Gamma Knife Surgery for Brain Metastases from Uterine Malignant Tumor

Factors associated with the local control of brain metastases: a systematic search and machine learning application

BACKGROUND

Enhancing Local Control (LC) of brain metastases is pivotal for improving overall survival, which makes the prediction of local treatment failure a crucial aspect of treatment planning. Understanding the factors that influence LC of brain metastases is imperative for optimizing treatment strategies and subsequently extending overall survival. Machine learning algorithms may help to identify factors that predict outcomes.

METHODS

This paper systematically reviews these factors associated with LC to select candidate predictor features for a practical application of predictive modeling. A systematic literature search was conducted to identify studies in which the LC of brain metastases is assessed for adult patients. EMBASE, PubMed, Web-of-Science, and the Cochrane Database were searched up to December 24, 2020. All studies investigating the LC of brain metastases as one of the endpoints were included, regardless of primary tumor type or treatment type. We first grouped studies based on primary tumor types resulting in lung, breast, and melanoma groups. Studies that did not focus on a specific primary cancer type were grouped based on treatment types resulting in surgery, SRT, and whole-brain radiotherapy groups. For each group, significant factors associated with LC were identified and discussed. As a second project, we assessed the practical importance of selected features in predicting LC after Stereotactic Radiotherapy (SRT) with a Random Forest machine learning model. Accuracy and Area Under the Curve (AUC) of the Random Forest model, trained with the list of factors that were found to be associated with LC for the SRT treatment group, were reported.

RESULTS

The systematic literature search identified 6270 unique records. After screening titles and abstracts, 410 full texts were considered, and ultimately 159 studies were included for review. Most of the studies focused on the LC of the brain metastases for a specific primary tumor type or after a specific treatment type. Higher SRT radiation dose was found to be associated with better LC in lung cancer, breast cancer, and melanoma groups. Also, a higher dose was associated with better LC in the SRT group, while higher tumor volume was associated with worse LC in this group. The Random Forest model predicted the LC of brain metastases with an accuracy of 80% and an AUC of 0.84.

CONCLUSION

This paper thoroughly examines factors associated with LC in brain metastases and highlights the translational value of our findings for selecting variables to predict LC in a sample of patients who underwent SRT. The prediction model holds great promise for clinicians, offering a valuable tool to predict personalized treatment outcomes and foresee the impact of changes in treatment characteristics such as radiation dose.

Surgically Treated Brain Metastases from Uterine Origin: A Case Series and Systematic Review

OBJECTIVE

We aimed to describe our institutional case series of 9 surgically treated uterine brain metastases and perform a survival analysis through a systematic review and a pooled individual patient data study.

METHODS

This study was divided into 2 sections: 1) a retrospective, single center patient series assessing outcomes of neurosurgical treatment modalities in patients with malignancy arising in the uterus with brain metastases and 2) a systematic review of the literature between 1980 and 2021 regarding treatment outcomes of individual patients with intracranial metastasis of uterine origin. Pooled cohort survival analysis was done via univariate and Cox regression multivariable analysis and Kaplan-Meier curves.

RESULTS

Final statistical analysis included a total of 124 pooled cohort patients: one hundred fifteen patients from literature review studies plus 9 patients from our institution. Median age at the time of diagnosis was 54 years. Median time from diagnosis of the primary cancer to brain metastasis was 19 months (0-166 months). Surgery and radiotherapy resulted in the highest median OS of 11 months (P < 0.001). Multivariable analyses indicated that the presence of more than one central nervous systemlesion had an increased risk on OS (P = 0.003). Microsurgery, stereotactic radiosurgery, and whole brain radiotherapy remain the evidence-based mainstay applicable to the treatment of multiple brain metastases.

CONCLUSIONS

Brain metastases of cancer arising in the uterus appear to result most often in multiple lesions with dismal prognosis. The seemingly most efficacious treatment modality is surgery and radiotherapy. However, this treatment is often not an option when more than 1 or 2 brain lesions are present.

Gamma Knife Radiosurgery for Metastatic Brain Tumors from Uterine Cervical and Endometrial Carcinomas: Histopathological Analysis of Survival and Local Control. A Japanese Multi-Institutional Cooperative and Retrospective Cohort Study

OBJECTIVE

A retrospective comparative analysis of the outcomes of gamma knife radiosurgery (GKRS) for brain metastases from uterine cervical carcinoma (CC) and endometrial carcinoma (EC), investigated the efficacy and prognostic factors for survival and local tumor control. Histopathological analysis was also performed.

METHODS

The authors retrospectively reviewed 61 patients with 260 tumors of CC and 73 patients with 302 tumors of EC who had undergone GKRS.

RESULTS

The survival times after GKRS had no difference between CC and EC. Uncontrolled primary cancer was significant unfavorable factor. CC resulted in significantly higher neurological death and post-GKRS neurological deterioration. New lesions appeared intracranially after GKRS, with no significant difference between CC and EC. Local tumor control rates at 6, 12, and 24 months after GKRS were 90.0%, 86.6%, and 78.0% for CC and 92.2%, 87.9%, and 86.4% for EC. Primary cancer of CC, more than 7 cm3 volume, and prescription dose less than 20 Gy were significantly correlated in control failure. Local tumor control rates were significantly lower for squamous cell carcinoma in CC. No significant differences were found between histopathological subtypes of EC.

CONCLUSIONS

This study established a relationship between the efficacy of GKRS for CC and EC brain metastases and the histopathological. Though, survival time after GKRS has no difference between CC and EC, CC was significantly higher neurogenic death and neurological deterioration after GKRS. Squamous cell carcinoma had a significantly lower rate of local tumor control among all CC, thereby resulting in CC having lower local tumor control than EC.

Prognostic features of endometrial cancer metastasis to the central nervous system

Objectives

Central nervous system metastases (CNSm) secondary to endometrial cancer (EC) are rare. As a result, prognostic factors for this patient population are not well described.

Methods

EC patients with CNSm were identified retrospectively from two academic centers. EC patients without CNSm (non-CNSm) were used as controls. Chi-square and Fisher’s exact tests were used for analysis of categorial variables. Wilcoxon tests were used for quantitative measures. Overall survival (OS) was compared with Log-rank test. Cox proportional hazard models were used to estimate hazard ratios for OS.

Results

22 EC patients with CNSm and 354 non-CNSm patients were included. Compared to non-CNSm EC, the CNSm cohort was younger (58.5 vs 62.0 years, p = 0.018) with lower BMI (27.7 vs. 33.7 kg/m², p = 0.005), and had more advanced stages (p = ≤ 0.001), grade 3 tumors (81.8% CNSm vs 25.1% non CNSm, p≤0.001) and serous histology (22.7% vs 8.5%, p = 0.010). Median survival after CNSm diagnosis was 9 months (95% CI 4, NA). CNSm was a strong poor prognostic factor (HR death 4.96, p = 0.022). Improved OS was seen with CNS as the only disease site (83m CNSm only vs 30m additional sites, p = 0.007) and less than five CNSm (49m <5 vs. 23m ≥5, p = 0.004). Surgical resection of CNSm (OS 83m surgery vs 33m no surgery, p = 0.003) or multimodal therapy (83m multimodal vs 33m single therapy, p = 0.027) resulted in longer OS.

Conclusions

CNSm is a poor prognostic factor in EC, however, low volume disease with aggressive treatment may result in more favorable survival outcomes.

Stereotactic radiosurgery for brain metastases from pelvic gynecological malignancies: oncologic outcomes, validation of prognostic scores, and dosimetric evaluation

INTRODUCTION

Stereotactic radiosurgery is a well-established treatment option in the management of brain metastases. Multiple prognostic scores for prediction of survival following radiotherapy exist, but are not disease-specific or validated for radiosurgery in women with primary pelvic gynecologic malignancies metastatic to the brain. The aim of the present study is to evaluate the feasibility, safety, outcomes, and impact of established prognostic scores.

METHODS

We retrospectively identified 52 patients treated with radiotherapy for brain metastases between 2008 and 2021. Stereotactic radiosurgery was utilized in 31 patients for an overall number of 75 lesions; the remaining 21 patients received whole-brain radiotherapy. Kaplan-Meier survival analysis and the log-rank test were used to calculate and compare survival curves and univariate and multivariate Cox regression to assess the influence of cofactors on recurrence, local control, and prognosis.

RESULTS

With a median follow-up of 10.7 months, overall survival rates post radiosurgery were 65.3%, 51.3%, and 27.7% for 1, 2, and 5 years, respectively, which were significantly higher than post whole-brain radiotherapy (p=0.049). Five local failures (6.7%) were detected, resulting in 1 and 2 year local cerebral control rates of 97.4% and 94.0%, respectively. Univariate factors for prediction of superior overall survival were high performance status (p=0.030) and application of three prognostic scores, especially the Recursive Partitioning Analysis score (p=0.028). Uni- and multivariate analysis revealed that extracranial progression prior to radiosurgery was significant for inferior overall survival (p<0.0001). Radionecrosis was diagnosed in five women (16%); long-term neurotoxicity was significantly worse after whole-brain radiotherapy compared with radiosurgery (p=0.023).

CONCLUSION

Stereotactic radiosurgery for brain metastases from pelvic gynecologic malignancies appears to be safe and well tolerated, achieving promising local cerebral control. Prognostic scores were shown to be transferable and radiosurgery should be recommended as primary intracranial treatment, especially in women with no prior extracranial progression and Recursive Partitioning Analysis class I.

Brain Metastases from Endometrial Cancer: Clinical Characteristics, Outcomes, and Review of the Literature

BACKGROUND

Brain metastases from endometrial cancer are rare and poorly described. We aimed to estimate the proportion of brain metastases at our institution that arose from endometrial cancer, and to detail clinicopathologic features and survival outcomes.

METHODS

We retrospectively identified and reviewed the charts of 30 patients with brain metastases from endometrial cancer seen at Stanford Hospital from 2008 to 2018.

RESULTS

Among all patients with brain metastases, the proportion arising from endometrial cancer was 0.84%. The median age at diagnosis was 62 years (range, 39-79 years), and the median overall survival from brain metastasis diagnosis was 6.8 months (range, 1.0-58.2 months). Most patients harbored endometrioid histology (53.3%), and some had concurrent metastases to lung (50.0%), bone (36.7%), and liver (20.0%). The median time from endometrial cancer diagnosis to brain metastasis development was 20.8 months (range, 1.4 months to 11.2 years), and the median number of brain metastases was 2 (range, 1-20). Patients with non-endometrioid histologies had more brain metastases than those with endometrioid histology (6.21 vs. 2.44, P = 0.029). There was no difference in overall survival by histology.

CONCLUSIONS

We describe the largest cohort to date of patients with brain metastases originating from endometrial cancer. These patients represent a small fraction of all patients with brain metastases and have poor prognoses. These data enable providers caring for patients with brain metastases from endometrial cancer to appropriately counsel their patients.