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

The Impact of Immune Checkpoint Inhibition on the Risk of Radiation Necrosis Following Stereotactic Radiotherapy for Metastatic Brain Cancer

Purpose/objective Forty percent of cancer patients develop brain metastases (BM) and are often treated with stereotactic radiation (SRS/SRT). Checkpoint inhibitor (CI) use is suspected of increasing the risk of radiation necrosis (RN). Our aim is to determine whether treatment with CI is associated with an increased risk of RN in BM patients treated with SRS/SRT. Methods We retrospectively identified the medical records of BM patients treated with SRS/SRT between 1/2017 and 12/2021 using an institutional database. RN was defined by MRI imaging read by neuroradiologists and/or surgical pathology. V12GY of patients with and without RN was compared using the Mann-Whitney test. The chi-square test was used to see if RN was associated with CI use, histology, particular CI agent used, > 1 course SRS/SRT, SRS/SRT dose, chemotherapy, whole brain radiotherapy (WBRT), age, or sex. Results Two hundred and fifty-nine patients treated with 455 courses of SRS/SRT were analyzed. The most common primary histologies were lung 56% (N=146), breast 14% (N= 37), melanoma 9% (N=24), and renal cancer 7% (N=18). A total of 53.8% (N = no. of patients) were treated with CI. The overall rate of any RN was 21.8% (N=27) in the CI group compared to 14.8% (N=141) in the non-CI group (p=0.174). Mean V12Gy was 15.525 cc and 9.419 cc in patients with and without RN (p=0.02768). Mean number of SRS/SRT courses was 2 and 1.53 for patients with and without RN, and >1 course of SRS/SRT was a predictor of RN (p <0.01). Other features analyzed were not significant. Conclusion RN was higher in the BM patients treated with SRS/SRT receiving CI compared to non-CI patients (21.8%, N=27, versus 14.6%, N= 16), but failed to reach statistical significance. V12Gy and > 1 course of SRS/SRT was associated with RN. Caution should be taken in treating patients with SRS/SRT and CI there might be an increased risk of RN.

Toxicity and outcomes of melanoma brain metastases treated with stereotactic radiosurgery: the risk of subsequent symptomatic intralesional hemorrhage exceeds that of radiation necrosis

PURPOSE

We aimed to assess the outcomes and patterns of toxicity in patients with melanoma brain metastases (MBM) treated with stereotactic radiosurgery (SRS) with or without immunotherapy (IO).

METHODS

From a prospective registry, we reviewed MBM patients treated with single fraction Gamma Knife SRS between 2008 and 2021 at our center. We recorded all systemic therapies (chemotherapy, targeted therapy, or immunotherapy) administered before, during, or after SRS. Patients with prior brain surgery were excluded. We captured adverse events following SRS, including intralesional hemorrhage (IH), radiation necrosis (RN) and local failure (LF), as well as extracranial disease status. Distant brain failure (DBF), extracranial progression-free survival (PFS) and overall survival (OS) were determined using a cumulative Incidence function and the Kaplan-Meier method.

RESULTS

Our analysis included 165 patients with 570 SRS-treated MBM. Median OS for patients who received IO was 1.41 years versus 0.79 years in patients who did not (p = 0.04). Ipilimumab monotherapy was the most frequent IO regimen (30%). In the absence of IO, the cumulative incidence of symptomatic (grade 2 +) RN was 3% at 24 months and remained unchanged with respect to the type or timing of IO. The incidence of post-SRS g2 + IH in patients who did not receive systemic therapy was 19% at 1- and 2 years compared to 7% at 1- and 2 years among patients who did (HR: 0.33, 95% CI 0.11-0.98; p = 0.046). Overall, neither timing nor type of IO correlated to rates of DBF, OS, or LF. Among patients treated with IO, the median time to extracranial PFS was 5.4 months (95% IC 3.2 - 9.1).

CONCLUSION

The risk of g2 + IH exceeds that of g2 + RN in MBM patients undergoing SRS, with or without IO. IH should be considered a critical adverse event following MBM treatments.

Immunotherapy: an emerging modality to checkmate brain metastasis

The diagnosis of brain metastasis (BrM) has historically been a dooming diagnosis that is nothing less than a death sentence, with few treatment options for palliation or prolonging life. Among the few treatment options available, brain radiotherapy (RT) and surgical resection have been the backbone of therapy. Within the past couple of years, immunotherapy (IT), alone and in combination with traditional treatments, has emerged as a reckoning force to combat the spread of BrM and shrink tumor burden. This review compiles recent reports describing the potential role of IT in the treatment of BrM in various cancers. It also examines the impact of the tumor microenvironment of BrM on regulating the spread of cancer and the role IT can play in mitigating that spread. Lastly, this review also focuses on the future of IT and new clinical trials pushing the boundaries of IT in BrM.

Evolving Management of Stage IV Melanoma

Significant advancements have been made in the treatment of advanced melanoma with the use of immune checkpoint inhibitors, novel immunotherapies, and BRAF/MEK-targeted therapies with numerous frontline treatment options. However, there remains suboptimal evidence to guide treatment decisions in many patients. These include patients with newly diagnosed disease, immune checkpoint inhibitor (ICI)-resistant/ICI-refractory disease, CNS metastases, history of autoimmune disease, and/or immune-related adverse events (irAEs). Uveal melanoma (UM) is a rare melanoma associated with a poor prognosis in the metastatic setting. Systemic treatments, including checkpoint inhibitors, failed to demonstrate any survival benefit. Tebentafusp, a bispecific molecule, is the first treatment to improve overall survival (OS) in patients with HLA A*02:01-positive metastatic UM.

Long-term neurocognitive function after whole-brain radiotherapy in patients with melanoma brain metastases in the era of immunotherapy

BACKGROUND

Whole-brain radiotherapy (WBRT) used to be standard of care for patients suffering from melanoma brain metastases (MBM) and may still be applicable in selected cases. Deterioration of neurocognitive function (NCF) is commonly seen during and after WBRT. Knowledge on long-term effects in melanoma patients is limited due to short survival rates. With the introduction of immune checkpoint inhibitors, patients may experience ongoing disease control, emphasizing the need for paying more attention to potential long-term adverse effects.

METHODS

In this single-center study, we identified in a period of 11 years all long-term survivors of MBM who received WBRT at least 1 year prior to inclusion. NCF was assessed by Neuropsychological Assessment Battery (NAB) screening and detailed neurological exam; confounders were documented.

RESULTS

Eight patients (median age 55 years) could be identified with a median follow-up of 5.4 years after WBRT. Six patients reported no subjective neurological impairment. NAB screening revealed an average-range score in 5/8 patients. In 3/8 patients a NAB score below average was obtained, correlating with subjective memory deficits in 2 patients. In these patients, limited performance shown in modalities like memory function, attention, and spatial abilities may be considerably attributed to metastasis localization itself. Six out of 8 patients were able to return to their previous work.

CONCLUSION

Five of 8 long-term survivors with MBM after WBRT experienced little to no restriction in everyday activities. In 3 out of 8 patients, cognitive decline was primarily explained by localization of the metastases in functionally relevant areas of the brain. The results of our small patient cohort do not support general avoidance of WBRT for treatment of brain metastases. However, long-term studies including pretreatment NCF tests are needed to fully analyze the long-term neurocognitive effects of WBRT.

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.

Managing Metastatic Melanoma in 2022: A Clinical Review

Cutaneous melanoma remains the most lethal of the primary cutaneous neoplasms, and although the incidence of primary melanoma continues to rise, the mortality from metastatic disease remains unchanged, in part through advances in treatment. Major developments in immunomodulatory and targeted therapies have provided robust improvements in response and survival trends that have transformed the clinical management of patients with metastatic melanoma. Additional advances in immunologic and cancer cell biology have contributed to further optimization in (1) risk stratification, (2) prognostication, (3) treatment, (4) toxicity management, and (5) surveillance approaches for patients with an advanced melanoma diagnosis. In this review, we provide a comprehensive overview of the historical and future advances regarding the translational and clinical implications of advanced melanoma and share multidisciplinary recommendations to aid clinicians in the navigation of current treatment approaches for a variety of patient cohorts.

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.

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.