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

Background

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

Methods

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

Results

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

Conclusion

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

Surgical resection versus stereotactic radiosurgery on local recurrence and survival for patients with a single brain metastasis: a systematic review and meta-analysis

BACKGROUND

Brain metastases (BM) are the most frequent intracranial tumours in adults. In patients with solitary BM, surgical resection (SR) or stereotactic radiosurgery (SRS) is performed. There is limited evidence comparing one treatment over the other.

OBJECTIVE

To compare SR versus SRS on patients with solitary BMs, regarding local recurrence (LR) and overall survival (OS) conducting a systematic review and meta-analysis.

METHODS

Systematic review of literature following PRISMA guidelines, using the databases of Medline, Clinicaltrials.gov, Embase, Web of Science, Sciencedirect, CINAHL, Wiley Online Library, Springerlink and LILACS. Following study selection based on inclusion and exclusion criteria, data extraction and a critical analysis of the literature was performed according to the GRADE scale. For quantitative analysis, a random effects model was used. Data were synthetized and evaluated on a forest plot and funnel plot.

RESULTS

Two randomized clinical trials, four cohort studies and one case-control studies met our inclusion criteria for the qualitative analysis. None was excluded subsequently. Overall, 614 patients with single metastasis were included. Studies had high heterogeneity. Multiple significant variables affecting the outcome were signalized. Meta-analysis showed no significant differences for survival (HR, 1.10; 95% CI, 0.75-1.45) or LR (HR, 0.81; 95% CI, 0.42-1.20).

CONCLUSIONS

According to current evidence, in patients with a single small metastasis there is no statistically significant difference in OS or LR among the chosen techniques (SR or SRS). Multiple significant co-variables may affect both outcomes. Different outcomes better than OS should be evaluated in further randomized studies.

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

BACKGROUND

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

METHOD

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

CONCLUSION

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

The effect of brain metastasis location on clinical outcomes: A review of the literature

It is common clinical practice to consider the location of a brain metastasis when making decisions regarding local therapies and, in some scenarios, estimating clinical outcomes, such as local disease control and patient survival. However, the location of a brain metastasis is not included in any validated prognostic nomogram and it is unclear if this is due to a lack of a relationship or a lack of support from published data. We performed a comprehensive review of the literature focusing on studies that have investigated a relationship between brain metastasis location and clinical outcomes, including patient survival. The vast majority of reports anatomically categorized brain metastases as supratentorial or infratentorial whereas some reports also considered other subdivisions of the brain, including different lobes or with particular areas defined as eloquent cortex. Results were variable across studies, with some finding a relationship between metastasis location and survival, but the majority finding either no relationship or a weak correlation that was not significant in the context of multivariable analysis. Here, we highlight the key findings and limitations of many studies, including how neurosurgical resection might influence the relative importance of metastasis location and in what ways future analyses may improve anatomical categorization and resection status.

Long-term outcome of gamma knife radiosurgery for metastatic brain tumors originating from lung cancer

Background:

Gamma knife radiosurgery (GKRS) has emerged as an important treatment option for metastasis brain tumors (MBTs). However, the long-term outcome of GKRS on MBTs originating from lung carcinoma is not well understood. The treatment of MBTs derived from lung cancer with GKRS at our institution is reviewed.

Methods:

We performed a retrospective review (2000-2013) of 173 patients with MBTs from lung cancer who received GKRS. Out of 173 patients, 38 patients had recurrent tumors after microsurgical resection and whole brain radiotherapy (WBT).

Results:

GKRS in MBTs metastasized from lung carcinoma showed significant variations in tumor growth control (decreased in 79 [45.7%] patients, arrested growth in 54 [31.2%] patients, and increased tumor size in 40 [23.1%] patients). The median survival in the study population was 14 months. Overall survival after 3 years was 25%, whereas progression-free survival after 3 years was 45%. The predictive factors for improving survival in the patients with MBTs were recursive partitioning analysis (RPA) class I (P = 0.005), absence of hydrocephalus (P = 0.001), Karnofsky performance scale (KPS) >70 (P = 0.007), age ≤65 (P = 0.041), tumor size ≤3 cm (P = 0.023), controlled primary tumor (P = 0.049), and single number of MBTS (P = 0.044).

Conclusion:

Long-term follow-up revealed that GKRS offers a high rate of tumor control and good overall survival period in both new and recurrent patients with MBTs originating from lung carcinoma. Thus, GKRS is an effective treatment option for new patients with MBTs from lung cancer, as well as an adjuvant therapy in patients with recurrent MBTs derived from lung cancer.

Long term outcome of Gamma Knife radiosurgery for metastatic brain tumors

Gamma Knife radiosurgery (GKRS; Elekta AB, Stockholm, Sweden) has emerged as an important treatment option for metastatic brain tumors (MBT). However, the long term outcome of GKRS on MBT is not well understood. We reviewed the treatment of MBT with GKRS at our institution. We performed a retrospective review (2000-2013) of 298 patients with MBT who received GKRS. The study population was monitored clinically and radiographically after GKRS treatment. Survival benefits and predictive factors of the outcome were analyzed using the Kaplan-Meier test and Cox regression model, respectively. GKRS in MBT showed significant variation in tumor growth control (decreased in 135 [45%] patients, arrested growth in 91 [37%] patients and increased tumor size in 72 [24%] patients). The median survival in the study population was 17 months. Overall and progression free survival after 3 years were 25% and 45%, respectively. The predictive factors for improving survival in the patients with MBT were recursive partitioning analysis class I (p<0.0001), absence of hydrocephalus (p<0.0001), Karnofsky Performance Status (KPS) >80 (p=0.007) and absence of recurrent MBT (p=0.01). Forty (12%), 15 (4.3%) and two (0.6%) patients required GKRS, resection and whole brain radiation, respectively, after initial GKRS due to tumor progression and worsening of signs and symptoms. Our findings revealed that GKRS offers a high rate of tumor control and good survival benefits in both new and recurrent patients with MBT. Thus, GKRS is an effective treatment option for new patients with MBT, as well as an adjuvant therapy in patients with recurrent MBT.

Are melanomas averse to cerebellum? Cerebellar metastases in a surgical series

OBJECTIVES

To study the propensity of different cancers to metastasize to the cerebrum and cerebellum, and to study overall survival (OS) and prognostic factors for patients after surgical resection for cerebellar metastases.

MATERIALS AND METHODS

From a prospectively collected tumor database, all patients that underwent a craniotomy for intracranial metastases between 2003 and 2011 at Oslo University Hospital were included.

RESULTS

One hundred and forty patients underwent resection for cerebellar metastases. Most common primary tumor sites were lung, colon/rectum, and breast in 45%, 19%, and 14%, respectively. None were prostate cancers. Melanoma metastases were significantly underrepresented, and colorectal cancer metastases significantly overrepresented in cerebellum, compared to the overall proportion of cerebellar/supratentorial metastases surgically resected (P < 0.05). Thirty-day post-operative mortality rate was 4.3%. Median OS was 7.7 months (95% CI 6.0-9.5 months) irrespective of post-operative adjuvant therapy. Median OS was 51.8, 8.4, and 3.4 months, respectively, for recursive partitioning analysis class 1(n = 11), 2 (n = 78) and 3 (n = 34). Significant negative prognostic factors were age ≥65 years, Karnofsky performance score (KPS) <70, extracranial metastases and uncontrolled systemic disease.

CONCLUSIONS

Melanoma metastases were significantly underrepresented in cerebellum, whereas colorectal cancer metastases were significantly overrepresented. Surgical mortality and OS after surgical treatment of cerebellar metastases were similar to the results of supratentorial metastases.