Stereotactic radiosurgery for brain metastases from malignant melanoma

Minimizing Intracranial Disease Before Stereotactic Radiation in Single or Solitary Brain Metastases

BACKGROUND AND OBJECTIVES

Stereotactic radiotherapy (SRT) in multiple fractions (typically ≤5) can effectively treat a wide range of brain metastases, including those less suitable for single-fraction stereotactic radiosurgery (SRS). Prior prospective studies on surgical resection with stereotactic radiation have focused exclusively on SRS, and retrospective studies have shown equivocal results regarding whether surgery is associated with improved outcomes compared with SRT alone. We compared resection with postoperative cavity SRT or SRS to SRT alone in patients with 1 brain metastasis, while including patients receiving SRS alone as an additional reference group.

METHODS

We studied 716 patients in a retrospective, single-institution cohort diagnosed with single or solitary brain metastases from 2007 to 2020. Patients receiving whole-brain radiotherapy were excluded. Cox proportional hazards models were constructed for overall survival and additional intracranial outcomes.

RESULTS

After adjustment for potential confounders, surgery with cavity SRT/SRS was associated with decreased all-cause mortality (hazard ratio [HR]: 0.39, 95% CI [0.27-0.57], P = 1.52 × 10 -6 ) compared with SRT alone, along with lower risk of neurological death attributable to intracranial tumor progression (HR: 0.46, 95% CI [0.22-0.94], P = 3.32 × 10 -2 ) and radiation necrosis (HR: 0.15, 95% CI [0.06-0.36], P = 3.28 × 10 -5 ). Surgery with cavity SRS was also associated with decreased all-cause mortality (HR: 0.52, 95% CI [0.35-0.78], P = 1.46 × 10 -3 ), neurological death (HR: 0.30, 95% CI [0.10-0.88], P = 2.88 × 10 -2 ), and radiation necrosis (HR: 0.14, 95% CI [0.03-0.74], P = 2.07 × 10 -2 ) compared with SRS alone. Surgery was associated with lower risk of all-cause mortality and neurological death in cardinality-matched subsets of the cohort. Among surgical patients, gross total resection was associated with extended overall survival (HR: 0.62, 95% CI [0.40-0.98], P = 4.02 × 10 -2 ) along with lower risk of neurological death (HR: 0.31, 95% CI [0.17-0.57], P = 1.84 × 10 -4 ) and local failure (HR: 0.34, 95% CI [0.16-0.75], P = 7.08 × 10 -3 ).

CONCLUSION

In patients with 1 brain metastasis, minimizing intracranial disease specifically before stereotactic radiation is associated with improved oncologic outcomes.

Increased risk for ex-vacuo ventriculomegaly with leukoencephalopathy (EVL) in whole brain radiation therapy and repeat radiosurgery treated brain metastasis patients

INTRODUCTION

Cerebral atrophy with leukoencephalopathy is a known morbidity after whole brain radiation therapy (WBRT), resulting in ex-vacuo ventriculomegaly with leukoencephalopathy (EVL). Here we studied the correlation between WBRT, stereotactic radiosurgery (SRS), and risk for EVL in brain metastases patients.

METHODS

In a retrospective study, we identified 195 patients (with 1,018 BM) who underwent SRS for BM (2007-2017) and had > 3 months of MRI follow-up. All patients who underwent ventriculoperitoneal shunting were excluded. Cerebral atrophy was measured by ex-vacuo-ventriculomegaly, defined based on Evans' criteria. Demographic and clinical variables were analyzed using logistic regression models.

RESULTS

Ex-vacuo ventriculomegaly was observed on pre-radiosurgery imaging in 29.7% (58/195) of the study cohort. On multivariate analysis, older age was the only variable associated with pre-radiosurgery ventriculomegaly. Of the 137 patients with normal ventricular size before radiosurgery, 27 (19.7 %) developed ex-vacuo ventriculomegaly and leukoencephalopathy (EVL) post-SRS. In univariate analysis, previous whole brain radiation therapy was the main factor associated with increased risk for developing EVL (OR = 5.08, p < 0.001). In bivariate models that included prior receipt of WBRT, both the number of SRS treatments (OR = 1.499, p = 0.025) and WBRT (OR = 11.321, p = 0.003 were independently associated with increased EVL risk.

CONCLUSIONS

While repeat radiosurgery contributes to the risk of EVL in BM patients, this risk is ∼20-fold lower than that associated with WBRT.

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

PURPOSE

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSION

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

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.

Current Treatment Approaches and Global Consensus Guidelines for Brain Metastases in Melanoma

Background

Up to 60% of melanoma patients develop melanoma brain metastases (MBM), which traditionally have a poor diagnosis. Current treatment strategies include immunotherapies (IO), targeted therapies (TT), and stereotactic radiosurgery (SRS), but there is considerable heterogeneity across worldwide consensus guidelines.

Objective

To summarize current treatments and compare worldwide guidelines for the treatment of MBM.

Methods

Review of global consensus treatment guidelines for MBM patients.

Results

Substantial evidence supported that concurrent IO or TT plus SRS improves progression-free survival (PFS) and overall survival (OS). Guidelines are inconsistent with regards to recommendations for surgical resection of MBM, since surgical resection of symptomatic lesions alleviates neurological symptoms but does not improve OS. Whole-brain radiation therapy is not recommended by all guidelines due to negative effects on neurocognition but can be offered in rare palliative scenarios.

Conclusion

Worldwide consensus guidelines consistently recommend up-front combination IO or TT with or without SRS for the treatment of MBM.

Management of Brain Metastasis. Surgical Resection versus Stereotactic Radiotherapy: A Meta-analysis

Background

Treatment of metastatic brain tumors often involves radiotherapy with or without surgical resection as the first step. However, the indications for when to use surgery are not clearly defined for certain tumor sizes and multiplicity. This study seeks to determine whether resection of brain metastases versus exclusive radiotherapy provided improved survival and local control in cases where metastases are limited in number and diameter.

Methods

According to PRISMA guidelines, this meta-analysis compares outcomes from treatment of a median number of brain metastases ≤4 with a median diameter ≤4 cm with exclusive radiotherapy versus surgery followed by radiotherapy. Four randomized control trials and 11 observational studies (1693 patients) met inclusion criteria. For analysis, studies were grouped based on whether radiation involved stereotactic radiosurgery (SRS) or whole-brain radiotherapy (WBRT).

Results

In both analyses, there was no difference in survival between surgery ±SRS versus SRS alone two years after treatment (OR 1.89 (95% CI: 0.47 - 7.55, p = 0.23) or surgery + WBRT versus radiotherapy alone (either WBRT and/or SRS) (OR 1.18 (95% CI: 0.76 – 1.84, p = 0.46). However, surgical patients demonstrated greater risk for local tumor recurrence compared to SRS alone (OR 2.20 (95% CI: 1.49 - 3.25, p &lt; 0.0001)) and compared to WBRT/SRS (OR 2.93; 95% CI: 1.68 - 5.13, p = 0.0002).

Conclusion

The higher incidence of local tumor recurrence for surgical patients suggests that more prospective studies are needed to clarify outcomes for treatment of 1-4 metastasis less than 4 cm diameter.

Stereotactic Laser Ablation (SLA) followed by consolidation stereotactic radiosurgery (cSRS) as treatment for brain metastasis that recurred locally after initial radiosurgery (BMRS): a multi-institutional experience

INTRODUCTION

The optimal treatment paradigm for brain metastasis that recurs locally after initial radiosurgery remains an area of active investigation. Here, we report outcomes for patients with BMRS treated with stereotactic laser ablation (SLA, also known as laser interstitial thermal therapy, LITT) followed by consolidation radiosurgery.

METHODS

Clinical outcomes of 20 patients with 21 histologically confirmed BMRS treated with SLA followed by consolidation SRS and > 6 months follow-up were collected retrospectively across three participating institutions.

RESULTS

Consolidation SRS (5 Gy × 5 or 6 Gy × 5) was carried out 16-73 days (median of 26 days) post-SLA in patients with BMRS. There were no new neurological deficits after SLA/cSRS. While 3/21 (14.3%) patients suffered temporary Karnofsky Performance Score (KPS) decline after SLA, no KPS decline was observed after cSRS. There were no 30-day mortalities or wound complications. Two patients required re-admission within 30 days of cSRS (severe headache that resolved with steroid therapy (n = 1) and new onset seizure (n = 1)). With a median follow-up of 228 days (range: 178-1367 days), the local control rate at 6 and 12 months (LC₆, LC₁₂) was 100%. All showed diminished FLAIR volume surrounding the SLA/cSRS treated BMRS at the six-month follow-up; none of the patients required steroid for symptoms attributable to these BMRS. These results compare favorably to the available literature for repeat SRS or SLA-only treatment of BMRS.

CONCLUSIONS

This multi-institutional experience supports further investigations of SLA/cSRS as a treatment strategy for BMRS.

The efficacy of laser interstitial thermal therapy for brain metastases with in-field recurrence following SRS: systemic review and meta-analysis

OBJECTIVE

To study the efficacy of LITT for BM patients experiencing in-field recurrence following SRS.

METHODS

A literature search was conducted to identify studies investigating local control (LC) rate and overall survival (OS) of LITT for BMs with IFR following SRS.

RESULTS

Analysis included 14 studies (470 patients with 542 lesions). The 6-month (LC-6) and 12-month (LC-12) local control rates were 78.5% (95% CI: 70.6-84.8%) and 69.0% (95% CI: 60.0-76.7%) separately. Pooled median OS was 17.15 months (95% CI: 13.27-24.8). The overall OS-6 and OS-12 rates were 76.0% (95% CI: 71.4-80.0%) and 63.4% (95% CI: 52.9-72.7%) separately. LITT provided more favorable local control efficacy in RN than BM recurrence (LC-6: 87.4% vs. 67.9%, p = 0.009; LC-12: 76.3% vs. 59.9%, p = 0.041).

CONCLUSIONS

LITT is an effective treatment for BM patients experiencing IFR following SRS. For different pathological entities, LITT showed more satisfactory local control efficacy on RN than BM recurrence.

Laser interstitial thermotherapy (LITT) for the treatment of tumors of the brain and spine: a brief review

Introduction

Laser Interstitial Thermotherapy (LITT; also known as Stereotactic Laser Ablation or SLA), is a minimally invasive treatment modality that has recently gained prominence in the treatment of malignant primary and metastatic brain tumors and radiation necrosis and studies for treatment of spinal metastasis has recently been reported.

Methods

Here we provide a brief literature review of the various contemporary uses for LITT and their reported outcomes.

Results

Historically, the primary indication for LITT has been for the treatment of recurrent glioblastoma (GBM). However, indications have continued to expand and now include gliomas of different grades, brain metastasis (BM), radiation necrosis (RN), other types of brain tumors as well as spine metastasis. LITT is emerging as a safe, reliable, minimally invasive clinical approach, particularly for deep seated, focal malignant brain tumors and radiation necrosis. The role of LITT for treatment of other types of tumors of the brain and for spine tumors appears to be evolving at a small number of centers. While the technology appears to be safe and increasingly utilized, there have been few prospective clinical trials and most published studies combine different pathologies in the same report.

Conclusion

Well-designed prospective trials will be required to firmly establish the role of LITT in the treatment of lesions of the brain and spine.

An integrated disease-specific graded prognostic assessment scale for melanoma: contributions of KPS, CITV, number of metastases, and BRAF mutation status

Background

Stereotactic radiosurgery (SRS) remains a mainstay therapy in the treatment of melanoma brain metastases (BM). While prognostic scales have been developed for melanoma patients who underwent SRS treatment for BM, the pertinence of these scales in the context of molecularly targeted therapies remains unclear.

Methods

Through a multi-institutional collaboration, we collated the survival patterns of 331 melanoma BM patients with known BRAF mutation status treated with SRS. We established a prognostic scale that was validated in an independent cohort of 174 patients. All patients with BRAF mutations in this series were treated with BRAF inhibitors. Prognostic utility was assessed using Net Reclassification Index (NRI > 0) and integrated discrimination improvement (IDI) metrics.

Results

In a multivariate Cox proportional hazards model, BRAF mutation status, KPS, number of metastases, and cumulative intracranial tumor volume (CITV) independently contributed to survival prognostication for melanoma patients with SRS-treated BM (P < .05 for all variables). These variables were incorporated into a prognostic scale using the disease-specific graded prognostic assessment (ds-GPA) framework. This integrated melanoma ds-GPA scale was validated in 2 independent cohorts collated through a multi-institutional collaboration. In terms of order of prognostic importance, BRAF mutation status exerted the greatest influence on survival, while KPS, the number of metastases, and CITV exhibited comparable, lesser impacts.

Conclusions

Optimal survival prognostication for SRS-treated patients with melanoma BM requires an integrated assessment of patient characteristics (KPS), tumor characteristics (CITV and number of metastases), and the mutational profile of the melanoma (BRAF mutation status).

Cumulative Intracranial Tumor Volume as a Prognostic Factor in Patients with Brain Metastases Undergoing Stereotactic Radiosurgery

Approximately 25-35% of all cancer patients suffer from brain metastases (BM), and many of them-in particular, those with a limited number of intracranial tumors-are treated with stereotactic radiosurgery (SRS). Accurate prediction of survival remains a key clinical challenge in this population. Several prognostic scales have been developed to facilitate this prognostication, including the Recursive Partitioning Analysis (RPA) classification, the modified Recursive Partitioning Analysis (mRPA) subclassifications, the Basic Score for Brain Metastases (BS-BM), the Score Index for Radiosurgery (SIR), the Graded Prognostic Assessment (GPA), and the diagnosis-specific Graded Prognostic Assessment (dsGPA). However, none of these scales include consideration of the cumulative intracranial tumor volume (CITV), which is defined as the sum of all intracranial tumor volumes. Since there is mounting evidence that the CITV carries significant prognostic value in SRS-treated patients with BM, this variable should be considered during survival prognostication, along with other pertinent clinical, pathological, and molecular characteristics.

Management of melanoma brain metastases: Evidence-based clinical practice guidelines by Cancer Council Australia

INTRODUCTION

The brain is a common site of metastatic disease for patients with advanced melanoma. Brain metastasis portends a poor prognosis, often causing deterioration in neurological function and quality of life, and leading to neurological death. Treatment approaches including surgery, radiotherapy and systemic therapy can lead to better control of this problem. Therefore, appropriate guidelines for the management of melanoma brain metastases need to be established, with regular updating when new treatment options become available.

METHODS

A multidisciplinary working party established by Cancer Council Australia has produced up-to-date, evidence-based clinical practice guidelines for the management of melanoma. After selecting key clinical questions, a comprehensive literature search for relevant studies was conducted, followed by systematic review of those studies. Data were summarised and the evidence was assessed, leading to the development of recommendations.

MAIN RECOMMENDATIONS

Symptomatic lesions are best treated with surgery, when possible; this provides safe and effective local control. For patients with single or a small number of asymptomatic brain metastases, stereotactic radiotherapy is recommended, but in asymptomatic patients who have not previously received systemic treatment, drug therapy can be considered as a first-line treatment option. Whole brain radiotherapy may provide palliative benefits in patients with multiple brain metastases. Whenever possible, melanoma patients with brain metastases should be managed by a multidisciplinary team of melanoma specialists that considers the optimal combination and sequencing of surgery, radiotherapy and systemic therapy.

Comparison of Surgical Resection and Stereotactic Radiosurgery in the Initial Treatment of Brain Metastasis

BACKGROUND

Brain metastasis (BM) is the most common brain malignancy and a common cause of death in cancer patients. However, the relative outcome-related advantages and disadvantages of surgical resection (SR) and stereotactic radiosurgery (SRS) in the initial treatment of BM are controversial.

METHOD

We systematically reviewed the English language literature up to March 2020 to compare the efficacy of SR and SRS in the initial treatment of BM. We identified cohort studies from the Cochrane Library, PubMed, and EMBASE databases and conducted a meta-analysis following the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. Twenty cohort studies involving 1,809 patients were included. Local control did not significantly differ between the SR and SRS groups overall (hazard ratio [HR] 1.02, 95% confidence interval (CI) 0.64-1.64, p = 0.92; I2 = 54%, p = 0.03) or in subgroup analyses of SR plus SRS vs. SRS alone, SR plus whole brain radiation therapy (WBRT) versus SRS plus WBRT, or SR plus WBRT versus SRS alone. Distant intracranial control did not significantly differ between the SR and SRS groups overall (HR 0.78, 95% CI 0.38-1.60, p = 0.49; I2 = 61%, p = 0.03) or in subgroup analyses of SR plus SRS versus SRS alone or SR plus WBRT versus SRS alone. In addition, overall survival (OS) did not significantly differ in the SR and SRS groups (HR 0.91, 95% CI 0.65-1.27, p = 0.57; I2 = 47%, p = 0.09) or in subgroup analyses of SR plus SRS versus SRS alone, SR plus WBRT versus SRS alone or SR plus WBRT versus SRS plus WBRT.

CONCLUSION

Initial treatment of BM with SRS may offer comparable local and distant intracranial control to SR in patients with single or solitary BM. OS did not significantly differ between the SR and SRS groups in people with single or solitary BM.

Surgical Considerations and Systemic Therapy of Melanoma

Recent advances in effective medical therapies have markedly improved the prognosis for patients with advanced melanoma. This article aims to highlight the current era of integrated multidisciplinary care of patients with advanced melanoma by outlining current approved therapies, including immunotherapy, targeted therapy, radiation therapy, and other strategies used in both the adjuvant and the neoadjuvant setting as well as the evolving role of surgical intervention in the changing landscape of advanced melanoma.

Clinical Outcomes of Stereotactic Body Radiotherapy in Oligometastatic Gynecological Cancer

OBJECTIVE

The objective of this study was to assess the role of stereotactic body radiotherapy (SBRT) in the treatment of distantly recurrent, oligometastatic gynecological cancer.

METHODS

The hospital records of 45 patients with F-fluorodeoxyglucose (F-FDG) positron emission tomography positive, distantly recurrent, oligometastatic gynecological cancer were reviewed. All these patients had a number of target lesions less than 5, with largest diameter less than 6 cm. The treatment was delivered with a TrueBeam LINAC and RapidArc technique, using 10 or 6 MV FFF beams. A total of 70 lesions were treated, and lymph nodes represented the most common site of metastases, followed by lung, liver, and soft tissues. Twenty lesions were treated with one single fraction of 24 Gy and 5 lesions received 27 Gy delivered in 3 fractions, depending on the ability to fulfill adequate target coverage and safe dose/volume constraints for the organ at risk with either regimen.

RESULTS

Positron emission tomography scan 3 months after SBRT showed a complete response (CR) in 45 lesions (64.3%), a partial response in 14 (20.0%), a stable disease in 5 (7.1%), and a progressive disease in 6 (8.6%). No lesions in CR after SBRT subsequently progressed. Overall acute toxicity occurred in 13 (28.9%) patients. The most common grade 1 to 2 adverse event was pain (n = 9, 20.0%), followed by nausea and vomiting (n = 5, 11.1%). No grade 3 to 4 acute toxicities occurred, and no late toxicities were observed. Patients who failed to achieve a CR had a 2.37-fold higher risk of progression and a 3.60-fold higher risk of death compared with complete responders (P = 0.04 and P = 0.03, respectively).

CONCLUSIONS

Stereotactic body radiotherapy offers an effective and safe approach for selected cases of oligometastatic gynecological cancer.

Melanoma central nervous system metastases: current approaches, challenges, and opportunities

Melanoma central nervous system metastases are increasing, and the challenges presented by this patient population remain complex. In December 2015, the Melanoma Research Foundation and the Wistar Institute hosted the First Summit on Melanoma Central Nervous System (CNS) Metastases in Philadelphia, Pennsylvania. Here, we provide a review of the current status of the field of melanoma brain metastasis research; identify key challenges and opportunities for improving the outcomes in patients with melanoma brain metastases; and set a framework to optimize future research in this critical area.