Stereotactic drainage and Gamma Knife radiosurgery of cystic brain metastasis

Brain metastases: Comparing clinical radiological differences in patients with lung and breast cancers treated with surgery

Purpose

Brain metastases (BMs) most frequently originate from the primary tumors of the lung and breast. Survival in patients with BM can improve if they are detected early. No studies attempt to consider all potential surgical predictive factors together by including clinical, radiological variables for their recognition.

Methods

The study aims to simultaneously analyze all clinical, radiologic, and surgical variables on a cohort of 314 patients with surgically-treated BMs to recognize the main features and differences between the two histotypes.

Results

The two groups consisted of 179 BM patients from lung cancer (Group A) and 135 patients from breast cancer (Group B). Analysis showed that BMs from breast carcinoma are more likely to appear in younger patients, tend to occur in the infratentorial site and are frequently found in patients who have other metastases outside of the brain (46 %, p = 0.05), particularly in bones. On the other hand, BMs from lung cancer often occur simultaneously with primitive diagnosis, are more commonly cystic, and have a larger edema volume. However, no differences were found in the extent of resection, postoperative complications or the presence of decreased postoperative performance status.

Conclusion

The data presented in this study reveal that while the two most prevalent forms of BM exhibit distinctions with respect to clinical onset, age, tumor location, presence of extra-cranial metastases, and lesion morphology from a strictly surgical standpoint, they are indistinguishable with regard to outcome, demonstrating comparable resection rates and a low risk of complications.

Extensive Stage Small-Cell Lung Cancer with Cystic Brain Metastases: A Report of Two Cases

Objective

Cystic brain metastases (BMs) are rare in small cell lung cancer (SCLC), and there are limited data on the treatment and prognosis of cystic BMs. Whole brain radiotherapy has been the mainstay for BMs since several years. Immune checkpoint inhibitors in extensive stage small cell lung cancer (ES-SCLC) have been shown to be suitable for patients who experienced better overall survival and progress-free survival and have been approved as the first-line treatment for ES-SCLC. In this report, we described two ES-SCLC patients developed cystic BMs after immunotherapy, after which the patients continued to treat the primary lesion with immune checkpoint inhibitors and the cystic BMs with radiotherapy.

Case Description

Two male patients were diagnosed with ES-SCLC at the first admission and were subsequently treated with immunotherapy plus platinum therapy, during which cystic BMs developed. One patient received whole brain radiotherapy and the other received whole brain radiotherapy and Gamma knife radiosurgery (GKRS). Immunotherapy was continued after the brain lesions were controlled. It has been 33 months since the first patient was diagnosed and is now in stable condition. The other patient achieved an overall survival of 30 months.

Conclusion

This report describes two patients with cystic brain metastases in ES-SCLC. Whole brain radiotherapy has a good effect on local control of cystic brain metastases in small cell lung cancer and can significantly improve the symptoms of patients. At the same time, we treat immunotherapy as the first-line treatment, and then perform cross-immunotherapy after disease progression, combined with anti-vascular targeting drugs. The patient did not develop severe iRAEs.

Evaluation of Radiotherapy Efficacy and Prognostic Analysis for Solid and Cystic Brain Metastases

OBJECTIVES

Brain metastases (BMs) are commonly categorized into cystic and solid. However, the difference in the prognosis of patients with either cystic or solid BMs following radiotherapy remains poorly understood. We used a retrospective design to elucidate the disparities in survival between these two patient groups undergoing radiotherapy and to identify factors influencing the overall survival (OS) of patients with BMs.

METHODS

This retrospective study encompasses 212 patients diagnosed with BMs. We meticulously analyzed the clinical characteristics, radiation therapy modalities, and risk factors influencing the OS among these patients, categorized by BMs type, post-brain radiation therapy.

RESULTS

A statistically significant difference in mOS was observed between the two cohorts (Solid vs Cystic: 23.1 vs 14.6 months). Subgroup analysis unveiled distinctions in mOS, particularly in patients with EGFR-mutant lung adenocarcinoma (Solid vs Cystic: 23.1 vs 6.43 months). The volume of BMs and the biological effective dose (BED) emerged as significantly prognostic factors for patients with cystic BMs. For patients with solid BMs, fraction dose, BED, and the number of BMs were identified as independent prognostic factors for survival.

CONCLUSION

Brain radiotherapy shows superior survival benefits for lung cancer patients with solid BMs compared to those with cystic BMs, particularly in EGFR-mutant lung cancer. In particular, patients receiving BED ≥60 Gy have a more favorable prognosis than those receiving BED <60 Gy, regardless of the type of BM (solid or cystic) in lung cancer.

Cystic Brain Metastasis Outcomes After Gamma Knife Radiation Therapy

Purpose

The response of cystic brain metastases (BMets) to radiation therapy is poorly understood, with conflicting results regarding local control, overall survival, and treatment-related toxicity. This study aims to examine the role of Gamma Knife (GK) in managing cystic BMets.

Methods and Materials

Volumetric analysis was conducted to measure tumor and edema volume at the time of GK and follow-up magnetic resonance imaging studies. Survival was described using the Kaplan-Meier method, and the cumulative incidence of progression was described using the Aalen-Johansen estimator. We evaluated the association of 4 variables with survival using Cox regression analysis.

Results

Between 2016 and 2021, 54 patients with 83 cystic BMets were treated with GK at our institution. Lung cancer was the most common pathology (51.9%), followed by breast cancer (13.0%). The mean target volume was 2.7 cm3 (range, 0.1-39.0 cm3), and the mean edema volume was 13.9 cm3 (range, 0-165.5 cm3). The median prescription dose of single-fraction and fractionated GK was 20 Gy (range, 14-27.5 Gy). With a median follow-up of 8.9 months, the median survival time (MST) was 11.1 months, and the 1-year local control rate was 75.9%. Gamma Knife was associated with decreased tumor and edema volumes over time, although 68.5% of patients required steroids after GK. Patients whose tumors grew beyond baseline after GK received significantly more whole-brain radiation therapy (WBRT) before GK than those whose tumors declined after GK. Higher age at diagnosis of BMets and pre-GK systemic therapy were associated with worse survival, with an MST of 7.8 months in patients who received it compared with 23.3 months in those who did not.

Conclusions

Pre-GK WBRT may select for BMets with increased radioresistance. This study highlights the ability of GK to control cystic BMets with the cost of high posttreatment steroid use.

Fractionated Gamma Knife radiosurgery after cyst aspiration for large cystic brain metastases: case series and literature review

Tumor cyst aspiration followed by Gamma Knife radiosurgery (GKRS) for large cystic brain metastases is a reasonable and effective management strategy. However, even with aspiration, the target lesion tends to exceed the dimensions of an ideal target for stereotactic radiosurgery. In this case, the local tumor control rate and the risk of complication might be a critical challenge. This study is aimed to investigate whether fractionated GKRS (f-GKRS) could solve these problems. Between May 2018 and April 2021, eight consecutive patients with nine lesions were treated with f-GKRS in five or ten sessions after cyst aspiration. The aspiration was repeated as needed throughout the treatment course to maintain the cyst size and shape. The patient characteristics, radiologic tumor response, and clinical course were reviewed using medical records. The mean follow-up duration was 10.2 (2-28) months. The mean pre-GKRS volume and maximum diameter were 16.7 (5-55.8) mL and 39.0 (31-79) mm, respectively. The mean tumor volume reduction achieved by aspiration was 55.4%. The tumor volume decreased for all lesions, and symptoms were alleviated in all patients. The median overall survival was 10.0 months, and the estimated 1-year survival rate was 41.7% (95% CI: 10.9-70.8%). The local tumor control rate was 100%. No irradiation-related adverse events were observed. f-GKRS for aspirated cystic brain metastasis is a safe, effective, and less invasive management option for large cystic brain metastases.

Case Report: Clinical and Procedural Implications of Ommaya Reservoir Implantation in Cystic Brain Metastases Followed by Radiosurgery Treatment

Background

Therapy for large or deep cystic brain metastases is a troublesome procedure in clinical departments. Stereotactic cyst aspiration, combined with Gamma Knife radiosurgery, can be an effective treatment for cystic brain metastases. However, there is still a possibility that a reaccumulation of cystic fluid may lead to poor efficacy or even reoperation.

Case presentation

We present a case of a 67-year-old man who was diagnosed with lung cancer brain metastasis. The intracranial lesion seen on imaging appeared to be cystic and located deep inside the brain with associated limb dysfunction. The patient did not respond well to chemotherapy and underwent cyst aspiration with Ommaya reservoir implantation under neuronavigation. Repeated cystic fluid reaccumulation and exacerbation of symptoms occurred during treatment. We performed repeated aspiration via the Ommaya reservoir to control the symptoms and combined it with radiotherapy. During the follow-up period of 14 months, the intracranial tumor was effectively and satisfactorily controlled.

Conclusions

We highlight that Ommaya reservoir implantation during stereotactic cyst aspiration is necessary to prevent fluid reaccumulation, thereby avoiding the need for a second surgical procedure.

Stereotactic cyst aspiration directly followed by Gamma Knife radiosurgery for large cystic brain metastases

BACKGROUND

Gamma Knife radiosurgery (GKRS) has been proven to be a successful primary treatment for metastatic brain tumors (BM). BM can come in cystic lesions and are often too large for GKRS. An alternative approach to treat cystic BM is stereotactic cyst aspiration (SCA) for volume reduction, making it suitable for GKRS afterwards.

OBJECTIVE

Our objective is evaluation of volumetric reduction after SCA, tumor control, and complications after SCA directly followed by GKRS.

METHODS

We performed a retrospective analysis of all patients who underwent SCA directly followed by GKRS at the Gamma Knife Center of the Elisabeth-Tweesteden Hospital in Tilburg between 2002 and 2015. In total, 54 patients had undergone this combined approach. Two patients were excluded because of prior intracranial treatment. The other 52 patients were included for analysis.

RESULTS

SCA resulted in a mean volumetric reduction of 56.5% (range 5.50-87.00%). In 83.6% of the tumors (46 tumors), SCA led to sufficient volumetric reduction making GKRS possible. The overall local tumor control (OLTC) of the aspirated lesions post-GKRS was 60.9% (28 out of 46 tumors). Median progression-free survival (PFS) and overall survival (OS) for all patients were 3 (range 5 days-14 months) and 12 months (range 5 days-58 months), respectively. Leptomeningeal disease was reported in 5 (9.6%) cases.

CONCLUSION

SCA directly followed by GKRS is an effective and time-efficient treatment for large cystic BM in selected patients in which surgery is contraindicated and those with deeply located lesions.

A case of impaired consciousness due to large cystic metastatic brain tumors from lung adenocarcinoma successfully controlled with Ommaya reservoir placement

Large cystic brain metastases from lung cancer are rare but cause substantial central nervous system symptoms that often deprive patients of opportunities to receive anticancer therapy. There are no standard therapeutic strategies against this relentless condition. Here we report a patient with large cystic brain metastases from lung adenocarcinoma successfully controlled with Ommaya reservoir placement and subsequent gamma knife surgery (GKS). A 62-year-old Japanese man presented with left upper extremity paresis. Magnetic resonance imaging revealed large cystic masses in both cerebral hemispheres and multiple brain nodules. Computed tomography of the chest showed irregular nodular shadows in the lower lobe of the right lung with multiple swollen lymph nodes. His performance status (PS) and level of consciousness worsened rapidly. Thus, at that time, we could not perform bronchoscopy with the goal of establishing a pathological diagnosis. Intracystic placement of an Ommaya reservoir followed by GKS dramatically improved his PS and level of consciousness. We were subsequently able to perform bronchoscopy, which resulted in a diagnosis of lung adenocarcinoma with 100% positivity of programmed cell death-1 ligand-1 expression. The patient was started on a 3-week cycle of pembrolizumab. Substantial reduction in tumor size was observed after one course of pembrolizumab treatment. The patient had a partial remission. He has been still receiving pembrolizumab with long-term efficacy. In conclusion, our report suggests that aggressive Ommaya reservoir placement should be considered for large cystic metastatic brain tumors, even in patients with undiagnosed cancer, poor PS, and impaired consciousness.

Acute intracranial hypertension management in metastatic brain tumor: A French national survey

BACKGROUND

Brain metastases occur in 15-30% of cancer patients and their frequency has increased over time. They can cause intracranial hypertension, even in the absence of hydrocephalus. Emergency surgical management of brain metastasis-related intracranial hypertension is not guided by specific recommendations.

OBJECTIVE

We aimed to make a French national survey of emergency management of intracranial hypertension without hydrocephalus in the context of cerebral metastasis.

METHODS

A national online survey of French neurosurgeons from 16 centers was conducted, consisting of three clinical files, with multiple-choice questions on diagnostic and therapeutic management in different emergency situations.

RESULTS

In young patients without any previously known primary cancer, acute intracranial hypertension due to a seemingly metastatic single brain tumor indicated emergency surgery for all those interviewed; 61% aimed at complete resection; brain MRI was mandatory for 74%. When a primary cancer was known, 74% of respondents were more likely to propose surgery if an oncologist confirmed the possibility of adjuvant treatment; 27% were more likely to operate on an emergency basis when resection was scheduled after multi-disciplinary discussion, prior to acute degradation.

CONCLUSION

Currently, there is no consensus on the emergency management of intracranial hypertension in metastatic brain tumor patients. In case of previously known primary cancer, a discussion with the oncology team seems necessary, even in emergency. Decision criteria emerge from our literature review, but require analysis in further studies.

[Stereotactic radiotherapy of brain metastases in complex situations]

Stereotactic radiation therapy of brain metastases is a treatment recognized as effective, well tolerated, applicable for therapeutic indications codified and validated by national and international guidelines. However, the effectiveness of this irradiation, the evolution of patient care and the technical improvements enabling its implementation make it possible to consider it in more complex situations: proximity of brain metastases to organs at risk; large, cystic, haemorrhagic or multiple brain metastases, combination with targeted therapies and immunotherapy, stereotactic radiotherapy in patients with a pacemaker. This article aims to put forward the arguments available to date in the literature and those resulting from clinical practice to provide decision support for the radiation oncologists.

Cystic brain metastases had slower speed of tumor shrinkage but similar prognosis compared with solid tumors that underwent radiosurgery treatment

Purpose

Traditionally, radiosurgery was considered less effective for patients with cystic brain metastases. However, comparisons of prognosis between cystic and solid brain metastases in cancer patients have been seldom reported. We aimed to compare the survival between cystic and solid brain metastases and assess risk factors for overall survival after brain metastases (BMOS) in patients who underwent radiosurgery treatment.

Patients and methods

The Kaplan-Meier method and multivariate Cox regression analysis were used to compare survival time and evaluate risk factors for BMOS.

Results

A total of 356 patients (including 498 brain metastases) were analyzed in our study, including 67 patients (67/356, 18.8%) with 75 cystic brain metastases. There is no statistical significance in BMOS between patients with cystic (17 months, range: 3-64 months) and solid (17.5 months, range: 1-65 months) brain metastases (P=0.148). However, the volume of cystic brain metastases decreased more slowly than solid brain metastases (P<0.05). The results indicated that high recursive partitioning analysis classification (P=0.006), large volume of brain metastases (P=0.006), and different primary lesion (especially gastrointestinal tract tumor) (P=0.001) were associated with poor prognosis in patients with brain metastases.

Conclusion

There is no difference in prognosis and local control between patients with cystic and solid brain metastases who underwent radiosurgery. However, the rate and speed of tumor shrinkage were lower in cystic brain metastases after radiotherapy. Patients with larger brain metastases had shorter survival time, regardless of cystic or solid brain metastases.

Local control after brain-directed radiation in patients with cystic versus solid brain metastases

PURPOSE

Brain metastases can be radiographically cystic or solid. Cystic metastases are associated with a greater intracranial disease burden and poorer oncologic outcomes, but the impact of cystic versus solid appearance on local control after radiation remains unknown. We investigated whether cystic versus solid nature is predictive of local control after management with stereotactic or whole brain radiation (WBRT) and whether the radiation modality utilized is an effect modifier.

METHODS

We identified 859 patients with 2211 newly-diagnosed brain metastases managed with upfront stereotactic radiation or WBRT without preceding resection/aspiration at Brigham and Women's Hospital/Dana-Farber Cancer Institute between 2000 and 2015. Multivariable Cox regression with an interaction term and sandwich covariance matrix was used to quantify local failure.

RESULTS

Cystic lesions were more likely to recur than solid ones when managed with stereotactic radiation (HR 2.33, 95% CI 1.32-4.10, p = 0.004) but not WBRT (HR 0.92, 95% CI 0.62-1.36, p = 0.67), p-interaction = 0.007. 1 year local control rates for cystic versus solid metastases treated with stereotactic radiation were 75% versus 88%, respectively; estimates with WBRT were 76% versus 76%, respectively. However, no significant differences were noted between the two cohorts in post-radiation outcomes including all-cause mortality and neurologic death (p > 0.05).

CONCLUSIONS

Among patients with brain metastases, stereotactic radiation yields improved local control and less morbidity than WBRT, and consequently for many patients the cystic versus solid designation does not impact treatment selection. However, our results suggest that in patients with a large number of cystic brain metastases, a lower threshold to consider WBRT, as opposed to stereotactic radiation, should be employed. If our results can be confirmed, further investigation into the underlying mechanism(s) would be warranted.

Hypofractionated Radiation Therapy for Large Brain Metastases

Single fraction radiosurgery (SRS) treatment is an effective and recognized alternative to whole brain radiation for brain metastasis. However, SRS is not always possible, especially in tumors of a larger diameter where the administration of high dose in a single fraction is limited by the possibility of acute and late side effects and the dose to the surrounding organs at risk. Hypofractionated radiation therapy allows the delivery of high doses of radiation per fraction while minimizing adverse events, all the while maintaining good local control of lesions. The optimal dose fractionation has however not been established. This overwiew presents available evidence and rationale supporting usage of hypofractionated radiation therapy in the treatment of large brain metastases.

Cystic brain metastases in ALK-rearranged non-small cell lung cancer

The central nervous system (CNS) is a common site of disease progression in patients with non-small-cell lung cancer (NSCLC) with anaplastic lymphoma kinase (ALK)-rearrangement treated with crizotinib. Cystic brain metastases (CBM) have been recently identified as one possible variant of this disease. An illustrative case report is presented along with a literature review performed in order to track relevant papers about CBM in ALK-rearranged NSCLC, including possible pathophysiology, differential diagnosis and treatment options for this condition. Three case reports have been published describing six ALK-rearranged NSCLC patients presenting with CBM, all of which were under treatment with crizotinib by the time of CBM diagnosis. Treatment with CNS-penetrating tyrosine kinase inhibitors (TKIs) resulted in CNS disease control in three of the six cases reported either as single therapy or in combination with radiation therapy (RT). Investigation of differential diagnoses of CBM might be necessary, which include inflammatory and demyelinating disorders, primary brain tumours and infectious diseases, especially neurocysticercosis that might mimic CBM images. Treatment options include RT, CNS-penetrating TKIs and invasive procedures, such as stereotactic drainage. Thus, CBM are associated with ALK-rearranged NSCLC, particularly in patients who use crizotinib and should prompt investigation of differential diagnosis. CNS-penetrating TKIs are effective in the control of solid brain metastases and also seem to be active in CBM as single therapy or in combination with RT.

Cystic brain metastasis is associated with poor prognosis in patients with advanced breast cancer

Purpose

Brain metastasis (BM) with a cystic component from breast cancer is rare and largely uncharacterized. The purpose of this study was to identify the characteristics of cystic BM in a large cohort of breast cancer patients.

Results

A total of 35 eligible patients with cystic BM and 255 patients with solid BM were analyzed. Three factors were significantly associated with an increased probability of developing cystic lesions: age at diagnosis ≤ 40 years, age at BM ≤ 45 years, and poor histological grade (p < 0.05). Patients with cystic metastasis were also characterized by a larger metastasis volume, a shorter progression-free survival (PFS) following their first treatment for BM, and poor overall survival after BM (p < 0.05). Multivariate analysis further demonstrated that local control of cystic BM was only potentially achieved for HER2-negative primary tumors (p = 0.084).

Methods

Breast cancer patients with parenchymal BM were reviewed from consecutive cases treated at our institution. Cystic BM was defined when the volume of a cystic lesion was greater than 50% of the aggregated volume of all lesions present. Clinicopathologic and radiographic variables were correlated with development of cystic lesions and with prognosis of cystic BM.

Conclusions

This study shows that cystic BM from breast cancer, a special morphological type of BM, had worse prognosis than the more commonly observed solid BM. Younger age and low tumor grade were associated with the development of cystic lesions. Further comprehensive research and management of cystic BM are warranted to improve its poor prognosis.

The usefulness of fibrin glue as a support in the dissection of malignant cystic brain tumors

BACKGROUND

If the complete microsurgical resection of a brain tumor is a logical oncologic goal, the surgical strategy for the cystic component remains controversial secondary to the risk of morbidity. The objective of this study was to analyze the interest of using fibrin glue in the resection of malignant cystic brain tumors (MCBT).

METHODS

Seven patients (median: 60-years-old (range [52-72]/sex ratio M/F: 2.5) were analyzed prospectively in the Neurosurgery Department at Strasbourg University Hospital, from October 2014 to November 2016. The surgical technique consisted of injecting fibrin glue into the tumor cyst after partial drainage. After the solidification of the glue, the cysts walls were removal by following the dissection plan around the fibrin glue. The primary objective was to evaluate the quality of surgical resection on brain MRI scans postoperatively with the use of ITK-SNAP software for precise measurements of tumor volume.

RESULTS

Four metastases and 3 glial lesions were operated on with this technique. An average reduction in cystic volume of 64.6% (P=0.016) and 82.1% (P=0.016) for contrast enhancement volume were observed. If two cases (#2 and #7) were excluded, the average contrast enhancement reduction was respectively 94% and 72% for the cystic volume. In addition, there were no complications, tumor recurrence or difference between gliomas and metastases and the Karnofsky score increased by at least 10% in all patients.

CONCLUSION

This procedure allowed to extend the resection to the cystic component of MCBT without increasing the risk of morbidity related to injury on the underlying parenchyma.

Assessment of stereotactic radiosurgery treatment response for brain metastases using MRI based diffusion index

Introduction

To investigate the clinical predictive values of the apparent diffusion coefficient (ADC) as a biomarker in radiation response of brain metastases.

Method

Forty-one patients with brain metastases treated with stereotactic radiosurgery (SRS) were imaged at baseline, one month post SRS, and six months post SRS using diffusion weighted MRI. The mean of ADC for metastases and tumor volume was calculated. A diffusion index (DI) was generated using the sum of 1/ADC among all the voxels in a tumor. Tumor response status was determined by lesion volume measured at six month post-SRS, or the last available follow-up MRI. Logistic regression analysis was used to account for factors associated with tumor response at baseline and one month post SRS.

Results

A higher ADC mean distinguished responders from non-responders only at six month post SRS (p < 0.05). However, a lower DI distinguished a responder from non-responders on the baseline, one month post SRS and six months post SRS, indicating better diagnostic performance of the DI with regard to a non-invasive biomarker in monitoring SRS treatment response. A multivariate logistic regression analysis identified the DI as a predictor of tumor response at baseline and one month post SRS (p = 0.002 and p = 0.001, respectively). However, logistic regression analysis identified the ADC mean as a predictor of tumor response only at six months post SRS (p = 0.019).

Conclusion

Our results support the hypothesis that ADC and tumor volume generated DT at baseline, one month and six months post SRS may be a promising biomarker predicting brain metastases’ response. Specifically, a lower DI at baseline and one month distinguished responders from non-responders.

Optimal implantation of Ommaya reservoirs for cystic metastatic brain tumors preceding Gamma Knife radiosurgery

INTRODUCTION

Although Ommaya reservoir implantation is effective in reducing the target volume of cystic brain metastases preceding stereotactic radiosurgery, adequate volume reduction cannot be achieved in some cases, and the factors leading to failure in volume reduction have not been clearly identified. In this study, we investigated the factors leading to failure in volume reduction after use of the Ommaya reservoir.

MATERIALS AND METHODS

Between December 2007 and February 2015, 38 consecutive patients with 40 cystic metastases underwent Ommaya reservoir implantation at our institution. The patient characteristics, treatment parameters, and all available clinical and neuroimaging follow-ups were analyzed retrospectively.

RESULTS

The rate of volume reduction was significantly related to the location of the tube tip inside the cyst. By placing the tip at or near the center, 58.7% reduction was achieved, whereas reduction of 42.6% and 7.7% occurred with deep and shallow tip placement, respectively (p=0.011). Although there was no additional surgery in the center placement group, additional surgeries were performed in 5 out of the 23 deep and shallow cases due to inadequate volume reduction. No other factors were correlated with successful volume reduction.

CONCLUSION

For adequate volume reduction using the Ommaya reservoir in the treatment of cystic brain metastases prior to stereotactic radiosurgery, the tip of the reservoir tube should be placed at the center of the cyst.

Gamma Knife radiosurgery combined with stereotactic aspiration as an effective treatment method for large cystic brain metastases

In the present study, the efficacy and clinical outcomes of stereotactic aspiration combined with the Gamma Knife radiosurgery (GKRS) method were evaluated retrospectively for patients with large cystic brain metastases. This combined method aims to decrease the tumor weight (volume) and increase the possible radiation dose. The present study involved 48 patients who were diagnosed with cystic metastatic brain tumors between January 2008 and December 2012 in the Department of Neurosurgery of Nanfang Hospital Southern Medical University (Guangzhou, China). Every patient underwent Leksell stereotactic frame, 1.5T magnetic resonance imaging (MRI)-guided stereotactic cyst aspiration and Leksell GKRS. Subsequent to the therapy, MRI was performed every 3 months. The results indicated that 48 cases were followed up for 24-72 months, with a mean follow-up duration of 36.2 months. Following treatment, 44 patients (91.7%) exhibited tumor control and 4 patients (8.3%) experienced progression of the local tumor. During this period, 35 patients (72.9%) succumbed, but only 2 (4.2%) of these succumbed to the brain metastases. The total local control rate was 91.7% and the median overall survival time of all patients was 19.5 months. The 1-year overall survival rate was 70.8% and the 2-year overall survival rate was 26.2%. In conclusion, these results indicated that the method of stereotactic cyst aspiration combined with GKRS was safe and effective for patients with large cystic brain metastases. This method is effective for patients whose condition is too weak for general anesthesia and in whom the tumors are positioned at eloquent areas. This method enables patients to avoid a craniotomy, and provides a good tumor control rate, survival time and quality of life.

Gamma Knife radiosurgery for cystic brain metastases

OBJECTIVE

The goal of this study was to investigate the treatment results of Gamma Knife radiosurgery (GKRS) for cystic brain metastases and relevant factors associated with local tumor control.

MATERIALS AND METHODS

We retrospectively reviewed the clinical, radiological, and dosimetry data of 37 cystic brain metastases of 28 patients who were treated with GKRS. Cyst drainage was performed in 8 large lesions before GKRS to decrease the target volume. The mean target volume was 4.8 (range, 0.3-15.8) cc at the time of GKRS, and the mean prescription dose was 16.6 (range, 13-22) Gy.

RESULTS

The actuarial median survival time was 17.7 ± 10.2 months, and the primary tumor status was a significant prognostic factor for survival. The actuarial local tumor control rate at 6 and 12 months was 93.1 and 82.3%, respectively. Among the various factors, only prescription dose (>15 Gy) was a significant factor related to local tumor control after multivariate analysis (p = 0.049). Cyst volume or cyst/total tumor volume ratio did not influence local control after GKRS, when the target volume was reduced to about 15 cc after cyst drainage.

CONCLUSION

According to our results, we suggest that stereotactic radiosurgery should be considered as one of the treatment options for cystic brain metastases, when large tumor volume can be reduced by surgical drainage before radiosurgery, especially for patients with a controlled primary tumor.

Characteristics and treatments of large cystic brain metastasis: radiosurgery and stereotactic aspiration

Brain metastasis represents one of the most common causes of intracranial tumors in adults, and the incidence of brain metastasis continues to rise due to the increasing survival of cancer patients. Yet, the development of cystic brain metastasis remains a relatively rare occurrence. In this review, we describe the characteristics of cystic brain metastasis and evaluate the combined use of stereotactic aspiration and radiosurgery in treating large cystic brain metastasis. The results of several studies show that stereotactic radiosurgery produces comparable local tumor control and survival rates as other surgery protocols. When the size of the tumor interferes with radiosurgery, stereotactic aspiration of the metastasis should be considered to reduce the target volume as well as decreasing the chance of radiation induced necrosis and providing symptomatic relief from mass effect. The combined use of stereotactic aspiration and radiosurgery has strong implications in improving patient outcomes.

Alternative treatment of stereotactic cyst aspiration and radiosurgery for cystic brain metastases

BACKGROUND

Surgical removal is the first choice of treatment for large cystic brain metastases. However, some patients cannot undergo surgical resection due to their general condition and/or the tumor location.

AIMS

In this study, we investigated the feasibility and safety of stereotactic cyst aspiration and gamma knife radiosurgery (GKR) as an alternative treatment for these lesions and followed the volumetric changes in cystic and solid portions.

METHODS

Between February 2005 and March 2012, a total of 24 patients underwent GKR after cyst aspiration for 29 cystic metastatic brain tumors. The median age was 60 years (range, 18-81). The number of male patients was 18 and that of female patients 6. Most of the patients were in class II (87.5%) based on the data of the Radiation Therapy Oncology Group using recursive partitioning analysis. We analyzed the changes in tumor volume, the local control rate, intracranial progression-free survival (PFS) and overall survival (OS).

RESULTS

Before aspiration, the mean total tumor volume was 32.7 cm(3) (range, 12.1-103.3) and cystic volume was 18.6 cm(3) (range, 8-72.3). The mean duration of cyst drainage was 1 day (range, 1-2). The mean amount of aspiration was 16.8 cm(3) (range, 6-67.4). After aspiration, the total mean volume was 12.4 cm(3) (range, 3.7-38.1) and cystic volume was 2.0 cm(3) (range, 0.1-9.5). The nature of the cyst was serous in 18, serous and hemorrhagic in 3, and serous and necrotic in 8. The median prescription dose was 16 Gy (range, 14-20). There was no treatment-related complication. The local control rate was 58.6% (17/29). The median survival to local recurrence was 6.0 (±1.42) months. During the follow-up period, an Ommaya reservoir was placed in 3 patients. Insertion of an Ommaya reservoir and whole-brain radiotherapy (WBRT) or GKR were done in 2 patients, WBRT in 2, GKR in 1 and operation in 1. The median intracranial PFS and OS after intracranial metastasis was 5.2 (±0.42) and 6.8 (±0.38) months.

CONCLUSIONS

Cyst aspiration and GKR were feasible and safe but not very efficient, which could be an alternative option for large cystic metastases in patients who could not expect longer survival time.

Gamma knife radiosurgery for the treatment of cystic cerebral metastases

PURPOSE

To assess the role of Gamma Knife radiosurgery (GKRS) in the treatment of nonsurgical cystic brain metastasis, and to determine predictors of response to GKRS.

METHODS

We reviewed a prospectively maintained database of brain metastases patients treated at our institution between 2006 and 2010. All lesions with a cystic component were identified, and volumetric analysis was done to measure percentage of cystic volume on day of treatment and consecutive follow-up MRI scans. Clinical, radiologic, and dosimetry parameters were reviewed to establish the overall response of cystic metastases to GKRS as well as identify potential predictive factors of response.

RESULTS

A total of 111 lesions in 73 patients were analyzed; 57% of lesions received prior whole-brain radiation therapy (WBRT). Lung carcinoma was the primary cancer in 51% of patients, 10% breast, 10% colorectal, 4% melanoma, and 26% other. Fifty-seven percent of the patients were recursive partitioning analysis class 1, the remainder class 2. Mean target volume was 3.3 mL (range, 0.1-23 mL). Median prescription dose was 21 Gy (range, 15-24 Gy). Local control rates were 91%, 63%, and 37% at 6, 12, and 18 months, respectively. Local control was improved in lung primary and worse in patients with prior WBRT (univariate). Only lung primary predicted local control in multivariate analysis, whereas age and tumor volume did not. Lesions with a large cystic component did not show a poorer response compared with those with a small cystic component.

CONCLUSIONS

This study supports the use of GKRS in the management of nonsurgical cystic metastases, despite a traditionally perceived poorer response. Our local control rates are comparable to a matched cohort of noncystic brain metastases, and therefore the presence of a large cystic component should not deter the use of GKRS. Predictors of response included tumor subtype. Prior WBRT decreased effectiveness of SRS for local control rates.

Gamma knife radiosurgery after stereotactic aspiration for large cystic brain metastases

OBJECTIVE

Several treatment options have proven effective for metastatic brain tumors, including surgery and stereotactic radiosurgery. Tumors with cystic components, however, are difficult to treat using a single method. We retrospectively assessed the outcome and efficacy of gamma knife radiosurgery (GKRS) for cystic brain metastases after stereotactic aspiration of cystic components to decrease the tumor volume.

METHODS

The study population consisted of 24 patients (13 males, 11 females; mean age, 58.3 years) with cystic metastatic brain tumors treated from January 2002 to August 2008. Non-small cell lung cancer was the most common primary origin. After Leksell stereotactic frame was positioned on each patient, magnetic resonance images (MRI)-guided stereotactic cyst aspiration and GKRS were performed (mean prescription dose : 20.2 Gy). After treatment, patients were evaluated by MRI every 3 or 4 months.

RESULTS

After treatment, 13 patients (54.2%) demonstrated tumor control, 5 patients (20.8%) showed local tumor progression, and 6 patients (25.0%) showed remote progression. Mean follow-up duration was 13.1 months. During this period, 10 patients (41.7%) died, but only 1 patient (4.2%) died from brain metastases. The overall median survival after these procedures was 17.8 months.

CONCLUSION

These results support the usefulness of GKRS after stereotactic cyst aspiration in patients with large cystic brain metastases. This method is especially effective for the patients whose general condition is very poor for general anesthesia and those with metastatic brain tumors located in eloquent areas.