Surgical management of single and multiple brain metastases: results of a retrospective study

Single brain metastases - prognostic factors and impact of residual tumor burden on overall survival

Background

Brain metastases (BM) are a common and challenging issue, with their incidence on the rise due to advancements in systemic therapies and increased patient survival. Most patients present with single BM, some of them without any further extracranial metastasis (i.e., solitary BM). The significance of postoperative intracranial tumor volume in the treatment of singular and solitary BM is still debated.

Objective

This study aimed to determine the impact of resection and postoperative tumor burden on overall survival (OS) in patients with single BM.

Methods

Patients with surgically treated single BM between 04/2007-01/2020 were retrospectively included. Residual tumor burden (RTB) was determined by manual segmentation of early postoperative brain MRI (72 h). Survival analyses were performed using Kaplan-Meier estimates for univariate analysis and Cox regression proportional hazards model for multivariate analysis, using preoperative Karnofsky performance status scale (KPSS), age, sex, RTB, incomplete resection and singular/solitary BM as covariates.

Results

340 patients were included, median age 64 years (54-71). 119 patients (35%) had solitary BM, 221 (65%) singular BM. Complete resection (RTB=0) was achieved in 73%, median preoperative tumor burden was 11.2 cm3 (5-25), and RTB 0 cm3 (0-0.2). Median OS of patients with singular BM was 13 months (4-33) vs 20 months (5-92) for solitary BM; p=0.062. Multivariate analysis revealed singular BM as independent risk factor for poorer OS: HR 1.840 (1.202-2.817), p=0.005. Complete vs. incomplete resection showed no significant OS difference (13 vs. 13 months, p=0.737). When focusing on solitary BM, complete resection led to a longer OS than incomplete resection (21 vs. 8 months), without statistical significance(p=0.250). Achieving RTB=0 resulted in higher OS for patients with solitary BM compared to singular BM (21 vs. 12 months, p=0.027). Patients who received postoperative radiotherapy (RT) had significantly longer OS compared to those without it (14 vs. 4 months, p<0.001), with favorable OS in those receiving stereotactic radiosurgery (SRS) (15 months (3-42), p<0.001) or hypofractionated stereotactic radiotherapy (HSRT).

Conclusion

When complete intracranial tumor resection RTB=0 is achieved, patients with solitary BM have a favorable outcome compared to singular BM. Singular BM was confirmed as independent risk factor. There is a strong presumption that complete resection leads to an improved oncological prognosis. Patients with solitary BM tend to benefit with a favorable outcome following complete resection. Hence, surgical resection should be considered as a treatment option for patients presenting with either no or minimal extracranial disease. Furthermore, the highly favorable impact of postoperative RT on OS was demonstrated and confirmed, especially with SRS or HSRT.

Single-center study on clinicopathological and typical molecular pathologic features of metastatic brain tumor

BACKGROUND

The metastatic brain tumor is the most common brain tumor. The aim of this study was to demonstrate the clinicopathological and molecular pathologic features of brain metastases (BM).

METHODS

A total of 269 patients were diagnosed with BM through surgical resection at Seoul St. Mary's Hospital from January 2010 to March 2020. We reviewed the clinicopathological features and molecular status of primary and metastatic brain tissues using immunohistochemistry and molecular pathology results.

RESULTS

Among 269 patients, 139 males and 130 females were included. The median age of primary tumor was 58 years (range, 13 to 87 years) and 86 patients (32.0%) had BM at initial presentation. Median BM free interval was 28.0 months (range, 1 to 286 months). The most frequent primary site was lung 46.5% (125/269), and followed by breast 15.6% (42/269), colorectum 10.0% (27/269). Epidermal growth factor receptor (EGFR) mutation was found in 50.8% (32/63) and 58.0% (40/69) of lung primary and BM, respectively. In both breast primary and breast cancer with BM, luminal B was the most frequent subtype at 37.9% (11/29) and 42.9% (18/42), respectively, followed by human epidermal growth factor receptor 2 with 31.0% (9/29) and 33.3% (14/42). Triple-negative was 20.7% (6/29) and 16.7% (7/42), and luminal A was 10.3% (3/29) and 7.1% (3/42) of breast primary and BM, respectively. In colorectal primary and colorectal cancer with BM, KRAS mutation was found in 76.9% (10/13) and 66.7% (2/3), respectively.

CONCLUSIONS

We report the clinicopathological and molecular pathologic features of BM that can provide useful information for understanding the pathogenesis of metastasis and for clinical trials based on the tumor's molecular pathology.

Surgical advances in the management of brain metastases

As the epidemiological and clinical burden of brain metastases continues to grow, advances in neurosurgical care are imperative. From standard magnetic resonance imaging (MRI) sequences to functional neuroimaging, preoperative workups for metastatic disease allow high-resolution detection of lesions and at-risk structures, facilitating safe and effective surgical planning. Minimally invasive neurosurgical approaches, including keyhole craniotomies and tubular retractors, optimize the preservation of normal parenchyma without compromising extent of resection. Supramarginal surgery has pushed the boundaries of achieving complete removal of metastases without recurrence, especially in eloquent regions when paired with intraoperative neuromonitoring. Brachytherapy has highlighted the potential of locally delivering therapeutic agents to the resection cavity with high rates of local control. Neuronavigation has become a cornerstone of operative workflow, while intraoperative ultrasound (iUS) and intraoperative brain mapping generate real-time renderings of the brain unaffected by brain shift. Endoscopes, exoscopes, and fluorescent-guided surgery enable increasingly high-definition visualizations of metastatic lesions that were previously difficult to achieve. Pushed forward by these multidisciplinary innovations, neurosurgery has never been a safer, more effective treatment for patients with brain metastases.

The Management of Brain Metastases-Systematic Review of Neurosurgical Aspects

Simple Summary

In this comprehensive review, we focused on the neurosurgical treatment as an integrative part of the challenging multidisciplinary management of cerebral metastases, a neuro-oncologic entity, which has been observed to have an increased incidence over the last years. In selected cases, the surgical removal of the space-occupying mass reduces the intracranial pressure, normalizes the metabolic environment, reduces the symptom burden, and allows for the intensification of local and systemic adjuvant treatment. In detail, we discuss the incidence of brain metastases, the role of surgical resection, as well as the evolution of current neurosurgical techniques, the surgical morbidity and mortality of single and multiple lesions, and we enlighten the role of surgery for recurrent tumors.

Abstract

The multidisciplinary management of patients with brain metastases (BM) consists of surgical resection, different radiation treatment modalities, cytotoxic chemotherapy, and targeted molecular treatment. This review presents the current state of neurosurgical technology applied to achieve maximal resection with minimal morbidity as a treatment paradigm in patients with BM. In addition, we discuss the contribution of neurosurgical resection on functional outcome, advanced systemic treatment strategies, and enhanced understanding of the tumor biology.

Surgical Management of Brain Metastases in the Perirolandic Region

Brain metastases (BM) are the most frequent intracranial tumors, which may result in significant morbidity and mortality when the lesions involve the perirolandic region. Surgical intervention for BM in the perirolandic region is still under discussion even though prompt relief of mass effect and avoidance of necrosis together with brain edema may not be achieved by radiotherapy. More recently, several researchers attempt to evaluate the benefit of surgery for BM within this pivotal sensorimotor area. Nevertheless, data are sparse and optimal treatment paradigm is not yet widely described. Since the advance in intraoperative neuroimaging and neurophysiology, resection of BM in the perirolandic region has been proven to be safe and efficacious, sparing this eloquent area while retaining reasonably low morbidity rates. Although management of BM becomes much more tailored and multimodal, surgery remains the cornerstone and principles of resection as well as indications for surgery should be well defined. This is the first review concerning the characteristics of BM involving the perirolandic region and the current impact of surgical therapy for the lesions. Future perspectives of advanced neurosurgical techniques are also presented.

Brain surgery in combination with tyrosine kinase inhibitor and whole brain radiotherapy for epidermal growth factor receptor-mutant non-small-cell lung cancer with brain metastases

The role of brain surgery (BS) on the survival of patients with non-small-cell lung cancer (NSCLC) and brain metastases (BM), particularly those with epidermal growth factor receptor (EGFR) mutations under tyrosine kinase inhibitors (TKIs) is yet to be defined. We aimed to investigate whether BS could improve the survival of patients in addition to the combination of TKIs and whole brain radiotherapy (WBRT). A cohort of 1394 NSCLC patients between 2011 and 2016 was retrospectively studied. One hundred patients with BM receiving TKI + RT were enrolled. Forty patients (40%) received TKI + BS + RT, and 60 patients (60%) received TKI + RT. Survival time was calculated from the date of BM diagnoses to the date of death or last follow-up. With a median follow-up of 25.6 months (95% CI, 18.6–35.7), the median survival after BM was 18.2 months (95% CI, 10.8 to 27.4) in the TKI + BS + RT group and 11.8 months (95% CI, 5.2 to18) in the TKI + RT group. Cox proportional hazards regression model for the patients with the largest BM over 1 cm showed that TKI + BS + RT group was associated with improved survival relative to TKI + RT group (HR, 0.49; 95% CI, 0.29 to 0.83; P = 0.008). BS adds significant survival benefits in addition to TKIs and WBRT, especially for patients with EGFR-mutant NSCLC and the largest BM over 1 cm.

Sodium fluorescein-guided brain tumor surgery under the YELLOW-560-nm surgical microscope filter in pediatric age group: feasibility and preliminary results

OBJECTIVE

To evaluate the feasibility and safety of sodium fluorescein (Na-Fl)-guided surgery with the use of the PENTERO 900 surgical microscope (Carl Zeiss, Meditec, Oberkochen, Germany) equipped with the YELLOW-560-nm filter and low-dose Na-Fl (2 mg/kg) in pediatric brain tumor surgery.

METHODS

The study included 23 pediatric patients with various intracranial pathologies, who underwent Na-Fl-guided surgery between April 2015 and February 2018. Clinical features, surgical observations, extent of resection, and tumor histopathology were retrospectively analyzed. The use of YELLOW-560-nm filter was found "helpful" if the discrimination of the pinkish brain tissue and bright yellow stained tumor tissue was clear. Otherwise, it was described as "not helpful."

RESULTS

There were 11 female and 12 male patients with a mean age of 9.4 years. There were 7 brain stem/tectal plate gliomas, 6 supratentorial tumors, 4 intraventricular tumors, 2 pineal tumors, 2 infratentorial tumors, 1 clivus tumor, and 1 tumor with supra- and infratentorial extensions in the current series. Na-Fl was found helpful by means of the tumor demarcation in 20 instances (87%). In 11 of these 20 operations (55%), a total resection was achieved regardless of the tumor pathology. A subtotal resection was achieved in the remaining 9 patients (45%). No adverse events or side effects were encountered with regard to Na-Fl use.

CONCLUSION

Na-Fl guidance with the use of the YELLOW-560 filter is safe and effective during brain tumor surgery in pediatric age group.

Retrospective study of 229 surgically treated patients with brain metastases: Prognostic factors, outcome and comparison of recursive partitioning analysis and diagnosis-specific graded prognostic assessment

Background:

Metastases are the most frequent tumors in the brain. Most often used scoring systems to predict the outcome are the RPA (Recursive Partitioning Analysis) classification and the DS-GPA (Diagnosis-Specific Graded Prognostic Assessment) score. The goal of our study was to determine prognostic factors which influence outcome in patients who undergo surgery for brain metastases and to compare different outcome scores.

Methods:

Two hundred and twenty-nine patients who underwent surgery for brain metastases in our institution between January 2005 and December 2014 were included in the study. Patient data were evaluated retrospectively.

Results:

The mean survival time was 19.2 months (median survival time, MST: 8 months), for patients with a single metastasis (n = 149) 17.6 months (MST: 8 months), and for patients with multiple metastases (n = 80) 17.9 months (MST: 6 months). Significant influence on MST had age <65 years (9 vs. 5 months, P = 0.002), female sex (10 vs. 6 months, P < 0.001), RPA Class I and II (11 vs. 4 months, P < 0.001), Karnofsky score >70% (11 vs. 4 months, P < 0.001), and postoperative radiotherapy (8 vs. 5 months, P < 0.002). To evaluate the diagnostic power of DS-GPA and RPA score in respect of survival, two Cox regressions were modeled, where the RPA classification showed a better predictive power.

Conclusion:

Favorable factors for prolonged survival were KPS >70%, RPA Class I and II, age <65 years, female sex, a DS-GPA Score of 2.5–3 and 3.5–4, and adjuvant radiotherapy. The RPA Classification was more accurate in predicting the outcome than the DS-GPA score.

Stereotactic radiosurgery versus whole-brain radiotherapy after intracranial metastasis resection: a systematic review and meta-analysis

Background

In patients with one to three brain metastases who undergo resection, options for post-operative treatments include whole-brain radiotherapy (WBRT) or stereotactic radiosurgery (SRS) of the resection cavity. In this meta-analysis, we sought to compare the efficacy of each post-operative radiation modality with respect to tumor recurrence and survival.

Methods

Pubmed, Embase and Cochrane databases were searched through June 2016 for cohort studies reporting outcomes of SRS or WBRT after metastasis resection. Pooled effect estimates were calculated using fixed-effect and random-effect models for local recurrence, distant recurrence, and overall survival.

Results

Eight retrospective cohort studies with 646 patients (238 with SRS versus 408 with WBRT) were included in the analysis. Comparing SRS to WBRT, the overall crude risk ratio using the fixed-effect model was 0.59 for local recurrence (95%-CI: 0.32–1.09, I²: 3.35%, P-heterogeneity = 0.36, 3 studies), 1.09 for distant recurrence (95%-CI: 0.74–1.60, I²: 50.5%, P-heterogeneity = 0.13; 3 studies), and 2.99 for leptomeningeal disease (95% CI 1.55–5.76; I²: 14.4% p-heterogeneity: 0.28; 2 studies). For the same comparison, the risk ratio for median overall survival was 0.47 (95% CI: 0.41–0.54; I²: 79.1%, P-heterogeneity < 0.01; 4 studies) in a fixed-effect model, but was no longer significant (0.63; 95%-CI: 0.40–1.00) in a random-effect model. SRS was associated with a lower risk of leukoencephalopathy (RR: 0.15, 95% CI: 0.07–0.33, 1 study), yet with a higher risk of radiation-necrosis (RR: 19.4, 95% CI: 1.21–310, 1 study).

Conclusion

Based on retrospective cohort studies, the results of this study suggest that SRS of the resection cavity may offer comparable survival and similar local and distant control as adjuvant WBRT, yet may be associated with a higher risk for developing leptomeningeal disease. Future research on SRS should focus on achieving a better understanding of the various factors that may favor SRS over WBRT.

The use of the YELLOW 560 nm surgical microscope filter for sodium fluorescein-guided resection of brain tumors: Our preliminary results in a series of 28 patients

OBJECTIVE

Sodium fluorescein (Na-Fl) is a fluorescent dye that accumulates in tumoral tissues via disrupted blood-brain barrier. It has been used in fluorescence-guided surgery for various brain tumors. Herein, we report our initial experience and preliminary results for the first 28 patients who were operated on under Na-Fl guidance with the use of a special filter on the surgical microscope.

PATIENT AND METHODS

Between January and November 2015, 200 mg (2-4 mg/kg) of Na-Fl was administered in 28 patients (30 surgeries) after anesthesia induction. The clinical features, surgical observations, extent of resection on the postoperative magnetic resonance imaging (MRI) and histopathology of the tumors were retrospectively analyzed. The use of YELLOW 560 nm filter was found "helpful" if the discrimination of the pinkish brain tissue and bright yellow stained tumor tissue was clear. Otherwise, it was described as "not helpful.

RESULTS

There were 23 high-grade and 7 metastatic tumors in our study group. Na-Fl was found helpful by means of the tumor demarcation in 29 of 30 operations (97%). In 23 of these 29 operations (79%), a total resection was achieved regardless of the tumor pathology. No adverse events were encountered regarding the use of Na-Fl.

CONCLUSION

Na-Fl guidance with the use of a YELLOW 560 filter is safe and effective in high-grade glioma and metastatic tumor surgery. We think it is feasible for increasing the extent of resection in these tumors.

Fluorescein sodium-guided resection of cerebral metastases—experience with the first 30 patients

BACKGROUND

Surgical resection is a key element of the multidisciplinary treatment of cerebral metastases (CMs). Recent studies have highlighted the importance of complete resection of CMs for improving recurrence-free and overall survival rates. This study presents the first data on the use of fluorescein sodium (FL) under the dedicated surgical microscope filter YELLOW 560 nm (Zeiss Meditec, Germany) in patients with CM.

METHODS

Thirty patients with CMs of different primary cancers were included (15 females, 15 males; mean age 61.1 years); 200 mg of FL was intravenously injected directly before CM resection. A YELLOW 560 nm filter was used for microsurgical tumor resection and resection control. Surgical reports were evaluated regarding the degree of fluorescent staining, postoperative MRIs regarding the extent of resection [gadolinium (Gd)-enhanced T1-weighted sequence] and the postoperative courses regarding any adverse effects.

RESULTS

Most patients (90.0%, n = 27) showed bright fluorescent staining, which markedly enhanced tumor visibility. Three patients (10.0%) (two with adenocarcinoma of the lung and one with melanoma of the skin) showed no or only insufficient FL staining. Another three patients (10.0%) showed residual tumor tissue in the postoperative MRI examination. In two other patients, radiographic examination could not exclude the possibility of very small areas of residual tumor tissue. Thus, gross-total resection was achieved in 83.3% (n = 25) of patients. No adverse effects were registered over the postoperative course.

CONCLUSIONS

FL and the YELLOW 560 nm filter are safe and practical tools for the resection of CM, but further prospective research is needed to confirm that this advanced technique will improve the quality of CM resection.

Through the patient's eyes: an emphasis on patient-centered values in operative decision making in the management of malignant glioma

The Joint Section on Tumors of the American Association of Neurological Surgeons and the Congress of Neurological Surgeons is now in its 30th year. In many ways its growth and development has paralleled neurosurgery and medicine as a whole. This is most evident in our endeavor towards more patient-centered care and focus on quantity and quality of life. As the push towards evidence-based care continues, it is important to ensure that individualized care remains a guiding principle. Conscientious surgeons continue to refine techniques and develop technologies that push the boundaries of surgical efficacy while better defining the risks of surgery and the impacts of surgical complications. This article provides a review of the factors involved in minimizing risk and obtaining maximal outcomes for patients through insightful patient selection and evidence-based surgical decision-making. Herein, we present the philosophy and practice of the Hermelin Brain Tumor Center at the Henry Ford Health System as one type of approach to caring for the patient with a malignant glioma.

Current approaches to the treatment of metastatic brain tumours

Metastatic tumours involving the brain overshadow primary brain neoplasms in frequency and are an important complication in the overall management of many cancers. Importantly, advances are being made in understanding the molecular biology underlying the initial development and eventual proliferation of brain metastases. Surgery and radiation remain the cornerstones of the therapy for symptomatic lesions; however, image-based guidance is improving surgical technique to maximize the preservation of normal tissue, while more sophisticated approaches to radiation therapy are being used to minimize the long-standing concerns over the toxicity of whole-brain radiation protocols used in the past. Furthermore, the burgeoning knowledge of tumour biology has facilitated the entry of systemically administered therapies into the clinic. Responses to these targeted interventions have ranged from substantial toxicity with no control of disease to periods of useful tumour control with no decrement in performance status of the treated individual. This experience enables recognition of the limits of targeted therapy, but has also informed methods to optimize this approach. This Review focuses on the clinically relevant molecular biology of brain metastases, and summarizes the current applications of these data to imaging, surgery, radiation therapy, cytotoxic chemotherapy and targeted therapy.

Safety and efficacy of outpatient gamma knife radiosurgery for multiple cerebral metastases

This review highlights the experience of a single institution using the Leksell gamma knife for 8 years. More than 500 patients with multiple cerebral metastases received outpatient radiosurgery. The results prove that there is a high efficacy and attractively low morbidity of modern outpatient radiosurgery. When compared with whole brain radiation therapy, radiosurgery improved survival in patients with cerebral metastases. Most importantly, the number of brain metastases had no prognostic impact in patients with non-small cell lung cancer, renal cell cancer, malignant melanoma and gastrointestinal cancer.

Surgery of recurrent brain metastases: retrospective analysis of 67 patients

OBJECTIVE

Treatment of patients with recurrent brain metastasis is one of the major challenges in neurooncology. Commonly, WBRT was applied after or as the initial treatment. Many patients received radiosurgery or their lesions were operated on. The question arises of what treatment modalities are appropriate and can be offered to the patients. In our retrospective analysis, we evaluated whether re-operation might be a useful measurement for the patients with respect to overall survival and quality of life.

METHODS

We included 67 patients who were treated between 1993 and 2008 in our department. The median age was 59 years. Metastases of 11 different primaries were diagnosed. The median OST was 7.5 months.

RESULTS

Statistically significant prognostic factors for OS were single lesions, completeness of resection, and time to recurrence, which was significantly influenced by WBRT after first operation. The one year survival rate correlated with the RPA classification: class I: 53.3 %, class II: 26.9 %, class III: 12.5 %. In 31.3 %, a second recurrence occurred which was treated by repeated surgery. Six patients survived as long-term survivors (25.7-132.2 months).

CONCLUSION

Surgery of recurrent brain metastasis is an important therapeutic option. A subgroup of patients, defined by prognostic factors, will profit with improvement of symptoms and prolongation of the overall survival time. Even long-term survivors can be expected.

The role of surgical resection in patients with brain metastases

Brain metastasis is a devastating complication of systemic malignancy that affects a considerable number of cancer patients. The appearance of brain metastases is often considered to be a sign of poor prognosis; in patients with brain metastases poor survival time has been reported in the literature. Therefore, treatment of these brain lesions in cancer patients is important for quality of life, providing local tumour control, preventing death from neurological causes, and improving survival, although potentially only in a minority of patients. Surgical resection of brain metastases has been the cornerstone treatment in select patients. Careful patient selection, the use of appropriate surgical techniques, and surgical adjuncts are the major determinants of favourable outcome in patients undergoing resection of brain metastases. In this review, we explain the role of surgical resection in the treatment of patients with brain metastases with consideration of patient selection, surgical techniques and the use of intraoperative adjuncts.

Sodium fluorescein-guided resection under the YELLOW 560 nm surgical microscope filter in malignant brain tumor surgery--a feasibility study

OBJECTIVE

In glioma surgery, the extent of resection (EOR) is one important predictor of progression-free survival. In 2006, fluorescence-guided surgery using 5-aminolevulinic acid (5-ALA) was shown to improve the EOR in malignant gliomas. However, the use of 5-ALA is complex and causes certain side effects. Sodium fluorescein (FL) is a fluorescent dye that is used for angiography in ophthalmic surgery. FL accumulates in areas of the disturbed blood-brain barrier and can be visualized under a 560-nm wavelength fluorescent light source (YELLOW 560 nm, Carl Zeiss Meditec, Oberkochen, Germany). Here, we present the first experiences with low-dose FL and YELLOW 560 nm in 35 patients with malignant brain tumors.

PATIENTS AND METHOD

A total of 200 mg of FL (3-4 mg/kg bodyweight) was administered in 35 patients during craniotomy as an off-label use between May and August 2012. We retrospectively analyzed the histology, pre-treatment, clinical parameters pre- and postoperatively and occurrence of any adverse effects. The feasibility and efficacy ('helpful,' 'not helpful') of FL under YELLOW 560 nm (demarcation of the tumor margin) was assessed by the responsible neurosurgeon (n = 5) for each surgical procedure.

RESULTS

Twenty-six patients had gliomas (1 WHO grade I, 3 WHO grade II, 5 WHO grade III, 17 WHO grade IV), 5 patients had cerebral metastases, 2 had non-malignant astrogliosis and 2 had post-radiation necrosis. The fluorescence signal was detected in all patients immediately after the FL administration. FL application was classified as 'helpful' in 28 patients, implying improved visualization of the tumor margins. The intensity of the fluorescence signal seemed to be correlated to the histology and was strongly dependent on the pre-treatment status. We did not record any allergic reactions or any other adverse effects.

CONCLUSION

The use of FL for the resection of brain tumors is safe and feasible. Presumably, the visualization of the tumor margin depends on the histopathology and on the pre-treatment status. A randomized evaluation of FL under the YELLOW 560 nm filter is planned to prospectively analyze the extent of resection in patients with malignant brain tumors.

Image guidance for brain metastases resection

The primary goal in removing a metastatic brain tumor is to maximize surgical resection while minimizing the risk of neurological injury. Intraoperative image guidance is frequently used in the resection of both primary and metastatic brain tumors. Stereotactic volumetric techniques allow for smaller craniotomies, facilitate lesion localization, and help neurosurgeons avoid eloquent structures. In turn, this leads to decreased patient morbidity and shorter hospitalizations. Image guidance is not without shortcomings, however, perhaps the most significant of which is inaccuracy of tumor resection associated with intraoperative brain shifts. The goal of this review is to expound on the uses of image guidance and discuss avoidance of technical pitfalls in the resection of cerebral metastatic lesions.

Neurosurgical treatment of breast cancer metastases to the neurocranium

Breast cancer metastases to the neurocranium might involve the bone, the dura, or the brain parenchyma. The latter location is the far most common. The annual incidence of brain metastases in patients with breast cancer is in the range of 4–11 per 100.000 persons per year. Symptoms and findings mainly result from the location of the lesion. The diagnostic method of choice is magnetic resonance imaging before and after administration of contrast material. Breast cancer brain metastases present as solid, cystic, or partially cystic lesions with marked contrast enhancement and perilesional edema. The therapeutic option of choice is microsurgical resection whenever possible. Adjuvant treatment includes radiotherapy, radiosurgery, and/or chemotherapy.

Surgical treatment for brain metastases: Prognostic factors and survival in 309 patients with regard to patient age

Brain metastases are the most common intracranial tumors. Overall, the only accepted prognostic factors are patient age and performance status. However, several other factors are considered before surgery. We performed a retrospective analysis of 309 patients who underwent surgical resection of newly diagnosed brain metastases between 1994 and 2004. Univariate survival analysis revealed age, performance status, extracranial metastases, complete resection, radiotherapy and re-craniotomy as prognostic indicators. Multivariate analysis determined that patient age, performance status, extracranial metastases, radiotherapy and re-craniotomy are independent factors of prolonged survival. We statistically estimated the age threshold separating patients with favorable outcomes from those with unfavorable prognoses. Using the Kaplan-Meier analysis this threshold can be set at 65 years. Multivariate analysis of patients >65 years revealed the presence of co-morbidities, the number of brain metastases, post-operative performance status and radiotherapy as independent prognostic factors.

Fluorescence-guided surgery of metastatic brain tumors using fluorescein sodium

We aimed to demonstrate the effectiveness of fluorescence-guided surgery of metastatic brain tumors using fluorescein sodium. The study comprised 38 patients with metastatic brain tumors who underwent tumor resection after intravenous injection of fluorescein sodium. The local recurrence rate was investigated in 36 of the 38 patients, and compared for patients who had undergone surgery only and surgery plus whole-brain radiotherapy (WBRT). In 31 of 36 patients, the tumors had been completely resected using fluorescence-guided surgery. Postoperative WBRT was not performed in 20 of the 31 patients who underwent gross total resection. Although the recurrence rate for these 20 patients was 20%, compared to 9.1% for the 11 patients who also underwent postoperative WBRT, the difference was not statistically significant. Use of fluorescein sodium in metastatic brain tumor surgery may reduce the rate of local recurrence, and thus help improve the quality of life for these patients.

Linac stereotactic radiosurgery: An effective and safe treatment for elderly patients with brain metastases

PURPOSE

To evaluate the outcomes of radiosurgery for brain metastases in patients 65 years or older.

PATIENTS AND METHODS

Between January 1994 and January 2003, 117 patients (47 women, 70 men), median age 71 years (range, 65-86 years), received radiosurgery for 227 metastases. Sixty-one patients (55%) presented symptoms in relation to the brain metastases. Thirty-eight patients (32%) received whole-brain radiotherapy. Median metastasis diameter and volume were 21 mm (range, 0.5-75 mm) and 1.7 cc (range, 0.02-71 cc), respectively.

RESULTS

Median follow-up was 7 months (range, 1-45 months), 9.5 months for alive patients (range, 1-45 months). Median minimum and maximum doses were 14.5 Gy (6.5 Gy, 19.5 Gy), and 20.4 Gy (13.2 Gy, 41.9 Gy), respectively. Median survival was 8 months from the date of radiosurgery. Overall survival rates at 6 and 24 months were 58% +/- 5% and 13% +/- 4%, respectively. According to multivariate analysis, a low Karnofsky performance status was an independent unfavorable prognostic factor for overall survival (p = 0.003; odds ratio [OR] = 0.28; 95% confidence interval [CI], 0.14-0.56). Median brain disease-free survival was 10 months. Brain disease-free survival rates at 6 and 24 months were 67% +/- 6% and 40% +/- 7%, respectively. According to multivariate analysis, a radiosensitive lesion was an independent favorable factor (p = 0.038; OR = 0.42; 95% CI, 0.18-0.95); more than two metastases and a low Karnofsky performance status were independent unfavorable factors for brain disease-free survival (p = 0.046; OR = 2.15; 95% CI, 1.01-4.58 and p = 0.003; OR = 30.4; 95% CI, 3.1-296, respectively). Local control rates were 98% +/- 2% and 91% +/- 8.5% at 6 and 24 months. Out of the 61 patients presenting symptoms before radiosurgery, complete symptomatic response was achieved in 12 patients (20%), partial improvement in 25 (41%), stabilization in 7 (11%), and worsening in 4 (6%) related to a progression of the irradiated metastasis. Seven cases of radionecrosis were described and were related to the margin dose (p = 0.03).

CONCLUSION

Radiosurgery for elderly patients was effective and safe. Age alone should not be a criterion for denying radiosurgery to any patient with brain metastases.

Therapy of Hematogenous Melanoma Brain Metastases with Endostatin

Purpose: Cerebral metastases represent the most common type of brain tumors. This study investigated the effects of endogenous endostatin on hematogenous cerebral melanoma metastases.

Experimental Design: Murine K1735 melanoma cells were transfected with the mouse endostatin cDNA. Experimental tumors were induced either by s.c. injection, intracerebral implantation, or via injection into the internal carotid artery to simulate hematogenous metastatic spread. The effects of endostatin expression on tumor incidence, growth pattern, and vascularity were analyzed.

Results: In vitro secretion of endostatin by 2.5 × 105 cells within 24 hours was 0.12 ± 0.03 ng, 4.35 ± 0.4, and 1.18 ± 0.7 ng/mL for wild type and two endostatin-transfected K1735 clones termed K1735-endo/2 and K1735-endo/8, respectively. Tumor inhibition in vivo correlated with endogenous endostatin production. Within 25 days, growth of s.c. K1735-endo/2 tumors was &lt;20% compared with wild-type controls. Following intracerebral implantation the average survival time of mice was 27.8 ± 2.6 versus 13.3 ± 3.7 days in the K1735-endo/2 versus the wild-type group, respectively. Intracarotid injection of 1 × 105 wild-type cells killed the mice within 24 ± 1.8 days. In contrast, endostatin expression prevented macroscopic metastatic tumor growth in 11 of 12 mice, although viable microscopic tumor pockets were detectable in all animals.

Conclusion: Endostatin inhibits tumor progression of multiple cerebral metastases in vivo. Hematogenous micrometastases are more efficiently suppressed than tumors resulting from high focal cell numbers which may be due to a higher angiogenic signaling exerted by massive cell deposits. Endostatin may prevent solid tumor growth more effectively by inhibition of early angiogenesis.

Gamma knife radiosurgery for patients with multiple cerebral metastases

Although efficacy of gamma knife radiosurgery has been demonstrated in numerous studies, the policies in patients with multiple metastases seem to be unequivocal. The maintained quality of life, the possibility of short hospitalization and the continuation of a systemic chemotherapy are increasingly important arguments in favor of a minimally invasive radiosurgical approach. These factors are particularly emphasized in patients with a dismal prognosis. The current retrospective analysis was undertaken to summarize the clinical results of radiosurgery in patients with multiple cerebral metastases of various primary cancer. Fractionated whole brain radiotherapy (WBRT) was omitted as prophylactic treatment and applied only in cases with general tumor spread. Clinical data of all consecutive patients (n = 215) who received gamma knife radiosurgery for cerebral metastases between January 2001 and January 2003 at the gamma knife Centers of the Karolinska Hospital and H.M. Queen Sophia Hospital (Sophiahemmet) Stockholm were analyzed retrospectively. 172 patients were treated for multiple metastases (198 treatments). The median prescription dose was 22 Gy (range 14-34 Gy). The Kaplan Meier plot shows a median survival (MST) of 7.8 months for patients with multiple cerebral metastases and 13.7 months for patients with single metastases. There was no relation between survival and number of metastases in patients with multiple metastases. Within this group 11.6% (20/172 patients) developed adverse radiation reactions. Tumor recurrences were documented by FDG-PET in 7 patients (out of 172 patients: 4.1%) after a median latency of 10 months after radiosurgery. In summary, gamma knife radiosurgery provides a highly effective and minimally invasive method to treat patients with multiple cerebral metastases even without prophylactic WBRT. Local control and patient survival in the present series of patients is in accordance with other retrospective series of patients with single and multiple metastases.

LINAC radiosurgery for brain metastasis of renal cell carcinoma

The purpose of the study was to evaluate the efficacy and toxicity of stereotactic radiotherapy in the treatment of the brain metastasis of renal cell carcinoma. From 1994 to 2001, 28 patients presenting with 65 metastases of renal cell cancer were treated by radiosurgery. Median age was 55 years (35-75), and median Karnofski performance status ranges between 50 and 100. Seven patients had received whole brain radiotherapy (WBRT) before radiosurgery. Twelve patients were treated by radiosurgery for 1 metastasis, 5 patients for two metastases and 6 for three, and 5 for more than three metastases. One procedure was performed in 22 patients and, 2 or 3 procedures for 6 patients. Median metastasis diameter was 19 mm (5-55 mm). Median metastasis volume was 1.28 cc (0.02-28 cc). Irradiation was delivered by linear accelerator. Median minimal dose (on the 70% isodose) was 14.7 Gy (10.8 Gy, 19.5 Gy), median maximal dose (at the isocenter) 20.5 Gy (14.3 Gy, 39.6 Gy). Median follow-up was 14 months (1-33). Two metastases progressed (3%), 2 and 12 months after radiosurgery. Overall, crude local control rate was 97% and 3-, 6- and 12-month local control rates were 98% +/- 2%, 98% +/- 2%, and 93% +/- 5%, respectively. In univariate analysis, no prognostic factor of local control was retrieved. Median brain disease-free survival was 25 months after RS. the 3-, 6- and 12-month distant brain control rates were 91% +/- 4%, 91% +/- 4%, and 70% +/- 12%, respectively. Median survival duration was 11 months. The 3-, 6-, 12- and 24-month overall survival rates were 82% +/- 7%, 67% +/- 9%, 48% +/- 10%, and 33% +/- 10%, respectively. According to univariate analysis, only site of metastasis was overall survival prognostic factor. Radiosurgery for brain metastasis of renal cell carcinoma is an effective and accurate treatment. The use of radiosurgery alone is an appropriate management strategy for many patients with brain metastasis of renal cell carcinoma. Radiosurgery is efficient even after development of new metastasis appearing after WBRT.

The role of gamma knife radiosurgery in the treatment of primary and metastatic brain tumors

With the widespread diffusion of stereotactic radiosurgical procedures, GKR treatments have gained considerable momentum as a major therapeutic option for patients harboring primary or metastatic brain tumors. Present results in high grade gliomas indicate a potential palliative role of this technique. The overall low radiosensitivity of these oncotypes and their infiltrative nature-with the resulting problems in properly defining the tumor target-are still a major obstacle to further development of the approach. In this regard, useful contributions are expected from advances in molecular neurobiology and functional neuroimaging as shown by preliminary investigations with MR spectroscopy. Surgery maintains a dominant role in the therapeutic armamentarium for low grade gliomas. However, in unfavorable cases (unresectable tumors, recurrences), GKR seems to be an effective alternative to conventional radiochemotherapy. In grade 2 astrocytomas and specifically in grade 1 pilocytic forms, short-to-mid-term reported studies have documented encouraging 70 to 93% local tumor control rates, with minimal cerebral toxicity. Finally, during the last decade, GKR has become a primary treatment choice for patients harboring small-to-medium-size brain metastases, with reasonable life expectancy and no impending intracranial hypertension. Focal tumor responses are consistently elevated, even in the most radioresistant oncotypes (melanoma, renal carcinoma); median and actuarial survival rates are far better than with conventional radiation treatments and are comparable to those observed in accurately selected surgical-radiation series.