Gamma Knife Radiosurgery of Brainstem Cavernous Malformations

Stereotactic radiosurgery for intracranial cavernous malformations of the deep-seated locations: systematic review and meta-analysis

OBJECTIVE

To determine the outcomes of stereotactic radiosurgery (SRS) for deep-seated (brainstem, basal ganglia, thalamus, cerebellar peduncle) intracranial cavernous malformations (ICMs).

METHODS

A systematic review and meta-analysis was performed according to PRISMA and MOOSE guidelines. The main outcomes were comparing pre- and post-SRS hemorrhage rates, using the pooled risk ratios (RR) as the measure of effect. Additionally, the study assessed lesion volume changes and radiation-injury incidence.

RESULTS

Data of 850 patients across 14 studies were included in the meta-analysis. The pooled RR of all deep-seated ICMs show a decrease in hemorrhage rate after SRS compared to pre-SRS over the total follow-up period (RR =0.13), initial 2 years (RR =0.22), and after 2 years (RR =0.07). For 9 studies that reported hemorrhage rate of the brainstem only, the pooled RR shows a decrease of hemorrhage rate after SRS compared to pre-SRS over the total follow-up period (RR =0.13), initial 2 years (RR =0.19), and after 2 years (RR =0.07). Volumetric regression was achieved in 44.25% and stability in 56.1%. The pooled incidence of symptomatic and permanent radiation injury was 9% (95% CI, 7-11) and 3% (95% CI, 0-1.9%), respectively.

CONCLUSION

SRS appears effective in reducing hemorrhage rates for deep-seated ICMs. The risk of symptomatic radiation injury is low. Given the high risk of surgical morbidity, SRS is a reasonable treatment option for patients with deep-seated ICMs with at least one prior hemorrhage.

The Impact of Volume Factor on the Long-Term Outcome of Gamma Knife Radiosurgery for Sporadic Cerebral Cavernous Malformations

OBJECTIVE

We aimed to evaluate the long-term outcome of gamma knife radiosurgery (GKRS) for the treatment of sporadic cerebral cavernous malformation (CCM), especially the influence of lesion volume on annual hemorrhage rate (AHR) of patients with CCM after GKRS.

METHODS

Fifty-one single-lesion patients with a history of hemorrhage who underwent radiosurgery at our institution were included and divided into 2 groups (A and B), based on their lesion volume. Group A included 25 patients with lesion volumes >1 cm³, whereas group B included 26 patients with lesion volumes ≤1 cm³. The clinical data of the patients were retrospectively analyzed.

RESULTS

All patients were followed up for more than 4 years after GKRS. The calculated AHR before GKRS was 18.49% in group A and 10.16% in group B. The calculated AHR after GKRS was 5.43% and 0.99% for groups A and B, respectively. Significant differences in AHR after GKRS were identified between group A and group B (P = 0.011). Thirty-seven patients with sporadic CCM (14 in group A, 23 in group B) experienced symptom improvement, and significant differences in symptom improvement were observed between group A and group B (P = 0.009).

CONCLUSIONS

GKRS decreased the risk of hemorrhage and was beneficial for symptomatic improvement in patients with sporadic CCM with a history of hemorrhage. The long-term clinical outcomes for patients with sporadic CCM with small lesion volumes (≤1 cm³) were better than those of patients with sporadic CCM with large lesion volumes (>1 cm³).

Gamma Knife Radiosurgery for Cavernous Malformations of Basal Ganglia and Thalamus: A Retrospective Study of 53 Patients

INTRODUCTION

Gamma Knife radiosurgery (GKRS) has been used to treat cavernous malformations (CMs) located in basal ganglia and thalamus. However, previous reports are limited by small patient population.

METHODS

We retrospectively reviewed the clinical and radiological data of 53 patients with CMs of basal ganglia and thalamus who underwent GKRS at West China Hospital between May 2009 and July 2018. All patients suffered at least once bleeding before GKRS. The mean volume of these lesions was 1.77 cm3, and the mean marginal dose was 13.2 Gy. After treatment, patients were followed to determine the change in symptom and hemorrhage event.

RESULTS

The mean follow-up period was 52.1 months (6.2-104.3 months). The calculated annual hemorrhage rate (AHR) was 48.5% prior to GKRS and 3.0% after treatment (p < 0.001). The Kaplan-Meier analysis revealed that 2-, 3-, and 5-year hemorrhage-free survival were 88, 80.9, and 80.9%, respectively. Preexisting symptoms were resolved in 11 patients, improved in 14, and stable in 5. Only 2 patients (3.8%) developed new neurological deficit.

CONCLUSION

Our study suggests that AHR after GKRS was comparable to the recorded AHR of natural history (3.1-4.1%) in previous studies. GKRS is a safe and effective treatment modality for CMs of basal ganglia and thalamus. Considering the relative insufficient understanding of natural history of CMs, future study warrants longer follow-up.

Microsurgery vs. Gamma Knife Radiosurgery for the Treatment of Brainstem Cavernous Malformations: A Systematic Review and Meta-Analysis

Background: Brainstem cavernous malformations (BSCMs) are a subset of cerebral cavernous malformations with precarious locations and potentially devastating clinical courses. The effects and outcomes of treating BSCMs by microsurgery or gamma knife radiosurgery (GKRS) vary across studies.

Methods: We searched the Medline, Web of Science, The Cochrane Library, PubMed, and China Biology Medicine disc databases for original articles published in peer-reviewed journals of cohort studies reporting on 20 or more patients of any age with BSCMs with at least 80% completeness of follow-up.

Results: We included 43 cohorts involving 2,492 patients. Both microsurgery (RR = 0.04, 95% CI 0.01–0.16, P < 0.01) and GKRS (RR = 0.11, 95% CI 0.08–0.16, P < 0.01) demonstrated great efficacy in reducing the rehemorrhage rate after treatment for BSCMs. The incidence rates of composite outcomes were 19.8 (95% CI 16.8–22.8) and 15.7 (95% CI 11.7–19.6) after neurosurgery and radiosurgery, respectively. In addition, we found statistically significant differences in the median numbers of patients between neurosurgical and radiosurgical cohorts in terms of symptomatic intracranial hemorrhage (ICH; neurosurgical cohorts: median 0, range 0–33; radiosurgical cohorts: median 4, range 1–14; P < 0.05) and persistent focal neurological deficit (FND; neurosurgical cohorts: median 5, range 0–140; radiosurgical cohorts: median 1, range 0–3; P < 0.05).

Conclusions: The reported effects of treating BSCMs by microsurgery or GKRS are favorable for reducing recurrent hemorrhage from BSCMs. Patients in the neurosurgery cohort had a lower incidence of symptomatic ICH, while patients in the radiosurgical cohort had a lower incidence of persistent FND.

Radiosurgery for Symptomatic Cavernous Malformation in the Brainstem: Two Difficult Cases with Large and Multiple Lesions

It is well known that cavernous malformations become much more hemorrhagic after the initial hemorrhage and that brainstem lesions are more dangerous than the lesions in the supratentorial location. It is very difficult to handle symptomatic cavernous malformations associated with repetitive hemorrhages in the brainstem. Patients may be suffering from brainstem syndromes such as hemiparesis, hemisensory disturbance, ataxia, and disturbed ocular movement. We have encountered two such difficult cases, one is very large and the other is multiple and familiar, accompanying repetitive brainstem hemorrhages. Since microsurgery seems to be very difficult and hazardous, these two cases were treated with radiosurgery after several hemorrhages.

Stereotactic radiosurgery for cerebral cavernous malformations: A systematic review

OBJECTIVE

The efficacy of stereotactic radiosurgery (SRS) for the treatment of cerebral cavernous malformations (CCMs) is uncertain, so we set out to quantify clinical outcomes after SRS for CCM and compare them to microsurgical excision or conservative management.

METHODS

We searched Ovid Medline and Ovid EMBASE from inception until June 1, 2018, for peer-reviewed publications describing clinical outcomes after SRS for ≥10 people with CCM in cohorts with or without a comparison group treated with neurosurgical excision or conservative management. Two reviewers independently extracted data from the included studies to quantify cohort characteristics and the incidence of the primary outcome (death attributable to CCM or its treatment) and secondary outcomes (incident nonfatal symptomatic intracerebral hemorrhage [ICH] and incident nonhemorrhagic persistent focal neurologic deficit [FND]). We assessed whether comparative studies showed a dramatic association (meaning the conventionally calculated probability comparing 2 differently managed patient groups from the same population was <0.01 with a rate ratio greater than 10).

RESULTS

We included 30 cohort studies involving a total of 1,576 patients undergoing SRS for CCM. Four nonrandomized studies compared SRS to other treatment strategies, but did not demonstrate dramatic associations. During a median follow-up of 48 (interquartile range 35-62) months after SRS, the annual incidences (95% confidence interval) of outcomes were death 0.18% (0.10-0.31), ICH 2.40% (2.05-2.80), FND 0.71% (0.53-0.96), and the composite of death, ICH, or FND 3.63% (3.17-4.16). Outcomes did not differ by CCM location or type of SRS.

CONCLUSION

After SRS for CCM, the annual incidences of death, ICH, and FND are <5% and seem comparable to outcomes without SRS. A randomized trial of SRS for CCM is needed.

Trans-labyrinthine Infra-trigeminal Approach for Recurrent Pontomedullary Cavernoma: A Step-wise Technical Note

Recurrent brainstem cavernoma is a challenging lesion due to the neurological risks associated with different surgical approaches. In this technical report, we present a 35-year-old female with a history of multiple brain cavernomas. She underwent midline suboccipital craniotomy and trans-fourth ventricle approach for resection of the brain stem cavernoma following two major bleeding episodes, one year prior to the presentation. Following the trans-labyrinthine infra-trigeminal approach, the patient recovered well postoperatively with a baseline neuro exam and was discharged to acute rehab on postoperative day 5 (POD5). The translabyrinthine approach is a safe and effective corridor for pontine or pontomedullary lesions in carefully selected patients. Appropriate selection of surgical approach (based on location), meticulous surgical technique, and intraoperative neuromonitoring help in maximizing surgical resection while minimizing neurological deficits.

Stereotactic Radiosurgery for Brainstem Cavernous Malformations: An Updated Systematic Review and Meta-Analysis

OBJECTIVE

This study was conducted to achieve more conclusive evidence for the efficacy of stereotactic radiosurgery (SRS) for brainstem cavernous malformations (BSCMs).

METHODS

A literature search of PubMed, EMBASE, and Web of Science was performed and studies reporting the outcomes of SRS for BSCMs were included. The primary outcome was the pre-SRS and post-SRS hemorrhage rates; the pooled incidence rate ratio (IRR) with 95% confidence interval was chosen as effect size. Lesion control, symptom change, and radiation-related complications were evaluated.

RESULTS

A total of 576 patients across 14 studies were included in this meta-analysis. The post-SRS hemorrhage rate was significantly decreased compared with the pre-SRS rate (IRR, 0.123; P < 0.001), and the hemorrhage rate 2 years after SRS was significantly lower than that within 2 years after SRS (IRR, 0.317; P < 0.001). Ten among 14 studies have shown that the symptoms were improved or stationary after SRS. Lesion volume was reduced in 47.3% of the patients and was stationary in 49.4% on the last follow-up images. Symptomatic adverse radiation effects (AREs) developed in 7.3% and permanent AREs were observed in 2.2%. In subgroup analysis, studies having mean marginal dose of ≤13 Gy showed statistically significantly lower development of symptomatic AREs than those having mean marginal dose of >13Gy (2.0% vs. 10.8%; P = 0.008).

CONCLUSIONS

SRS using a relatively low marginal dose can be a safe and effective treatment for BSCM. Further prospective studies are necessary to confirm the optimal radiation dose and efficacy of SRS for BSCMs.

Contemporary radiosurgery of cerebral cavernous malformations: Part 1. Treatment outcome for critically located hemorrhagic lesions

OBJECTIVE

Long-term benefits of radiosurgery (RS) applying modern protocols to treat cavernous malformations (CMs) remain unclear as critics may consider the decrease in the rebleed rate generally observed 2 years after RS as a reflection of the lesion's natural history. The authors adopted an early intention-to-treat attitude since rehemorrhage from deep-seated CMs ultimately leads to stepwise neurological deterioration. The safety of this early policy was previously demonstrated. Here, the authors revisit their current practice in a larger population with a longer follow-up time to assess the long-term effects of RS in the context of current knowledge on the natural history of CMs.

METHODS

The authors conducted a retrospective analysis of 210 patients with 210 hemorrhagic CMs located in the brainstem, thalamus, or basal ganglia and treated with Gamma Knife RS between 1995 and 2014. Two hundred six patients had available follow-up, which was a median of 5.5 years (range 1-20 years). The median age was 37 years (0.5-77 years) at presentation and 43 (2-78) at treatment. One hundred twenty-seven CMs had bled once and 83 had had multiple hemorrhages prior to treatment.

RESULTS

The lifetime annual bleed rate of CMs having a single hemorrhage prior to treatment was 2.4% per lesion. The hemorrhage rate stabilized at 1.1% after a temporary increase of 4.3% within the first 2 years after RS. The annual pretreatment hemorrhage rate was 2.8% for the lesions having multiple bleeds prior to RS with a pretreatment rebleed rate of 20.7% and with a modest gradual decrease within the first 5 years and remaining stable at 11.55% thereafter. The rebleed rate fell to 7.9% for the first 2 years after RS and declined further to 1.3% thereafter, which was significantly lower than the long-term pretreatment rebleed risk. The rate of hemorrhage-free survival remained 86.4% and 75.1% (1 patient each) at 20 years after RS in the single- and multiple-bleed groups, respectively.Pretreatment hemorrhages resulted in permanent deficits in 48.8% of the cases with a single bleed and in 77.1% of the cases with multiple bleeds. Both the rate and severity of deficits were significantly lower in the first group. Only mild and a low rate of permanent neurological deficits were caused either by posttreatment hemorrhages (7.4%) or by radiation (7.2%). The rate of persistent morbidity in the single-bleed group remained significantly lower at the end of the study than pretreatment morbidity in the multiple-bleed group (OR 2.9, 95% CI 1.6-5.3). Lesion-specific mortality was < 1%.

CONCLUSIONS

The hemorrhage rate of CMs after RS remained low after the first 2 years during the longer follow-up period. The benefit of early treatment appears to be confirmed by the study results as repeated hemorrhages carry the risk of significantly higher cumulative morbidity than the morbidity associated with RS.

The Efficacy of Gamma Knife Radiosurgery for Cavernous Malformations: A Meta-Analysis and Review

OBJECTIVE

This meta-analysis is to evaluate the clinical efficacy of gamma knife radiosurgery (GKRS) for treating cavernous malformations.

METHODS

PubMed, Ovid Embase, and Ovid Medline electronic databases were searched. The primary outcome is hemorrhage rate and this meta-analysis is performed.

RESULTS

Nine studies are included in this meta-analysis. The overall risk ratio (RR) of hemorrhage rate of pre-GKRS and post-GKRS is 6.08 (95% confidence interval [CI], 5.04-7.35). The overall RR is 3.03 (95% CI, 2.65-4.11) between the hemorrhage rate of pre-GKRS and the first 2 years postradiosurgery, and the overall RR is 12.13 (95% CI, 1.73-85.07) comparing pre-GKRS with 2 years after GKRS. There is no significant difference of the hemorrhage rate between the first 2 years postradiosurgery and 2 years after GKRS (RR = 2.81; 95% CI, 0.20-13.42). The neurologic deficiency is the most common radiosurgery-related complication.

CONCLUSIONS

Patients with cerebral cavernous malformations, especially ones that were deep seated and surgically inaccessible, seem to benefit from GKRS owing to a reduction of annual hemorrhage rate in the first 2 years and 2 years after, despite several cases that suffer from negative side effects of radiation.

Long-Term Outcome of Gamma Knife Radiosurgery for Symptomatic Brainstem Cavernous Malformation

OBJECTIVE

We sought to analyze the long-term outcome of Gamma Knife radiosurgery (GKS) for symptomatic brainstem cavernous malformation (s-BSCM).

METHODS

Forty-five patients (14 males, 31 females) were treated with GKS for s-BSCM from January 1998 to December 2011. All patients were followed up for >5 years, and their clinical data were analyzed retrospectively. All patients had a history of symptomatic bleeding once or more before GKS. These hemorrhages caused neurologic deficits including cranial nerve deficits, hemiparesis, hemisensory deficits, spasticity, or chorea. The mean target volume of s-BSCM was 1.82 cm³, and the median prescribed marginal dose of radiation was 13 Gy. The mean clinical and imaging follow-up period was 9.31 years (range 5.1-19.4 years).

RESULTS

The 45 patients had 69 hemorrhagic events before GKS. During the follow-up period after GKS, 35 patients had no hemorrhagic event, 6 patients had 1 episode of symptomatic hemorrhage, and 4 patients had 2 episodes. The calculated annual hemorrhage rate was 40.06% at pre-GKS, 3.3% at 2 years after GKS, 1.48% at 5 years after GKS, and 4.64% at >5 years after GKS. In this study of 45 patients, symptomatic radiation-induced complications developed in only 1 patient (2.2%). No patients had died at the last follow-up.

CONCLUSIONS

GKS for s-BSCM is a safe and effective alternative to surgical resection for reducing the rate of recurrent hemorrhage. Because the annual hemorrhage rate increases >5 years after GKS, clinicians should monitor patients closely to determine their subsequent treatment.