoring of the therapeutic outcomes. Iron oxide nanoparticles (IONPs) are promising candidates for use in immunotherapy as they are biocompatible, have flexible surface chemistry, and display magnetic properties that may be used in contrast-enhanced magnetic resonance imaging (MRI). In this review, advances in application of IONPs in cell tracking and cancer immunotherapy are presented. Following a brief overview of the cancer immunity cycle, developments in labeling and tracking various immune cells using IONPs are highlighted. We also discuss factors that influence the effectiveness of IONPs as MRI contrast agents. Finally, we outline different approaches for cancer immunotherapy and highlight current efforts that utilize IONPs to stimulate immune cells to enhance their activity and response to cancer.

The combined use of steroids and immune checkpoint inhibitors in brain metastasis patients: a systematic review and meta-analysis

BACKGROUND

Immune checkpoint inhibitors (ICI) have been a breakthrough for selected cancer patients, including those with brain metastases (BMs). Likewise, steroids have been an integral component of symptomatic management of BM patients. However, clinical evidence on the interaction between ICI and steroids in BM patients is conflicting and has not adequately been summarized thus far. Hence, the aim of this study was to perform a systematic literature review and meta-analysis on the association between steroid use and overall survival (OS) in BM patients receiving ICI.

METHODS

A systematic literature search was performed. Pooled effect estimates were calculated using random-effects models across included studies.

RESULTS

After screening 1145 abstracts, 15 observational studies were included. Fourteen studies reported sufficient data for meta-analysis, comprising 1102 BM patients of which 32.1% received steroids. In the steroid group, median OS ranged from 2.9 to 10.2 months. In the nonsteroid group, median OS ranged from 4.9 to 25.1 months. Pooled results demonstrated significantly worse OS (HR = 1.84, 95% CI 1.22-2.77) and systemic progression-free survival (PFS; HR = 2.00, 95% CI 1.37-2.91) in the steroid group. Stratified analysis showed a consistent effect across the melanoma subgroup; not in the lung cancer subgroup. No significant association was shown between steroid use and intracranial PFS (HR = 1.31, 95% CI 0.42-4.07).

CONCLUSIONS

Administration of steroids was associated with significantly worse OS and PFS in BM patients receiving ICI. Further research on dose, timing, and duration of steroids is needed to elucidate the cause of this association and optimize outcomes in BM patients receiving ICI.

Role of stereotactic radiosurgery for the treatment of brain metastasis in the era of immunotherapy: A systematic review on current evidences and predicting factors

Stereotactic radiosurgery (SRS) in combination with immunotherapy (IT) is increasingly used in the setting of melanoma and non-small cell lung cancer (NSCLC) brain metastases (BM). The synergistic properties of this treatment combination are still not deeply understood. IT-SRS appropriate combination has been envisioned as a strategic point in patients' management. Authors performed a systematic review on current evidences up to December 2020. The impact of SRS-IT and different IT schedules on survival, local/distant intracranial control and toxicity, as well as predictive factors for relevant oncological and radiological outcomes has been analyzed. Authors retrieved 23 pertinent studies. Combining SRS with IT resulted in a significant improvement in OS and lesion response with no increase in radionecrosis, hemorrhage or other complications. The present review suggests that combining IT to SRS is safe and effective in providing a significant improvement in relevant clinical and radiological outcomes in melanoma and NSCLC BMs patients.

A Case of Symptomatic Cerebral Radiation Necrosis for an Extra-Cranial Neoplasm from Conventional Radiotherapy With Concurrent Immunotherapy

Cerebral radiation necrosis (RN) is a known complication of brain radiotherapy (RT). The incidence rate of RN varies with the total dose, dose fractionation, and radiotherapy modality. Concurrent treatment with immunotherapy can increase the risk factors for developing RN through a synergistic mechanism. Here, we describe a patient who developed cerebral RN after receiving conventional RT to an extra-cranial site, while he was receiving immune checkpoint inhibitor (ICI) therapy.

MRI characteristics in treatment for cerebral melanoma metastasis using stereotactic radiosurgery and concomitant checkpoint inhibitors or targeted therapeutics

Introduction

Combination therapy for melanoma brain metastases (MM) using stereotactic radiosurgery (SRS) and immune checkpoint-inhibition (ICI) or targeted therapy (TT) is currently of high interest. In this collective, time evolution and incidence of imaging findings indicative of pseudoprogression is sparsely researched. We therefore investigated time-course of MRI characteristics in these patients.

Methods

Data were obtained retrospectively from 27 patients (12 female, 15 male; mean 61 years, total of 169 MMs). Single lesion volumes, total MM burden and edema volumes were analyzed at baseline and follow-up MRIs in 2 months intervals after SRS up to 24 months. The occurrence of intralesional hemorrhages was recorded.

Results

17 patients (80 MM) received ICI, 8 (62 MM) TT and 2 (27 MM) ICI + TT concomitantly to SRS. MM-localization was frontal (n = 89), temporal (n = 23), parietal (n = 20), occipital (n = 10), basal ganglia/thalamus/insula (n = 10) and cerebellar (n = 10). A volumetric progression of MM 2–4 months after SRS was observed in combined treatment with ICI (p = 0.028) and ICI + TT (p = 0.043), whereas MMs treated with TT showed an early volumetric regression (p = 0.004). Edema volumes moderately correlated with total MM volumes (r = 0.57; p < 0.0001). Volumetric behavior did not differ significantly over time regarding lesions’ initial sizes or localizations. No significant differences between groups were observed regarding rates of post-SRS intralesional hemorrhages.

Conclusion

Reversible volumetric increases in terms of pseudoprogression are observed 2–4 months after SRS in patients with MM concomitantly treated with ICI and ICI + TT, rarely after TT. Edema volumes mirror total MM volumes. Medical treatment type does not significantly affect rates of intralesional hemorrhage.

Is There a Benefit of Combining Immunotherapy and Radiotherapy in Bladder Cancer?

Immune checkpoint inhibitors have transformed the management of patients with metastatic urothelial cancer, by leading to long-term response and prolongation of survival in a subset of patients. Unfortunately, only one in five patients with metastatic urothelial cancer responds to anti-programmed death ligand-1 ([AQ1]anti-PD-1) monotherapy. Preclinical and early clinical evidence indicates that radiotherapy not only acts locally, but also exerts systemic anti-tumour effects by modulating the immune system. It is hypothesised that combining checkpoint inhibitors with radiotherapy might enhance an anti-tumour immune response and increase response rates. So far, a handful of early phase clinical trials have been performed seeking to answer this question in urothelial cancer patients. The current review summarises the available preclinical and clinical evidence on radiotherapy/immunotherapy combinations in locally advanced and metastatic bladder cancer and suggests future avenues worthy of exploration.

Imaging challenges of immunotherapy and targeted therapy in patients with brain metastases: response, progression, and pseudoprogression

The advent of immunotherapy using immune checkpoint inhibitors (ICIs) and targeted therapy (TT) has dramatically improved the prognosis of various cancer types. However, following ICI therapy or TT-either alone (especially ICI) or in combination with radiotherapy-imaging findings on anatomical contrast-enhanced MRI can be unpredictable and highly variable, and are often difficult to interpret regarding treatment response and outcome. This review aims at summarizing the imaging challenges related to TT and ICI monotherapy as well as combined with radiotherapy in patients with brain metastases, and to give an overview on advanced imaging techniques which potentially overcome some of these imaging challenges. Currently, major evidence suggests that imaging parameters especially derived from amino acid PET, perfusion-/diffusion-weighted MRI, or MR spectroscopy may provide valuable additional information for the differentiation of treatment-induced changes from brain metastases recurrence and the evaluation of treatment response.

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.

Immune Checkpoint Inhibitor with or without Radiotherapy in Melanoma Patients with Brain Metastases: A Systematic Review and Meta-Analysis

Objective

Immune checkpoint inhibitor (ICI) therapy has shown activity against melanoma brain metastases. Recently, promising results have also been reported for ICI combination therapy and ICI combined with radiotherapy. We aimed to evaluate radiologic response and adverse event rates of these therapeutic options by a systematic review and meta-analysis.

Materials and Methods

A systematic literature search of Ovid-MEDLINE and EMBASE was performed up to October 12, 2019 and included studies evaluating the intracranial objective response rates (ORRs) and/or disease control rates (DCRs) of ICI with or without radiotherapy for treating melanoma brain metastases. We also evaluated safety-associated outcomes.

Results

Eleven studies with 14 cohorts (3 with ICI combination therapy; 5 with ICI combined with radiotherapy; 6 with ICI monotherapy) were included. ICI combination therapy {pooled ORR, 53% (95% confidence interval [CI], 44–61%); DCR, 57% (95% CI, 49–66%)} and ICI combined with radiotherapy (pooled ORR, 42% [95% CI, 31–54%]; DCR, 85% [95% CI, 63–95%]) showed higher local efficacy compared to ICI monotherapy (pooled ORR, 15% [95% CI, 11–20%]; DCR, 26% [95% CI, 21–32%]). The grade 3 or 4 adverse event rate was significantly higher with ICI combination therapy (60%; 95% CI, 52–67%) compared to ICI monotherapy (11%; 95% CI, 8–17%) and ICI combined with radiotherapy (4%; 95% CI, 1–19%). Grade 3 or 4 central nervous system (CNS)-related adverse event rates were not different (9% in ICI combination therapy; 8% in ICI combined with radiotherapy; 5% in ICI monotherapy).

Conclusion

ICI combination therapy or ICI combined with radiotherapy showed better local efficacy than ICI monotherapy for treating melanoma brain metastasis. The grade 3 or 4 adverse event rate was highest with ICI combination therapy, and the CNS-related grade 3 or 4 event rate was similar. Prospective trials will be necessary to compare the efficacy of ICI combination therapy and ICI combined with radiotherapy.

Stereotactic Radiosurgery With Concurrent Immunotherapy in Melanoma Brain Metastases Is Feasible and Effective

Objective: Stereotactic radiosurgery (SRS) is an established treatment for brain metastases in the management of metastasized melanoma. The increasing use of checkpoint inhibitors in melanoma therapy leads to combined treatment schemes consisting of immunotherapy and SRS that need to be evaluated regarding safety and feasibility. Methods: We retrospectively analyzed 36 patients suffering from cerebral metastasized melanoma. Between November 2011 and May 2016, altogether 66 brain metastases were treated with single-fraction SRS (18-20 Gy prescribed to the 80% isodose) in combination with a checkpoint inhibitor (ipilimumab: 82%, pembrolizumab: 14% or nivolumab: 4%), administered within 3 months before or after SRS. Toxicity was evaluated with focus on the incidence of central nervous system (CNS) radiation necrosis (CRN). Overall survival (OS), freedom from local progression (FFLP), freedom from central nervous system radiation necrosis (FFCRN), and freedom from distant intracranial progression (FFDIP) were analyzed using the Kaplan-Meier method. Results: The median follow-up was 25 months (range: 2-115 months). Two patients (6%) presented with cerebral edema CTCAE °III and another two patients (6%) presented with one-sided muscle weakness CTCAE °III after SRS. One of these four symptomatic cases correlated with an observed CRN, the other three symptomatic cases were related to local tumor progression (n = 2) or related to the performance of additional whole brain radiotherapy (WBRT). No further CTCAE °III or °IV toxicity was seen. During follow-up, seven of the growing contrast-enhanced lesions were resected, revealing two cases of CRN and five cases of local tumor progression. Altogether, the observed CRN rate of the irradiated metastases was 6-17% at the time of analysis, ranging due to the radiologically challenging differentiation between CRN and local tumor progression. The observed ranges of the 1- and 2-years FFLP rates were 82-85% and 73-80%, respectively. The median FFDIP was 6.1 months, the median OS was 22.2 months. Conclusion: In the presented cohort, the combination of SRS and checkpoint inhibitors in the management of cerebral metastasized melanoma was safe and effective. Compared to historic data on SRS only, the observed CRN rate was acceptable. To gain resilient data on the incidence of CRN after combined treatment schemes, prospective trials are needed.

Changing Hands: A Rising Role of the Tumor Surgeon in Teaching Sylvian Fissure Dissection

OBJECTIVE

The landscape of microneurosurgery has changed considerably over the past 2 decades, with a decline in indications for open surgery on cerebrovascular pathology and ever-increasing indications for open resection of brain tumors. This study investigated how these trends in case volume affected residents' training experiences in microsurgery and, specifically, Sylvian fissure dissection.

METHODS

Resident case logs were reviewed, identifying open cerebrovascular operations and craniotomies for tumor. Operations involving Sylvian fissure dissection were identified through operative reports. Changes in case number by resident were plotted over time, and linear regression was applied.

RESULTS

Among 23 chief residents, 3045 operations were identified, 1071 of which were for cerebrovascular pathology and 1974 for tumor. Open cerebrovascular experience decreased (P < 0.0001) while tumor volume remained unchanged (P = 0.221). The number of Sylvian fissure dissections per resident did not change over time overall (P = 0.583) or within cerebrovascular operations (P = 0.071). The number of Sylvian fissure dissections in tumor operations increased (P = 0.004). This effect was predominated by an increase in intraaxial tumors approached via Sylvian fissure dissection (P = 0.003). The proportion of Sylvian fissure dissections in tumor surgery increased from 15% in 2009 to 34% by 2019 (P = 0.003).

CONCLUSIONS

Residents are seeing an increasing proportion of their Sylvian fissure dissection experience during tumor operations. The distribution of this experience will continue to evolve as surgical indications change but suggests a growing role for tumor surgeons in resident training in microsurgery.

Intracranial radiotherapy with or without immune checkpoint inhibition for brain metastases: a systematic review and meta-analysis

BACKGROUND

With the development of immunotherapy in recent years, the prognosis of patients is expected to improve due to immune checkpoint inhibition (ICI) combined with radiotherapy (RT). However, studies on combination therapy (ICI + intracranial RT) have reported inconsistent results, and it is unclear whether the combination has increased toxicity. By analyzing the latest relevant literature, we performed a meta-analysis to further clarify the effectiveness and safety of intracranial RT combined with ICI in patients with brain metastases (BMs).

METHODS

We searched PubMed, Embase and the Cochrane Library for published studies that compared the efficacy and safety of intracranial RT combined with ICI versus intracranial RT alone in the treatment of BMs. Overall survival (OS), local brain failure (LBF), distant brain failure (DBF), and radiation necrosis (RN) were pooled with the use of the hazard ratio (HR) or odds ratio (OR).

RESULTS

A total of 26 retrospective observation cohort studies were included, and over 1,500 patients who received ICI and intracranial RT were evaluated. Compared with intracranial RT alone, RT combined with ICI significantly improved OS in patients with BMs [HR =0.55, 95% confidence interval (CI): 0.48-0.64, P<0.001 when OS was defined from the date of diagnosis of BMs; HR =0.45, 95% CI: 0.39-0.52, P<0.001 when OS was defined from the date of RT], though the risk of RN was similar to that of RT alone (HR =1.27, 95% CI: 0.58-2.79, P=0.55). However, significant improvement in LBF and DBF was not obtained with RT combined with ICI (1-year LBF: OR =1.71, 95% CI: 0.38-7.67, P=0.48; LBF: HR =0.49, 95% CI: 0.28-0.87, P=0.01; 1-year DBF: OR =1.05, 95% CI: 0.47-2.33, P=0.90).

CONCLUSIONS

ICI combined with intracranial RT confers a significant OS benefit for patients with BMs without significantly increasing treatment-related toxicity, but further research regarding the specific details of combined treatment application is needed to improve the survival and quality of life of patients with BMs.

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.

Immune Checkpoint Inhibitors for Brain Metastases: A Primer for Neurosurgeons

Immune checkpoint inhibitors enhance immune recognition of tumors by interfering with the cytotoxic T-lymphocyte-associated antigen 4 (CTLA4) and programmed death 1 (PD1) pathways. In the past decade, these agents brought significant improvements to the prognostic outlook of patients with metastatic cancers. Recent data from retrospective analyses and a few prospective studies suggest that checkpoint inhibitors have activity against brain metastases from melanoma and nonsmall cell lung cancer, as single agents or in combination with radiotherapy. Some studies reported intracranial response rates that were comparable with systemic ones. In this review, we provide a comprehensive summary of clinical data supporting the use of anti-CTLA4 and anti-PD1 agents in brain metastases. We also touch upon specific considerations on the assessment of intracranial responses in patients and immunotherapy-specific toxicities. We conclude that a subset of patients with brain metastases benefit from the addition of checkpoint inhibitors to standard of care therapeutic modalities, including radiotherapy and surgery.

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.

Laser Interstitial Thermal Therapy for Metastatic Melanoma After Failed Radiation Therapy: A Case Series

BACKGROUND

Laser interstitial thermal therapy (LITT) is a growing technology to treat a variety of brain lesions. It offers an alternative to treatment options, such as open craniotomy and stereotactic radiosurgery.

OBJECTIVE

To analyze our experience using LITT for metastatic melanoma.

METHODS

This is a retrospective chart review of the patients from our institution. Our case series involves 5 patients who had previously failed radiation treatment.

RESULTS

Our patients have low complication rates and short hospital stays. Both are considerably lower when compared to the literature for metastatic melanoma.

CONCLUSION

LITT is a safe therapy, with few complications and short hospital stays.

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.

Radiobiology of stereotactic ablative radiotherapy (SABR): perspectives of clinical oncologists

Stereotactic ablative radiotherapy (SABR) is a novel radiation treatment method that delivers an intense dose of radiation to the treatment targets with high accuracy. The excellent local control and tolerance profile of SABR have made it become an important modality in cancer treatment. The radiobiology of SABR is a key factor in understanding and further optimizing the benefits of SABR. In this review, we have addressed several issues in the radiobiology of SABR from the perspective of clinical oncologists. The appropriateness of the linear-quadratic (LQ) model for SABR is controversial based on preclinical data, but it is a reliable tool from the perspective of clinical application because the biological effective dose (BED) calculated with it can represent the tumor control probability (TCP). Hypoxia is a common phenomenon in SABR in spite of the relatively small tumor size and has a negative effect on the efficacy of SABR. Preliminary studies indicate that a hypoxic radiosensitizer combined with SABR may be a feasible strategy, but so far there is not adequate evidence to support its application in routine practice. The vascular change of endothelial apoptosis and blood perfusion reduction in SABR may enhance the response of tumor cells to radiation. Combination of SABR with anti-angiogenesis therapy has shown promising efficacy and good tolerance in advanced cancers. SABR is more powerful in enhancing antitumor immunity and works better with immune checkpoint inhibitors (ICIs) than conventional fractionation radiotherapy. Combination of SABR with ICIs has become a practical option for cancer patients with metastases.

Combination of Ipilimumab and Nivolumab in Cancers: From Clinical Practice to Ongoing Clinical Trials

Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death protein 1 (PD-1) are inhibitory checkpoints that are commonly seen on activated T cells and have been offered as promising targets for the treatment of cancers. Immune checkpoint inhibitors (ICIs)targeting PD-1, including pembrolizumab and nivolumab, and those targeting its ligand PD-L1, including avelumab, atezolizumab, and durvalumab, and two drugs targeting CTLA-4, including ipilimumab and tremelimumab have been approved for the treatment of several cancers and many others are under investigating in advanced trial phases. ICIs increased antitumor T cells’ responses and showed a key role in reducing the acquired immune system tolerance which is overexpressed by cancer and tumor microenvironment. However, 50% of patients could not benefit from ICIs monotherapy. To overcome this, a combination of ipilimumab and nivolumab is frequently investigated as an approach to improve oncological outcomes. Despite promising results for the combination of ipilimumab and nivolumab, safety concerns slowed down the development of such strategies. Herein, we review data concerning the clinical activity and the adverse events of ipilimumab and nivolumab combination therapy, assessing ongoing clinical trials to identify clinical outlines that may support combination therapy as an effective treatment. To the best of our knowledge, this paper is one of the first studies to evaluate the efficacy and safety of ipilimumab and nivolumab combination therapy in several cancers.

Oligometastasis and local ablation in the era of systemic targeted and immunotherapy

Background

During these last years, new agents have dramatically improved the survival of the metastatic patients. Oligometastases represent a continuous field of interest in which the integration of metastases-directed therapy and drugs could further improve the oncologic outcomes.

Herein a narrative review is performed regarding the main rationale in combining immunotherapy and target therapies with SBRT looking at the available clinical data in case of oligometastatic NSCLC, Melanoma and Kidney cancer.

Material and method

Narrative Review regarding retrospective and prospective studies published between January 2009 to November 2019 with at least 20 patients analyzed.

Results

Concerning the combination between SBRT and Immunotherapy, the correct sequence of remains uncertain, and seems to be drug-dependent. The optimal patients’ selection is crucial to expect substantial benefits to SBRT/Immunotherapy combination and, among several factors. A potential field of interest is represented by the so-called oligoprogressed disease, in which SBRT could improve the long-term efficacy of the existing target therapy.

Conclusions

A low tumor burden seems to be the most relevant, thus making the oligometastatic disease represent the ideal setting for the use of combination therapies with immunological drugs.

Toxicity and efficacy of Gamma Knife radiosurgery for brain metastases in melanoma patients treated with immunotherapy or targeted therapy-A retrospective cohort study

Background

Few safety data of concurrent stereotactic radiosurgery and targeted therapy (TT) or immunotherapy (IT) are available. The aim of the study was to evaluate the outcome of melanoma patients with brain metastases (MBM) after Gamma Knife Radiosurgery (GKRS) in relation to IT/TT.

Methods

We evaluated 182 MBM patients, who were treated with GKRS in the modern radiosurgical and oncological era.

Results

The median time between the initial melanoma diagnosis and occurrence of MBM was 2.4 years. The median overall survival time was 5.4 years after melanoma diagnosis. The estimated median survival after the initial diagnosis of MBM was 1.0 year (95% CI = 0.7‐1.2 years). Patients treated with anti‐PD‐1 or a combination of anti‐CTLA‐4/PD‐1 showed a significantly longer survival after first GKRS compared to all other forms of treatment. In addition, patients treated with anti‐PD‐1, anti‐CTLA‐4, or a combination of anti‐CTLA‐4/PD‐1 showed a significantly longer time to new MBM after GKRS1 compared to patients treated with other forms and combinations of the oncological therapy. The occurrence of hemorrhage or radiation reaction/necrosis after GKRS did not show any statistically significant differences in relation to IT/TT.

Conclusion

In MBM patients, complications after GKRS are not significantly increased if IT/TT treatment is performed at the time of or after radiosurgery. Further, a clear benefit in distant control and survival is seen in MBM patients treated with GKRS and checkpoint inhibitors. Thus, concomitant treatment of MBM with GKRS and IT/TT seems to be a safe and powerful treatment option although further prospective studies should be conducted.

Brain metastasis formation and irradiation by stereotactic radiation therapy combined with immunotherapy: A systematic review

INTRODUCTION

Brain metastasis (BM) is a complex process that implies immune cells and microglia. Stereotactic radiation therapy (SRT) and immunotherapy (IT) are established to increase the immune response; but their association has never been prospectively studied.

MATERIALS AND METHODS

Two reviewers performed a systematic review in original papers published up to September 2019. We analysed OS, local (mLRF) and regional (mBRF) median disease-free survival in patients with BMs after SRT with and without IT.

RESULTS

Upon 14 studies, eleven concerned melanoma, three concerned lung cancers. SRT-IT showed better OS, mLRF and mBRF than SRT. mBRF was better if SRT was performed with short delay from IT. No higher rates of radionecrosis and haemorrhage were found among groups.

CONCLUSION

This review suggests SRT combined to IT in melanoma is safe and could provide better BRF, suggesting a lymphocytic immune reaction in brain. No improvement trend was found in lung cancer BM.

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.