Improving the Prognostic Value of Disease-Specific Graded Prognostic Assessment Model for Renal Cell Carcinoma by Incorporation of Cumulative Intracranial Tumor Volume

Preoperative Versus Postoperative Radiosurgery of Brain Metastases: A Meta-Analysis

OBJECTIVE

While postoperative resection cavity radiosurgery (post-SRS) is an accepted treatment paradigm for brain metastasis (BM) patients who undergo surgical resection, there is emerging interest in preoperative radiosurgery (pre-SRS) followed by surgical resection as an alternative treatment paradigm. Here, we performed a meta-analysis of the available literature on this matter.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a search of all studies evaluating pre-SRS and post-SRS was completed. Local recurrence (LR), overall survival (OS), radiation necrosis (RN), and leptomeningeal disease (LMD) were evaluated from the available data. Moderator analysis and pooled effect sizes were performed using a proportional meta-analysis with R using the metafor package. Statistics are presented as mean [95% confidence interval].

RESULTS

We identified 6 pre-SRS and 33 post-SRS studies with comparable tumor volume (4.5-17.6 cm3). There were significant differences in the pooled estimates of LR and LMD, favoring pre-SRS over post-SRS. Pooled aggregate for LR was 11.0% [4.9-13.7] and 17.5% [15.1-19.9] for pre- and post-SRS studies (P = 0.014). Similarly, pooled estimates of LMD favored pre-SRS, 4.4% [2.6-6.2], relative to post-SRS, 12.3% [8.9-15.7] (P = 0.019). In contrast, no significant differences were found in terms of RN and OS. Pooled estimates for RN were 6.4% [3.1-9.6] and 8.9% [6.3-11.6] for pre- and post-SRS studies (P = 0.393), respectively. Pooled estimates for OS were 60.2% [55.8-64.6] and 60.5% [56.9-64.0] for pre- and post-SRS studies (P = 0.974).

CONCLUSIONS

This meta-analysis supports further exploration of pre-SRS as a strategy for the treatment of BM.

Navigating Post-Operative Outcomes: A Comprehensive Reframing of an Original Graded Prognostic Assessment in Patients with Brain Metastases

BACKGROUND

Graded Prognostic Assessment (GPA) has been proposed for various brain metastases (BMs) tailored to the primary histology and molecular profiles. However, it does not consider whether patients have been operated on or not and does not include surgical outcomes as prognostic factors. The residual tumor burden (RTB) is a strong predictor of overall survival. We validated the GPA score and introduced "volumetric GPA" in the largest cohort of operated patients and further explored the role of RTB as an additional prognostic factor.

METHODS

A total of 630 patients with BMs between 2007 and 2020 were included. The four GPA components were analyzed. The validity of the original score was assessed using Cox regression, and a modified index incorporating RTB was developed by comparing the accuracy, sensitivity, specificity, F1-score, and AUC parameters.

RESULTS

GPA categories showed an association with survival: age (p < 0.001, hazard ratio (HR) 2.9, 95% confidence interval (CI) 2.5-3.3), Karnofsky performance status (KPS) (p < 0.001, HR 1.3, 95% CI 1.2-1.5), number of BMs (p = 0.019, HR 1.4, 95% CI 1.1-1.8), and the presence of extracranial manifestation (p < 0.001, HR 3, 95% CI 1.6-2.5). The median survival for GPA 0-1 was 4 months; for GPA 1.5-2, it was 12 months; for GPA 2.5-3, it was 21 months; and for GPA 3.5-4, it was 38 months (p < 0.001). RTB was identified as an independent prognostic factor. A cut-off of 2 cm3 was used for further analysis, which showed a median survival of 6 months (95% CI 4-8) vs. 13 months (95% CI 11-14, p < 0.001) for patients with RTB > 2 cm3 and <2 cm3, respectively. RTB was added as an additional component for a modified volumetric GPA score. The survival rates with the modified GPA score were: GPA 0-1: 4 months, GPA 1.5-2: 7 months, GPA 2.5-3: 18 months, and GPA 3.5-4: 34 months. Both scores showed good stratification, with the new score showed a trend towards better discrimination in patients with more favorable prognoses.

CONCLUSION

The prognostic value of the original GPA was confirmed in our cohort of patients who underwent surgery for BM. The RTB was identified as a parameter of high prognostic significance and was incorporated into an updated "volumetric GPA". This score provides a novel tool for prognosis and clinical decision making in patients undergoing surgery. This method may be useful for stratification and patient selection for further treatment and in future clinical trials.

Effectiveness of immune checkpoint inhibitors in combination with stereotactic radiosurgery for patients with brain metastases from renal cell carcinoma: inverse probability of treatment weighting using propensity scores

OBJECTIVE

Stereotactic radiosurgery (SRS) is the mainstay for treating brain metastases (BMs) from renal cell carcinoma (RCC). In recent years, immune checkpoint inhibitors (ICIs) have been applied to metastatic RCC and have contributed to improved outcomes. The authors investigated whether SRS with concurrent ICIs for RCC BM prolongs overall survival (OS) and improves intracranial disease control and whether there are any safety concerns.

METHODS

Patients who underwent SRS for RCC BMs at the authors' institution between January 2010 and January 2021 were included. Concurrent use of ICIs was defined as no more than 3 months between SRS and ICI administration. The time-to-event analysis of OS and intracranial progression-free survival (IC-PFS) between the groups with and without ICIs (ICI+SRS and SRS, respectively) was performed using inverse probability of treatment weighting (IPTW) based on propensity scores (PSs) to control for selection bias. Four baseline covariates (Karnofsky Performance Scale score, extracranial metastases, hemoglobin, and number of BMs) were selected to calculate PSs.

RESULTS

In total, 57 patients with 147 RCC BMs were eligible. The median OS for all patients was 9.1 months (95% CI 6.0-18.9 months), and the median IC-PFS was 4.4 months (95% CI 3.1-6.8 months). Twelve patients (21%) received concurrent ICIs. The IPTW-adjusted 1-year OS rates in the ICI+SRS and SRS groups were 66% and 38%, respectively (HR 0.30, 95% C 0.13-0.69; p = 0.005), and the IPTW-adjusted 1-year IC-PFS rates were 52% and 16%, respectively (HR 0.30, 95% CI 0.14-0.62; p = 0.001). Severe tumor hemorrhage (Common Terminology Criteria for Adverse Events [CTCAE] grade 4 or 5) occurred immediately after SRS in 2 patients in the SRS group. CTCAE grade 2 or 3 toxicity was observed in 2 patients in the ICI+SRS group and 5 patients in the SRS group.

CONCLUSIONS

Although the patient number was small and the analysis preliminary, the present study found that SRS with concurrent ICIs for RCC BM patients prolonged survival and provided durable intracranial disease control, with no apparent increase in treatment-related adverse events.

Stereotactic Radiosurgery as Treatment for Brain Metastases: An Update

Stereotactic radiosurgery (SRS) is a mainstay treatment option for brain metastasis (BM). While guidelines for SRS use have been outlined by professional societies, consideration of these guidelines should be weighed in the context of emerging literature, novel technology platforms, and contemporary treatment paradigms. Here, we review recent advances in prognostic scale development for SRS-treated BM patients and survival outcomes as a function of the number of BM and cumulative intracranial tumor volume. Focus is placed on the role of stereotactic laser thermal ablation in the management of BM that recur after SRS and the management of radiation necrosis. Neoadjuvant SRS prior to surgical resection as a means of minimizing leptomeningeal spread is also discussed.

Multimodal Treatments for Brain Metastases from Renal Cell Carcinoma: Results of a Multicentric Retrospective Study

The aim of this study was to evaluate the clinical outcomes of a large series of brain metastatic renal cell carcinoma (BMRCC) patients treated in three Italian centers.

METHODS

A total of 120 BMRCC patients with a total of 176 lesions treated were evaluated. Patients received surgery plus postoperative HSRS, single-fraction SRS, or hypofractionated SRS (HSRS). Local control (LC), brain distant failure (BDF), overall survival (OS), toxicities, and prognostic factors were assessed.

RESULTS

The median follow-up time was 77 months (range 16-235 months). Surgery plus HSRS was performed in 23 (19.2%) cases, along with SRS in 82 (68.3%) and HSRS in 15 (12.5%). Seventy-seven (64.2%) patients received systemic therapy. The main total dose and fractionation used were 20-24 Gy in single fraction or 32-30 Gy in 4-5 daily fractions. Median LC time and 6 month and 1, 2 and 3 year LC rates were nr, 100%, 95.7% ± 1.8%, 93.4% ± 2.4%, and 93.4% ± 2.4%. Median BDF time and 6 month and 1, 2 and 3 year BDF rates were n.r., 11.9% ± 3.1%, 25.1% ± 4.5%, 38.7% ± 5.5%, and 44.4% ± 6.3%, respectively. Median OS time and 6 month and 1, 2 and 3 year OS rates were 16 months (95% CI: 12-22), 80% ± 3.6%, 58.3% ± 4.5%, 30.9% ± 4.3%, and 16.9% ± 3.6, respectively. No severe neurological toxicities occurred. Patients with a favorable/intermediate IMDC score, a higher RCC-GPA score, an early occurrence of BMs from primary diagnosis, absence of EC metastases, and a combined local treatment (surgery plus adjuvant HSRS) had a better outcome.

CONCLUSIONS

SRS/HSRS is proven to be an effective local treatment for BMRCC. A careful evaluation of prognostic factors is a valid step to manage the optimal therapeutic strategy for BMRCC patients.

Efficacy and safety of combined immunotherapy and stereotactic radiosurgery in NSCLCBM patients and a novel prognostic nomogram: A real-world study

Objective

To explore the effectiveness of combined immunotherapy (IT) and stereotactic radiosurgery (SRS) and address the gap between evidence-based clinical practice and academic knowledge of optimal timing of IT relative to SRS. In addition, to meet the unmet need for an up-to-date prognostic assessment model in the era of IT.

Methods

The data of 86 non-small cell lung cancer brain metastasis (NSCLCBM) patients treated with SRS to 268 brain metastases (BMs) were retrospectively extracted from our hospital database. The Kaplan-Meier analysis was employed for overall survival (OS) and a log-rank test for comparison between groups. Cox proportional hazards regression models were used to identify the significant prognostic factors. The prognostic nomogram was established utilizing the rms package of R software.

Results

IT was found to be associated with improved OS (from BM diagnosis: HR 0.363, 95% CI 0.199 - 0.661, P < 0.001; from SRS: HR 0.472, 95% CI 0.260 - 0.857, P = 0.014). Individuals who received IT in combination with SRS had better OS than those who didn't (from the day of BM diagnosis: 16.8 vs. 8.4 months, P = 0.006; from the day of SRS: 12 vs. 7 months, P = 0.037). Peri-SRS timing of IT administration was a significant prognostic factor for OS (from BM diagnosis: HR 0.132, 95% CI 0.034 - 0.517, P = 0.004; from SRS: HR 0.14, 95% CI 0.044 - 0.450, P = 0.001). Initiating IT after SRS led to superior OS than concurrent or before (from BM diagnosis: 26.5 vs. 14.1 vs. 7.1 months; from SRS: 21.4 vs. 9.9 vs. 4.1 months, respectively). Additionally, we build a nomogram incorporating IT, cumulative intracranial tumor volume (CITV), and recursive partitioning analysis (RPA), demonstrating a remarkable prognosis prediction performance for SRS-treated NSCLCBM patients.

Conclusion

Peri-SRS IT is a promising approach in treating NSCLCBM, as improved OS was observed without significantly increasing adverse events. Receipt of IT post-SRS was associated with superior OS than those who received IT concurrently or before. Incorporating IT and CITV into the RPA index could augment its prognosis assessment value for SRS-treated NSCLCBM patients, predominantly in the wild-type.

Treatment of brain metastases from gastrointestinal primaries: Comparing whole-brain radiotherapy and stereotactic radiosurgery in terms of survival

Objective:

The objective of the study was to analyze the clinical features and prognostic factors for survival in patients with brain metastasis (BM) from gastrointestinal primaries treated with whole-brain radiotherapy (WBRT) or stereotactic radiosurgery (SRS).

Methods:

We retrospectively investigated patients with BMs resulting from gastrointestinal primaries who underwent WBRT or SRS. The effects of treatment modalities on overall survival (OS) were calculated by the Kaplan–Meier method.

Results:

WBRT and SRS were applied to 24 and 17 patients, respectively. In the WBRT group, radiotherapy was delivered at 20–30 Gy in 5–10 fractions (fx). In the SRS group, a median dose of 22 Gy (range: 18–27 Gy) was applied in 1–3 fx. At BM diagnosis, all patients had synchronous extracranial metastases which were mostly detected in the lung and liver. Median OS values were 9 months and 4 months in the SRS and WBRT groups, respectively (p=0.005). Karnofsky performance status (KPS) score (≥70 vs. <70), diagnosis-specific graded prognostic index, gastrointestinal (GI) graded prognostic index, cumulative intracranial tumor volume (CITV), controlled systemic disease, and treatment modality (WBRT vs. SBRT) were found to be related with OS.

Conclusion:

In patients with GI cancer-related BMs, SRS should be preferred in those with longer OS expectancy who have controlled extracranial disease, good KPS and CITV values of <10 cm³.

Safety and efficacy of upfront stereotactic radiosurgery for brain metastases with high cumulative intracranial tumor volume (> 7 ml): analysis of 233 consecutive patients

BACKGROUND

The cumulative intracranial tumor volume (CITV) has recently been suggested to be a more relevant predictive factor for patients with brain metastases (BM) treated with stereotactic radiosurgery (SRS). We aimed to investigate the feasibility of upfront SRS for patients with BM having a high CITV, i.e., exceeding 7 ml.

METHODS

Two hundred thirty-three consecutive patients with BM having a CITV > 7 ml who underwent SRS as first-line treatment from 2011 to 2019 were retrospectively identified. The overall survival (OS) and intracranial disease control rates were analyzed. Multivariate proportional hazards models were used to identify prognostic factors associated with treatment outcome. Toxicity and salvage therapy were also investigated.

RESULTS

The median OS was 8.7 months (95% confidence interval: 7.1-10.4), and 6-month and 1-year OS rates were 60 and 40%, respectively. Systemic anticancer therapy (hazard ratio (HR): 0.45, p < 0.001), female sex (HR: 0.61, p = 0.001), synchronous SRS (HR: 0.57, p = 0.003), number of BM (HR: 1.04, p = 0.008), controlled extracranial disease (HR: 0.56, p = 0.009), Karnofsky performance status (HR: 0.87, p = 0.015), and staged SRS (HR: 0.71, p = 0.037) were found to be factors independently associated with OS. Post-SRS toxicities of CTCAE grades 3, 4, and 5 were observed in 14, 5, and 1 patient, respectively. As salvage management, repeat SRS, whole brain radiotherapy, and surgical resection were required for 84, 16, and 10 patients, respectively, CONCLUSIONS: With vigilant surveillance and appropriate salvage management, upfront SRS alone can be considered as a relatively safe and effective treatment strategy even for BM with CITV > 7 ml.

An integrated disease-specific graded prognostic assessment scale for melanoma: contributions of KPS, CITV, number of metastases, and BRAF mutation status

Background

Stereotactic radiosurgery (SRS) remains a mainstay therapy in the treatment of melanoma brain metastases (BM). While prognostic scales have been developed for melanoma patients who underwent SRS treatment for BM, the pertinence of these scales in the context of molecularly targeted therapies remains unclear.

Methods

Through a multi-institutional collaboration, we collated the survival patterns of 331 melanoma BM patients with known BRAF mutation status treated with SRS. We established a prognostic scale that was validated in an independent cohort of 174 patients. All patients with BRAF mutations in this series were treated with BRAF inhibitors. Prognostic utility was assessed using Net Reclassification Index (NRI > 0) and integrated discrimination improvement (IDI) metrics.

Results

In a multivariate Cox proportional hazards model, BRAF mutation status, KPS, number of metastases, and cumulative intracranial tumor volume (CITV) independently contributed to survival prognostication for melanoma patients with SRS-treated BM (P < .05 for all variables). These variables were incorporated into a prognostic scale using the disease-specific graded prognostic assessment (ds-GPA) framework. This integrated melanoma ds-GPA scale was validated in 2 independent cohorts collated through a multi-institutional collaboration. In terms of order of prognostic importance, BRAF mutation status exerted the greatest influence on survival, while KPS, the number of metastases, and CITV exhibited comparable, lesser impacts.

Conclusions

Optimal survival prognostication for SRS-treated patients with melanoma BM requires an integrated assessment of patient characteristics (KPS), tumor characteristics (CITV and number of metastases), and the mutational profile of the melanoma (BRAF mutation status).

Cumulative Intracranial Tumor Volume as a Prognostic Factor in Patients with Brain Metastases Undergoing Stereotactic Radiosurgery

Approximately 25-35% of all cancer patients suffer from brain metastases (BM), and many of them-in particular, those with a limited number of intracranial tumors-are treated with stereotactic radiosurgery (SRS). Accurate prediction of survival remains a key clinical challenge in this population. Several prognostic scales have been developed to facilitate this prognostication, including the Recursive Partitioning Analysis (RPA) classification, the modified Recursive Partitioning Analysis (mRPA) subclassifications, the Basic Score for Brain Metastases (BS-BM), the Score Index for Radiosurgery (SIR), the Graded Prognostic Assessment (GPA), and the diagnosis-specific Graded Prognostic Assessment (dsGPA). However, none of these scales include consideration of the cumulative intracranial tumor volume (CITV), which is defined as the sum of all intracranial tumor volumes. Since there is mounting evidence that the CITV carries significant prognostic value in SRS-treated patients with BM, this variable should be considered during survival prognostication, along with other pertinent clinical, pathological, and molecular characteristics.

Current Multimodality Treatments Against Brain Metastases from Renal Cell Carcinoma

Simple Summary

Brain metastasis (BM) is generally one of poor prognostic factors in patients with advanced renal cell carcinoma. However, because of longer control of extra-cranial disease by the recent introduction of molecular target therapy and immune checkpoint inhibitor, the incidence of BM has been recently increasing and to progress the treatment of BM is one of urgent medical unmet needs. Although the pivotal clinical trials usually excluded patients with BM, BM subgroup data from the prospective and retrospective series have been gradually accumulated. To select the appropriate strategy, individual patient and tumor characteristics (e.g., Karnofsky Performance Status (KPS), systemic cancer burden, the number/size/location of BM) are important information. Among the local treatments, the technology of stereotactic radiosurgery (SRT) has been especially advanced and its adaptation has been expanded. The combination of SRT with molecular target therapy and/or immune checkpoint inhibitor would be promising to further enhance the efficacy without increased toxicity.

Abstract

In patients with renal cell carcinoma, brain metastasis is generally one of the poor prognostic factors. However, the recent introduction of molecular target therapy and immune checkpoint inhibitor has remarkably advanced the systemic treatment of metastatic renal cell carcinoma and prolonged the patients’ survival. The pivotal clinical trials of those agents usually excluded patients with brain metastasis. The incidence of brain metastasis has been increasing in the actual clinical setting because of longer control of extra-cranial disease. Brain metastasis subgroup data from the prospective and retrospective series have been gradually accumulated about the risk classification of brain metastasis and the efficacy and safety of those new agents for brain metastasis. While the local treatment against brain metastasis includes neurosurgery, stereotactic radiosurgery, and conventional whole brain radiation therapy, the technology of stereotactic radiosurgery has been especially advanced, and the combination with systemic therapy such as molecular target therapy and immune checkpoint inhibitor is considered promising. This review summarizes recent progression of multimodality treatment of brain metastasis of renal cell carcinoma from literature data and explores the future direction of the treatment.

The Role of Stereotactic Radiosurgery in the Management of Brain Metastases From a Health-Economic Perspective: A Systematic Review

BACKGROUND

Stereotactic radiosurgery (SRS) is an effective option in the management of brain metastases, offering improved overall survival to whole-brain radiation therapy (WBRT). However, given the need for active surveillance and the possibility of repeated interventions for local/distant brain recurrences, the balance between clinical benefit and economic impact must be evaluated.

OBJECTIVE

To conduct a systematic review of health-economic analyses of SRS for brain metastases, compared with other existing intervention options, to determine the cost-effectiveness of this treatment across different clinical scenarios.

METHODS

The MEDLINE, EMBASE, Cochrane, CRD, and EconLit databases were searched for health-economic analyses, according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, using terms relevant to brain metastases and radiation-based therapies. Simple cost analysis studies were excluded. Quality analysis was based on BMJ Consolidated Health Economics Reporting Standards (CHEERS) checklist.

RESULTS

Eleven eligible studies were identified. For lesions with limited mass effect, SRS was more cost-effective than surgical resection (6 studies). In patients with Karnofsky performance scale (KPS) >70 and good predicted survival, SRS was cost-effective compared to WBRT (7 studies); WBRT became cost-effective with poor performance status or low anticipated life span. Following SRS, routine magnetic resonance imaging surveillance saved $1326/patient compared to symptomatic imaging due to reduced surgical salvage and hospital stay (1 study).

CONCLUSION

Based on our findings, SRS is cost-effective in the management of brain metastases, particularly in high-functioning patients with longer expected survival. However, before an optimal care pathway can be proposed, emerging factors such as tumor molecular subtype, diagnosis-specific graded prognostic assessment, neuroprognostic score, tailored surveillance imaging, and patient utilities need to be studied in greater detail.

Cumulative intracranial tumour volume prognostic assessment: a new predicting score index for patients with brain metastases treated by stereotactic radiosurgery

Brain metastases (BM) represent the most common intracranial malignancy in adults. Limitations of existing prognostic models reduce their predictivity and clinical applicability. The aim of this study is to validate the cumulative intracranial tumour volume prognostic assessment (CITVPA) as a new prognostic score system for patients with BM treated by Stereotactic Radiosurgery (SRS). Between January 2001 and December 2015, 1894 patients underwent Gamma Knife SRS treatment. The CITVPA model was implemented and validated as follows: the CITV cut-offs were identified thanks to a receiver-operating characteristic (ROC) curve analysis; the survival predictive factors were selected through a Cox proportional hazard model; its prognostic power was compared to RPA, SIR and GPA through the Harrel concordance index (HCI). According to the ROC curve analysis, the CITV cut-off values were set at 1.5 and 4.0 cc. Based on the multivariate analysis, the CITVPA model included: age (OR 1.010, 95% CI 1.005-1.015, p < 0.001), KPS (OR 0.960, 95% CI 0.956-0.965, p < 0.001), extracranial metastases (OR 1.287, 95% CI 1.154-1.437, p < 0.001), BM number (OR 1.193, 95% CI 1.047-1.360, p = 0.008), and CITV (OR 1.028, 95% CI 1.020-1.036, p < 0.001). A score between 0 and 1 was attributed to each prognosticator; a global CITVPA score ranging from 0 to 5 was assigned with higher results corresponding to worse outcomes. The CITVPA (HCI = 0.64) exhibited a significantly (p < 0.001) higher prognostic power compared to RPA (HCI = 0.55), SIR (HCI = 0.55) and GPA (HCI = 0.61). The CITVPA represents a reliable prognostic system for patients with BM treated by SRS. However, further prospective and multicentric studies are necessary before its applicability in clinical practice.

Brain metastases from cervical cancer reduce longevity independent of overall tumor burden

Background:

Isolated brain metastasis (IBM) from cervical cancer is a very rare encounter in neurosurgery. We sought to understand how patients with isolated brain metastases differ from those with metastases in the setting of widespread disease.

Methods:

A systematic review was completed using PubMed and the Cochrane Library. Patients with isolated brain metastases (IBM) and non-isolated brain metastases (NIBM, or brain metastases in the setting of disseminated disease), were compared. Two-sided statistical tests were used to determine significance. Survival function was carried out using the Kaplan–Meier method.

Results:

A total of 89 patients, 25 with IBM and 64 with NIBM, were identified. The time interval between initial diagnosis of cervical cancer and diagnosis of brain lesion was significantly shorter in the IBM group (median 7.5 vs. 20.05 months, and IBM vs. NIBM, respectively; P = 0.006). Overall survival from initial diagnosis of cervical cancer was significantly shorter for the IBM group versus the NIBM group (7.63 vs. 26.3 months, respectively; P = 0.0005). Data demonstrate a 3.4-fold reduction of median life expectancy to 7.63 months. Survival after diagnosis of brain metastases did not differ between groups (median, IBM 7 months vs. NIBM 4 months, P = 0.08).

Conclusion:

Taken together, our data suggest that for cervical cancer patients with brain metastasis intracranial metastasis itself (and not overall tumor burden) represent a sentinel event in limiting longevity. While the present study is underpowered to compare treatment options directly, further work should be focused on determining the optimal treatment for these patients.

Prognostic factors and survival in Japanese patients with brain metastasis from renal cell cancer

BACKGROUND

Patients with brain metastasis from renal cell carcinoma have poor outcomes despite recent advances in diagnosis and treatment. Moreover, factors affecting such poor outcomes are unclear. This study aimed to evaluate the prognostic factors associated with overall survival in renal cell carcinoma patients with brain metastasis.

METHODS

We retrospectively reviewed the data of 50 consecutive patients with brain metastasis from renal cell carcinoma at our institution between 1988 and 2017. The evaluated prognostic factors for overall survival included clinicopathological factors at diagnosis, treatment for brain metastasis, and the Graded Prognostic Assessment score of renal cell carcinoma. The associations between preoperative clinicopathological factors and overall survival were assessed using the log-rank test and Cox proportional hazards models for univariate and multivariate analyses, respectively.

RESULTS

Forty-five patients were included, among whom 39 died during follow-up. The median follow-up was 8.2 months. The median survival time was 8.2 months (95% confidence interval 5.5-13.7). A Graded Prognostic Assessment score ≤ 2 (hazard ratio 1.967; 95% confidence interval 1.024-3.892; P = 0.042), the presence of sarcomatoid components (hazard ratio 3.299; 95% confidence interval 1.424-7.193; P = 0.007), and no treatment for brain metastasis (hazard ratio 2.594; 95% confidence interval 1.033-5.858; P = 0.043) were independently associated with poor prognosis in the multivariate analysis.

CONCLUSIONS

Patients with renal cell carcinoma who develop brain metastasis have poor overall survival. The Graded Prognostic Assessment score, sarcomatoid components, and treatment for brain metastasis from renal cell carcinoma were independent factors associated with prognosis.

Cystic Formation After Stereotactic Radiosurgery of Brain Metastasis

BACKGROUND

Limited information is available on the natural history and etiology of cystic formation after stereotactic radiosurgery (SRS) for brain metastases (BM). We aimed to characterize the natural history of cyst formation after SRS of BM and analyze potential risk factors.

METHODS

We retrospectively reviewed 214 consecutive patients who underwent a total of 1106 SRSs for BM. Demographic, clinical, dosimetric, and magnetic resonance imaging MRI data were reviewed. Statistical analysis was accomplished using Student's t test, and univariate and multivariate logistic regression.

RESULTS

The median patient age was 61 years (range, 19-91 years), and the median duration of follow-up was 424 days (range, 91-2934 days). Eleven cases of cyst formation (0.9% of 1106 treated lesions) were identified at SRS-treated BM sites among 9 patients (2 patients developed cysts at independent sites). The median interval between first SRS and first evidence of cyst was 218 days. Seven of the 9 patients (78%) sustained progressive cyst expansion and neurologic decline requiring steroid treatment. Four of these 7 patients (57%) experienced continued neurologic decline and needed surgical fenestration. On univariate analysis, receipt of >4 rounds of SRS was the sole variable associated with an increased risk of cyst formation (odds ratio, 16.58; P = 0.001). This association remained robust after adjusting for duration of follow-up (odds ratio, 13.59; P = 0.003).

CONCLUSIONS

In our experience with 1106 SRS-treated cases of BM, cyst formation was a rare phenomenon. However, 1 in 3 patients who underwent >4 rounds of SRS sustained cyst formation. A high proportion (78%) of SRS-associated cysts progressively expanded and required medical or surgical treatment.

The growing importance of lesion volume as a prognostic factor in patients with multiple brain metastases treated with stereotactic radiosurgery

Stereotactic Radiosurgery (SRS) is considered standard of care for patients with 1–3 brain metastases (BM). Recent observational studies have shown equivalent OS in patients with 5+ BM compared to those with 2–4, suggesting SRS alone may be appropriate in these patients. We aim to review outcomes of patients treated with SRS with 2–4 versus 5+ BM. This analysis included consecutive patients from 1994 to 2015 treated with SRS. Of 1017 patients, we excluded patients with a single BM and patients without adequate survival data, resulting in 391 patients. All risk factors were entered into univariate analysis using Cox proportional hazards model, and significant factors were entered into multivariate analysis (MVA). We additionally analyzed outcomes after excluding patients with prior surgery or whole‐brain radiotherapy (WBRT). Median follow‐up was 7.1 months. Median KPS was 90, mean age was 59, and most common histologies were melanoma and lung. Median tumor volume was 3.41 cc. Patients with 2–4 BM had a median OS of 8.1 months compared to 6.2 months for those with 5+ BM (P = 0.0136). On MVA, tumor volume, KPS, and histology remained significant for OS, whereas lesion number did not. Similar results were found when excluding patients with prior surgery or WBRT. Rather than lesion number, the strongest prognostic factors for patients undergoing SRS were tumor volume >10 cc, KPS, and histology. BM number may therefore not be the most important criterion for candidacy for SRS. Patients with 5 or more BM should be considered for SRS.