Fractionated Stereotactic Radiosurgery for Large Brain Metastases

Two-Day Fraction Gamma Knife Radiosurgery for Large Brain Metastasis

OBJECTIVE

We investigated how treating large brain metastasis (LBM) using 2-day fraction Gamma Knife radiosurgery (GKRS) affects tumor control and patient survival. A prescription dose of 10.3 Gy was applied for 2 consecutive days, with a biologically effective dose equivalent to a tumor single-fraction dose of 16.05 Gy and a brain single-fraction dose of 15.12 Gy.

METHODS

Between November 2017 and December 2021, 42 patients (mean age, 68.3 years; range, 50-84 years; male, 29 [69.1%]; female, 13 [30.9%]) with 44 tumors underwent 2-day fraction GKRS to treat large volume brain metastasis. The main cancer types were non-small cell lung cancer (n=16), small cell lung cancer (n=7), colorectal cancer (n=7), breast cancer (n=3), gastric cancer (n=2), and other cancers (n=7). Twenty-one patients (50.0%) had a single LBM, 19 (46.3%) had a single LBM and other metastases, and two had two (4.7%) large brain metastases. At the time of the 2-day fraction GKRS, the tumors had a mean volume of 23.1 mL (range, 12.5-67.4). On each day, radiation was administered at a dose of 10.3 Gy, mainly using a 50% isodose-line.

RESULTS

We obtained clinical and magnetic resonance imaging follow-up data for 34 patients (81%) with 35 tumors, who had undergone 2-day fraction GKRS. These patients did not experience acute or late radiation-induced complications during follow-up. The median and mean progression-free survival (PFS) periods were 188 and 194 days, respectively. The local control rates at 6, 9, and 12 months were 77%, 40%, and 34%, respectively. The prognostic factors related to PFS were prior radiotherapy (p=0.019) and lung cancer origin (p=0.041). Other factors such as tumor volumes, each isodose volumes, and peri-GKRS systemic treatment were not significantly related to PFS. The overall survival period of the 44 patients following repeat stereotactic radiosurgery (SRS) ranged from 15-878 days (median, 263±38 days; mean, 174±43 days) after the 2-day fraction GKRS. Eight patients (18.2%) were still alive.

CONCLUSION

Considering the unsatisfactory tumor control, a higher prescription dose should be needed in this procedure as a salvage management. Moreover, in the treatment for LBM with fractionated SRS, using different isodoses and prescription doses at the treatment planning for LBMs should be important. However, this report might be a basic reference with the same fraction number and prescription dose in the treatment for LBMs with frame-based SRS.

Hypofractionated Stereotactic Radiosurgery in the Management of Brain Metastases

Stereotactic radiosurgery (SRS) is an important weapon in the management of brain metastases. Single-fraction SRS is associated with local control rates ranging from approximately 70% to 100%, which are largely dependent on lesion and postoperative cavity size. The rates of local control and improved neurocognitive outcomes compared with conventional whole-brain radiation therapy have led to increased adoption of SRS in these settings. However, when treating larger targets and/or targets located in eloquent locations, the risk of normal tissue toxicity and adverse radiation effects within healthy brain tissue becomes significantly higher. Thus, hypofractionated SRS has become a widely adopted approach, which allows for the delivery of ablative doses of radiation while also minimizing the risk of toxicity. This approach has been studied in multiple retrospective reports in both the postoperative and intact settings. While there are no reported randomized data to date, there are trials underway evaluating this paradigm. In this article, we review the role of hypofractionated SRS in the management of brain metastases and emerging data that will serve to validate this treatment approach. Pertinent articles and references were obtained from a comprehensive search of PubMed/MEDLINE and clinicaltrials.gov .

Novel radiotherapeutic strategies in the management of brain metastases: Challenging the dogma

The role of radiation therapy in the management of brain metastasis is evolving. Advancements in machine learning techniques have improved our ability to both detect brain metastasis and our ability to contour substructures of the brain as critical organs at risk. Advanced imaging with PET tracers and magnetic resonance imaging-based artificial intelligence models can now predict tumor control and differentiate tumor progression from radiation necrosis. These advancements will help to optimize dose and fractionation for each patient's lesion based on tumor size, histology, systemic therapy, medical comorbidities/patient genetics, and tumor molecular features. This review will discuss the current state of brain directed radiation for brain metastasis. We will also discuss future directions to improve the precision of stereotactic radiosurgery and optimize whole brain radiation techniques to improve local tumor control and prevent cognitive decline without forming necrosis.

Comparison of Staged Stereotactic Radiosurgery and Fractionated Stereotactic Radiotherapy in Patients with Brain Metastases > 2 cm without Prior Whole Brain Radiotherapy: A Systematic Review and Meta-Analysis

OBJECTIVE

To compare fractionated stereotactic radiotherapy (FSRT) with staged stereotactic radiosurgery (SSRS) in patients with brain metastases >2 cm without prior whole brain radiotherapy.

METHODS

In this systematic review and meta-analysis, PubMed, Scopus, Web of Science, Embase, and Cochrane were searched to include studies that evaluated FSRT and/or SSRS for brain metastases >2 cm or 4 cm3 in adult patients with a known primary malignancy and no prior history of whole brain radiotherapy. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed and an indirect random-effect meta-analyses was conducted to compare treatment outcomes between the two modalities.

RESULTS

A total of 10 studies were included, comprising 612 (778 metastases) and 250 patients (265 metastases) in the SSRS and FSRT groups, respectively. The SSRS group had significantly older patients (66.6 ± 17.51 years vs. 62.37 ± 37.89 years; P = 0.029) with lower rate of control of primary disease (11.59% vs. 78.7%, P < 0.00001), and more patients with Karnofsky performance status ≥70 at baseline (92.81% vs. 88.56%; P = 0.045). FSRT was associated with a statistically nonsignificant but clinically important lower 12-month overall survival (44.75% [95% confidence interval [CI]: 30.48%-59.95%] vs. 53.25% [95%CI: 45.15%-61.19%], P = 0.1615) and higher rate of salvage radiotherapy (18.18% [95%CI: 8.75%-34%] vs. 12.27% [95%CI: 5.98%-23.53%], P = 0.0841). Both groups had comparable rates of local tumor control, mortality, tumor progression, recurrence, neurological death, and 6-month overall survival.

CONCLUSIONS

SSRS and FSRT were found to be comparable for treating brain metastases >2 cm not previously irradiated. Given the paucity of such studies, trials directly comparing the two treatment strategies are warranted to support these findings.

Fractionated versus staged gamma knife radiosurgery for mid-to-large brain metastases: a propensity score-matched analysis

PURPOSE

To compare treatment results between fractionated gamma knife radiosurgery (f-GKRS) and staged gamma knife radiosurgery (s-GKRS) for mid-to-large brain metastases (BMs).

METHODS

We retrospectively analyzed data of patients with medium (4-10 mL) to large (> 10 mL) BMs who underwent s-GKRS or f-GKRS between March 2008 and September 2022. Patients were treated with (i) s-GKRS before May 2018 and (ii) f-GKRS after May 2018. Patients who underwent follow-up magnetic resonance imaging at least once were enrolled. Case-matched studies were conducted by applying propensity score matching to minimize treatment selection bias and potential confounding. Local control (LC) was set as the primary endpoint and overall survival (OS) as the secondary endpoint.

RESULTS

This study included 129 patients with 136 lesions and 70 patients with 78 lesions who underwent s-GKRS and f-GKRS, respectively. Overall, 124 lesions (62 lesions in each group) were selected in the case-matched group. No differences were observed in the 6-month and 1-year cumulative incidences of LC failure between the s-GKRS and f-GKRS groups (15.6% vs. 15.9% at 6 months and 25.6% vs. 25.6% at 1 year; p = 0.617). One-year OS rates were 62.6% (95% confidence interval [CI]: 45.4-75.7%) and 73.9% (95% CI: 58.8-84.2%) in the s-GKRS and f-GKRS groups, respectively. The post-GKRS median survival time was shorter in the s-GKRS group than in the f-GKRS group (17 vs. 36 months), without significance (p = 0.202).

CONCLUSIONS

This is the first study to compare f-GKRS and s-GKRS in large BMs. Fractionation is as effective as staged GKRS for treating mid-to-large BMs.

SAFESTEREO: phase II randomized trial to compare stereotactic radiosurgery with fractionated stereotactic radiosurgery for brain metastases

BACKGROUND

Stereotactic radiosurgery (SRS) is a frequently chosen treatment for patients with brain metastases and the number of long-term survivors is increasing. Brain necrosis (e.g. radionecrosis) is the most important long-term side effect of the treatment. Retrospective studies show a lower risk of radionecrosis and local tumor recurrence after fractionated stereotactic radiosurgery (fSRS, e.g. five fractions) compared with stereotactic radiosurgery in one or three fractions. This is especially true for patients with large brain metastases. As such, the 2022 ASTRO guideline of radiotherapy for brain metastases recommends more research to fSRS to reduce the risk of radionecrosis. This multicenter prospective randomized study aims to determine whether the incidence of adverse local events (either local failure or radionecrosis) can be reduced using fSRS versus SRS in one or three fractions in patients with brain metastases.

METHODS

Patients are eligible with one or more brain metastases from a solid primary tumor, age of 18 years or older, and a Karnofsky Performance Status ≥ 70. Exclusion criteria include patients with small cell lung cancer, germinoma or lymphoma, leptomeningeal metastases, a contraindication for MRI, prior inclusion in this study, prior surgery for brain metastases, prior radiotherapy for the same brain metastases (in-field re-irradiation). Participants will be randomized between SRS with a dose of 15-24 Gy in 1 or 3 fractions (standard arm) or fSRS 35 Gy in five fractions (experimental arm). The primary endpoint is the incidence of a local adverse event (local tumor failure or radionecrosis identified on MRI scans) at two years after treatment. Secondary endpoints are salvage treatment and the use of corticosteroids, bevacizumab, or antiepileptic drugs, survival, distant brain recurrences, toxicity, and quality of life.

DISCUSSION

Currently, limiting the risk of adverse events such as radionecrosis is a major challenge in the treatment of brain metastases. fSRS potentially reduces this risk of radionecrosis and local tumor failure.

TRIAL REGISTRATION

ClincalTrials.gov, trial registration number: NCT05346367 , trial registration date: 26 April 2022.

Time interval from diagnosis to treatment of brain metastases with stereotactic radiosurgery is not associated with radionecrosis or local failure

Introduction

Brain metastases are the most common intracranial tumor diagnosed in adults. In patients treated with stereotactic radiosurgery, the incidence of post-treatment radionecrosis appears to be rising, which has been attributed to improved patient survival as well as novel systemic treatments. The impacts of concomitant immunotherapy and the interval between diagnosis and treatment on patient outcomes are unclear.

Methods

This single institution, retrospective study consisted of patients who received single or multi-fraction stereotactic radiosurgery for intact brain metastases. Exclusion criteria included neurosurgical resection prior to treatment and treatment of non-malignant histologies or primary central nervous system malignancies. A univariate screen was implemented to determine which factors were associated with radionecrosis. The chi-square test or Fisher’s exact test was used to compare the two groups for categorical variables, and the two-sample t-test or Mann-Whitney test was used for continuous data. Those factors that appeared to be associated with radionecrosis on univariate analyses were included in a multivariable model. Univariable and multivariable Cox proportional hazards models were used to assess potential predictors of time to local failure and time to regional failure.

Results

A total of 107 evaluable patients with a total of 256 individual brain metastases were identified. The majority of metastases were non-small cell lung cancer (58.98%), followed by breast cancer (16.02%). Multivariable analyses demonstrated increased risk of radionecrosis with increasing MRI maximum axial dimension (OR 1.10, p=0.0123) and a history of previous whole brain radiation therapy (OR 3.48, p=0.0243). Receipt of stereotactic radiosurgery with concurrent immunotherapy was associated with a decreased risk of local failure (HR 0.31, p=0.0159). Time interval between diagnostic MRI and first treatment, time interval between CT simulation and first treatment, and concurrent immunotherapy had no impact on incidence of radionecrosis or regional failure.

Discussion

An optimal time interval between diagnosis and treatment for intact brain metastases that minimizes radionecrosis and maximizes local and regional control could not be identified. Concurrent immunotherapy does not appear to increase the risk of radionecrosis and may improve local control. These data further support the safety and synergistic efficacy of stereotactic radiosurgery with concurrent immunotherapy.

Treatment Outcome of Gamma Knife Radiosurgery for Brain Metastasis from Thyroid Cancer: Favorable Local Control but Poor Survival

BACKGROUND

Brain metastasis from thyroid cancer (TCBM) is extremely rare; thus, despite a good treatment outcome for thyroid cancer, TCBM has shown poor clinical outcomes. Considering the short survival and poor general condition of patients with TCBM, stereotactic radiosurgery may be preferred to achieve local control.

METHODS

A total of 25 patients with TCBM who underwent Gamma Knife radiosurgery (GKS) were initially included in this study; however, 3 patients were excluded because of a lack of data.

RESULTS

There were 7 men (31.8%) and 15 women (68.2%) and the mean age was 63.7 years. The most common type of thyroid cancer histology was papillary carcinoma. Fourteen patients (63.6%) harbored single brain metastatic tumor and 8 (36.3%) had multiple brain metastatic tumors. The mean duration from thyroid cancer diagnosis to detection of brain metastasis was 7.7 years (range, 0-23 years). The median dose of radiation of GKS was 22 Gy (range, 18-25 Gy). There was no radiation-induced complication after GKS. The median overall survival (OS) was 15 months and the 1-year OS of patients with TCBM was 63%, the 2-year OS was 38%, and the 5-year OS was 28%. The 6-month progression-free survival (PFS) for local recurrence of TCBM was 90.4%, the 1-year PFS was 84%, and the 3-year PFS was 84%.

CONCLUSIONS

GKS showed favorable local control for TCBM. However, the rate of distant brain metastasis was high and median survival of patients with TCBM was only 15 months.

Up-front single-session radiosurgery for large brain metastases-volumetric responses and outcomes

BACKGROUND

Patients presenting with large brain metastases (LBM) pose a management challenge to the multidisciplinary neuro-oncologic team. Treatment options include surgery, whole-brain or large-field radiation therapy (WBRT), stereotactic radiosurgery (SRS), or a combination of these.

OBJECTIVE

To determine if corticosteroid therapy followed by SRS allows for efficient minimally invasive care in patients with LBMs not compromised by mass effect.

METHODS

We analyzed the change in tumor volume to determine the efficacy of single-session SRS in the treatment of LBM in comparison to other treatment modalities. Twenty-nine patients with systemic cancer and brain metastasis (≥ 2.7 cm in greatest diameter) who underwent single-session SRS were included.

RESULTS

Among 29 patients, 69% of patients had either lung, melanoma, or breast cancer. The median initial tumor size (maximal diameter) was 32 mm (range 28-43), and the median initial tumor volume was 9.56 cm³ (range 1.56-25.31). The median margin dose was 16 Gy (range 12-18). The average percent decrease in tumor volume compared to pre-SRS volume was 55% on imaging at 1-2 months, 58% at 3-5 months, 64% at 6-8 months, and 57% at > 8 months. There were no adverse events immediately following SRS. Median corticosteroid use after SRS was 21 days. Median survival after radiosurgery was 15 months.

CONCLUSION

Initial high-dose corticosteroid therapy followed by prompt single-stage SRS is a safe and efficacious method to manage patients with LBMs (defined as ≥ 2.7 cm).

Upfront and Repeated Stereotactic Radiosurgery in Patients With Brain Metastases From NSCLC

INTRODUCTION

Approximately 40% of non-small-cell lung cancer (NSCLC) patients develop brain metastases (BM). Stereotactic radiosurgery (SRS) instead of whole-brain radiotherapy (WBRT) is increasingly administered as an upfront treatment to patients with a limited number of BM. We present outcomes and validation of prognostic scores for these patients treated with upfront SRS.

METHODS

We retrospectively analyzed 199 patients with a total of 268 SRS courses for 539 brain metastases. Median patient age was 63 years. For larger BM, dose reduction to 18 Gy or hypofractionated SRS in 6 fractions was applied. We analyzed the BMV-, the RPA-, the GPA- and the lung-mol GPA score. Cox proportional hazards models with univariate and multivariate analyses were fitted for overall survival (OS) and intracranial progression-free survival (icPFS).

RESULTS

Sixty-four patients died, 7 of them of neurological causes. Thirty eight patients (19,3%) required a salvage WBRT. Median OS was 38, 8 months (IQR: 6-NA). In univariate analysis as well as multivariate analysis, the Karnofsky performance scale index (KPI) ≥90% (P = 0, 012 and P = 0, 041) remained as independent prognostic factor for longer OS. All 4 prognostic scoring indices could be validated for OS assessment (BMV P = 0, 007; RPA P = 0, 026; GPA P = 0, 003; lung-mol GPA P = 0, 05).

CONCLUSION

In this large cohort of NSCLC patients with BM treated with upfront and repeated SRS, OS was markedly favourable, in comparison to literature. Upfront SRS is an effective treatment approach in those patients and can decidedly reduce the impact of BM on overall prognosis. Furthermore, the analysed scores are useful prognostic tools for OS prediction.

Five-Fraction Stereotactic Radiotherapy for Brain Metastases-A Retrospective Analysis

PURPOSE

To determine the safety and outcome profile of five-fraction stereotactic radiotherapy (FSRT) for brain metastases (BM), either as a definitive or adjuvant treatment.

METHODS

We assessed clinical data of patients receiving five fractions of 7 Gy each (cumulative physical dose of 35 Gy) to BM or surgical cavities. The primary endpoints were toxicity and radiation necrosis (RN) rates. Secondary endpoints were 1-year cumulative local control rate (LCR) and estimated overall survival (OS).

RESULTS

A total of 36 eligible patients receiving FSRT to a total of 49 targets were identified and included. The median follow up was 9 (1.1-56.2) months. The median age was 64.5 (34-92) years, the median ECOG score was 1, and the median Diagnostic-Specific Graded Prognostic Assessment (DS-GPA) score was 2. Treatment was well tolerated and there were no grade 3 adverse events or higher. The overall RN rate was 14.3% and the median time to RN was 12.9 (1.8-23.8) months. RN occurrence was associated with immunotherapy, young age (≤45 years), and large PTV. The cumulative 1-year local control rate was 83.1% and the estimated median local progression free-survival was 18.8 months. The estimated median overall survival was 11 (1.1-56.2) months and significantly superior in those patients presenting with RN.

CONCLUSIONS

FSRT with 5 × 7 Gy represents a feasible, safe, and efficient fast track approach of intensified FSRT with acceptable LC and comparable RN rates for both the adjuvant and definitive RT settings.

A Comparison of Single Fraction and Multi Fraction Radiosurgery on the Gamma Knife ICON: A Single Institution Review

Purpose

Brain metastases are a common development in patients with malignant solid tumors. Stereotactic radiosurgery (SRS) has a long track record of effectively and safely treating these patients, with some limitations to the use of single fraction SRS based on size and volume. In this study, we reviewed outcomes of patients treated using SRS and fractionated SRS (fSRS) to compare predictors and outcomes of those treatments.

Methods and Materials

Two hundred patients treated with SRS or fSRS for intact brain metastases were included. We tabulated baseline characteristics and performed a logistic regression to identify predictors of fSRS. Cox regression was used to identify predictors of survival. Kaplan-Meier analysis was used to calculate survival, local failure, and distant failure rates. A receiver operating characteristic curve was generated to determine timepoint from planning to treatment associated with local failure.

Results

The only predictor of fSRS was tumor volume >2.061 cm³. There was no difference in local failure, toxicity, or survival by fractionation of biologically effective dose. Predictors of worse survival were age, extracranial disease, history of whole brain radiation therapy, and volume. Receiver operating characteristic analysis identified 10 days as potential factor in local failure. At 1 year, local control was 96.48 and 76.92% for those patients treated before or after that interval, respectively (P = .0005).

Conclusions

Fractionated SRS is a safe and effective alternative for patients with larger volume tumors not suitable for single fraction SRS. Care should be taken to treat these patients expeditiously as a delay was shown to affect local control in this study.

A Multi-Disciplinary Approach to Diagnosis and Treatment of Radionecrosis in Malignant Gliomas and Cerebral Metastases

Radiation necrosis represents a potentially devastating complication after radiation therapy in brain tumors. The establishment of the diagnosis and especially the differentiation from progression and pseudoprogression with its therapeutic implications requires interdisciplinary consent and monitoring. Herein, we want to provide an overview of the diagnostic modalities, therapeutic possibilities and an outlook on future developments to tackle this challenging topic. The aim of this report is to provide an overview of the current morphological, functional, metabolic and evolving imaging tools described in the literature in order to (I) identify the best criteria to distinguish radionecrosis from tumor recurrence after the radio-oncological treatment of malignant gliomas and cerebral metastases, (II) analyze the therapeutic possibilities and (III) give an outlook on future developments to tackle this challenging topic. Additionally, we provide the experience of a tertiary tumor center with this important issue in neuro-oncology and provide an institutional pathway dealing with this problem.

Retrospective study of hypofractionated stereotactic radiotherapy combined with whole brain radiotherapy for patients with brain metastases

Background and purpose

To evaluate the clinical outcomes of hypofractionated stereotactic radiotherapy (HFSRT) combined with whole brain radiotherapy (WBRT) in patients with brain metastases (BMs).

Materials and methods

From May 2018 to July 2020, 50 patients (111 lesions) received HFSRT (18 Gy/3F) + WBRT (40 Gy/20F). The RECIST 1.1 and RANO-BM criteria were used to evaluate treatment efficacy. Five prognostic indexes (RPA, GPA, SIR, BS-BM, and GGS) were applied. The primary endpoint was intracranial local control (iLC). Secondary endpoints were overall survival (OS) and the safety of treatment.

Results

Intracranial objective response rates (iORR) using the RECIST 1.1 and RANO-BM criteria were 62.1% and 58.6%, respectively. The iLC rate was 93.1%, the 6- and 12-month iLC rates were 90.8% and 57.4%, respectively. The median intracranial progression-free survival (iPFS) was not reached (range 0–23 months). The 6-, 12-, and 24-month OS rates were 74.2%, 58.2%, and 22.9%, respectively. The KPS score showed statistical significance in univariate analysis of survival. The 6, 12, and 24 month OS rates for patients with KPS ≥ 70 were 83.8%, 70.5%, and 29.7%, respectively. The median survival time (MST) for all patients and for patients with KPS ≥ 70 were 13.6 and 16.5 months, respectively. Sex, KPS score, and gross tumor volume were significant factors in the multivariate analysis of survival. OS was significantly associated with RPA, SIR, BS-BM, and GGS classes. No acute toxicities of grade 3 or higher were noted.

Conclusion

HFSRT combined with WBRT is a safe and effective local treatment modality for BM patients.

Dose-Response Effect and Dose-Toxicity in Stereotactic Radiotherapy for Brain Metastases: A Review

Simple Summary

Brain metastases are one of the most frequent complications for cancer patients. Stereotactic radiosurgery is considered a cornerstone treatment for patients with limited brain metastases and the ideal dose and fractionation schedule still remain unknown. The aim of this literature review is to discuss the dose-effect relation in brain metastases treated by stereotactic radiosurgery, accounting for fractionation and technical considerations.

Abstract

For more than two decades, stereotactic radiosurgery has been considered a cornerstone treatment for patients with limited brain metastases. Historically, radiosurgery in a single fraction has been the standard of care but recent technical advances have also enabled the delivery of hypofractionated stereotactic radiotherapy for dedicated situations. Only few studies have investigated the efficacy and toxicity profile of different hypofractionated schedules but, to date, the ideal dose and fractionation schedule still remains unknown. Moreover, the linear-quadratic model is being debated regarding high dose per fraction. Recent studies shown the radiation schedule is a critical factor in the immunomodulatory responses. The aim of this literature review was to discuss the dose–effect relation in brain metastases treated by stereotactic radiosurgery accounting for fractionation and technical considerations. Efficacy and toxicity data were analyzed in the light of recent published data. Only retrospective and heterogeneous data were available. We attempted to present the relevant data with caution. A BED10 of 40 to 50 Gy seems associated with a 12-month local control rate >70%. A BED10 of 50 to 60 Gy seems to achieve a 12-month local control rate at least of 80% at 12 months. In the brain metastases radiosurgery series, for single-fraction schedule, a V12 Gy < 5 to 10 cc was associated to 7.1–22.5% radionecrosis rate. For three-fractions schedule, V18 Gy < 26–30 cc, V21 Gy < 21 cc and V23 Gy < 5–7 cc were associated with about 0–14% radionecrosis rate. For five-fractions schedule, V30 Gy < 10–30 cc, V 28.8 Gy < 3–7 cc and V25 Gy < 16 cc were associated with about 2–14% symptomatic radionecrosis rate. There are still no prospective trials comparing radiosurgery to fractionated stereotactic irradiation.

Peri-radiosurgical administration of bevacizumab improves radiographic response to single and fractionated stereotactic radiosurgery for large brain metastasis

INTRODUCTION

Stereotactic radiosurgery (SRS) is a standard of care for brain metastases (BM) patients, yet large BM are at a greater risk for radionecrosis and local progression (LP). Concomitant bevacizumab and radiotherapy has been shown to improve outcomes in primary and metastatic brain tumors. This retrospective study investigated the efficacy and safety of concurrent bevacizumab and SRS for large BM.

METHODS

From 2015 to 2019, patients with a BM diameter ≥ 2 cm who received either combination therapy (n = 49, SRS + BVZ group), or SRS alone (n = 73, SRS group) were enrolled. Bevacizumab was given peri-radiosurgically with a 2-week interval. Radiographic response was assessed using the RECIST version 1.1. Competing risk and logistic regression analysis were performed to evaluate prognostic factors.

RESULTS

Radiographic response was achieved in 41 patients (84%) in the SRS + BVZ group and 37 patients (51%) in the SRS group (p = 0.001). In the multivariate regression analysis, concurrent bevacizumab was independently associated with a better radiographic response (p = 0.003). The cumulative incidences of LP and ≥ grade 2 radionecrosis at 12 months between the SRS + BVZ group and SRS group were 2% versus 6.8%, and 14.3% versus 14.6%, respectively. For patients with BM size ≥ 3 cm, the cumulative incidence of LP was significantly lower in the SRS + BVZ group (p = 0.03). No ≥ grade 4 toxicity was observed in either group.

CONCLUSIONS

Concurrent bevacizumab and SRS for large BM is highly effective, with a better radiographic response and minimal excessive treatment-related toxicities. Peri-radiosurgical bevacizumab preferentially reduced the risk of LP, especially for BM size ≥ 3 cm.

Hypofractionated frameless gamma knife radiosurgery for large metastatic brain tumors

Hypofractionated stereotactic radiosurgery has become an alternative for metastatic brain tumors (METs). We aimed to analyze the efficacy and safety of frameless hypofractionated Gamma Knife radiosurgery (hfGKRS) in the management of unresected, large METs. All patients who were managed with hfGKRS for unresected, large METs (> 4 cm³) between June 2017 and June 2020 at a single center were reviewed in this retrospective study. Local control (LC), progression-free survival (PFS), overall survival (OS), and toxicities were investigated. A total of 58 patients and 76 METs with regular follow-up were analyzed. LC rate was 98.5% at six months, 96.0% at one year, and 90.6% at 2 years during a median follow-up of 12 months (range, 2-37). The log-rank test indicated no difference in the distribution of LC for any clinical or treatment variable. PFS was 86.7% at 6 months, 66.6% at 1 year, and 58.5% at 2 years. OS was 81% at 6 months, 63.6% at one year, and 50.7% at 2 years. On the log-rank test, clinical parameters such as control status of primary cancer, presence of extracranial metastases, RTOG-RPA class, GPA group, and ds-GPA group were significantly associated with PFS and OS. Patients presented with grade 1 (19.0%), grade 2 (3.5%) and grade 3 (5.2%) side effects. Radiation necrosis was not observed in any patients. Our current results suggest that frameless hfGKRS for unresected, large METs is a rational alternative in selected patients with promising results.

Outcome evaluation of patients treated with fractionated Gamma Knife radiosurgery for large (> 3 cm) brain metastases: a dose-escalation study

OBJECTIVE

Fractionated Gamma Knife radiosurgery (GKS) represents a feasible option for patients with large brain metastases (BM). However, the dose-fractionation scheme balanced between local control and radiation-induced toxicity remains unclear. Therefore, the authors conducted a dose-escalation study using fractionated GKS as the primary treatment for large (> 3 cm) BM.

METHODS

The exclusion criteria were more than 3 lesions, evidence of leptomeningeal disease, metastatic melanoma, poor general condition, and previously treated lesions. Patients were randomized to receive 24, 27, or 30 Gy in 3 fractions (8, 9, or 10 Gy per fraction, respectively). The primary endpoint was the development of radiation necrosis assessed by a neuroradiologist blinded to the study. The secondary endpoints included the local progression-free survival (PFS) rate, change in tumor volume, development of distant intracranial progression, and overall survival.

RESULTS

Between September 2016 and April 2018, 60 patients were eligible for the study, with 46 patients (15, 17, and 14 patients in the 8-, 9-, and 10-Gy groups, respectively) available for analysis. The median follow-up duration was 9.6 months (range 2.5-25.1 months). The 6-month estimated cumulative incidence of radiation necrosis was 0% in the 8-Gy group, 13% (95% confidence interval [CI] 0%-29%) in the 9-Gy group, and 37% (95% CI 1%-58%) in the 10-Gy group. Being in the 10-Gy group was a significant risk factor for the development of radiation necrosis (p = 0.047; hazard ratio [HR] 7.2, 95% CI 1.1-51.4). The 12-month local PFS rates were 65%, 80%, and 75% in the 8-, 9-, and 10-Gy groups, respectively. Being in the 8-Gy group was a risk factor for local treatment failure (p = 0.037; HR 2.5, 95% CI 1.1-29.6). The mean volume change from baseline was a 47.5% decrease in this cohort. Distant intracranial progression and overall survival did not differ among the 3 groups.

CONCLUSIONS

In this dose-escalation study, 27 Gy in 3 fractions appeared to be a relevant regimen of fractionated GKS for large BM because 30 Gy in 3 fractions resulted in unacceptable toxicities and 24 Gy in 3 fractions was associated with local treatment failure.

Volumetric changes of intracranial metastases during the course of fractionated stereotactic radiosurgery and significance of adaptive planning

OBJECTIVE

Fractionated Gamma Knife surgery (FGKS) has recently been used to treat large brain metastases. However, little is known about specific volume changes of lesions during the course of treatment. The authors investigated short-term volume changes of metastatic lesions during FGKS.

METHODS

The authors analyzed 33 patients with 40 lesions who underwent FGKS for intracranial metastases of non-small-cell lung cancer (NSCLC; 25 patients with 32 lesions) and breast cancer (8 patients with 8 lesions). FGKS was performed in 3-5 fractions. Baseline MRI was performed before the first fraction. MRI was repeated after 1 or 2 fractions. Adaptive planning was executed based on new images. The median prescription dose was 8 Gy (range 6-10 Gy) with a 50% isodose line.

RESULTS

On follow-up MRI, 18 of 40 lesions (45.0%) showed decreased tumor volumes (TVs). A significant difference was observed between baseline (median 15.8 cm3) and follow-up (median 14.2 cm3) volumes (p < 0.001). A conformity index was significantly decreased when it was assumed that adaptive planning was not implemented, from baseline (mean 0.96) to follow-up (mean 0.90, p < 0.001). The average reduction rate was 1.5% per day. The median follow-up duration was 29.5 weeks (range 9-94 weeks). During the follow-up period, local recurrence occurred in 5 lesions.

CONCLUSIONS

The TV showed changes with a high dose of radiation during the course of FGKS. Volumetric change caused a significant difference in the clinical parameters. It is expected that adaptive planning would be helpful in the case of radiosensitive tumors such as NSCLCs or breast cancer to ensure an adequate dose to the target area and reduce unnecessary exposure of normal tissue to radiation.

Single-fraction radiosurgery versus fractionated stereotactic radiotherapy in patients with brain metastases: a comparative study

To compare the local control and brain radionecrosis in patients with brain metastasis primarily treated by single-fraction radiosurgery (SRS) or hypofractionated stereotactic radiotherapy (HFSRT). Between January 2012 and December 2017, 179 patients with only 1-3 brain metastases (total: 287) primarily treated by SRS (14 Gy) or HFSRT (23.1 Gy in 3 fractions of 7.7 Gy, every other day) were retrospectively analyzed in a single center. Follow-up imaging data were available in 152 patients with 246 lesions. The corresponding Biological Effective Dose (BED) were 33.6 Gy and 40.9 Gy respectively for SRS and HFSRT group, assuming an α/β of 10 Gy. Local control (LC) and risk of radionecrosis (RN) were calculated by the Kaplan-Meier method. The actuarial local control rates at 6 and 12 months were 94% and 88.1% in SRS group, and 87.6% and 78.4%, in HFSRT group (p = 0.06), respectively. Only the total volume of edema was associated with worse LC (p = 0.01, HR 1.02, 95% CI [1.004-1.03]) in multivariate analysis. Brain radionecrosis occurred in 1 lesion in SRS group and 9 in HFSRT group. Median time to necrosis was 5.5 months (range 1-9). Only the volume of GTV was associated with RN (p = 0.02, HR 1.09, 95% CI [1.01-1.18]) in multivariate analysis. Multi-fraction SRT dose of 23.31 Gy in 3 fractions has similar efficacy to single-fraction SRT dose of 14 Gy in patients with brain metastases. A slightly higher occurrence of radionecrosis appeared in HFSRT group.

Retrospective analysis of hypofractionated stereotactic radiotherapy for tumors larger than 2 cm

Stereotactic radiosurgery for large brain metastases (BM) not amenable to surgical resection is associated with limited local control and neurotoxicity, while hypofractionated stereotactic radiotherapy (HFSRT) has emerged as a promising option. We retrospectively evaluated 61 patients with BM larger than 2 cm in the maximum diameter, who were treated with HFSRT (mainly 35 Gy/5 fractions) in our center between 2006–2016, focusing on the effect of BM size on outcomes. Eligible patients were divided according to the maximum BM diameter (group A [23 patients]: ≥3 cm, group B [22 patients]: <3 cm) to assess the relationship between tumor size and prognosis or safety. The primary outcome was the local control rate (LCR), and secondary outcomes were the response rate (RR), brain progression-free survival (BPFS), median survival time (MST), and radionecrosis (RN). Univariate and multivariate analyses for LCR were conducted using Cox’s proportional hazards model. In the 45 eligible patients (58 lesions) enrolled in this study, the RR was 86.4% with an overall LCR of 64.7% at 12 months (67.1% for group A and 61.5% for group B [p = 0.45]). The median BPFS and MST were 11.6 and 14.2 months, respectively. Univariate analyses revealed that female patients and gynecological cancer patients had poorer LCR, but they were not significantly independent prognostic factors (p = 0.06, 0.09, respectively). Two patients (4.4%) experienced RN that was detected more than 4 years after HFSRT. We conclude that HFSRT is safe for large BM but further studies are needed to determine optimal doses and fractions.

Two-staged stereotactic radiosurgery for the treatment of large brain metastases: Single institution experience and review of literature

Introduction: Two-staged stereotactic radiosurgery (SRS) has been shown as an effective treatment for brain metastases that are too large for single fraction SRS. Methods: Patients with large brain metastases (>4 cm³) treated with two-staged SRS from January 2017 to December 2019 at our institution were retrospectively identified. Results: There were 23 brain metastases treated. The normal brain volume receiving equivalent 12Gy-in-single-fraction was defined as V_12E. The V_12E for original single-fraction GKS plan (mean of 41.4 cm³, range 5.6-146.1 cm³) was significantly higher compared to that of the second stage (mean of 23.7 cm³, range 2.8-92.7 cm³). The median tumor volume measured at the second stage (4.30 cm³) was reduced by an average of 52.2% compared to the first stage (9.58 cm³). Three patients (27.3%) showed local tumor progression in 4 tumors (20%). The median time to progression was 152 days. Conclusions: Two-staged SRS is an effective treatment technique for large brain metastasis that results in significant reduction of tumor volume at the second stage SRS. Optimal treatment dose has not yet been defined.

[Stereotactic body radiotherapy: Passing fad or revolution?]

Stereotactic body radiotherapy (SBRT) is a young technology that can deliver a high dose of radiation to the target, utilizing either a single dose or a small number of fractions with a high degree of precision within the body. Various technical solutions co-exist nowadays, with particular features, possibilities and limitations. Health care authorities have currently validated SBRT in a very limited number of locations, but many indications are still under investigation. It is therefore challenging to accurately appreciate the SBRT therapeutic index, its place and its role within the anticancer therapeutic arsenal. The aim of the present review is to provide SBRT definitions, current indications, and summarize the future ways of research. There are three validated indications for SBRT: un-resecable T1-T2 non small cell lung cancer, <3 slow-growing pulmonary metastases secondary to a stabilized primary, and the tumours located close to the medulla. In other situations, the benefit of SBRT is still to be demonstrated. One of the most promising way of research is the ablative treatment of oligo metastatic cancers, with recent studies suggesting a survival benefit. Furthermore, the most recent data suggest that SBRT is safe. Finally, the SBRT combined with immune therapies is promising, since it could theoretically trigger the adaptative anticancer response.

Stereotactic Radiosurgery in the Management of Limited (1-4) Brain Metasteses: Systematic Review and International Stereotactic Radiosurgery Society Practice Guideline

BACKGROUND

Guidelines regarding stereotactic radiosurgery (SRS) for brain metastases are missing recently published evidence.

OBJECTIVE

To conduct a systematic review and provide an objective summary of publications regarding SRS in managing patients with 1 to 4 brain metastases.

METHODS

Using Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, a systematic review was conducted using PubMed and Medline up to November 2016. A separate search was conducted for SRS for larger brain metastases.

RESULTS

Twenty-seven prospective studies, critical reviews, meta-analyses, and published consensus guidelines were reviewed. Four key points came from these studies. First, there is no detriment to survival by withholding whole brain radiation (WBRT) in the upfront management of brain metastases with SRS. Second, while SRS on its own provides a high rate of local control (LC), WBRT may provide further increase in LC. Next, WBRT does provide distant brain control with less need for salvage therapy. Finally, the addition of WBRT does affect neurocognitive function and quality of life more than SRS alone. For larger brain metastases, surgical resection should be considered, especially when factoring lower LC with single-session radiosurgery. There is emerging data showing good LC and/or decreased toxicity with multisession radiosurgery.

CONCLUSION

A number of well-conducted prospective and meta-analyses studies demonstrate good LC, without compromising survival, using SRS alone for patients with a limited number of brain metastases. Some also demonstrated less impact on neurocognitive function with SRS alone. Practice guidelines were developed using these data with International Stereotactic Radiosurgery Society consensus.

Single-fraction versus hypofractionated stereotactic radiosurgery for medium-sized brain metastases of 2.5 to 3 cm

PURPOSE

Given recently suggested utility of hypofractionated stereotactic radiosurgery (SRS) in treating large brain metastases (BMs) > 3 cm, we sought to prospectively control tumor size variable to investigate the efficacy and safety of hypofractionated SRS for medium-sized BMs (2.5 to 3 cm) compared with single-fraction SRS.

METHODS

Between 2011 and 2015, a total of 100 patients with newly diagnosed BMs (n = 105) of 2.5 to 3 cm had been treated with either single-fraction (n = 67; median dose 20 Gy) or hypofractionated SRS (n = 38; median cumulative dose 35 Gy in 5 daily fractions). No patients received any prior or upfront whole brain radiotherapy. In each patient, treatment outcome was measured by local tumor control (LTC), overall and progression-free survival (OS and PFS), and the occurrence of radiation necrosis (RN).

RESULTS

With a median follow-up of 14 months, significant differences were observed between the single-fraction versus hypofractionated SRS groups in the incidence of RN (29.9% vs. 5.3%, P < 0.001) and LTC (1-year LTC rates 66.6% vs. 92.4%, P = 0.028). There were no differences in PFS (median 6 months vs. 6 months, P = 0.381) and OS (median 13 months vs. 18 months, P = 0.239). Treatment-related adverse events ( ≥ grade 2 toxicity by CTCAE ver. 4.0) occurred more frequently in single-fraction group, although the difference did not reach statistical significance (56.3% vs. 36.1%, P = 0.084).

CONCLUSIONS

Our results suggest a better safety and efficacy profile of hypofractionated SRS for medium-sized BMs compared with single-fraction SRS. Further prospective studies are needed to confirm these results.

Comparison of treatment results between 3- and 2-stage Gamma Knife radiosurgery for large brain metastases: a retrospective multi-institutional study

OBJECTIVE

In order to obtain better local tumor control for large (i.e., > 3 cm in diameter or > 10 cm3 in volume) brain metastases (BMs), 3-stage and 2-stage Gamma Knife surgery (GKS) procedures, rather than a palliative dose of stereotactic radiosurgery, have been proposed. Here, authors conducted a retrospective multi-institutional study to compare treatment results between 3-stage and 2-stage GKS for large BMs.

METHODS

This retrospective multi-institutional study involved 335 patients from 19 Gamma Knife facilities in Japan. Major inclusion criteria were 1) newly diagnosed BMs, 2) largest tumor volume of 10.0-33.5 cm3, 3) cumulative intracranial tumor volume ≤ 50 cm3, 4) no leptomeningeal dissemination, 5) no more than 10 tumors, and 6) Karnofsky Performance Status 70% or better. Prescription doses were restricted to between 9.0 and 11.0 Gy in 3-stage GKS and between 11.8 and 14.2 Gy in 2-stage GKS. The total treatment interval had to be within 6 weeks, with at least 12 days between procedures. There were 114 cases in the 3-stage group and 221 in the 2-stage group. Because of the disproportion in patient numbers and the pre-GKS clinical factors between these two GKS groups, a case-matched study was performed using the propensity score matching method. Ultimately, 212 patients (106 from each group) were selected for the case-matched study. Overall survival, tumor progression, neurological death, and radiation-related adverse events were analyzed.

RESULTS

In the case-matched cohort, post-GKS median survival time tended to be longer in the 3-stage group (15.9 months) than in the 2-stage group (11.7 months), but the difference was not statistically significant (p = 0.65). The cumulative incidences of tumor progression (21.6% vs 16.7% at 1 year, p = 0.31), neurological death (5.1% vs 6.0% at 1 year, p = 0.58), or serious radiation-related adverse events (3.0% vs 4.0% at 1 year, p = 0.49) did not differ significantly.

CONCLUSIONS

This retrospective multi-institutional study showed no differences between 3-stage and 2-stage GKS in terms of overall survival, tumor progression, neurological death, and radiation-related adverse events. Both 3-stage and 2-stage GKS performed according to the aforementioned protocols are good treatment options in selected patients with large BMs.

Intraoperative brachytherapy for resected brain metastases

Brain metastases are the most common intracranial malignancies in adults. Surgical resection is the preferred treatment approach when a pathological diagnosis is required, for symptomatic patients who are refractory to steroids, and to decompress lesions causing mass effect. Radiotherapy is administered to improve local control rates after surgical resection. After a brief review of the literature describing the treatment of brain metastases using whole-brain radiotherapy, postoperative stereotactic radiosurgery, preoperative radiosurgery, and brachytherapy, we compare patient-related, technical, practical, and radiobiological considerations of each technique. Finally, we focus our discussion on intraoperative brachytherapy, with an emphasis on the technical aspects, benefits, efficacy, and outcomes of studies utilizing permanent Cs-131 implants.

Velocity-based Adaptive Registration and Fusion for Fractionated Stereotactic Radiosurgery Using the Small Animal Radiation Research Platform

PURPOSE

To implement Velocity-based image fusion and adaptive deformable registration to enable treatment planning for preclinical murine models of fractionated stereotactic radiosurgery (fSRS) using the small animal radiation research platform (SARRP).

METHODS AND MATERIALS

C57BL6 mice underwent 3 unique cone beam computed tomography (CBCT) scans: 2 in the prone position and a third supine. A single T1-weighted post-contrast magnetic resonance imaging (MRI) series of a murine metastatic brain tumor model was selected for MRI-to-CBCT registration and gross tumor volume (GTV) identification. Two arms were compared: Arm 1, where we performed 3 individual MRI-to-CBCT fusions using rigid registration, contouring GTVs on each, and Arm 2, where the authors performed MRI-to-CBCT fusion and contoured GTV on the first CBCT followed by Velocity-based adaptive registration. The first CBCT and associated GTV were exported from MuriPlan (Xstrahl Life Sciences) into Velocity (Varian Medical Systems, Inc, Palo Alto, CA). In Arm 1, the second and third CBCTs were exported similarly along with associated GTVs (Arm 1), while in Arm 2, the first (prone) CBCT was fused separately to the second (prone) and third (supine) CBCTs, performing deformable registrations on initial CBCTs and applying resulting matrices to the contoured GTV. Resulting GTVs were compared between Arms 1 and 2.

RESULTS

Comparing GTV overlays using repeated MRI fusion and GTV delineation (Arm 1) versus those of Velocity-based CBCT and GTV adaptive fusion (Arm 2), mean deviations ± standard deviation in the axial, sagittal, and coronal planes were 0.46 ± 0.16, 0.46 ± 0.22, and 0.37 ± 0.22 mm for prone-to-prone and 0.52 ± 0.27, 0.52 ± 0.36, and 0.68 ± 0.31 mm for prone-to-supine adaptive fusions, respectively.

CONCLUSIONS

Velocity-based adaptive fusion of CBCTs and contoured volumes allows for efficient fSRS planning using a single MRI-to-CBCT fusion. This technique is immediately implementable on current SARRP systems, facilitating advanced preclinical treatment paradigms using existing clinical treatment planning software.

Single versus Multifraction Stereotactic Radiosurgery for Large Brain Metastases: An International Meta-analysis of 24 Trials

PURPOSE

Multifraction (MF) stereotactic radiosurgery (SRS) purportedly reduces radionecrosis risk over single-fraction (SF) SRS in the treatment of large brain metastases. The purpose of the current work is to compare local control (LC) and radionecrosis rates of SF-SRS and MF-SRS in the definitive (SF-SRS_D and MF-SRS_D) and postoperative (SF-SRS_P and MF-SRS_P) settings.

METHODS AND MATERIALS

Population, Intervention, Control, Outcomes, Study Design/Preferred Reporting Items for Systematic Reviews and Meta-analyses and Meta-analysis of Observational Studies in Epidemiology guidelines were used to select articles in which patients had "large" brain metastases (Group A: 4-14 cm³, or about 2-3 cm in diameter; Group B: >14 cm³, or about >3 cm in diameter); 1-year LC and/or rates of radionecrosis were reported; radiosurgery was administered definitively or postoperatively. Random effects meta-analyses using fractionation scheme and size as covariates were conducted. Meta-regression and Wald-type tests were used to determine the effect of increasing tumor size and fractionation on the summary estimate, where the null hypothesis was rejected for P < .05.

RESULTS

Twenty-four studies were included, published between 2008 and 2017, with 1887 brain metastases. LC random effects estimate at 1 year was 77.6% for Group A/SF-SRS_D and 92.9% for Group A/MF-SRS_D (P = .18). LC random effects estimate at 1 year was 77.1% for Group B/SF-SRS_D and 79.2% for Group B/MF-SRS_D (P = .76). LC random effects estimate at 1 year was 62.4% for Group B/SF-SRS_P and 85.7% for Group B/MF-SRS_P (P = .13). Radionecrosis incidence random effects estimate was 23.1% for Group A/SF-SRS_D and 7.3% for Group A/MF-SRS_D (P = .003). Radionecrosis incidence random effects estimate was 11.7% for Group B/SF-SRS_D and 6.5% for Group B/MF-SRS_D (P = .29). Radionecrosis incidence random effects estimate was 7.3% for Group B/SF-SRS_P and 7.5% for Group B/MF-SRS_P (P = .85). Metaregression assessing 1-year LC and radionecrosis as a continuous function of increasing tumor volume was not statistically significant.

CONCLUSIONS

Treatment for large brain metastases with MF-SRS regimens may offer a relative reduction of radionecrosis while maintaining or improving relative rates of 1-year LC compared with SF-SRS. These findings are hypothesis-generating and require validation by ongoing and planned prospective clinical trials.

Diagnosis and Management of Radiation Necrosis in Patients With Brain Metastases

The use of radiotherapy, either in the form of stereotactic radiosurgery (SRS) or whole-brain radiotherapy (WBRT), remains the cornerstone for the treatment of brain metastases (BM). As the survival of patients with BM is being prolonged, due to improved systemic therapy (i.e., for better extra-cranial control) and increased use of SRS (i.e., for improved intra-cranial control), patients are clinically manifesting late effects of radiotherapy. One of these late effects is radiation necrosis (RN). Unfortunately, symptomatic RN is notoriously hard to diagnose and manage. The features of RN overlap considerably with tumor recurrence, and misdiagnosing RN as tumor recurrence may lead to deleterious treatment which may cause detrimental effects to the patient. In this review, we will explore the pathophysiology of RN, risk factors for its development, and the strategies to evaluate and manage RN.

Quantitative analysis in peritumoral volumes of brain metastases treated with stereotactic radiotherapy

PURPOSE

The purpose of this study was to verify changes in diffusion tensor imaging (DTI) factors in patients with brain metastases treated with stereotactic radiotherapy (SRT). We also investigated the impact of SRT on peritumoral volumes though the use of DTI.

METHODS

A total of 28 patients with brain metastases who had undergone SRT between March 2014 and December 2015 were enrolled. Magnetic resonance imaging with DTI factors, such as fractional anisotropy (FA) and apparent diffusion tensor (ADC) value, was performed 1 day before the procedure and 3 months after the procedure. DTI data from tumor lesions, edema volumes, and the volumes that received 12Gy were measured.

RESULTS

Tumor volume (P=0.001) and ADC values in the volumes that received 12Gy (P=0.018) and the edema volumes (P=0.003) significantly decreased after the procedure. Decreases in tumor volume were only correlated with decreases in edema volumes (P<0.001). Decreases in edema volumes were correlated with increases in FA values and decreases in ADC values of the volumes that received 12Gy [P=0.019 (FA)/0.002 (ADC)] and the edema volumes [P=0.011 (FA)/0.002 (ADC)].

CONCLUSIONS

It was possible to quantify changes in peritumoral volumes in patients with brain metastases after SRT by using DTI. ADC values of peritumoral volumes decreased significantly after SRT. Therefore, it was confirmed through DTI that performing SRT on tumor lesions has a positive effect on the structure and function of peritumoral volumes.

Improved effectiveness of stereotactic radiosurgery in large brain metastases by individualized isotoxic dose prescription: an in silico study

INTRODUCTION

In large brain metastases (BM) with a diameter of more than 2 cm there is an increased risk of radionecrosis (RN) with standard stereotactic radiosurgery (SRS) dose prescription, while the normal tissue constraint is exceeded. The tumor control probability (TCP) with a single dose of 15 Gy is only 42%. This in silico study tests the hypothesis that isotoxic dose prescription (IDP) can increase the therapeutic ratio (TCP/Risk of RN) of SRS in large BM.

MATERIALS AND METHODS

A treatment-planning study with 8 perfectly spherical and 46 clinically realistic gross tumor volumes (GTV) was conducted. The effects of GTV size (0.5-4 cm diameter), set-up margins (0, 1, and 2 mm), and beam arrangements (coplanar vs non-coplanar) on the predicted TCP using IDP were assessed. For single-, three-, and five-fraction IDP dose-volume constraints of V_12Gy = 10 cm³, V_19.2 Gy = 10 cm³, and a V_20Gy = 20 cm³, respectively, were used to maintain a low risk of radionecrosis.

RESULTS

In BM of 4 cm in diameter, the maximum achievable single-fraction IDP dose was 14 Gy compared to 15 Gy for standard SRS dose prescription, with respective TCPs of 32 and 42%. Fractionated SRS with IDP was needed to improve the TCP. For three- and five-fraction IDP, a maximum predicted TCP of 55 and 68% was achieved respectively (non-coplanar beams and a 1 mm GTV-PTV margin).

CONCLUSIONS

Using three-fraction or five-fraction IDP the predicted TCP can be increased safely to 55 and 68%, respectively, in large BM with a diameter of 4 cm with a low risk of RN. Using IDP, the therapeutic ratio of SRS in large BM can be increased compared to current SRS dose prescription.

Impact of 2-staged stereotactic radiosurgery for treatment of brain metastases ≥ 2 cm

OBJECTIVE Stereotactic radiosurgery (SRS) is the primary modality for treating brain metastases. However, effective radiosurgical control of brain metastases ≥ 2 cm in maximum diameter remains challenging and is associated with suboptimal local control (LC) rates of 37%-62% and an increased risk of treatment-related toxicity. To enhance LC while limiting adverse effects (AEs) of radiation in these patients, a dose-dense treatment regimen using 2-staged SRS (2-SSRS) was used. The objective of this study was to evaluate the efficacy and toxicity of this treatment strategy. METHODS Fifty-four patients (with 63 brain metastases ≥ 2 cm) treated with 2-SSRS were evaluated as part of an institutional review board-approved retrospective review. Volumetric measurements at first-stage stereotactic radiosurgery (first SSRS) and second-stage SRS (second SSRS) treatments and on follow-up imaging studies were determined. In addition to patient demographic data and tumor characteristics, the study evaluated 3 primary outcomes: 1) response at first follow-up MRI, 2) time to local progression (TTP), and 3) overall survival (OS) with 2-SSRS. Response was analyzed using methods for binary data, TTP was analyzed using competing-risks methods to account for patients who died without disease progression, and OS was analyzed using conventional time-to-event methods. When needed, analyses accounted for multiple lesions in the same patient. RESULTS Among 54 patients, 46 (85%) had 1 brain metastasis treated with 2-SSRS, 7 patients (13%) had 2 brain metastases concurrently treated with 2-SSRS, and 1 patient underwent 2-SSRS for 3 concurrent brain metastases ≥ 2 cm. The median age was 63 years (range 23-83 years), 23 patients (43%) had non-small cell lung cancer, and 14 patients (26%) had radioresistant tumors (renal or melanoma). The median doses at first and second SSRS were 15 Gy (range 12-18 Gy) and 15 Gy (range 12-15 Gy), respectively. The median duration between stages was 34 days, and median tumor volumes at the first and second SSRS were 10.5 cm³ (range 2.4-31.3 cm³) and 7.0 cm³ (range 1.0-29.7 cm³). Three-month follow-up imaging results were available for 43 lesions; the median volume was 4.0 cm³ (range 0.1-23.1 cm³). The median change in volume compared with baseline was a decrease of 54.9% (range -98.2% to 66.1%; p < 0.001). Overall, 9 lesions (14.3%) demonstrated local progression, with a median of 5.2 months (range 1.3-7.4 months), and 7 (11.1%) demonstrated AEs (6.4% Grade 1 and 2 toxicity; 4.8% Grade 3). The estimated cumulative incidence of local progression at 6 months was 12% ± 4%, corresponding to an LC rate of 88%. Shorter TTP was associated with greater tumor volume at baseline (p = 0.01) and smaller absolute (p = 0.006) and relative (p = 0.05) decreases in tumor volume from baseline to second SSRS. Estimated OS rates at 6 and 12 months were 65% ± 7% and 49% ± 8%, respectively. CONCLUSIONS 2-SSRS is an effective treatment modality that resulted in significant reduction of brain metastases ≥ 2 cm, with excellent 3-month (95%) and 6-month (88%) LC rates and an overall AE rate of 11%. Prospective studies with larger cohorts and longer follow-up are necessary to assess the durability and toxicities of 2-SSRS.

The radiosurgery fractionation quandary: single fraction or hypofractionation?

Stereotactic radiosurgery (SRS), typically administered in a single session, is widely employed to safely, efficiently, and effectively treat small intracranial lesions. However, for large lesions or those in close proximity to critical structures, it can be difficult to obtain an acceptable balance of tumor control while avoiding damage to normal tissue when single-fraction SRS is utilized. Treating a lesion in 2 to 5 fractions of SRS (termed "hypofractionated SRS" [HF-SRS]) potentially provides the ability to treat a lesion with a total dose of radiation that provides both adequate tumor control and acceptable toxicity. Indeed, studies of HF-SRS in large brain metastases, vestibular schwannomas, meningiomas, and gliomas suggest that a superior balance of tumor control and toxicity is observed compared with single-fraction SRS. Nonetheless, a great deal of effort remains to understand radiobiologic mechanisms for HF-SRS driving the dose-volume response relationship for tumors and normal tissues and to utilize this fundamental knowledge and the results of clinic studies to optimize HF-SRS. In particular, the application of HF-SRS in the setting of immunomodulatory cancer therapies offers special challenges and opportunities.

Is Fractionated Gamma Knife Radiosurgery a Safe and Effective Treatment Approach for Large-Volume (>10 cm3) Intracranial Meningiomas?

BACKGROUND

Even with great advances in surgery and improved clinical outcome, morbidity and mortality are still high for large-volume intracranial meningiomas (MNGs). Recently, Gamma Knife radiosurgery (GKS) has proven to be a safe and effective treatment for many patients with intracranial MNGs. However, single-session GKS may increase the risk of radiation-induced toxicity for large MNGs. Recently, fractionated GKS (FGKS) has been performed for an increasing number of patients with surgically high-risk and large intracranial tumors. In this study, we report our results on the efficacy and safety of FGKS for large MNGs.

METHODS

The authors performed a retrospective review of 70 patients who underwent GKS for large-volume (>10 cm³) intracranial MNGs between 2004 and 2015, with a minimum follow-up of 12 months. The authors classified these patients into 2 groups of single-session GKS, FGKS. The patients were followed by clinical examination and serial imaging with magnetic resonance imaging.

RESULTS

In the single-session GKS group (42 patients), the median tumor volume was 15.2 cm³ (range 10.3-48.3 cm³); the median prescription dose was 12 Gy (range 8-14 Gy), and the median follow-up duration was 57.8 months (range 14.5-128.4 months). In the FGKS group (28 patients), the median tumor volume was 21 cm³ (range 10.2-54.7 cm³), and the median prescription was 7.5 Gy in 2 fractions (range 5-8 Gy), 6 Gy in 3 fractions (range 5-6.5 Gy), and 4.5 Gy in 4 fractions. The median follow-up duration for the FGKS group was 50 months (range 12.5-90.6 months). The overall 5-year tumor control rate was 92.9% in the FGKS group and 88.1% in the single-session GKS group. Fourteen (33.3%) symptomatic complications after single-session GKS were noted, including 5 cases of hemiparesis, 4 of seizure, 3 of peritumoral edema, and 2 of hydrocephalus. Two (7.1%) symptomatic complications after FGKS were noted, including 2 cases of hemiparesis. The FGKS group had higher progression-free survival (PFS) rate at 5 years (92.9% vs. 88.1%), but the differences did not reach statistical significance (P = 0.389). The patients in the FGKS group, however, experienced a lower complication rate compared with patients with a single-session GKS group (P = 0.017, hazard ratio, 5.7:1).

CONCLUSION

When the large-volume (>10 cm³) intracranial MNGs are expected to have high morbidity after microsurgery and for patients that have a poor medical status for surgery, FGKS can be considered an alternative with good tumor control and lower complications rates compared with single-session GKS (P = 0.017).

Resection and brain brachytherapy with permanent iodine-125 sources for brain metastasis

OBJECTIVE Stereotactic radiosurgery (SRS) with or without whole-brain radiotherapy can be used to achieve local control (> 90%) for small brain metastases after resection. However, many brain metastases are unsuitable for SRS because of their size or previous treatment, and whole-brain radiotherapy is associated with significant neurocognitive morbidity. The purpose of this study was to investigate the efficacy and toxicity of surgery and iodine-125 (¹²⁵I) brachytherapy for brain metastases. METHODS A total of 95 consecutive patients treated for 105 brain metastases at a single institution between September 1997 and July 2013 were identified for this analysis retrospectively. Each patient underwent MRI followed by craniotomy with resection of metastasis and placement of ¹²⁵I sources as permanent implants. The patients were followed with serial surveillance MRIs. The relationships among local control, overall survival, and necrosis were estimated by using the Kaplan-Meier method and compared with results of log-rank tests and multivariate regression models. RESULTS The median age at surgery was 59 years (range 29.9-81.6 years), 53% of the lesions had been treated previously, and the median preoperative metastasis volume was 13.5 cm³ (range 0.21-76.2 cm³). Gross-total resection was achieved in 81% of the cases. The median number of ¹²⁵I sources implanted per cavity was 28 (range 4-93), and the median activity was 0.73 mCi (range 0.34-1.3 mCi) per source. A total of 476 brain MRIs were analyzed (median MRIs per patient 3; range 0-22). Metastasis size was the strongest predictor of cavity volume and shrinkage (p < 0.0001). Multivariable regression modeling failed to predict the likelihood of local progression or necrosis according to metastasis volume, cavity volume, or the rate of cavity remodeling regardless of source activity or previous SRS. The median clinical follow-up time in living patients was 14.4 months (range 0.02-13.6 years), and crude local control was 90%. Median overall survival extended from 2.1 months in the shortest quartile to 62.3 months in the longest quartile (p < 0.0001). The overall risk of necrosis was 15% and increased significantly for lesions with a history of previous SRS (p < 0.05). CONCLUSIONS Therapeutic options for patients with large or recurrent brain metastases are limited. Data from this study suggest that resection with permanent ¹²⁵I brachytherapy is an effective strategy for achieving local control of brain metastasis. Although metastasis volume significantly influences resection cavity size and remodeling, volumetric parameters do not seem to influence local control or necrosis. With careful patient selection, this treatment regimen is associated with minimal toxicity and can result in long-term survival for some patients. ▪ CLASSIFICATION OF EVIDENCE Type of question: therapeutic; study design: retrospective case series; evidence: Class IV.

Hypofractionated stereotactic radiotherapy for brain metastases from lung cancer : Evaluation of indications and predictors of local control

AIM

To evaluate the efficacy and toxicity of hypofractionated stereotactic radiotherapy (HSRT) for brain metastases (BMs) from lung cancer, and to explore prognostic factors associated with local control (LC) and indication.

PATIENTS AND METHODS

We evaluated patients who were treated with linac-based HSRT for BMs from lung cancer. Lesions treated with stereotactic radiosurgery (SRS) in the same patients during the same periods were analysed and compared with HSRT in terms of LC or toxicity. There were 53 patients with 214 lesions selected for this analysis (HSRT: 76 lesions, SRS: 138 lesions). For HSRT, the median prescribed dose was 35 Gy in 5 fractions.

RESULTS

The 1‑year LC rate was 83.6 % in HSRT; on multivariate analysis, a planning target volume (PTV) of <4 cm(3), biologically effective dose (BED10) of ≥51 Gy, and adenocarcinoma were significantly associated with better LC. Moreover, in PTVs ≥ 4 cm(3), there was a significant difference in LC between BED10 < 51 Gy and ≥ 51 Gy (p = 0.024). On the other hand, in PTVs < 4 cm(3), both HSRT and SRS had good LC with no significant difference (p = 0.195). Radiation necrosis emerged in 5 of 76 lesions (6.6 %) treated with HSRT and 21 of 138 (15.2 %) lesions treated with SRS (p = 0.064).

CONCLUSION

Linac-based HSRT was safe and effective for BMs from lung cancer, and hence might be particularly useful in or near an eloquent area. PTV, BED10, and pathological type were significant prognostic factors. Furthermore, in BMs ≥ 4 cm(3), a dose of BED ≥ 51 Gy should be considered.

Efficacy and Safety of Fractionated Stereotactic Radiosurgery for Large Brain Metastases

Objective

To investigate the efficacy and safety of fractionated stereotactic radiosurgery for large brain metastases (BMs).

Methods

Between June 2011 and December 2013, a total of 38 large BMs >3.0 cm in 37 patients were treated with fractionated Cyberknife radiosurgery. These patients comprised 16 men (43.2%) and 21 women, with a median age of 60 years (range, 38-75 years). BMs originated from the lung (n=19, 51.4%), the gastrointestinal tract (n=10, 27.0%), the breast (n=5, 13.5%), and other tissues (n=3, 8.1%). The median tumor volume was 17.6 cc (range, 9.4-49.6 cc). For Cyberknife treatment, a median peripheral dose of 35 Gy (range, 30-41 Gy) was delivered in 3 to 5 fractions.

Results

With a median follow-up of 10 months (range, 1-37 months), the crude local tumor control (LTC) rate was 86.8% and the estimated LTC rates at 12 and 24 months were 87.0% and 65.2%, respectively. The median overall survival (OS) and progression-free survival (PFS) rates were 16 and 11 months, respectively. The estimated OS and PFS rates at 6, 12, and 18 months were 81.1% and 65.5%, 56.8% and 44.9%, and 40.7% and 25.7%, respectively. Patient performance status and preoperative focal neurologic deficits improved in 20 of 35 (57.1%) and 12 of 17 patients (70.6%), respectively. Radiation necrosis with a toxicity grade of 2 or 3 occurred in 6 lesions (15.8%).

Conclusion

These results suggest a promising role of fractionated stereotactic radiosurgery in treating large BMs in terms of both efficacy and safety.

Stereotactic radiosurgery for large brain metastases

We evaluated patient outcomes following stereotactic radiosurgery (SRS)-treatment of large brain metastasis (⩾3 cm) at our institution. SRS is an established treatment for limited brain metastases. However, large tumors pose a challenge for this approach. For this study, 343 patients with 754 total brain metastases were treated with SRS, of which 93 had large tumors. The tumor size was 3-3.5, 3.5-4, and ⩾4 cm in 29%, 32%, and 39% of these patients. Surgical resection was performed prior to SRS in 68% of patients, and 53% achieved a gross total resection. The local control of large metastases was inferior compared to smaller tumors, with 1 year local control of 68 versus 86%, respectively (p<0.001). Among the patients with large metastases, no correlation between local control and surgical resection (p=0.747), or extent of surgery (gross total versus subtotal resection; p=0.120), was identified. Histology (p=0.939), tumor size (3-4 versus >4 cm; p=0.551), and SRS dose (⩽16 versus >16 Gy; p=0.539) also showed no correlation with local failure. The overall survival at 1, 2, and 5 years was 46%, 29% and 5%, respectively. Prolonged survival was seen in patients with age <65 years (p=0.009), primary treatment compared with salvage (p=0.077), and controlled primary tumors (p=0.022). Radiation necrosis developed in 10 patients (11.8%). For patients with large brain metastases, SRS is well tolerated and can achieve local central nervous system disease control in the majority of patients, and extended survival in some, though the local control rate is suboptimal. Further strategies to improve the outcomes in this subgroup of patients are needed.

A minimally invasive treatment option for large metastatic brain tumors: long-term results of two-session Gamma Knife stereotactic radiosurgery

Background

Large brain metastases (BM) remain a significant cause of morbidity and death for cancer patients despite current advances in multimodality therapies. The goal of the present study was to evaluate the efficacy and limitations of 2-session Gamma Knife stereotactic radiosurgery (SRS) for patients with large BM.

Methods

This is a prospective, open-label and single arm study analyzing 58 consecutive patients who received 2-session SRS for large BM (≥ 10 mL). The median age was 66 years, and the median Karnofsky performance status (KPS) score was 70. SRS was the initial treatment in 51 large tumors (84%) and was used as salvage after failed prior treatments for 10 tumors (16%). The fraction protocol was 20-30 Gy given in 2 fractions with 3–4 weeks between fractions. Overall survival (OS) and neurological death (ND), local tumor control and KPS were analyzed.

Results

The median follow-up time was 9.0 months. One- and 2-year OS rates were 47% and 20%, respectively. The median OS time was 11.8 months (95% CI: 5.5-15.6). The causes of death were intracranial local progression in 5 cases, meningeal carcinomatosis in 3 and progression of the primary lesion in 39. One- and 2-year ND-free survival rates were 91% and 84%, respectively. In 52 of 61 large BM (85%) with sufficient radiological follow-up data, 6- and 12-month local tumor control rates were 85% and 64%, respectively. The mean KPS improved from 70 at the 1st SRS to 82 at the 2nd; the first follow-up mean KPS was 87 (P < 0.001). Symptomatic radiation injury developed and required conservative treatment in 3 patients (5%).

Conclusions

Long-term follow-up showed that two-session Gamma Knife SRS achieved durable tumor control rates as well as acceptable treatment-related morbidity. This treatment method may potentially merit being offered to patients with large BM who are in poor condition or are otherwise ineligible for standard care.

Stereotactic radiosurgery for treatment of brain metastases. A report of the DEGRO Working Group on Stereotactic Radiotherapy

BACKGROUND

This report from the Working Group on Stereotaktische Radiotherapie of the German Society of Radiation Oncology (Deutsche Gesellschaft für Radioonkologie, DEGRO) provides recommendations for the use of stereotactic radiosurgery (SRS) on patients with brain metastases. It considers existing international guidelines and details them where appropriate.

RESULTS AND DISCUSSION

The main recommendations are: Patients with solid tumors except germ cell tumors and small-cell lung cancer with a life expectancy of more than 3 months suffering from a single brain metastasis of less than 3 cm in diameter should be considered for SRS. Especially when metastases are not amenable to surgery, are located in the brain stem, and have no mass effect, SRS should be offered to the patient. For multiple (two to four) metastases--all less than 2.5 cm in diameter--in patients with a life expectancy of more than 3 months, SRS should be used rather than whole-brain radiotherapy (WBRT). Adjuvant WBRT after SRS for both single and multiple (two to four) metastases increases local control and reduces the frequency of distant brain metastases, but does not prolong survival when compared with SRS and salvage treatment. As WBRT carries the risk of inducing neurocognitive damage, it seems reasonable to withhold WBRT for as long as possible.

CONCLUSION

A single (marginal) dose of 20 Gy is a reasonable choice that balances the effect on the treated lesion (local control, partial remission) against the risk of late side effects (radionecrosis). Higher doses (22-25 Gy) may be used for smaller (< 1 cm) lesions, while a dose reduction to 18 Gy may be necessary for lesions greater than 2.5-3 cm. As the infiltration zone of the brain metastases is usually small, the GTV-CTV (gross tumor volume-clinical target volume) margin should be in the range of 0-1 mm. The CTV-PTV (planning target volume) margin depends on the treatment technique and should lie in the range of 0-2 mm. Distant brain recurrences fulfilling the aforementioned criteria can be treated with SRS irrespective of previous WBRT.

Radiotherapy and the tumor stroma: the importance of dose and fractionation

Ionizing radiation is a non-specific but highly effective way to kill malignant cells. However, tumor recurrence sustained by a minor fraction of surviving tumor cells is a commonplace phenomenon caused by the activation of both cancer cell intrinsic resistance mechanisms, and also extrinsic intermediaries of therapy resistance, represented by non-malignant cells and structural components of the tumor stroma. The improved accuracy offered by advanced radiotherapy (RT)-technology permits reduced volume of healthy tissue in the irradiated field, and has been triggering an increase in the prescription of high-dose oligo-fractionated regimens in the clinics. Given the remarkable clinical success of high-dose RT and the current therapeutic shift occurring in the field, in this review we revise the existing knowledge on the effects that different radiation regimens exert on the different compartments of the tumor microenvironment, and highlight the importance of anti-tumor immunity and other tumor cell extrinsic mechanisms influencing therapeutic responses to high-dose radiation.

Fractionated stereotactic radiotherapy using CyberKnife for the treatment of large brain metastases: a dose escalation study

AIMS

To evaluate the toxicity and efficacy of fractionated stereotactic radiotherapy (FSRT) with doses of 18-30 Gy in three fractions and 21-35 Gy in five fractions against large brain metastases.

MATERIALS AND METHODS

Between 2005 and 2012, 61 large brain metastases (≥ 2.5 cm in maximum diameter) of a total of 102 in 54 patients were treated with FSRT as a first-line therapy. Neurological symptoms were observed in 47 of the 54 patients before FSRT. Three fractions were applied to tumours with a maximum diameter ≥ 2.5 cm and <4 cm, and five fractions were used for brain metastases ≥ 4 cm. After ensuring that the toxicities were acceptable (≤ grade 2), doses were escalated in steps. Doses to the large brain metastases were as follows: level I, 18-22 Gy/three fractions or 21-25 Gy/five fractions; level II, 22-27 Gy/three fractions or 25-31 Gy/five fractions; level III, 27-30 Gy/three fractions or 31-35 Gy/five fractions. Level III was the target dose level.

RESULTS

Overall survival rates were 52 and 31% at 6 and 12 months, respectively. Local tumour control rates of the 102 total brain metastases were 84 and 78% at 6 and 12 months, respectively. Local tumour control rates of the 61 large brain metastases were 77 and 69% at 6 and 12 months, respectively. Grade 3 or higher toxicities were not observed.

CONCLUSIONS

The highest dose levels of 27-30 Gy/three fractions and 31-35 Gy/five fractions seemed to be tolerable and effective in controlling large brain metastases. These doses can be used in future studies on FSRT for large brain metastases.

Stereotactic radiosurgery for brain metastases from hepatocellular carcinoma

The purpose of this study is to investigate the possible role of stereotactic radiosurgery (SRS) in the management of patients with brain metastases from hepatocellular carcinoma (HCC). Thirty-two consecutive patients with 80 brain metastases from HCC were treated with SRS. Twenty-eight (87.5 %) patients were male, and the mean age of the patients was 54 ± 12 years (range 22-73). Twenty-seven (84.4 %) patients were classified as RTOG RPA Class 2. The mean tumor volume was 6.14 ± 11.3 cm(3) (range 0.01-67.3). The mean marginal dose prescribed was 20.1 ± 3.6 Gy (range 10.0-25.0). The median overall survival time after SRS was 11.3 ± 5.8 weeks (95 % CI 0-22.7). A greater total volume of brain metastases (>14 cm(3)) was the only independent prognostic factor (HR = 2.419; 95 % CI 1.040-5.624; p = 0.040). The actuarial control rate of brain metastases was 51.3 % at 4 months after SRS. The prescribed marginal dose (>18 Gy) was significantly related with the actuarial tumor control (HR = 0.254; 95 % CI 0.089-0.725; p = 0.010). The prognosis of patients with brain metastases from HCC is dismal even with the modern technology of radiosurgery. The marginal dose prescribed should be reevaluated to improve upon the current poor local control rates.