Posterior fossa metastases: risk of leptomeningeal disease when treated with stereotactic radiosurgery compared to surgery

Outcomes of Gamma Knife Radiosurgery for Brain Metastases in the Motor Cortex

BACKGROUND AND OBJECTIVES

To study the clinical, imaging, and survival outcomes in patients with motor cortex brain metastases treated with stereotactic radiosurgery (SRS).

METHODS

Imaging and clinical data were obtained from our prospective patient registry. Tumor volumes were obtained from serial imaging data.

RESULTS

The outcomes of 208 patients with metastases involving the motor cortex who underwent SRS between 2012 and 2021 were analyzed. A total of 279 metastases (0.01 cm 3 -12.18 cm 3 , mean 0.74 cm 3 ) were irradiated. The SRS margin dose varied from 10 to 20 Gy (mean 16.9 Gy). The overall tumor control rate was 97.8%. Perilesional edema was noted in 69 (25%) tumors at presentation. Adverse radiation effects (ARE) were noted in 6% of all tumors but were symptomatic in only 1.4%. Median time to appearance of symptomatic ARE was 8 months. Edema without ARE was observed in 13%. New focal seizures were noted in 5 patients (2%) and new generalized seizures in 1 patient (0.3%). Thirty-six patients (17%) presented with motor deficits. At final follow-up, 32 (85%) were improved or unchanged, 13 (41%) had a normal examination, 10 (31%) had mild deficits, and 9 (28%) still had moderate deficits. New remote brain metastases were found in 31% of patients at a median of 8 months. After treatment, the Karnofsky performance score distribution of the population showed an overall right shift and a median survival of 10 months. Patients with incidentally found brain metastases had significantly better survival than those presenting with deficits (median 13 vs 9 months) ( P = .048). Absence of a neurological deficit, recursive partitioning analysis Class I and II, and dose >18 Gy were each associated with a significant survival advantage.

CONCLUSION

SRS for motor cortex metastases is safe in most patients and effective in providing tumor control. Patients treated before neurological deficits develop show better outcomes.

Predicting leptomeningeal disease spread after resection of brain metastases using machine learning

OBJECTIVE

The incidence of leptomeningeal disease (LMD) has increased as treatments for brain metastases (BMs) have improved and patients with metastatic disease are living longer. Sample sizes of individual studies investigating LMD after surgery for BMs and its risk factors have been limited, ranging from 200 to 400 patients at risk for LMD, which only allows the use of conventional biostatistics. Here, the authors used machine learning techniques to enhance LMD prediction in a cohort of surgically treated BMs.

METHODS

A conditional survival forest, a Cox proportional hazards model, an extreme gradient boosting (XGBoost) classifier, an extra trees classifier, and logistic regression were trained. A synthetic minority oversampling technique (SMOTE) was used to train the models and handle the inherent class imbalance. Patients were divided into an 80:20 training and test set. Fivefold cross-validation was used on the training set for hyperparameter optimization. Patients eligible for study inclusion were adults who had consecutively undergone neurosurgical BM treatment, had been admitted to Brigham and Women's Hospital from January 2007 through December 2019, and had a minimum of 1 month of follow-up after neurosurgical treatment.

RESULTS

A total of 1054 surgically treated BM patients were included in this analysis. LMD occurred in 168 patients (15.9%) at a median of 7.05 months after BM diagnosis. The discrimination of LMD occurrence was optimal using an XGboost algorithm (area under the curve = 0.83), and the time to LMD was prognosticated evenly by the random forest algorithm and the Cox proportional hazards model (C-index = 0.76). The most important feature for both LMD classification and regression was the BM proximity to the CSF space, followed by a cerebellar BM location. Lymph node metastasis of the primary tumor at BM diagnosis and a cerebellar BM location were the strongest risk factors for both LMD occurrence and time to LMD.

CONCLUSIONS

The outcomes of LMD patients in the BM population are predictable using SMOTE and machine learning. Lymph node metastasis of the primary tumor at BM diagnosis and a cerebellar BM location were the strongest LMD risk factors.

Collagen deposition within brain metastases is associated with leptomeningeal failure after cavity-directed radiosurgery

Background

Leptomeningeal failure (LMF) represents a devastating progression of disease following resection of brain metastases (BrM). We sought to identify a biomarker at time of BrM resection that predicts for LMF using mass spectrometry-based proteomic analysis of resected BrM and to translate this finding with histochemical assays.

Methods

We retrospectively reviewed 39 patients with proteomic data available from resected BrM. We performed an unsupervised analysis with false discovery rate adjustment (FDR) to compare proteomic signature of BrM from patients that developed LMF versus those that did not. Based on proteomic analysis, we applied trichrome stain to a total of 55 patients who specifically underwent resection and adjuvant radiosurgery. We used competing risks regression to assess predictors of LMF.

Results

Of 39 patients with proteomic data, FDR revealed type I collagen-alpha-1 (COL1A1, P = .045) was associated with LMF. The degree of trichrome stain in each block correlated with COL1A1 expression (β = 1.849, P = .001). In a cohort of 55 patients, a higher degree of trichrome staining was associated with an increased hazard of LMF in resected BrM (Hazard Ratio 1.58, 95% CI 1.11-2.26, P = .01).

Conclusion

The degree of trichrome staining correlated with COL1A1 and portended a higher risk of LMF in patients with resected brain metastases treated with adjuvant radiosurgery. Collagen deposition and degree of fibrosis may be able to serve as a biomarker for LMF.

Surgical Management of Recurrent Brain Metastasis: A Systematic Review of Laser Interstitial Thermal Therapy

The incidence of recurrent metastatic brain tumors is increasing due to advances in local therapy, including surgical and radiosurgical management, as well as improved systemic disease control. The management of recurrent brain metastases was previously limited to open resection and/or irradiation. In recent years, laser interstitial thermal therapy (LITT) has become a promising treatment modality. As systemic and intracranial disease burden increases in a patient, patients may no longer be candidates for surgical resection. LITT offers a relatively minimally invasive option for patients that cannot tolerate or do not want open surgery, as well as an option for accessing deep-seated tumors that may be difficult to access via craniotomy. This manuscript aims to critically review the available data regarding the use of LITT for recurrent intracranial brain metastasis. Ten of seventy-two studies met the criteria for review. Generally, the available literature suggests that LITT is a safe and feasible option for the treatment of recurrent brain metastases involving supratentorial and cortical brain, as well as posterior fossa and deep-seated locations. Among all studies, only one directly compared craniotomy to LITT in the setting of recurrent brain metastasis. Prospective studies are needed to better elucidate the role of LITT in the management of recurrent brain metastases.

Surgical and anatomic factors predict development of leptomeningeal disease in patients with melanoma brain metastases

BACKGROUND

Leptomeningeal disease (LMD) is a devastating complication of systemic malignancy, of which there is an unclear etiology. The aim of this study is to determine if surgical or anatomic factors can predict LMD in patients with metastatic melanoma.

METHODS

A retrospective chart review was performed of 1162 patients treated at single institution for melanoma brain metastases (MBM). Patients with fewer than 3 months follow-up or lacking appropriate imaging were excluded. Demographic information, surgical, and anatomic data were collected.

RESULTS

Eight hundred and twenty-seven patients were included in the final review. On multivariate analysis for the entire cohort, female gender, dural-based and intraventricular metastasis, and tumor bordering CSF spaces were associated with increased risk of LMD. Surgical resection was not significant for risk of LMD. On multivariate analysis of patients who have undergone surgical resection of a metastatic tumor, dural-based and intraventricular metastasis, ventricular entry during surgery, and metastasis in the infratentorial space were associated with increased risk of LMD. On multivariate analysis of patients who did not undergo surgery, chemotherapy after initial diagnosis and metastasis bordering CSF spaces were associated with increased risk of LMD.

CONCLUSION

In a single-institution cohort of MBM, we found that surgical resection alone did not result in an increased risk of LMD. Anatomical factors such as dural-based and intraventricular metastasis were significant for developing LMD, as well as entry into a CSF space during surgical resection. These data suggest a strong correlation between anatomic location and tumor cell seeding in relation to the development of LMD.

Laser Interstitial Thermal Therapy for Posterior Fossa Lesions: A Systematic Review and Analysis of Multi-Institutional Outcomes

Background: Laser interstitial thermal therapy (LITT) has emerged as a treatment option for deep-seated primary and metastatic brain lesions; however, hardly any data exist regarding LITT for lesions of the posterior fossa. Methods: A quantitative systematic review was performed. Article selection was performed by searching MEDLINE (using PubMed), Scopus, and Cochrane electronic bibliographic databases. Inclusion criteria were studies assessing LITT on posterior fossa tumors. Results: 16 studies comprising 150 patients (76.1% female) with a mean age of 56.47 years between 2014 and 2021 were systematically reviewed for treatment outcomes and efficacy. Morbidity and mortality data could be extracted for 131 of the 150 patients. Death attributed to treatment failure, disease progression, recurrence, or postoperative complications occurred in 6.87% (9/131) of the pooled sample. Procedure-related complications, usually including new neurologic deficits, occurred in approximately 14.5% (19/131) of the pooled sample. Neurologic deficits improved with time in most cases, and 78.6% (103/131) of the pooled sample experienced no complications and progression-free survival at the time of last follow-up. Conclusions: LITT for lesions of the posterior fossa continues to show promising data. Future clinical cohort studies are required to further direct treatment recommendations.

Leptomeningeal disease in neurosurgical brain metastases patients: A systematic review and meta-analysis

Background

Leptomeningeal disease (LMD) is a complication distinguished by progression of metastatic disease into the leptomeninges and subsequent spread via cerebrospinal fluid (CSF). Although treatments for LMD exist, it is considered fatal with a median survival of 2–4 months. A broader overview of the risk factors that increase the brain metastasis (BM) patient's risk of LMD is needed. This meta-analysis aimed to systematically review and quantitatively assess risk factors for LMD after surgical resection for BM.

Methods

A systematic literature search was performed on 7 May 2021. Pooled effect sizes were calculated using a random-effects model for variables reported by three or more studies.

Results

Among 503 studies, thirteen studies met the inclusion criteria with a total surgical sample size of 2105 patients, of which 386 patients developed LMD. The median incidence of LMD across included studies was 16.1%. Eighteen unique risk factors were reported as significantly associated with LMD occurrence, including but not limited to: larger tumor size, infratentorial BM location, proximity of BM to cerebrospinal fluid spaces, ventricle violation during surgery, subtotal or piecemeal resection, and postoperative stereotactic radiosurgery. Pooled results demonstrated that breast cancer as the primary tumor location (HR = 2.73, 95% CI: 2.12–3.52) and multiple BMs (HR = 1.37, 95% CI: 1.18–1.58) were significantly associated with a higher risk of LMD occurrence.

Conclusion

Breast cancer origin and multiple BMs increase the risk of LMD occurrence after neurosurgery. Several other risk factors which might play a role in LMD development were also identified.

The effect of Gamma Knife radiosurgery on large posterior fossa metastases and the associated mass effect from peritumoral edema

OBJECTIVE

Gamma Knife radiosurgery (GKRS) as monotherapy is an option for the treatment of large (≥ 2 cm) posterior fossa brain metastases (LPFMs). However, there is concern regarding possible posttreatment increase in peritumoral edema (PTE) and associated compression of the fourth ventricle. This study evaluated the effects and safety of GKRS on tumor and PTE control in LPFM.

METHODS

The authors performed a single-center retrospective review of 49 patients with 51 LPFMs treated with GKRS. Patients with at least 1 clinical and radiological follow-up visit were included. Tumor, PTE, and fourth ventricle volumetric measurements were used to assess efficacy and safety. Overall survival was a secondary outcome.

RESULTS

Fifty-one lesions in 49 consecutive patients were identified; 57.1% of patients were male. At the time of GKRS, the median age was 61.5 years, and the median Karnofsky Performance Status score was 90. The median number of LPFMs and overall brain metastases were 1 and 2, respectively. The median overall tumor, PTE, and fourth ventricle volumes at diagnosis were 4.96 cm3 (range 1.4-21.1 cm3), 14.98 cm3 (range 0.6-71.8 cm3), and 1.23 cm3 (range 0.3-3.2 cm3), respectively, and the median lesion diameter was 2.6 cm (range 2.0-5.07 cm). The median follow-up time was 7.3 months (range 1.6-57.2 months). At the first follow-up, 2 months posttreatment, the median tumor volume decreased by 58.66% (range -96.95% to +48.69%, p < 0.001), median PTE decreased by 78.10% (range -99.92% to +198.35%, p < 0.001), and the fourth ventricle increased by 24.97% (range -37.96% to +545.6%, p < 0.001). The local control rate at first follow-up was 98.1%. The median OS was 8.36 months. No patient required surgical intervention, external ventricular drainage, or shunting between treatment and first follow-up. However, 1 patient required a ventriculoperitoneal shunt at 23 months from treatment. Posttreatment, 65.30% received our general steroid taper, 6.12% received no steroids, and 28.58% required prolonged steroid treatment.

CONCLUSIONS

In this retrospective analysis, patients with LPFMs treated with GKRS had a statistically significant posttreatment reduction in tumor size and PTE and marked opening of the fourth ventricle (all p < 0.001). This study demonstrates that GKRS is well tolerated and can be considered in the management of select cases of LPFMs, especially in patients who are poor surgical candidates.

Sector Irradiation vs. Whole Brain Irradiation After Resection of Singular Brain Metastasis-A Prospective Randomized Monocentric Trial

To minimize recurrence following resection of a cerebral metastasis, whole-brain irradiation therapy (WBRT) has been established as the adjuvant standard of care. With prolonged overall survival in cancer patients, deleterious effects of WBRT gain relevance. Sector irradiation (SR) aims to spare uninvolved brain tissue by applying the irradiation to the resection cavity and the tumor bed. 40 were randomized to receive either WBRT (n = 18) or SR (n = 22) following resection of a singular brain metastasis. Local tumor control was satisfactory in both groups. Recurrence was observed earlier in the SR (median 3 months, 1–6) than in the WBRT cohort (median 8 months, 7–9) (HR, 0.63; 95% CI, 0.03–10.62). Seventeen patients experienced a distant intracranial recurrence. Most relapses (n = 15) occurred in the SR cohort, whereas only two patients in the WBRT group had new distant tumor manifestation (HR, 6.59; 95% CI, 1.71–11.49; p = 0.002). Median overall survival (OS) was 15.5 months (range: 1–61) with longer OS in the SR group (16 months, 1–61) than in the WBRT group (13 months, 3–52), without statistical significance (HR, 0.55; 95% CI, 0.69–3.64). Concerning neurocognition, patients in the SR group improved in the follow-up assessments, while this was not observed in the WBRT group. There were positive signals in terms of QOL within the SR group, but no significant differences in the global QLQ and QLQ-C30 summary scores were found. Our results indicate comparable efficacy of SR in terms of local control, with better maintenance of neurocognitive function. Unsurprisingly, more distant intracranial relapses occurred.

Clinical Trial Registration:ClinicalTrials.gov, identifier NCT01667640.

Acute Management of Gamma Knife Radiosurgery for Asymptomatic Obstructive Hydrocephalus Associated with Posterior Fossa Metastases

OBJECTIVE

We retrospectively assessed the effectiveness and safety of Gamma Knife radiosurgery (GKRS) for asymptomatic obstructive hydrocephalus associated with posterior fossa metastases, which was known empirically but not well discussed.

METHODS

We reviewed the medical records of 27 patients who underwent GKRS for asymptomatic obstructive hydrocephalus related to posterior fossa metastases.

RESULTS

Cumulative control rates of hydrocephalus were 11.1%, 51.9%, 70.4%, and 74.6% at 1, 2, 3, and 6 months after GKRS. Primary gastrointestinal tract cancer (P = 0.001) was significantly correlated with unfavorable management. Evans ratio at GKRS (median 0.31) improved significantly compared with that at 1-3 months after GKRS (median 0.26) (P < 0.0001) and maintained at 6 to 12 months. Cumulative local tumor control rates were 91.7%, 70.8%, and 64.4% at 3, 6, and 12 months after GKRS. Primary gastrointestinal tract cancer (P = 0.018) and no conventional systemic agents (P = 0.027) were significantly correlated with unfavorable control. Cumulative incidence rates of adverse radiation effects were 0.0%, 16.7%, and 24.2% at 6, 9, and 12 months after GKRS. Primary gastrointestinal tract cancer (P < 0.0001) and single and 2- or 3-fraction GKRS (P < 0.0001) were significantly correlated with unfavorable outcomes. All but 1 patient avoided surgical procedure for hydrocephalus after GKRS.

CONCLUSIONS

The present findings suggest that GKRS is an effective and safe treatment for asymptomatic obstructive hydrocephalus caused by posterior fossa metastases, and all but 1 could avoid invasive surgical procedures for hydrocephalus. Posterior fossa metastases from gastrointestinal tract cancer resulted in unsatisfactory outcomes for control of hydrocephalus, tumor progression, and adverse radiation effects.

Initial Approach to Patients with a Newly Diagnosed Solitary Brain Metastasis

Solitary brain metastasis is defined by a single metastatic brain lesion as the only site of metastasis. The initial approach to this condition consists of radiographical evaluation to establish diagnosis, followed by assessment of functional and prognostic status. Neurologic symptom management consists of using dexamethasone and antiepileptic medications. Treatment consists of a combination of surgical and radiation therapy. Surgical treatment is indicated where there is a need for tissue diagnosis or immediate alleviation of neurologic symptoms and mass effect. Stereotactic radiosurgery has become an effective treatment modality. Whole-brain radiation therapy may have a role as an adjunctive therapy.

Hemorrhagic and Cystic Brain Metastases Are Associated With an Increased Risk of Leptomeningeal Dissemination After Surgical Resection and Adjuvant Stereotactic Radiosurgery

BACKGROUND

Brain metastases (BM) treated with surgical resection and focal postoperative radiotherapy have been associated with an increased risk of subsequent leptomeningeal dissemination (LMD). BMs with hemorrhagic and/or cystic features contain less solid components and may therefore be at higher risk for tumor spillage during resection.

OBJECTIVE

To investigate the association between hemorrhagic and cystic BMs treated with surgical resection and stereotactic radiosurgery and the risk of LMD.

METHODS

One hundred thirty-four consecutive patients with a single resected BM treated with adjuvant stereotactic radiosurgery from 2008 to 2016 were identified. Intracranial outcomes including LMD were calculated using the cumulative incidence model with death as a competing risk. Univariable analysis and multivariable analysis were assessed using the Fine & Gray model. Overall survival was analyzed using the Kaplan-Meier method.

RESULTS

Median imaging follow-up was 14.2 mo (range 2.5-132 mo). Hemorrhagic and cystic features were present in 46 (34%) and 32 (24%) patients, respectively. The overall 12- and 24-mo cumulative incidence of LMD with death as a competing risk was 11.0 and 22.4%, respectively. On multivariable analysis, hemorrhagic features (hazard ratio [HR] 2.34, P = .015), cystic features (HR 2.34, P = .013), breast histology (HR 3.23, P = .016), and number of brain metastases >1 (HR 2.09, P = .032) were independently associated with increased risk of LMD.

CONCLUSION

Hemorrhagic and cystic features were independently associated with increased risk for postoperative LMD. Patients with BMs containing these intralesion features may benefit from alternative treatment strategies to mitigate this risk.

Nodular Leptomeningeal Disease-A Distinct Pattern of Recurrence After Postresection Stereotactic Radiosurgery for Brain Metastases: A Multi-institutional Study of Interobserver Reliability

PURPOSE

For brain metastases, surgical resection with postoperative stereotactic radiosurgery is an emerging standard of care. Postoperative cavity stereotactic radiosurgery is associated with a specific, underrecognized pattern of intracranial recurrence, herein termed nodular leptomeningeal disease (nLMD), which is distinct from classical leptomeningeal disease. We hypothesized that there is poor consensus regarding the definition of LMD, and that a formal, self-guided training module will improve interrater reliability (IRR) and validity in diagnosing LMD.

METHODS AND MATERIALS

Twenty-two physicians at 16 institutions, including 15 physicians with central nervous system expertise, completed a 2-phase survey that included magnetic resonance imaging and treatment information for 30 patients. In the "pretraining" phase, physicians labeled cases using 3 patterns of recurrence commonly reported in prospective studies: local recurrence (LR), distant parenchymal recurrence (DR), and LMD. After a self-directed training module, participating physicians completed the "posttraining" phase and relabeled the 30 cases using the 4 following labels: LR, DR, classical leptomeningeal disease, and nLMD.

RESULTS

IRR increased 34% after training (Fleiss' Kappa K = 0.41 to K = 0.55, P < .001). IRR increased most among non-central nervous system specialists (+58%, P < .001). Before training, IRR was lowest for LMD (K = 0.33). After training, IRR increased across all recurrence subgroups and increased most for LMD (+67%). After training, ≥27% of cases initially labeled LR or DR were later recognized as nLMD.

CONCLUSIONS

This study highlights the large degree of inconsistency among clinicians in recognizing nLMD. Our findings demonstrate that a brief self-guided training module distinguishing nLMD can significantly improve IRR across all patterns of recurrence, and particularly in nLMD. To optimize outcomes reporting, prospective trials in brain metastases should incorporate central imaging review and investigator training.

Association of Neurosurgical Resection With Development of Pachymeningeal Seeding in Patients With Brain Metastases

Importance

Neurosurgical resection represents an important management strategy for patients with large, symptomatic brain metastases and increasingly is followed by stereotactic radiation as opposed to whole-brain radiation. Whether neurosurgical resection is associated with tumor spread beyond the resection site and adjuvant stereotactic radiation field remains unknown.

Objective

To characterize the association and incidence of pachymeningeal seeding with neurosurgical resection in patients with brain metastases treated with adjuvant stereotactic radiation.

Design, Setting, and Participants

Retrospective cohort study of a consecutive sample of patients with newly diagnosed brain metastases managed with neurosurgical resection and stereotactic radiation (n = 318) vs radiation alone (n = 870) between 2001 and 2015.

Main Outcomes and Measures

Incidence of pachymeningeal seeding (dural and/or outer arachnoid) and leptomeningeal disease in patients treated with neurosurgical resection and stereotactic radiation vs radiation alone and the risk factors and outcomes associated with pachymeningeal seeding in patients treated with neurosurgical resection followed by stereotactic radiation.

Results

In 1188 patients with newly diagnosed brain metastases, 133 men and 185 women (mean [SD] age, 58.9 [11.5] years) underwent neurosurgical resection. Resection was found to be associated with pachymeningeal seeding (36 of 318 patients vs 0 of 870 patients; P < .001) but not leptomeningeal disease (hazard ratio [HR], 1.14; 95% CI, 0.73-1.77; P = .56). In total, 36 (8.4%) of 428 operations were complicated by pachymeningeal seeding, with a higher incidence noted with resection of previously irradiated vs unirradiated metastases (HR, 2.39; 95% CI, 1.25-4.57; P = .008). Patients with pachymeningeal seeding had relatively low rates of subsequent development of new brain metastases and leptomeningeal disease (8 [16%] of 51 and 6 [13%] of 48, respectively). Among patients with pachymeningeal seeding, neurologic death primarily owing to progressive pachymeningeal disease accounted for 26 (72%) of 36 deaths, but when treated with salvage radiation, 49.1% of patients survived 1 year or longer.

Conclusions and Relevance

In the era of omission of adjuvant whole-brain radiation after neurosurgical resection, pachymeningeal seeding beyond the stereotactic radiation field represents a notable oncologic event that often proves difficult to salvage. However, in some patients, disease control can be achieved with radiotherapeutic approaches.

Outcome after surgery in supratentorial and infratentorial solitary brain metastasis

BACKGROUND

The aim of this retrospective study was to investigate and compare the outcome after surgery in patients with a supratentorial solitary metastasis (SSM) and an infratentorial solitary metastasis (ISM). A worse prognosis has been reported in ISM.

METHODS

Fifty-two patients with a newly diagnosed solitary brain metastasis on MRI were included to identify risk factors affecting the outcome. Key variables included tumor size, staging of the primary tumor, time span of presurgical work-up, and surgical technique. Outcome variables included postoperative complications, tumor recurrence, and mortality. Kaplan-Meier survival analysis was applied.

RESULTS

Thirty patients with a SSM and 22 patients with an ISM underwent gross total resection. The tumor size did not have a statistical significant effect on survival. Presurgical work-up time was similar in SSM and ISM. Postoperative complications were more frequently encountered in ISM. Recurrence rate was comparable in SSM and ISM. Carcinomatous meningitis (CM) was more frequently seen in ISM, and CM was seen more often with the piecemeal resection technique. There was no statistical difference in overall survival between SSM and ISM.

CONCLUSIONS

This study identified factors that play a role in the outcome after surgery in patients with ISM and SSM on MRI. Postoperative complications seemed to be higher in ISM and CM was more often seen in ISM, but the worse prognosis in patients with ISM compared with SSM could not be confirmed.

Neoadjuvant Stereotactic Radiosurgery Before Surgical Resection of Cerebral Metastases

OBJECTIVE

Stereotactic radiosurgery (SRS) has redefined the treatment paradigm for cerebral metastases. The benefits of SRS after surgical resection of a metastatic brain tumor have been well-defined. However, it is unclear whether preoperative SRS can improve the outcomes in select patients. The present study examined the safety and efficacy of preoperative neoadjuvant SRS (NaSRS) for the treatment of cerebral metastases.

METHODS

We performed a retrospective review of 12 patients treated at The University of Texas Southwestern Medical Center. All patients underwent NaSRS, followed by surgical resection of a cerebral metastasis, from 2011 to 2015. Recurrence and overall survival were characterized using Kaplan-Meier and log-rank analyses.

RESULTS

The mean age was 57.5 years (range, 39-69). The median follow-up period was 13 months (range, 1-22.6). The median maximum tumor diameter was 3.66 cm (range, 2.19-4.85). The 6- and 12-month local control rates were 81.8% and 49.1%, respectively. The distant disease control rates were 72.7% and 14.5% at 6 and 12 months, respectively. Overall survival was 83.3% and 74.1% at 6 and 12 months, respectively. Two patients developed leptomeningeal disease at a mean of 11.3 months. A trend toward increased local failure was seen with larger tumor volumes and diameters (P = 0.06).

CONCLUSIONS

NaSRS is a promising new approach for the treatment of select cerebral metastases that require surgical intervention. The approach is safe and effective at achieving local control. Further randomized studies with larger patient cohorts are necessary to determine whether the long-term outcomes are improved.

Comparing Preoperative With Postoperative Stereotactic Radiosurgery for Resectable Brain Metastases: A Multi-institutional Analysis

BACKGROUND

Stereotactic radiosurgery (SRS) is an increasingly common modality used with surgery for resectable brain metastases (BM).

OBJECTIVE

To present a multi-institutional retrospective comparison of outcomes and toxicities of preoperative SRS (Pre-SRS) and postoperative SRS (Post-SRS).

METHODS

We reviewed the records of patients who underwent resection of BM and either Pre-SRS or Post-SRS alone between 2005 and 2013 at 2 institutions. Pre-SRS used a dose-reduction strategy based on tumor size, with planned resection within 48 hours. Cumulative incidence with competing risks was used to determine estimated rates.

RESULTS

A total of 180 patients underwent surgical resection for 189 BM: 66 (36.7%) underwent Pre-SRS and 114 (63.3%) underwent Post-SRS. Baseline patient characteristics were balanced except for higher rates of performance status 0 (62.1% vs 28.9%, P < .001) and primary breast cancer (27.2% vs 10.5%, P = .010) for Pre-SRS. Pre-SRS had lower median planning target volume margin (0 mm vs 2 mm) and peripheral dose (14.5 Gy vs 18 Gy), but similar gross tumor volume (8.3 mL vs 9.2 mL, P = .85). The median imaging follow-up period was 24.6 months for alive patients. Multivariable analyses revealed no difference between groups for overall survival (P = .1), local recurrence (P = .24), and distant brain recurrence (P = .75). Post-SRS was associated with significantly higher rates of leptomeningeal disease (2 years: 16.6% vs 3.2%, P = .010) and symptomatic radiation necrosis (2 years: 16.4% vs 4.9%, P = .010).

CONCLUSION

Pre-SRS and Post-SRS for resected BM provide similarly favorable rates of local recurrence, distant brain recurrence, and overall survival, but with significantly lower rates of symptomatic radiation necrosis and leptomeningeal disease in the Pre-SRS cohort. A prospective clinical trial comparing these treatment approaches is warranted.

ABBREVIATIONS

BM, brain metastasesCI, confidence intervalCTV, clinical target volumeDBR, distant brain recurrenceGTV, gross tumor volumeLC, local controlLMD, leptomeningeal diseaseLR, local recurrenceMVA, multivariable analysisOS, overall survivalPost-SRS, postoperative stereotactic radiosurgeryPre-SRS, preoperative stereotactic radiosurgeryPTV, planning target volumeRN, radiation necrosisSRN, symptomatic radiation necrosisSRS, stereotactic radiosurgeryWBRT, whole-brain radiation therapy.

Leptomeningeal failure in patients with breast cancer receiving stereotactic radiosurgery for brain metastases

PURPOSE

Prior studies suggest a high incidence of leptomeningeal failure (LMF) in breast cancer metastatic to brain. This study examines breast cancer-specific variables affecting development of LMF and survival after Gamma-Knife Radiosurgery (GKS).

METHODS

Between 2000-2010, 149 (breast) and 658 other-histology patients were treated with GKS. Hormone/HER2, age, local/distant brain failure, prior craniotomy, and prior whole-brain radiotherapy (WBRT) were assessed. Median follow-up was 54months (range, 0-106). Serial MRI determined local and distant-brain failure and LMF. Statistical analysis with categorical/continuous data comparisons were done with Fisher's-exact, Wilcoxon rank-sum, log-rank tests, and Cox-Proportional Hazard models.

RESULTS

Of 149 patients, 21 (14%) developed LMF (median time of 11.9months). None of the following predicted for LMF: Her2-status (HR=0.49, p=0.16), hormone-receptor status (HR=1.15, p=0.79), prior craniotomy (HR=1.58, p=0.42), prior WBRT (HR=1.36, p=0.55). Non-significant factors between patients that did (n=21) and did not (n=106) develop LMF included neurologic death (p=0.34) and median survival (8.6 vs 14.2months, respectively). Breast patients who had distant-failure after GKS (65/149; 43.6%) were more likely to later develop LMF (HR 4.2, p=0.005); including 15/65 (23%) patients who had distant-failure and developed LMF. Median time-to-death for patients experiencing LMF was 6.1months (IQR 3.4-7.8) from onset of LMF. Median survival from LMF to death was much longer in breast (6.1months) than in other (1.7months) histologies CONCLUSION: Breast cancer patients had a longer survival after diagnosis of LMF versus other histologies. Neither ER/PR/HER2 status, nor prior surgery or prior WBRT predicted for development of LMF in breast patients.

Prognostic factors and long-term survival in surgically treated brain metastases from non-small cell lung cancer

OBJECTIVE

Brain metastases (BMs) are the most common malignant brain tumors in adults. Despite multimodal treatment options such as microsurgery, radiotherapy and chemotherapy, prognosis still remains very poor. Non-small cell lung cancer (NSCLC) constitutes the most common source of brain metastases. In this study, prognostic factors in this patient population were identified through an in-depth analysis of clinical parameters of patients with BMs from NSCLC.

PATIENTS AND METHODS

Clinical data of 114 NSCLC cancer patients who underwent surgery for BMs at the University Hospital Heidelberg were retrospectively reviewed for age, gender, type of treatment, time course of the disease, presence of neurologic symptoms, Karnofsky Performance Status (KPS), smoking history, presence of extracranial metastases at initial diagnosis of NSCLC, number, location and size of brain metastases. Univariate and multivariate survival analyses were performed using the Log-rank test and Cox' proportional hazard model, respectively.

RESULTS

Median survival time from surgery for BMs was 11.2 months. 18.4% (21 of 114) patients were long-term survivors (>24 months; range 26.3-75.1 months). Age, gender, size and number of intracranial metastases were not significantly associated with patient survival. Univariate analysis identified complete resection, postoperative whole brain radiotherapy (WBRT) and a preoperative KPS of >80% as positive prognostic factors. Infratentorial location and presence of extracranial metastases were shown to be negative prognostic factors. Surgery for the primary tumor was associated with a superior patient outcome both in univariate and multivariate analyses.

CONCLUSION

Our data strongly suggest that surgical treatment of the primary tumor and complete resection of brain metastases in NSCLC patients followed by WBRT improve survival. Moreover, long-term survivors (>2 years) were more frequent than previously reported.

Patterns of Failure after Stereotactic Radiosurgery of the Resection Cavity Following Surgical Removal of Brain Metastases

BACKGROUND

Whole brain radiation treatment (WBRT) is considered standard treatment for BM. However, exposing large volumes of normal brain tissue to irradiation can cause neurotoxicity. This study describes our experience with 100 consecutive patients with brain metastases who were managed with surgical extirpation followed by stereotactic radiosurgery (SRS) to the resection cavity.

METHODS

Patients with 1-3 brain metastases (BM), who underwent resection of 1-2 BM between June 2005 and December 2013, were treated with SRS directed to the tumor cavity and for any synchronous BM. Local and distant treatment failures were determined based on neuroimaging. Kaplan-Meier curves were generated for local and distant failure rates and overall survival.

RESULTS

One hundred and two resection cavities were treated with SRS in 100 consecutive patients. Thirty-two additional synchronous metastases were treated in 27 patients during the same session. The median overall survival was 18.9 months. Local control rate at 1 year was 84%. Longer delays between surgery and SRS were associated with increased risk of local failure (hazard ratio, -1.46; P = 0.02). Distant progression occurred in 44% of the patients at a mean of 8.8 ± 6.6 months after SRS treatment. Ten cases of leptomeningeal spread occurred around the resection cavities (9.8%). Central nervous system failure was not significantly associated with survival. Multivariate Cox regression analysis showed that recursive partitioning analysis and active systemic disease were significantly associated with survival.

CONCLUSION

The strategy described provides acceptable local disease control when compared with WBRT following surgery. This approach can delay and even annul WBRT in the majority of selected BM patients, especially recursive partitioning analysis class I patients. SRS should be scheduled as soon as possible after surgery.

Tumor progression in patients receiving adjuvant whole-brain radiotherapy vs localized radiotherapy after surgical resection of brain metastases

BACKGROUND

Surgery followed by adjuvant radiotherapy is a well-established treatment paradigm for brain metastases.

OBJECTIVE

To examine the effect of postsurgical whole-brain radiotherapy (WBRT) or localized radiotherapy (LRT), including stereotactic radiosurgery and intraoperative radiotherapy, on the rate of recurrence both local and distal to the resection site in the treatment of brain metastases.

METHODS

We retrospectively identified patients who underwent surgery for brain metastasis at the Cleveland Clinic between 2004 and 2012. Institutional review board-approved chart review was conducted, and patients who had radiation before surgery, who had nonmetastatic lesions, or who lacked postadjuvant imaging were excluded.

RESULTS

The final analysis included 212 patients. One hundred fifty-six patients received WBRT, 37 received stereotactic radiosurgery only, and 19 received intraoperative radiotherapy. One hundred forty-six patients were deceased, of whom 60 (41%) died with no evidence of recurrence. Competing risks methodology was used to test the association between adjuvant modality and progression. Multivariable analysis revealed no significant difference in the rate of recurrence at the resection site (hazard ratio [HR] 1.46, P = .26) or of unresected, radiotherapy-treated lesions (HR 1.70, P = .41) for LRT vs WBRT. Patients treated with LRT had an increased hazard of the development of new lesions (HR 2.41, P < .001) and leptomeningeal disease (HR 2.45, P = .04). Median survival was 16.5 months and was not significantly different between groups.

CONCLUSION

LRT as adjuvant treatment to surgical resection of brain metastases is associated with an increased rate of development of new distant metastases and leptomeningeal disease compared with WBRT, but not with recurrence at the resection site or of unresected lesions treated with radiation.

Leptomeningeal disease following stereotactic radiosurgery for brain metastases from breast cancer

Leptomeningeal disease (LMD) is a highly aggressive and usually rapidly fatal condition. The purpose of this study is to identify clinical factors that can serve to predict for LMD at the time of stereotactic radiosurgery (SRS) for brain metastases from breast carcinoma. We conducted a retrospective review of patients with brain metastases from breast cancer treated with SRS from 1995 to 2014 at our institution. Clinical, radiographic, and dosimetric data were collected. LMD was diagnosed by cerebrospinal fluid (CSF) cytology or MRI demonstrating CSF seeding. Comparative statistical analyses were conducted using Cox proportional hazards regression, binary logistic regression, and/or log-rank test. 126 patients met inclusion criteria. Eighteen patients (14 %) developed LMD following SRS. From the time of SRS, the actuarial rate of LMD at 12 months from diagnosis of brain metastasis was 9 % (11 patients). Active disease in the chest at the time of SRS was associated with development of LMD (p = 0.038). Factors including receptor status, tumor size, number of intra-axial tumors, cystic tumor morphology, prior WBRT, active bone metastases, and active liver metastases were not significantly associated with the development of LMD. In patients with brain metastasis from breast cancer that undergo SRS, there is a relatively low rate of LMD. We found that while tumor hormonal status, bone metastases, and hepatic metastases were not associated with the development of LMD, active lung metastases at SRS was associated with LMD. Further research may help to delineate a causative relationship between metastatic lung disease and LMD.

Stereotactic radiosurgery to the resection bed for intracranial metastases and risk of leptomeningeal carcinomatosis

OBJECT

Following resection of a brain metastasis, stereotactic radiosurgery (SRS) to the cavity is an emerging alternative to postoperative whole-brain radiation therapy (WBRT). This approach attempts to achieve local control without the neurocognitive risks associated with WBRT. The authors aimed to report the outcomes of a large patient cohort treated with this strategy.

METHODS

A retrospective review identified 91 patients without a history of WBRT who received Gamma Knife (GK) SRS to 96 metastasis resection cavities between 2007 and 2013. Patterns of intracranial control were examined in the 86 cases with post-GK imaging. Survival, local failure, and distant failure were estimated by the Kaplan-Meier method. Prognostic factors were tested by univariate (log-rank test) and multivariate (Cox proportional hazards model) analyses.

RESULTS

Common primary tumors were non-small cell lung (43%), melanoma (14%), and breast (13%). The cases were predominantly recursive partitioning analysis Class I (25%) or II (70%). Median preoperative metastasis diameter was 2.8 cm, and 82% of patients underwent gross-total resection. A median dose of 16 Gy was delivered to the 50% isodose line, encompassing a median treatment volume of 9.2 cm(3). Synchronous intact metastases were treated in addition to the resection bed in 43% of cases. Patients survived a median of 22.3 months from the time of GK. Local failure developed in 16 cavities, for a crude rate of 18% and 1-year actuarial local control of 81%. Preoperative metastasis diameter ≥ 3 cm and residual or recurrent tumor at the time of GK were associated with local failure (p = 0.04 and 0.008, respectively). Distant intracranial failure occurred in 55 cases (64%) at a median of 7.3 months from GK. Salvage therapies included WBRT and additional SRS in 33% and 31% of patients, respectively. Leptomeningeal carcinomatosis developed in 12 cases (14%) and was associated with breast histology and infratentorial cavities (p = 0.024 and 0.012, respectively).

CONCLUSIONS

This study bolsters the existing evidence for SRS to the resection bed. Local control rates are high, but patients with larger preoperative metastases or residual/recurrent tumor at the time of SRS are more likely to fail at the cavity. While most patients develop distant intracranial failure, an SRS approach spared or delayed WBRT in the majority of cases. The risk of leptomeningeal carcinomatosis does not appear to be elevated with this strategy.

Brain metastasis and treatment

Despite major therapeutic advances in the management of patients with systemic malignancies, management of brain metastases remains a significant challenge. These patients often require multidisciplinary care that includes surgical resection, radiation therapy, chemotherapy, and targeted therapies. Complex decisions about the sequencing of therapies to control extracranial and intracranial disease require input from neurosurgeons, radiation oncologists, and medical/neuro-oncologists. With advances in understanding of the biology of brain metastases, molecularly defined disease subsets and the advent of targeted therapy as well as immunotherapeutic agents offer promise. Future care of these patients will entail tailoring treatment based on host (performance status and age) and tumor (molecular cytogenetic characteristics, number of metastases, and extracranial disease status) factors. Considerable work involving preclinical models and better clinical trial designs that focus not only on effective control of tumor but also on quality of life and neurocognition needs to be done to improve the outcome of these patients.

Risk factors for leptomeningeal carcinomatosis in patients with brain metastases who have previously undergone stereotactic radiosurgery

Our objective was to explore the hypothesis that the risk of leptomeningeal dissemination (LMD) in patients who underwent stereotactic radiosurgery (SRS) for brain metastases is influenced by the site of the primary cancer, the addition of whole brain radiation therapy (WBRT), surgical resection, and control over their systemic disease. We conducted a retrospective cohort analysis of 805 patients who were treated with SRS for brain metastases between 1999 and 2012 at the Wake Forest Baptist Medical Center, and excluded all patients with evidence of LMD before SRS. The primary outcome was LMD. Forty-nine of 795 patients developed LMD with a cumulative incidence of 6.2% (95% Confidence Interval (CI), 4.7-8.0). Median time from SRS to LMD was 7.4 months (Interquartile Range (IQR), 3.3-15.4). A colorectal primary site (Hazard Ratio (HR), 4.5; 95% CI 2.5-8.0; p < 0.0001), distant brain failure (HR, 2.0; 95% CI 1.2-3.2; p = 0.007), breast primary site (HR, 1.6; 95% CI 1.0-2.7; p = 0.05), the number of intracranial metastases at time of initial SRS (HR, 1.1; 95% CI 1.0-1.2; p = 0.02), and age (by 5-year interval) (HR, 0.9; 95% CI 0.8, 0.9; p = 0.0006) were independent factors associated with LMD. There was no evidence that surgical resection before SRS altered the risk of LMD (HR, 1.1; 95 % CI 0.6-2.0, p = 0.78). In patients who underwent SRS for brain metastases, a colorectal or breast primary site, distant brain failure, younger age, and an increased number of intracranial metastases were independently associated with LMD. Given its relative rarity as an outcome, multi-institutional prospective studies will likely be necessary to validate and quantify these relationships.

Long-term stabilization of leptomeningeal disease with whole-brain radiation therapy in a patient with metastatic melanoma treated with vemurafenib: a case report

We present a patient with metastatic BRAF-mutated melanoma who achieved long-term stabilization of leptomeningeal disease (LMD) with sequential whole-brain radiation therapy and vemurafenib. A 53-year-old woman with melanoma that harbored the BRAF V600E mutation and had that metastasized to multiple lymph nodes, lungs, breast, and subcutaneous tissue had developed symptomatic LMD 16 months after starting vemurafenib treatment despite achieving a substantial response at the existing metastatic sites. Vemurafenib was discontinued for 7 days, she received whole-brain radiation therapy (30 Gy in 10 fractions), and 7 days after completing the radiation therapy, she resumed vemurafenib therapy. The neurologic symptoms improved significantly, and a cerebrospinal fluid examination revealed disappearance of melanoma cells. She remained alive with radiologically stable LMD for at least 18 months after the whole-brain radiation therapy.

Imaging changes following stereotactic radiosurgery for metastatic intracranial tumors: differentiating pseudoprogression from tumor progression and its effect on clinical practice

Stereotactic radiosurgery has become standard adjuvant treatment for patients with metastatic intracranial lesions. There has been a growing appreciation for benign imaging changes following radiation that are difficult to distinguish from true tumor progression. These imaging changes, termed pseudoprogression, carry significant implications for patient management. In this review, we discuss the current understanding of pseudoprogression in metastatic brain lesions, research to differentiate pseudoprogression from true progression, and clinical implications of pseudoprogression on treatment decisions.

Risk of leptomeningeal disease in patients treated with stereotactic radiosurgery targeting the postoperative resection cavity for brain metastases

PURPOSE

We sought to determine the risk of leptomeningeal disease (LMD) in patients treated with stereotactic radiosurgery (SRS) targeting the postsurgical resection cavity of a brain metastasis, deferring whole-brain radiation therapy (WBRT) in all patients.

METHODS AND MATERIALS

We retrospectively reviewed 175 brain metastasis resection cavities in 165 patients treated from 1998 to 2011 with postoperative SRS. The cumulative incidence rates, with death as a competing risk, of LMD, local failure (LF), and distant brain parenchymal failure (DF) were estimated. Variables associated with LMD were evaluated, including LF, DF, posterior fossa location, resection type (en-bloc vs piecemeal or unknown), and histology (lung, colon, breast, melanoma, gynecologic, other).

RESULTS

With a median follow-up of 12 months (range, 1-157 months), median overall survival was 17 months. Twenty-one of 165 patients (13%) developed LMD at a median of 5 months (range, 2-33 months) following SRS. The 1-year cumulative incidence rates, with death as a competing risk, were 10% (95% confidence interval [CI], 6%-15%) for developing LF, 54% (95% CI, 46%-61%) for DF, and 11% (95% CI, 7%-17%) for LMD. On univariate analysis, only breast cancer histology (hazard ratio, 2.96) was associated with an increased risk of LMD. The 1-year cumulative incidence of LMD was 24% (95% CI, 9%-41%) for breast cancer compared to 9% (95% CI, 5%-14%) for non-breast histology (P=.004).

CONCLUSIONS

In patients treated with SRS targeting the postoperative cavity following resection, those with breast cancer histology were at higher risk of LMD. It is unknown whether the inclusion of whole-brain irradiation or novel strategies such as preresection SRS would improve this risk or if the rate of LMD is inherently higher with breast histology.

CyberKnife therapy of 24 multiple brain metastases from lung cancer: A case report

Brain metastasis is a significant cause of morbidity and mortality and a critical complication of non-central nervous system primary carcinoma. The present study describes the clinical case of a 46-year-old male with lung cancer and life-threatening brain metastases. The patient was diagnosed with lung cancer with a clinical stage of T2N0M1 (stage IV). Six months after the initial diagnosis and administration of conformal radiotherapy combined with three cycles of chemotherapy, an enhanced computed tomography (CT) scan of the brain revealed abnormalities with double-dosing of intravenous contrast. The CT scan identified >24 lesions scattered in the whole brain. The patient was treated with three-fraction Cyberknife radiotherapy at 22 Gy, delivered to the brain metastases at the Center for Tumor Treatment of People's Liberation Army 107th Hospital. Following CyberKnife therapy, a CT scan of the brain revealed that most of the tumors had disappeared with almost no residual traces. The stereotactic radiosurgery (SRS) conducted using CyberKnife, an image-guided frameless robotic technology for whole-body radiosurgery, had produced a marked response. The present case report demonstrates that CyberKnife therapy plays a significant role in the management of multiple meta-static brain tumors.

Incidence and risk factors for leptomeningeal carcinomatosis in breast cancer patients with parenchymal brain metastases

OBJECTIVE

The objective of study is to evaluate the incidence of leptomeningeal carcinomatosis (LMC) in breast cancer patients with parenchymal brain metastases (PBM) and clinical risk factors for the development of LMC.

METHODS

We retrospectively analyzed 27 patients who had undergone surgical resection (SR) and 156 patients with whole brain radiation therapy (WBRT) as an initial treatment for their PBM from breast cancer in our institution and compared the difference of incidence of LMC according to clinical factors. The diagnosis of LMC was made by cerebrospinal fluid cytology and/or magnetic resonance imaging.

RESULTS

A total of 27 patients (14%) in the study population developed LMC at a median of 6.0 months (range, 1.0-50). Ten of 27 patients (37%) developed LMC after SR, whereas 17 of 156 (11%) patients who received WBRT were diagnosed with LMC after the index procedure. The incidence of LMC was significantly higher in the SR group compared with the WBRT group and the hazard ratio was 2.95 (95% confidence interval; 1.33-6.54, p<0.01). Three additional factors were identified in the multivariable analysis : the younger age group (<40 years old), the progressing systemic disease showed significantly increased incidence of LMC, whereas the adjuvant chemotherapy reduce the incidence.

CONCLUSION

There is an increased risk of LMC after SR for PBM from breast cancer compared with WBRT. The young age (<40) and systemic burden of cancer in terms of progressing systemic disease without adjuvant chemotherapy could be additional risk factors for the development of LMC.

Risk for leptomeningeal seeding after resection for brain metastases: implication of tumor location with mode of resection

Object

Surgical spillage has been one of the causative factors for the development of leptomeningeal seeding (LMS) after resection of brain metastases. In this paper, the authors' goal was to define the factors related to the development of LMS and to evaluate the difference according to tumor location.

Methods

The authors retrospectively analyzed 242 patients who had undergone resection for brain metastases. The factors investigated included tumor location with proximity to the CSF pathway (that is, contacting, involved with, or separated from the CSF pathway), the method of resection, and the use of the Cavitron Ultrasonic Surgical Aspirator (CUSA).

Results

A total of 39 patients (16%) developed LMS at a median of 6.0 months (range 1–42 months) after resection. The risk of developing LMS was significantly higher in patients whose tumors were resected piecemeal than in those whose tumors were removed en bloc, with a hazard ratio (HR) of 4.08 (p < 0.01). The incidence of LMS was significantly higher in patients in whom the CUSA was used, and the HR was 2.64 (p < 0.01). The proximity of tumor to the CSF pathway in the involved group conferred an increased risk of LMS compared with the separated group (HR 11.36, p < 0.01). The risk of piecemeal resection for LMS was significant only in involved lesions (p < 0.01), and the use of the CUSA in both contact and involved lesions increased the incidence of LMS (p < 0.01 and p < 0.03, respectively).

Conclusions

The authors suggest that piecemeal resection using the CUSA should be limited because of the risk of postsurgical LMS, especially when the tumor is in contact with the CSF pathway.

Management of brain metastases

OPINION STATEMENT

As systemic cancer therapies have improved, the natural history and importance of treating brain metastases continues to evolve. Historically, most patients with brain metastases have been managed with whole brain radiation therapy (WBRT) with surgical resection or radiosurgery added for patients with single or few metastases. Because the potential late toxicity of WBRT is increasingly recognized when systemic tumor is more effectively controlled, there has been increased interest in the use of focal therapies such as radiosurgery with deferred WBRT even for patients with larger numbers of metastases. Although WBRT in combination with radiosurgery or surgical resection significantly reduces central nervous system recurrences at the treated site and elsewhere in the brain, it is not clear whether a patient's quality of life is more affected by tumor recurrence or by treatment with WBRT. In our practice, most patients with fewer than 7 to 10 tumors are treated with radiosurgery alone, with WBRT initially deferred because of concerns about its late toxicity. The ongoing technical improvements in radiosurgery have made this transition away from WBRT clinically feasible. This approach also allows patients to begin systemic therapy sooner, rather than waiting 2 to 4 weeks to complete WBRT. For patients with large or very symptomatic tumors, surgical resection is performed, followed by postoperative radiosurgery to the resection cavity, again initially deferring WBRT for many patients. This focal-only approach in the postoperative setting is associated with a higher rate of subdural dissemination and needs further prospective study, as some would argue that tumor progression is the major determinant of loss of function. Ultimately, better survival will require better systemic therapy that both controls extracranial disease and penetrates the brain to reduce intracranial recurrences. Unfortunately, many clinical trials of novel agents exclude patients with brain metastases.

Known and emerging biomarkers of leptomeningeal metastasis and its response to treatment

Leptomeningeal metastasis (LM) is the metastatic dissemination of malignant cells to the leptomeninges and the subarachnoid space of the CNS, affecting approximately 8% of all cancer patients. Cerebrospinal fluid cytology is currently the gold standard for diagnosis of LM and assessment of treatment response, but it has relatively low sensitivity. Thus, specific biomarkers of LM may allow for earlier diagnosis and treatment. This article reviews known tumor markers for LM and describes recent work to find LM-specific markers, such as angiogenesis-related proteins. Novel methods of protein profiling that may aid this search are also described; these methods still need to be standardized and validated to gain widespread acceptance. Nevertheless, we anticipate that future biomarkers will have not only the potential to detect LM, but to predict its progression and response to treatment.

The role of intra-cerebrospinal fluid treatment and prophylaxis in patients with solid tumors

Metastasis to the central nervous system (CNS), including neoplastic meningitis (NM), is a devastating complication of systemic cancer. With the improved survival of cancer patients, the incidence of CNS metastasis is rising, especially among those with breast or lung carcinoma. New therapies that effectively treat these primary tumors outside of the CNS have underscored the significance of CNS metastases; they have become a significant clinical issue and a therapeutic challenge. This review discusses clinical situations in which treatment or chemoprophylaxis of CNS metastases and NM from breast or lung cancer may play an important role. Potential clinical trials to assess these assumptions also will be proposed.

Comparative risk of leptomeningeal dissemination of cancer after surgery or stereotactic radiosurgery for a single supratentorial solid tumor metastasis

OBJECTIVE

To test the hypothesis that differential risks of developing leptomeningeal disease (LMD) exist in patients having a single supratentorial brain metastasis resected via a piecemeal or en bloc approach or treated with stereotactic radiosurgery (SRS).

METHODS

Between 1993 and 2006, 827 patients with a supratentorial brain metastasis underwent resection or SRS at The University of Texas M.D. Anderson Cancer Center. The primary outcome was the incidence of LMD.

RESULTS

Resection was performed piecemeal in 191 patients and en bloc in 351 patients; 285 patients received SRS. LMD occurred in 33 patients, 29 in the resection group and 4 in the SRS group. Risk of LMD was significantly higher with piecemeal tumor resection than with other procedures (SRS: hazard ratio [HR] for piecemeal, 5.8; 95% confidence interval [CI], 1.9-17.2; P = 0.002; en bloc, HR for piecemeal, 2.7; 95% CI, 1.3-5.6; P = 0.009). The difference between piecemeal and en bloc was particularly pronounced in patients with a melanoma primary (HR, 8.4; 95% CI, 1.8-39.2; P = 0.007). The risk of LMD was not significantly different between en bloc resection and SRS (HR for en bloc, 2.1; 95% CI, 0.7-6.4; P = 0.21). Similar results were obtained when comparing effects of SRS and both resection approaches after limiting the sample to patients with tumors in a specific volume range.

CONCLUSION

Piecemeal resection of a supratentorial brain metastasis carries a higher risk of LMD than en bloc resection or SRS. Further assessment of the role of the 2 surgical resection approaches and SRS in a controlled prospective setting with large numbers of patients is warranted.

Treatment of central nervous system metastases: parenchymal, epidural, and leptomeningeal

PURPOSE OF REVIEW

With prolonged survival from systemic therapies in the adjuvant and salvage setting, and because these agents cannot cross the intact blood-brain barrier, central nervous system metastases are becoming a therapeutic challenge in oncology.

RECENT FINDINGS

Recent therapeutic achievements include an extended use of surgery and radiosurgery. Although each of these treatment modalities has its own indications, in patients eligible for both treatments the upfront comparison of these two techniques has not been performed yet. Systemic chemotherapies and biotherapies may be effective in the management of central nervous system metastases as they may act on both neurologic and extra-central nervous system lesions. In the treatment of epidural metastases, a surgical procedure providing immediate direct circumferential decompression of the spinal cord followed by local irradiation has been demonstrated in a prospective randomized trial. The management of leptomeningeal metastases remains controversial and of limited efficacy especially in chemoresistant tumours and still relies on the combination of chemotherapy (intrathecal and intravenous) and focal radiotherapy.

SUMMARY

Aggressive treatments in patients with early diagnosis and in whom central nervous system metastases are the life-threatening location may provide a substantial increase in survival and favourably affect quality of life.

Comparative risk of leptomeningeal disease after resection or stereotactic radiosurgery for solid tumor metastasis to the posterior fossa

Object

The authors tested the hypothesis that patients with metastatic posterior fossa lesions (MPFLs) treated with resection have a higher risk of leptomeningeal disease (LMD) than those with MPFLs treated with stereotactic radiosurgery (SRS).

Methods

Between 1993 and 2004, 379 patients with MPFLs were treated with resection or SRS at The University of Texas M. D. Anderson Cancer Center. The authors' primary study outcome was the incidence of LMD, as diagnosed with cerebrospinal fluid cytological analysis and/or neuroimaging.

Results

Resection was performed in 260 patients, whereas 119 patients underwent SRS. The median patient age was 56 years, 51% of patients were male, and 93% had a Karnofsky Performance Scale score $ 70. The most common primary cancers were those of the lung, breast, and kidney, as well as melanoma. Leptomeningeal dissemination of cancer occurred in 33 patients: 26 in the resection group and 7 in the SRS group (resection group: rate ratio [RR] 2.06, 95% confidence interval [CI] 0.89–4.75, p = 0.09). Piecemeal tumor resection (137 cases) was associated with a significantly higher risk of LMD than en bloc resection (123 cases; RR 3.4, 95% CI 1.43–8.12, p = 0.006) or SRS (RR 3.37, 95% CI 1.41–8.04, p = 0.006), and there was no significant difference in the risk for LMD between en bloc resection and SRS (en bloc resection: RR 0.98, 95% CI 0.34–2.81, p = 0.98). The multivariate RR and significance associated with piecemeal resection, however, were consistent, with a strong effect (RR 2.45, 95% CI 1.19–5.02, p = 0.02) and no indication of biases associated with tumor size, location, or cystic/necrotic appearance.

Conclusions

There is an increased risk of LMD after piecemeal resection of an MPFL. This increase, although clinically and statistically significant, is not as alarming as previously reported and is absent when en bloc removal is achieved. Further assessment of the role of resection in a controlled prospective setting is warranted.

Radiosurgery in the treatment of brain metastases: critical review regarding complications

Stereotactic radiosurgery (SRS) has been described as an effective treatment option for brain metastases. In general, SRS has been indicated for the treatment of lesions smaller than 3 cm in maximum diameter and for lesions considered not surgically treatable, owing to the patient's clinical status or because the lesion was located in or near eloquent brain areas. In several studies, SRS has been associated with clinical and radiographic improvement of the lesions and has been compared with surgery as the modality of choice for brain metastases. Beyond the high rate of local disease control with SRS, the few complications that have been described occurred mainly in the acute post treatment period. Most publications have addressed the outcome and effectiveness of this treatment modality but have not critically analyzed long-term complications, steroid dependency, or results relating to specific brain locations. It is important to understand the radiobiologic effects of a well-demarcated high dose of radiation on the brain lesion, controlling the tumor growth and not causing significant alteration of the related brain region, especially in an area controlling eloquent function.

Brain metastases

PURPOSE OF REVIEW

Brain metastases occur in 10-30% of cancer patients, and they are associated with a dismal prognosis. Radiation therapy has been the mainstay of treatment for patients without surgically treatable lesions. For patients with good prognostic factors and a single metastasis, surgical resection is recommended. The management of patients with multiple metastases, poor prognostic factors, or unresectable lesions is, however, controversial. Recently published data will be reviewed.

RECENT FINDINGS

Radiation therapy has been shown to substantially reduce the risk of local recurrence after surgical resection of brain metastases, although this does not translate into improved survival. Recently, stereotactic radiosurgery has emerged as an increasingly important alternative to surgery that appears to be associated with less morbidity and similar outcomes. Other potentially promising therapies under investigation include interstitial brachytherapy, new chemotherapeutic agents that cross the blood-brain barrier, and targeted molecular agents.

SUMMARY

Patients with brain metastases are now eligible for a number of treatment options that are increasingly likely to improve outcomes. Randomized, prospective trials are necessary to better define the utility of radiosurgery versus surgery in the management of patients with brain metastases. Future investigations should address quality of life and neurocognitive outcomes, in addition to traditional outcome measures such as recurrence and survival rates. The potentially substantial role for chemotherapeutics that cross the blood-brain barrier and for novel targeted molecular agents is now being elucidated.