First interim analysis of a randomised trial of whole brain radiotherapy in melanoma brain metastases confirms high data quality

Melanoma Brain Metastases: A Systematic Review of Opportunities for Earlier Detection, Diagnosis, and Treatment

Introduction: Melanoma continues to represent the most serious skin cancer worldwide. However, few attempts have been made to connect the body of research on advanced melanoma. In the present review, we report on strides made in the diagnosis and treatment of intracranial metastatic melanoma. Methods: Relevant Cochrane reviews and randomized-controlled trials published by November 2022 were systematically retrieved from the Cochrane Library, EMBASE, and PubMed databases (N = 27). Search and screening methods adhered to the 2020 revision of the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. Results: Although the research surrounding the earlier detection of melanoma brain metastasis is scarce, several studies have highlighted specific markers associated with MBM. Such factors include elevated BRAFV600 mutant ctDNA, high LDH concentration, and high IGF-1R. The approach to treating MBM is moving away from surgery and toward nonsurgical management, namely, a combination of stereotactic radiosurgery (SRS) and immunotherapeutic agents. There is an abundance of emerging research seeking to identify and improve both novel and established treatment options and diagnostic approaches for MBM, however, more research is still needed to maximize the clinical efficacy, especially for new immunotherapeutics. Conclusions: Early detection is optimal for the efficacy of treatment and MBM prognosis. Current treatment utilizes chemotherapies and targeted therapies. Emerging approaches emphasize biomarkers and joint treatments. Further exploration toward preliminary identification, the timing of therapies, and methods to ameliorate adverse treatment effects are needed to advance MBM patient care.

Adjuvant Whole-Brain Radiation Therapy Compared With Observation After Local Treatment of Melanoma Brain Metastases: A Multicenter, Randomized Phase III Trial

PURPOSE

The brain is a common site of metastasis for patients with high-risk melanoma. Although surgery or stereotactic radiosurgery are highly effective local treatments for a small number of metastases, there is a high risk of developing additional brain metastases. The role of adjuvant whole-brain radiotherapy (WBRT) in reducing new metastases is controversial, with a lack of high-level evidence specifically for melanoma.

METHODS

In this randomized phase III trial, patients who had local treatment of one to three melanoma brain metastases were randomly assigned to WBRT or observation. The primary end point was distant intracranial failure within 12 months, and secondary end points included time to intracranial failure, survival, and time to deterioration in performance status.

RESULTS

Between April 2009 and September 2017, 215 patients were randomly assigned from 24 centers. Median follow-up was 48.1 months (range, 39.6 to 68 months). Forty-two percent of patients in the WBRT group and 50.5% of those in the observation developed distant intracranial failure within 12 months (odds ratio, 0.71; 95% CI, 0.41 to 1.23; P = .22) and the rates over the entire follow-up period were 52.0% and 57.9%, respectively (odds ratio, 0.79; 95% CI, 0.45 to 1.36; P = .39). Local failure rate was lower after WBRT (20.0% v 33.6%; P = .03). At 12 months, 41.5% of patients in the WBRT group and 51.4% of patients in the observation group had died (P = .28), with no difference in the rate of neurologic death. Median time to deterioration in performance status was 3.8 months after WBRT and 4.4 months with observation (P = .32). WBRT was associated with more grade 1 to 2 acute toxicity.

CONCLUSION

After local treatment of one to three melanoma brain metastases, adjuvant WBRT does not provide clinical benefit in terms of distant intracranial control, survival, or preservation of performance status.

Whole brain radiotherapy (WBRT) after local treatment of brain metastases in melanoma patients: Statistical Analysis Plan

Background

The WBRTMel trial is a multinational, open-label, phase III randomised controlled trial comparing whole brain radiotherapy (WBRT) to observation following local treatment of one to three melanoma brain metastases with surgery and/or stereotactic irradiation. The primary trial endpoint was to determine the effect of adding WBRT to local treatment on distant intracranial control, and the secondary endpoints were neurocognitive function, quality of life (QoL), performance status, overall survival, death from intracranial causes, death from melanoma and cost-effectiveness.

Objective

The objective of this update is to outline and publish the pre-determined statistical analysis plan (SAP) before the database lock and the start of analysis.

Methods

The SAP describes basic analysis principles, methods for dealing with a range of commonly encountered data analysis issues and the specific statistical procedures for analysing efficacy and safety outcomes. The SAP was approved after closure of recruitment and before completion of patient follow-up. It outlines the planned primary analyses and a range of subgroup and sensitivity analyses regarding the clinical and QoL outcomes. Health economic outcomes are not included in this plan but will be analysed separately. The SAP will be adhered to for the final data analysis of this trial to avoid analysis bias arising from knowledge of the data.

Results

The resulting SAP is consistent with best practice and will allow open and transparent reporting.

Conclusion

We have developed a SAP for the WBRTMel trial which will be followed to ensure high-quality standards of internal validity to minimise analysis bias.

Trial registration

ANZ Clinical Trials Registry, ACTRN12607000512426. Registered on 9 October 2007. ClinicalTrials.gov, NCT01503827. Registered on 4 January 2012. Trial group reference numbers ANZMTG 01.07, TROG 08.05.

Quality assurance analysis of hippocampal avoidance in a melanoma whole brain radiotherapy randomized trial shows good compliance

BACKGROUND

Melanoma brain metastases (MBM) often cause morbidity and mortality for stage IV melanoma patients. An ongoing randomised phase III trial (NCT01503827 - WBRT-Mel) evaluates the role of adjuvant whole brain radiotherapy (WBRT) following local treatment of MBM. Hippocampal avoidance during WBRT (HA-WBRT) has shown memory and neurocognitive function (NCF) preservation in the RTOG-0933 phase II study. This study assessed the quality assurance of HA-WBRT within the WBRT-Mel trial according to RTOG-0933 study criteria.

METHODS

Hippocampal avoidance was allowed in approved centres with intensity-modulated radiotherapy capability. Patients treated by HA-WBRT were not randomized within the WBRT arm. The RTOG 0933 contouring Atlas was used to contour hippocampi. In the trial co-ordinating centre, patients were treated with volumetric modulated arc therapy using complementary arcs; similar techniques were used at other sites. Dosimetric data were extracted retrospectively and analysed in accordance with RTOG 0933 study constraints criteria.

RESULTS

Among the 215 patients accrued to the WBRT-Mel study between April 2009 and September 2017, 107 were randomized to the WBRT arm, 22 were treated by HA-WBRT in 4 centers. Eighteen patients were treated in the same centre. The median age was 65 years. The commonest (91%) HA-WBRT schema was 30 Gy in 10 fractions. Prior to HA-WBRT, 10 patients had been treated by surgery alone, six by radiosurgery alone, four by surgery and radiosurgery and two exclusively by simultaneous integrated boost concurrent to HA-WBRT. Twenty patients were treated with intention to spare both hippocampi and two patients had MBM close to one hippocampus and were treated with intention to spare the contralateral hippocampus. According to RTOG-0933 study criteria, 18 patients (82%) were treated within constraints and four patients (18%) had unacceptable deviation in just one hippocampus.

CONCLUSIONS

This dosimetric quality assurance study shows good compliance (82%) according to RTOG-0933 study dosimetric constraints. Indeed, all patients respected RTOG hippocampal avoidance constraints on at least one hippocampus. In the futureanalysis of the WBRT-Mel trial, the NCF of patients on the observation arm, WBRT arm and with HA-WBRT arm will be compared.

Whole brain radiotherapy for the treatment of newly diagnosed multiple brain metastases

BACKGROUND

This is an update to the review published in the Cochrane Library (2012, Issue 4).It is estimated that 20% to 40% of people with cancer will develop brain metastases during the course of their illness. The burden of brain metastases impacts quality and length of survival.

OBJECTIVES

To assess the effectiveness and adverse effects of whole brain radiotherapy (WBRT) given alone or in combination with other therapies to adults with newly diagnosed multiple brain metastases.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase to May 2017 and the National Cancer Institute Physicians Data Query for ongoing trials.

SELECTION CRITERIA

We included phase III randomised controlled trials (RCTs) comparing WBRT versus other treatments for adults with newly diagnosed multiple brain metastases.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and abstracted information in accordance with Cochrane methods.

MAIN RESULTS

We added 10 RCTs to this updated review. The review now includes 54 published trials (45 fully published reports, four abstracts, and five subsets of data from previously published RCTs) involving 11,898 participants.Lower biological WBRT doses versus controlThe hazard ratio (HR) for overall survival (OS) with lower biological WBRT doses as compared with control (3000 cGy in 10 daily fractions) was 1.21 (95% confidence interval (CI) 1.04 to 1.40; P = 0.01; moderate-certainty evidence) in favour of control. The HR for neurological function improvement (NFI) was 1.74 (95% CI 1.06 to 2.84; P = 0.03; moderate-certainty evidence) in favour of control fractionation.Higher biological WBRT doses versus controlThe HR for OS with higher biological WBRT doses as compared with control (3000 cGy in 10 daily fractions) was 0.97 (95% CI 0.83 to 1.12; P = 0.65; moderate-certainty evidence). The HR for NFI was 1.14 (95% CI 0.92 to 1.42; P = 0.23; moderate-certainty evidence).WBRT and radiosensitisersThe addition of radiosensitisers to WBRT did not confer additional benefit for OS (HR 1.05, 95% CI 0.99 to 1.12; P = 0.12; moderate-certainty evidence) or for brain tumour response rates (odds ratio (OR) 0.84, 95% CI 0.63 to 1.11; P = 0.22; high-certainty evidence).Radiosurgery and WBRT versus WBRT aloneThe HR for OS with use of WBRT and radiosurgery boost as compared with WBRT alone for selected participants was 0.61 (95% CI 0.27 to 1.39; P = 0.24; moderate-certainty evidence). For overall brain control at one year, the HR was 0.39 (95% CI 0.25 to 0.60; P < 0.0001; high-certainty evidence) favouring the WBRT and radiosurgery boost group.Radiosurgery alone versus radiosurgery and WBRTThe HR for local brain control was 2.73 (95% CI 1.87 to 3.99; P < 0.00001; high-certainty evidence)favouring the addition of WBRT to radiosurgery. The HR for distant brain control was 2.34 (95% CI 1.73 to 3.18; P < 0.00001; high-certainty evidence) favouring WBRT and radiosurgery. The HR for OS was 1.00 (95% CI 0.80 to 1.25; P = 0.99; moderate-certainty evidence). Two trials reported worse neurocognitive outcomes and one trial reported worse quality of life outcomes when WBRT was added to radiosurgery.We could not pool data from trials related to chemotherapy, optimal supportive care (OSC), molecular targeted agents, neurocognitive protective agents, and hippocampal sparing WBRT. However, one trial reported no differences in quality-adjusted life-years for selected participants with brain metastases from non-small-cell lung cancer randomised to OSC and WBRT versus OSC alone.

AUTHORS' CONCLUSIONS

None of the trials with altered higher biological WBRT dose-fractionation schemes reported benefit for OS, NFI, or symptom control compared with standard care. However, OS and NFI were worse for lower biological WBRT dose-fractionation schemes than for standard dose schedules.The addition of WBRT to radiosurgery improved local and distant brain control in selected people with brain metastases, but data show worse neurocognitive outcomes and no differences in OS.Selected people with multiple brain metastases from non-small-cell lung cancer may show no difference in OS when OSC is given and WBRT is omitted.Use of radiosensitisers, chemotherapy, or molecular targeted agents in conjunction with WBRT remains experimental.Further trials are needed to evaluate the use of neurocognitive protective agents and hippocampal sparing with WBRT. As well, future trials should examine homogeneous participants with brain metastases with focus on prognostic features and molecular markers.

The Treatment of Melanoma Brain Metastases

Melanoma is the malignancy with the highest rate of dissemination to the central nervous system once it metastasizes. Until recently, the prognosis of patients with melanoma brain metastases (MBM) was poor. In recent years, however, the prognosis has improved due to high-resolution imaging that facilitates early detection of small asymptomatic brain metastases and early intervention with local modalities such as stereotactic radiosurgery. More recently, a number of systemic therapies have been approved by the Food and Drug Administration for metastatic melanoma, resulting in improved survival for many MBM patients. Registration trials for these newer therapies excluded patients with untreated brain metastases, and a number of studies specifically tailored to this population of patients have been conducted or are underway. Herein, we review contemporary locoregional and systemic therapies and describe the unique challenges posed by treatment of brain metastases, such as radionecrosis, cerebral edema, and pseudoprogression. Since the number of systemic and combined modality clinical trials has increased, we expect that the treatment landscape for patients with melanoma brain metastasis will change dramatically. In addition to ongoing clinical trials, which show great promise, we conclude that our understanding of intracranial metastasis remains quite limited. In addition to inter-disciplinary, multi-modality studies, bench-side work to better understand the process of cerebrotropism is needed to fuel more drug development and further improve outcomes.

Activity and safety of radiotherapy with anti-PD-1 drug therapy in patients with metastatic melanoma

The anti-PD-1 antibodies nivolumab and pembrolizumab are active in metastatic melanoma; however, there is limited data on combining anti-PD-1 antibody and radiotherapy (RT). We sought to review clinical outcomes of patients receiving RT and anti-PD-1 therapy. All patients receiving anti-PD-1 antibody and RT for metastatic melanoma were identified. RT and systemic treatment, clinical outcome, and toxicity data were collected. Fifty-three patients were included; 35 patients received extracranial RT and/or intracranial stereotactic radiosurgery (SRS) and 21 received whole brain radiotherapy (WBRT) (three of whom also received SRS/extracranial RT). Patients treated with extracranial RT or SRS received treatment either sequentially (RT then anti-PD-1, n = 11), concurrently (n = 16), or concurrent "salvage" treatment to lesions progressing on anti-PD-1 therapy (n = 15). There was no excessive anti-PD-1 or RT toxicity observed in patients receiving extracranial RT. Of six patients receiving SRS, one patient developed grade 3 radiation necrosis. In 21 patients receiving WBRT, one patient developed Stevens-Johnson syndrome, one patient developed acute neurocognitive decline, and one patient developed significant cerebral edema in the setting of disease. Response in irradiated extracranial/intracranial SRS lesions was 44% for sequential treatment and 64% for concurrent treatment (p=0.448). Likewise there was no significant difference between sequential or concurrent treatment in lesional response of non-irradiated lesions. For progressing lesions subsequently irradiated, response rate was 45%. RT and anti-PD-1 antibodies can be safely combined, with no detectable excess toxicity in extracranial sites. WBRT and anti-PD-1 therapy is well tolerated, although there are rare toxicities and the role of either anti-PD-1 or WBRT in the etiology of these is uncertain.

Debate: adjuvant whole brain radiotherapy or not? More data is the wiser choice

Every year 170,000 patients are diagnosed with brain metastases (BMs) in the United States. Traditionally, adjuvant whole brain radiotherapy (AWBRT) has been offered following local therapy with neurosurgery (NSx) and/or stereotactic radiosurgery (SRS) to BMs. The aim is to increase intracranial control, thereby decreasing symptoms from intracranial progression and a neurological death. There is a rapidly evolving change in the radiation treatment of BMs happening around the world. AWBRT is now being passed over in favour of repeat scanning at regular intervals and more local therapies as more BMs appear radiologically, BMs that may never become symptomatic. This change has happened after the American Society for Radiation Oncology (ASTRO) in Item 5 of its “Choosing Wisely 2014” list recommended: “Don't routinely add adjuvant whole brain radiation therapy to SRS for limited brain metastases”. The guidelines are supposed to be based on the highest evidence to hand at the time. This article debates that the randomised controlled trials (RCTs) published prior to this recommendation consistently showed AWBRT significantly increases intracranial control, and avoids a neurological death, what it is meant to do. It also points out that, despite the enormity of the problem, only 774 patients in total had been randomised over more than three decades. These trials were heterogeneous in many respects. This data can, at best, be regarded as preliminary. In particular, there are no single histology AWBRT trials yet completed. A phase two trial investigating hippocampal avoiding AWBRT (HAWBRT) showed significantly less NCF decline compared to historical controls. We now need more randomised data to confirm the benefit of adjuvant HAWBRT. However, the ASTRO Guideline has particularly impacted accrual to trials investigating this, especially the international ANZMTG 01.07 WBRTMel trial. This is an RCT investigating AWBRT following local treatment in patients with one to three BMs from melanoma. WBRTMel has accrued 196 of a required 220 to date but accrual has slowed. HAWBRT may now never be tested in a randomised setting. Encouraging more data in AWBRT is the wiser choice.

A phase 2 study of radiosurgery and temozolomide for patients with 1 to 4 brain metastases

PURPOSE

To determine if temozolomide reduces the risk of distant brain failure (DBF, metachronous brain metastases) in patients with 1 to 4 brain metastases treated with radiosurgery without whole-brain radiation therapy (WBRT).

METHODS AND MATERIALS

Twenty-five patients with newly diagnosed brain metastases were enrolled in a single institution phase 2 trial of radiosurgery (15-24 Gy) and adjuvant temozolomide. Temozolomide was continued for a total of 12 cycles unless the patient developed DBF, unacceptable toxicity, or systemic progression requiring other therapy.

RESULTS

Twenty-five patients were enrolled between 2002 and 2005; 3 were not evaluable for determining DBF. Of the remaining 22 patients, tumor types included non-small cell lung cancer (n = 8), melanoma (n = 7), and other (n = 7). Extracranial disease was present in 10 (45%) patients. The median number of tumors at the time of radiosurgery was 3 (range, 1-6). The median overall survival was 31 weeks. The median radiographic follow-up for patients who did not develop DBF was 33 weeks. Six patients developed DBF. The 1-year actuarial risk of DBF was 37%.

CONCLUSIONS

In this study, there was a relatively low risk of distant brain failure observed in the nonmelanoma subgroup receiving temozolamide. However, patient selection factors rather than chemotherapy treatment efficacy are more likely the reason for the relatively low risk of distant brain failure observed in this study. Future trial design should account for these risk factors.

Evolving treatment options for melanoma brain metastases

Melanoma is a leading cause of lost productivity due to premature cancer mortality. Melanoma frequently spreads to the brain and is associated with rapid deterioration in quality and quantity of life. Until now, treatment options have been restricted to surgery and radiotherapy, although neither modality has been well studied in clinical trials. However, the new immune checkpoint inhibitors and molecularly targeted agents that have been introduced for treatment of metastatic melanoma are active against brain metastases and offer new opportunities to improve disease outcomes. New challenges arise, including how to integrate or sequence multiple treatment modalities, and current practice varies widely. In this Review, we summarise evidence for the treatment of melanoma brain metastases, and discuss the rationale and evidence for combination modalities, highlighting areas for future research.