Gamma knife radiosurgery for ten or more brain metastases

Economic evaluation of stereotactic radiotherapy and stereotactic radiosurgery technologies in the treatment of cancers: a systematic review

INTRODUCTION

This systematic review study investigated the cost-effectiveness of stereotactic radiotherapy (SRT) and stereotactic radiosurgery (SRS) for treatment of various types of cancers.

METHODS

PubMed, Scopus, and Web of Science were searched from 30 December 1990 to 1 January 2023. The entered studies were screened in accordance with the inclusion criteria. The inclusion criteria encompassed all types of economic evaluation studies that investigated SRT/SRS technologies in the treatment of various cancers.

RESULTS

A total of 47 articles were included in the review. The findings suggest that the use of Linear accelerator technology for the treatment of lung cancer (8 out of 12 studies) and prostate cancer (4 out of 5 studies) was a cost-effective strategy. Linear accelerator was found to be cost-effective in the treatment of liver metastases and liver cancer (2 out of 5 studies). All of the included studies that used Gamma Knife technology in brain metastases reported Gamma-Knife was a cost-effective treatment. Furthermore, in the treatment of prostate and liver cancer, proton therapy was identified as a cost-effective option than other treatments.

CONCLUSIONS

This study confirms that SRT/SRS is a cost-effective procedure for the treatment of various types of cancers. Therefore, it is recommended to use SRT/SRS technology for optimal use of resources.

Overall survival following stereotactic radiosurgery for ten or more brain metastases: a systematic review and meta-analysis

BACKGROUND

Brain metastases are the most common intracranial tumours. Variation exists in the use of stereotactic radiosurgery for patients with 10 or more brain metastases. Concerns include an increasing number of brain metastases being associated with poor survival, the lack of prospective, randomised data and an increased risk of toxicity.

METHODS

We performed a systematic review and meta-analysis to assess overall survival of patients with ten or more brain metastases treated with stereotactic radiosurgery as primary therapy. The search strings were applied to MEDLINE, Embase and the Cochrane Central Register of Controlled Trials (CENTRAL). Log hazard ratios and standard errors were estimated from each included study. A random-effects meta-analysis using the DerSimonian and Laird method was applied using the derived log hazard ratios and standard errors on studies which included a control group.

RESULTS

15 studies were included for systematic review. 12 studies were used for pooled analysis for overall survival at set time points, with a predicted 12 month survival of 20-40%. The random-effects meta-analysis in five studies of overall survival comparing ten or greater metastases against control showed statistically worse overall survival in the 10 + metastases group (1.10, 95% confidence interval 1.03-1.18, p-value = < 0.01, I2 = 6%). A funnel plot showed no evidence of bias. There was insufficient information for a meta-analysis of toxicity.

DISCUSSION

Overall survival outcomes of patients with ten or more brain metastases treated with SRS is acceptable and should not be a deterrent for its use. There is a lack of prospective data and insufficient real-world data to draw conclusions on toxicity.

PROSPERO ID

CRD42021246115.

Single-Session Gamma Knife Radiosurgery for Patients With 20 or More Brain Metastases

BACKGROUND

Stereotactic radiosurgery (SRS) is a widely accepted treatment modality for brain metastases. The role of SRS in patients with higher numbers of metastases remains controversial.

OBJECTIVES

To define outcomes in patients with ≥20 brain metastases managed using single-session SRS.

METHODS

This single-institution retrospective cohort study studied 75 patients (26 non-small-cell lung cancer, 21 small-cell lung cancer, 14 breast cancer, and 14 melanoma) undergoing single-session SRS. The median number of tumors per patient was 24, and the median cumulative tumor volume was 3.70 cc. The median margin dose prescribed to each individual tumor was 16 Gy. The median integral cranial dose was 5492 mJ. The median beam on time was 160 minutes. Univariate and multivariate analyses were performed with significance set at P < .05.

RESULTS

The median overall survival after SRS was 8.8 months (patients with non-small-cell lung cancer), 4.6 months (patients with small-cell lung cancer), 11.3 months (patients with breast cancer), and 4.1 months (patients with melanoma). Primary cancer type, number of brain metastases, and concurrent immunotherapy were significant factors in predicting survival. Local tumor control rate per patient was 97.3% and 94.6% at 6 and 12 months after SRS, respectively. Thirty-six patients underwent additional SRS for new tumor development with a median time after SRS of 5 months. Three patients experienced adverse radiation events.

CONCLUSION

Single-session SRS is a well-tolerated palliative treatment option even in patients with ≥20 brain metastases, achieving local control rate >90% with low risks of neurotoxicity while continuing concurrent systemic oncological care.

Metastatic Lesions of the Brain and Spine

Brain and spinal metastases are common in cancer patients and are associated with significant morbidity and mortality. Continued advancement in the systemic care of cancer has increased the life expectancy of patients, and consequently, the incidence of brain and spine metastasis has increased. There has been an increase in the understanding of oncogenic mutations, and research has also demonstrated spatial and temporal mutations in patients that may drive overall treatment resistance and failure. Combinatory treatments with radiation, surgery, and newer systemic therapies have continued to increase the life expectancy of patients with brain and spine metastases. Given the overall complexity of brain and spine metastases, this chapter aims to give a comprehensive overview and cover important topics concerning brain and spine metastases. This will include the molecular, genetic, radiographic, surgical, and non-surgical treatments of brain and spinal metastases.

Radiosurgery for Five to Fifteen Brain Metastases: A Single Centre Experience and a Review of the Literature

Purpose

Stereotactic radiosurgery (SRS) is now mainstream for patients with 1-4 brain metastases however the management of patients with 5 or more brain metastases remains controversial. Our aim was to evaluate the clinical outcomes of patients with 5 or more brain metastases and to compare with published series as a benchmarking exercise.

Methods

Patients with 5 or more brain metastases treated with a single isocentre dynamic conformal arc technique on a radiosurgery linac were identified from the institutional database. Endpoints were local control, distant brain failure, leptomeningeal disease and overall survival. Dosimetric data were extracted from the radiosurgery plans. Series reporting outcomes following SRS for multiple brain metastases were identified by a literature search.

Results

36 patients, of whom 35 could be evaluated, received SRS for 5 or more brain metastases between February 2015 and October 2021. 25 patients had 5-9 brain metastases (group 1) and 10 patients had 10-15 brain metastases (group 2). The mean number of brain metastases in group 1 was 6.3 (5-9) and 12.3 (10-15) in group 2. The median cumulative irradiated volume was 4.6 cm³ (1.25-11.01) in group 1 and 7.2 cm³ (2.6-11.1) in group 2. Median follow-up was 12 months. At last follow-up, local control rates per BM were 100% and 99.8% as compared with a median of 87% at 1 year in published series. Distant brain failure was 36% and 50% at a median interval of 5.2 months and 7.4 months after SRS in groups 1 and 2 respectively and brain metastasis velocity at 1 year was similar in both groups (9.7 and 11). 8/25 patients received further SRS and 7/35 patients received whole brain radiotherapy. Median overall survival was 10 months in group 1 and 15.7 months in group 2, which compares well with the 7.5 months derived from the literature. There was one neurological death in group 2, leptomeningeal disease was rare (2/35) and there were no cases of radionecrosis.

Conclusion

With careful patient selection, overall survival following SRS for multiple brain metastases is determined by the course of the extracranial disease. SRS is an efficacious and safe modality that can achieve intracranial disease control and should be offered to patients with 5 or more brain metastases and a constellation of good prognostic factors.

Hippocampal Metastasis Rate Based on Non-Small Lung Cancer TNM Stage and Molecular Markers

Hippocampal-avoidance whole-brain radiation therapy (HA-WBRT) is justified because of low hippocampal brain metastases (BM) rate and its prevention of cognitive decline. However, we hypothesize that the risk of developing BM in the hippocampal-avoidance region (HAR) may differ depending on the lung-cancer stage and molecular status. We retrospectively reviewed 123 patients with non-small cell lung cancer (NSCLC) at the initial diagnosis of BM. The number of BMs within the HAR (5 mm expansion) was counted. The cohort was divided into patients with and without BMs in the HAR, and their clinical variables, TNM stage, and epidermal growth factor receptor (EGFR) status were compared. The most influential variable predicting BMs in the HAR was determined using multi-variable logistic regression, classification and regression tree (CART) analyses, and gradient boosting method (GBM). The feasibility of HAR expansion was tested using generalized estimating equation marginal model. Patients with BMs in the HAR were more frequently non-smokers, and more likely to have extra-cranial metastases and EGFR mutations (p<0.05). Multi-variable analysis revealed that extra-cranial metastases were independently associated with the presence of BM in the HAR (odds ratio=8.75, p=0.04). CART analysis and GBM revealed that the existence of extra-cranial metastasis was the most influential variable predicting BM occurrence in the HAR (variable importance: 23% and relative influence: 37.38). The estmated BM incidence of patients without extra-cranial metastases in th extended HAR (7.5-mm and 10-mm expansion) did not differ significantly from that in the conventional HAR. In conclusion, NSCLC patients with extra-cranial metastases were more likely to have BMs in the HAR than those without extra-cranial metastases.

A multidisciplinary management algorithm for brain metastases

The incidence of brain metastases continues to present a management issue despite the advent of improved systemic control and overall survival. While the management of oligometastatic disease (ie, 1-4 brain metastases) with surgery and radiation has become fairly straightforward in the era of radiosurgery, the management of patients with multiple metastatic brain lesions can be challenging. Here we review the available evidence and provide a multidisciplinary management algorithm for brain metastases that incorporates the latest advances in surgery, radiation therapy, and systemic therapy while taking into account the latest in precision medicine-guided therapies. In particular, we argue that whole-brain radiation therapy can likely be omitted in most patients as up-front therapy.

Comparison of dosimetric impact of intra-fractional setup discrepancy between multiple- and single-isocenter approaches in linac-based stereotactic radiotherapy of multiple brain metastases

Introduction

Treatment of multiple brain metastases by linac‐based stereotactic radiotherapy (SRT) can employ either a multiple‐isocenter (MI) or single‐isocenter (SI) approach. The purposes of this study were to evaluate the dosimetric results of MI and SI approaches and compare the impacts of intra‐fractional setup discrepancies on the robustness of respective approaches using isocenter shifts, whether the same magnitude of translational and rotational effects could lead to a significant difference between the two approaches.

Methods

Twenty‐two patients with multiple brain metastases treated by linac‐based SRT were recruited. Treatment plans were computed with both the MI and SI approaches. For the MI approach, the isocenter was located at the geometric center of each planning target volumes (PTVs), whereas the isocenter of the SI approach was located midway between the PTV centroids. To simulate the intra‐fractional errors, isocenter displacements including translational and rotational shifts were hypothetically applied. Apart from the dosimetric outcomes of the two approaches, the impact of the isocenter shifts on PTVs and organs at risk (OARs) were recorded in terms of the differences (δ) in dose parameters relative to the reference plan and was then compared between the MI and SI approaches.

Results

Both MI and SI plans met the plan acceptance criteria. The mean Paddick conformity index (Paddick CI) and D_max of most OARs between MI and SI plans did not show a significant difference, except that higher doses to the left optic nerve and optic chiasm were found in SI plans (p = 0.03). After the application of the isocenter shifts, δCI increased with an increase in the magnitude of the isocenter shift. When comparing between MI and SI plans, the δCIs were similar (p > 0.05) for all extents of translational shifts, but δCIs were significantly higher in SI plans after application of all rotations particularly ±1.5° and ±2.0° shifts. Despite the result that the majority of δD_Max of OARs were higher in the SI plans, only the differences in the left optic nerve and chiasm showed generally consistent significance after both translational ≥±1 mm and rotational shifts of ≥±1∘.

Conclusion

Both MI and SI approaches could produce clinically acceptable plans. However, isocenter shifts brought dosimetric impacts to both MI and SI approaches and the effects increased with the increase of the shift magnitude. Although similar impacts were shown in plans of both approaches after translational isocenter shift, SI plans were relatively more vulnerable than MI plans to rotational shifts.

Executive summary from American Radium Society's appropriate use criteria on neurocognition after stereotactic radiosurgery for multiple brain metastases

BACKGROUND

The American Radium Society (ARS) Appropriate Use Criteria brain malignancies panel systematically reviewed (PRISMA [Preferred Reporting Items for Systematic Reviews and Meta-Analyses]) published literature on neurocognitive outcomes after stereotactic radiosurgery (SRS) for patients with multiple brain metastases (BM) to generate consensus guidelines.

METHODS

The panel developed 4 key questions (KQs) to guide systematic review. From 11 614 original articles, 12 were selected. The panel developed model cases addressing KQs and potentially controversial scenarios not addressed in the systematic review (which might inform future ARS projects). Based upon quality of evidence, the panel confidentially voted on treatment options using a 9-point scale of appropriateness.

RESULTS

The panel agreed that SRS alone is usually appropriate for those with good performance status and 2-10 asymptomatic BM, and usually not appropriate for >20 BM. For 11-15 and 16-20 BM there was (between 2 case variants) agreement that SRS alone may be appropriate or disagreement on the appropriateness of SRS alone. There was no scenario (among 6 case variants) in which conventional whole-brain radiotherapy (WBRT) was considered usually appropriate by most panelists. There were several areas of disagreement, including: hippocampal sparing WBRT for 2-4 asymptomatic BM; WBRT for resected BM amenable to SRS; fractionated versus single-fraction SRS for resected BM, larger targets, and/or brainstem metastases; optimal treatment (WBRT, hippocampal sparing WBRT, SRS alone to all or select lesions) for patients with progressive extracranial disease, poor performance status, and no systemic options.

CONCLUSIONS

For patients with 2-10 BM, SRS alone is an appropriate treatment option for well-selected patients with good performance status. Future study is needed for those scenarios in which there was disagreement among panelists.

Tumor Control Probability of Radiosurgery and Fractionated Stereotactic Radiosurgery for Brain Metastases

PURPOSE

As part of the American Association of Physicists in Medicine Working Group on Stereotactic Body Radiotherapy, tumor control probability (TCP) after stereotactic radiosurgery (SRS) and fractionated stereotactic radiosurgery (fSRS) for brain metastases was modeled based on pooled dosimetric and clinical data from published English-language literature.

METHODS AND MATERIALS

PubMed-indexed studies published between January 1995 and September 2017 were used to evaluate dosimetric and clinical predictors of TCP after SRS or fSRS for brain metastases. Eligible studies had ≥10 patients and included detailed dose-fractionation data with corresponding ≥1-year local control (LC) data, typically evaluated as a >20% increase in diameter of the targeted lesion using the pre-SRS diameter as a reference.

RESULTS

Of 2951 potentially eligible manuscripts, 56 included sufficient dose-volume data for analyses. Accepting that necrosis and pseudoprogression can complicate the assessment of LC, for tumors ≤20 mm, single-fraction doses of 18 and 24 Gy corresponded with >85% and 95% 1-year LC rates, respectively. For tumors 21 to 30 mm, an 18 Gy single-fraction dose was associated with 75% LC. For tumors 31 to 40 mm, a 15 Gy single-fraction dose yielded ∼69% LC. For 3- to 5-fraction fSRS using doses in the range of 27 to 35 Gy, 80% 1-year LC has been achieved for tumors of 21 to 40 mm in diameter.

CONCLUSIONS

TCP for SRS and fSRS are presented. For small lesions ≤20 mm, single doses of ≈18 Gy appear generally associated with excellent rates of LC; for melanoma, higher doses seem warranted. For larger lesions >20 mm, local control rates appear to be ≈ 70% to 75% with usual doses of 15 to 18 Gy, and in this setting, fSRS regimens should be considered. Greater consistency in reporting of dosimetric and LC data is needed to facilitate future pooled analyses. As systemic and biologic therapies evolve, updated analyses will be needed to further assess the necessity, efficacy, and toxicity of SRS and fSRS.

Stereotactic Radiosurgery Results for Patients with 5-10 versus 11-20 Brain Metastases: A Retrospective Cohort Study Combining 2 Databases Totaling 2319 Patients

OBJECTIVE

The treatment of patients with ≥11 brain metastases (BMs) with stereotactic radiosurgery (SRS) alone has yet to be established. The aim of this study was to compare results of SRS alone in patients with 5-10 BMs versus 11-20 BMs.

METHODS

This was an institutional review board-approved, retrospective cohort study using our prospectively accumulated database including 1515 patients with 5-10 tumors and 804 patients with 11-20 tumors treated with Gamma Knife SRS by 2 experienced neurosurgeons between 1998 and 2018. The Kaplan-Meier method was applied to determine post-SRS survival times, and competing risk analyses were used to estimate cumulative incidences of the secondary end points.

RESULTS

The post-SRS median survival time was slightly longer in the group with 5-10 tumors (7.7 months) than in the group with 11-20 tumors (6.5 months) (P < 0.0001). Median survival time differences were statistically significant for patients with lung cancers but not for patients with breast, gastrointestinal tract, kidney, and other cancers. Multivariable analysis revealed female sex, better Karnofsky performance scale score, controlled primary cancer, and absence of extracerebral metastases to be statistically significant predictors of longer survival in the 2 patient cohorts. Crude and cumulative incidences of local recurrences were significantly lower in the group with 11-20 tumors than in the group with 5-10 tumors, while those of other secondary end points were similar to or lower in the group with 11-20 tumors than in the group with 5-10 tumors. Post-SRS outcomes were relatively poor in patients with 11-20 tumors from kidney or other cancers.

CONCLUSIONS

Carefully selected patients with 11-20 BMs are not unfavorable candidates for SRS alone.

Role of radiation therapy in brain metastases management

The challenge of the management of brain metastases has not finished yet. Although new diagnosis-specific prognostic assessment classifications and guidelines for patients with brain metastases help to guide treatment more appropriately, and even if the development of modern technologies in imaging and radiation treatment, as well as improved new systemic therapies, allow to reduce cognitive side effects and make retreatment or multiple and combined treatment possible, several questions remain unanswered. However, tailoring the treatment to the patient and his expectations is still essential; in other words, patients with a poor prognosis should not be over-treated, and those with a favorable prognosis may not be subtracted to the best treatment option. Some ongoing trials with appropriate endpoints could better inform our choices. Finally, a case-by-case inter-disciplinary discussion remains essential.

A Cohort Study of Stereotactic Radiosurgery Results for Patients With 5 to 15 Versus 2 to 4 Brain Metastatic Tumors

Purpose

The role of stereotactic radiosurgery (SRS) alone for patients with ≥5 brain metastases is not fully understood. The objective of the study was to compare SRS-alone treatment results for 2 to 4 versus 5 to 15 tumors.

Methods and Materials

This was an institutional review board-approved, retrospective cohort study using our prospectively accumulated database including 1150 patients with 2 to 4 tumors and 939 with 5 to 15 tumors who underwent Gamma Knife SRS during a 20-year period (1998-2018). The Kaplan-Meier method was used to determine post-SRS survival times, and competing risk analyses were applied to estimate cumulative incidences of the secondary endpoints.

Results

The post-SRS median survival time was slightly longer in the group with 2 to 4 tumors (8.1 months) than in that with 5 to 15 tumors (7.2 months, P = .0010). Median survival time differences were statistically significant for non-small cell lung cancer, gastrointestinal tract cancer, and others but not for small cell lung cancer, breast cancer, and kidney cancer. Multivariable analysis demonstrated female sex, better Karnofsky Performance Status score, non-small cell lung cancer (vs gastrointestinal tract cancer), younger age, controlled primary cancer, and no extracerebral metastases to be significant predictors of a longer survival period in both tumor number groups. Crude and cumulative incidences of salvage whole brain radiation therapy were significantly higher in the group with 5 to 15 tumors than in that with 2 to 4 tumors, although those of other secondary endpoints were similar to or lower in the 5 to 15 tumor number group than those in the group with 2 to 4 tumors.

Conclusions

We conclude that carefully selected patients with ≥5 to 15 tumors are not unfavorable candidates for SRS alone.

Stereotactic Radiosurgery to More Than 10 Brain Metastases: Evidence to Support the Role of Radiosurgery for Ideal Hippocampal Sparing in the Treatment of Multiple Brain Metastases

BACKGROUND

Brain metastases are a common occurrence, with literature supporting the treatment of a limited number of brain metastases with stereotactic radiosurgery (SRS), as opposed to whole brain radiotherapy (WBRT). Less well understood is the role of SRS in patients with ≥10 brain metastases.

METHODS

Patients treated with SRS to ≥10 brain metastases without concurrent WBRT between March 1999 and December 2016 were reviewed. Analysis was performed for overall survival, treated lesion freedom from progression (FFP), freedom from new metastases (FFNMs), and adverse radiation effect. Hippocampal volumes were retrospectively generated in patients treated with up-front SRS for evaluation of dose volume metrics.

RESULTS

A total of 143 patients were identified with 75 patients having up-front SRS and 68 patients being treated as salvage therapy after prior WBRT. The median number of lesions per patient was 13 (interquartile range [IQR], 11-17). Median total volume of treatment was 4.1 cm³ (IQR, 2.0-9.9 cm³). The median 12-month FFP for up-front and salvage treatment was 96.8% (95% confidence interval [CI], 95.5-98.1) and 83.6% (95% CI, 79.9-87.5), respectively (P < 0.001). Twelve-month FFNMs for up-front and salvage SRS was 18.8% (95% CI, 10.9-32.3) versus 19.2% (95% CI, 9.7-37.8), respectively (P = 0.90). The mean hippocampal dose was 150 cGy (IQR, 100-202 cGy).

CONCLUSIONS

Excellent rates of local control can be achieved when treating patients with >10 intracranial metastases either in the up-front or salvage setting. Hippocampal sparing is readily achievable with expected high rates of new metastatic lesions in treated patients.

Multi-Institutional Dosimetric Evaluation of Modern Day Stereotactic Radiosurgery (SRS) Treatment Options for Multiple Brain Metastases

Purpose/Objectives: There are several popular treatment options currently available for stereotactic radiosurgery (SRS) of multiple brain metastases: ⁶⁰Co sources and cone collimators around a spherical geometry (GammaKnife), multi-aperture dynamic conformal arcs on a linac (BrainLab Elements™ v1.5), and volumetric arc therapy on a linac (VMAT) calculated with either the conventional optimizer or with the Varian HyperArc™ solution. This study aimed to dosimetrically compare and evaluate the differences among these treatment options in terms of dose conformity to the tumor as well as dose sparing to the surrounding normal tissues. Methods and Materials: Sixteen patients and a total of 112 metastases were analyzed. Five plans were generated per patient: GammaKnife, Elements, HyperArc-VMAT, and two Manual-VMAT plans to evaluate different treatment planning styles. Manual-VMAT plans were generated by different institutions according to their own clinical planning standards. The following dosimetric parameters were extracted: RTOG and Paddick conformity indices, gradient index, total volume of brain receiving 12Gy, 6Gy, and 3Gy, and maximum doses to surrounding organs. The Wilcoxon signed rank test was applied to evaluate statistically significant differences (p < 0.05). Results: For targets ≤ 1 cm, GammaKnife, HyperArc-VMAT and both Manual-VMAT plans achieved comparable conformity indices, all superior to Elements. However, GammaKnife resulted in the lowest gradient indices at these target sizes. HyperArc-VMAT performed similarly to GammaKnife for V_12Gy parameters. For targets ≥ 1 cm, HyperArc-VMAT and Manual-VMAT plans resulted in superior conformity vs. GammaKnife and Elements. All SRS plans achieved clinically acceptable organs-at-risk dose constraints. Beam-on times were significantly longer for GammaKnife. Manual-VMAT_A and Elements resulted in shorter delivery times relative to Manual-VMAT_B and HyperArc-VMAT. Conclusion: The study revealed that Manual-VMAT and HyperArc-VMAT are capable of achieving similar low dose brain spillage and conformity as GammaKnife, while significantly minimizing beam-on time. For targets smaller than 1 cm in diameter, GammaKnife still resulted in superior gradient indices. The quality of the two sets of Manual-VMAT plans varied greatly based on planner and optimization constraint settings, whereas HyperArc-VMAT performed dosimetrically superior to the two Manual-VMAT plans.

Tumor control and survival in patients with ten or more brain metastases treated with stereotactic radiosurgery: a retrospective analysis

INTRODUCTION

To assess tumor control and survival in patients treated with stereotactic radiosurgery (SRS) for 10 or more metastatic brain tumors.

METHODS

Patients were retrospectively identified. Clinical records were reviewed for follow-up data, and post-treatment MRI studies were used to assess tumor control. For tumor control studies, patients were separated based on synchronous or metachronous treatment, and control was assessed at 3-month intervals. The Kaplan-Meier method was employed to create survival curves, and regression analyses were employed to study the effects of several variables.

RESULTS

Fifty-five patients were treated for an average of 17 total metastases. Forty patients received synchronous treatment, while 15 received metachronous treatment. Univariate analysis revealed an association between larger brain volumes irradiated with 12 Gy and decreased overall survival (p = 0.0406); however, significance was lost on multivariate analysis. Among patients who received synchronous treatment, the median percentage of tumors controlled was 100%, 91%, and 82% at 3, 6, and 9 months, respectively. Among patients who received metachronous treatment, the median percentage of tumors controlled after each SRS encounter was 100% at all three time points.

CONCLUSIONS

SRS can be used to treat patients with 10 or more total brain metastases with an expectation of tumor control and overall survival that is equivalent to that reported for patients with four or fewer tumors. Development of new metastases leading to repeat SRS is not associated with worsened tumor control or survival. Survival may be adversely affected in patients having a higher volume of normal brain irradiated.

Comparison between stereotactic radiosurgery and whole-brain radiotherapy for 10-20 brain metastases from non-small cell lung cancer

The efficacy and safety of stereotactic radiosurgery (SRS) in comparison with whole brain radiotherapy (WBRT) for brain metastases (BMs) remains unclear. The present study retrospectively reviewed 44 patients who received SRS or WBRT as an initial treatment for 10-20 BMs from non-small cell lung cancer between 2009 and 2016. Of the patients, 24 (54.5%) were treated with SRS and 20 (45.5%) were treated with WBRT. Overall survival (OS), time to intracranial progression (TTIP), neurological survival (NS), and prognostic factors were examined. OS did not significantly differ between the two groups: 7.3 months in the SRS group vs. 7.2 months in the WBRT group (P=0.502). Median TTIP was significantly shorter in the SRS group than in the WBRT group (7.1 vs. 19.1 months, P=0.009). In contrast, there were no significant differences in NS between the two groups (14.5 months in the SRS group vs. 12.9 months in the WBRT group, P=0.346). Univariate and multivariate analysis revealed that the type of initial treatment for BMs (WBRT or SRS) was not a significant prognostic factor (hazard ratio=0.80, 95% confidence interval: 0.42-1.52, P=0.502). However, histology, performance status, subsequent molecular targeted drugs, subsequent chemotherapy and salvage treatment were independent prognostic factors. There were no significant differences in OS and NS between treatment with SRS and treatment with WBRT in patients with 10-20 BMs, although TTIP was improved with WBRT. As an upfront treatment for 10-20 BMs, SRS may delay WBRT and the adverse events associated with WBRT.

Stereotactic Radiosurgery for Multiple Brain Metastases

PURPOSE OF REVIEW

To give an overview on the current evidence for stereotactic radiosurgery of brain metastases with a special focus on multiple brain metastases.

RECENT FINDINGS

While the use of stereotactic radiosurgery in patients with limited brain metastases has been clearly defined, its role in patients with multiple lesions (> 4) is still a matter of controversy. Whole-brain radiation therapy (WBRT) has been the standard treatment approach for patients with multiple brain lesions and is still the most commonly used treatment approach worldwide. Although distant brain failure is improved by WBRT, the overall survival is not readily impacted. As WBRT is associated with significant neurocognitive decline compared to stereotactic radiosurgery (SRS), SRS has been explored and increasingly utilized for selected patients with multiple brain metastases. Recent clinical data indicated the feasibility of stereotactic radiosurgery to multiple brain metastases with a similar survival in patients with more than 4 brain metastases versus patients with a maximum of 4 brain metastases. Also, neurocognitive function and quality of life was maintained after stereotactic radiosurgery which is essential in a palliative setting. The application of stereotactic radiosurgery with Gamma Knife, Cyberknife, or LINAC-based equipment has emerged as an effective and widely available treatment option for patients with limited brain metastases. Although not formally proven in prospective studies, SRS may also be considered as a safe and effective treatment option in selected patients with multiple brain metastases. Especially in patients with a favorable prognosis, survival over several years is observed also in the setting of multiple BM. For these patients, avoidance of the neurocognitive damage of WBRT is desirable, and SRS is often a more appropriate treatment in the current multimodality treatment of BM in which systemic treatment is often the cornerstone of the treatment. For patients with an intermediate (3-12 months) and poor prognosis (< 3 months), the application of WBRT becomes more and more controversial, because of its acute side effects, such as hair loss and fatigue and, thereby, detrimental effect on quality of life. For these patients, best supportive care, primary systemic treatment, and even SRS may be preferred over WBRT on an individualized patient basis.

Modern management for brain metastasis patients using stereotactic radiosurgery: literature review and the authors' gamma knife treatment experiences

Historically, whole brain radiotherapy was administered to most patients with brain metastases. However, over the past three decades, stereotactic radiosurgery (SRS), targeted at individual cranial lesions, has been accepted widely. In this study, based on the authors' experiences along with published data, recent trends in SRS for brain metastases are discussed. This article focuses on the following issues: 1) How many tumors can or should be treated with SRS? 2) Two-/three-staged SRS for relatively large tumors, 3) post- or preoperative SRS, and 4) repeat SRS.

Nanocarrier-Mediated Photochemotherapy and Photoradiotherapy

Photothermal therapy (PTT) and photodynamic therapy (PDT) both utilize light to induce a therapeutic effect. These therapies are rapidly gaining importance due to the noninvasiveness of light and the limited adverse effect associated with these treatments. However, most preclinical studies show that complete elimination of tumors is rarely observed. Combining PDT and PTT with chemotherapy or radiotherapy can improve the therapeutic outcome and simultaneously decrease side effects of these conventional treatments. Nanocarriers can help to facilitate such a combined treatment. Here, the most recent advancements in the field of photochemotherapy and photoradiotherapy, in which nanocarriers are employed, are reviewed.

Cumulative Doses to Brain and Other Critical Structures After Multisession Gamma Knife Stereotactic Radiosurgery for Treatment of Multiple Metastatic Tumors

Purpose

Repeat stereotactic radiosurgery (SRS) is an attractive alternative to whole brain radiation therapy (WBRT) for treatment of recurrent brain metastases (BM). The purpose of this study is to determine the cumulative doses to the brain and critical normal structures in patients who underwent repeat courses of Gamma Knife (GK) SRS.

Materials and methods

We retrospectively identified ten patients who received at least three GK-SRS sessions for multiply recurrent BM at our institution from 2013 to 2016. We used Velocity™ 3.1.0 software to co-register the magnetic resonance imaging images and the dose data of all treatment sessions for each patient. The cumulative doses to brain, lenses, eyes, brainstem, optic nerves, chiasm, and hippocampi were calculated. Dose–volume histograms, as well as the mean, median and maximum doses of these structures, were analyzed.

Results

The median number of SRS was five sessions (range = 3–7 sessions) per patient over a median treatment span of 510 days (112–1,197 days), whereas the median number of metastatic tumors treated per patient was 25.0 (10–63). The median of the total tumor volume was 9.5 cc (2.3–75.9 cc). The median of the mean cumulative dose to the whole brain was 4.1 Gy (1.7–16.4 Gy). The medians of the maximum doses to the critical structures were as follows: brainstem, 6.1 Gy (2.2–28.9 Gy), chiasm, 3.9 Gy (1.8–10.8 Gy), right optic nerve, 2.9 Gy (1.2–9.0 Gy), and left optic nerve, 2.6 Gy (1.0–6.5 Gy). The medians of the mean and maximum cumulative doses to the hippocampi were 3.4 Gy (1.0–14.4 Gy) and 13.8 Gy (1.5–39.3 Gy), respectively. The median survival for the entire cohort was 26.7 months, and no patients developed radiation necrosis.

Conclusion

Our study demonstrated that multisession GKSRS could be delivered with low cumulative doses to critical normal structures. Further studies are required to fully establish its role as an alternative treatment strategy to WBRT for the treatment of multiply recurrent BM.

A randomised trial to compare cognitive outcome after gamma knife radiosurgery versus whole brain radiation therapy in patients with multiple brain metastases: research protocol CAR-study B

BACKGROUND

Gamma Knife radiosurgery (GKRS) is increasingly applied in patients with multiple brain metastases and is expected to have less adverse effects in cognitive functioning than whole brain radiation therapy (WBRT). Effective treatment with the least negative cognitive side effects is increasingly becoming important, as more patients with brain metastases live longer due to more and better systemic treatment options. There are no published randomized trials yet directly comparing GKRS to WBRT in patients with multiple brain metastases that include objective neuropsychological testing.

METHODS

CAR-Study B is a prospective randomised trial comparing cognitive outcome after GKRS or WBRT in adult patients with 11-20 newly diagnosed brain metastases on a contrast-enhanced MRI-scan, KPS ≥70 and life expectancy of at least 3 months. Randomisation by the method of minimization, is stratified by the cumulative tumour volume in the brain, systemic treatment, KPS, histology, baseline cognitive functioning and age. The primary endpoint is the between-group difference in the percentage of patients with significant memory decline at 3 months. Secondary endpoints include overall survival, local control, development of new brain metastases, cognitive functioning over time, quality of life, depression, anxiety and fatigue. Cognitive functioning is assessed by a standardised neuropsychological test battery. Assessments (cognitive testing, questionnaires and MRI-scans) are scheduled at baseline and at 3, 6, 9, 12 and 15 months after treatment.

DISCUSSION

Knowledge gained from this trial may be used to inform individual patients with BM more precisely about the cognitive effects they can expect from treatment, and to assist both doctors and patients in making (shared) individual treatment decisions. This trial is currently recruiting. Target accrual: 23 patients at 3-months follow-up in both groups.

TRIAL REGISTRATION

The Netherlands Trials Register number NTR5463. ClinicalTrials.gov registration number NCT02953717 , first received October 27, 2016, 8 patients were enrolled in this study on 31 July 2017.

Stereotactic radiosurgery alone for multiple brain metastases? A review of clinical and technical issues

Over the past three decades several randomized trials have enabled evidence-based practice for patients presenting with limited brain metastases. These trials have focused on the role of surgery or stereotactic radiosurgery (SRS) with or without whole brain radiation therapy (WBRT). As a result, it is clear that local control should be optimized with surgery or SRS in patients with optimal prognostic factors presenting with up to 4 brain metastases. The routine use of adjuvant WBRT remains debatable, as although greater distant brain control rates are observed, there is no impact on survival, and modern outcomes suggest adverse effects from WBRT on patient cognition and quality of life. With dramatic technologic advances in radiation oncology facilitating the adoption of SRS into mainstream practice, the optimal management of patients with multiple brain metastases is now being put forward. Practice is evolving to SRS alone in these patients despite a lack of level 1 evidence to support a clinical departure from WBRT. The purpose of this review is to summarize the current state of the evidence for patients presenting with limited and multiple metastases, and to present an in-depth analysis of the technology and dosimetric issues specific to the treatment of multiple metastases.

Treatment of high numbers of brain metastases with Gamma Knife radiosurgery: a review

Effectiveness of stereotactic radiosurgery (SRS) has been shown in patients with one to four brain metastases. Work has been done to evaluate the role of SRS alone treatment without whole-brain radiation therapy in patients with more than four metastases. A recent multiinstitutional JLGK 0901 prospective study revealed the class-2 evidence that SRS without whole-brain radiation therapy is an effective treatment for patients up to 10 metastatic lesions. Several retrospective studies exist to show the efficacy and safety of SRS for patients with even more than 10 lesions. However, patient selection is very critical for SRS alone treatment. The PubMed database was searched using combinations of search terms and synonyms for multiple brain metastases, Gamma Knife and SRS published between January 1, 2005 and January 1, 2015 in order to address the effectiveness of Gamma Knife for patients with multiple brain metastases. Good performance status, controlled primary disease, total treated tumor volume of 15 cm(3) or less have been found to be significant predictors for survival among patients with two or more brain lesions. The data suggest that SRS can be used and whole brain radiation therapy can be withheld in selected patients with multiple lesions to avoid acute or chronic adverse effects, especially neurocognitive decline, without causing survival disadvantage. In this review, we assessed the evidence for SRS treatment of patients with multiple brain metastases.

Single-Isocenter Frameless Volumetric Modulated Arc Radiosurgery for Multiple Intracranial Metastases

BACKGROUND

Stereotactic radiosurgery (SRS) is a well-accepted treatment for patients with intracranial metastases, but outcomes with volumetric modulated arc radiosurgery (VMAR) are poorly described.

OBJECTIVE

To report our initial clinical experience applying a novel single-isocenter technique to frameless VMAR for simultaneous treatment of multiple intracranial metastases.

METHODS

We performed a retrospective analysis of 15 patients undergoing frameless VMAR for multiple intracranial metastases using a single, centrally located isocenter in the period 2009 and 2011. Of these, 3 patients were treated for progressive or recurrent intracranial disease. A total of 62 metastases (median, 3 per patient; range, 2-13) were treated to a median dose of 20 Gy (range, 15-30 Gy). Three patients were treated with fractionated SRS. Follow-up including clinical examination and magnetic resonance imaging (MRI) occurred every 3 months.

RESULTS

The median follow-up for all patients was 7.1 months (range, 1.1-24.3), with 11 patients (73.3%) followed until death. For the remaining 4 patients alive at the time of analysis, the median follow-up was 19.6 months (range, 9.2-24.3). Local control at 6 and 12 months was 91.7% (95% confidence interval [CI], 84.6%-100.0%) and 81.5% (95% CI, 67.9%-100.0%), respectively. Regional failure was observed in 9 patients (60.0%), and 7 patients (46.7%) received salvage therapy. Overall survival at 6 months was 60.0% (95% CI, 40.3%-88.2%). Grade 3 or higher treatment-related toxicity was not observed. The median total treatment time was 7.2 minutes (range, 2.8-13.2 minutes).

CONCLUSION

Single-isocenter, frameless VMAR for multiple intracranial metastases is a promising technique that may provide similar clinical outcomes compared with conventional radiosurgery.

Potential role for LINAC-based stereotactic radiosurgery for the treatment of 5 or more radioresistant melanoma brain metastases

OBJECT

Linear accelerator (LINAC)-based stereotactic radiosurgery (SRS) is a treatment option for patients with melanoma in whom brain metastases have developed. Very limited data are available on treating patients with ≥5 lesions. The authors sought to determine the effectiveness of SRS in patients with ≥5 melanoma brain metastases.

METHODS

A retrospective analysis of metastatic melanoma treated with SRS in a single treatment session for ≥5 lesions was performed. Magnetic resonance imaging studies were reviewed post-SRS to evaluate local control (LC). Disease progression on imaging was defined using the 2009 Response Evaluation Criteria in Solid Tumors (RECIST). Survival curves were calculated from the date of brain metastases diagnosis or the date of SRS by using the Kaplan-Meier (KM) method. Univariate and multivariate analysis (UVA and MVA, respectively) were performed using the Cox proportional-hazards model.

RESULTS

The authors identified 149 metastatic brain lesions treated in 28 patients. The median patient age was 60.5 years (range 38-83 years), and the majority of patients (24 [85.7%]) had extracranial metastases. Four patients (14.3%) had received previous whole-brain radiotherapy (WBRT), and 11 (39.3%) had undergone previous SRS. The median planning target volume (PTV) was 0.34 cm3 (range 0.01-12.5 cm3). Median follow-up was 6.3 months (range 1-46 months). At the time of treatment, 7% of patients were categorized as recursive partitioning analysis (RPA) Class I, 89% as RPA Class II, and 4% as RPA Class III. The rate of local failure was 11.4%. Kaplan-Meier LC estimates at 6 and 12 months were 91.3% and 82.2%, respectively. A PTV volume≥0.34 cm3 was a significant predictor of local failure on UVA (HR 16.1, 95% CI 3.2-292.6, p<0.0001) and MVA (HR 14.8, 95% CI 3.0-268.5, p=0.0002). Sixteen patients (57.1%) were noted to have distant failure in the brain with a median time to failure of 3 months (range 1-15 months). Nine patients with distant failures received WBRT, and 7 received additional SRS. Median overall survival (OS) was 9.4 and 7.6 months from the date of brain metastases diagnosis and the date of SRS, respectively. The KM OS estimates at 6 and 12 months were 57.8% and 28.2%, respectively, from the time of SRS treatment. The RPA class was a significant predictor of KM OS estimates from the date of treatment (p=0.02). Patients who did not receive WBRT after SRS treatment had decreased OS on MVA (HR 3.5, 95% CI 1.1-12.0, p=0.03), and patients who did not receive WBRT prior to SRS had improved OS (HR 0.11, 95% CI 0.02-0.53, p=0.007).

CONCLUSIONS

Stereotactic radiosurgery for ≥5 lesions appears to be effective for selected patients with metastatic melanoma, offering excellent LC. This is particularly important for patients as new targeted systemic agents are improving outcomes but still have limited efficacy within the central nervous system.

Role of stereotactic radiosurgery in patients with more than four brain metastases

For patients presenting with brain metastases, two methods of radiation treatment currently exist: stereotactic radiosurgery (SRS) and whole-brain radiation therapy (WBRT). SRS is a minimally invasive to noninvasive technique that delivers a high dose of ionizing radiation to a precisely defined focal target volume, whereas WBRT involves multiple smaller doses of radiation delivered to the whole brain. Evidence exists from randomized controlled trials for SRS in the treatment of patients with one to four brain metastases. Patients with more than four brain metastases generally receive WBRT, which can effectively treat undetected metastases and protect against intracranial relapse. However, WBRT has been associated with an increased potential for toxic neurocognitive side effects, including memory loss and early dementia, and does not provide 100% protection against relapse. For this reason, physicians at many medical centers are opting to use SRS as first-line treatment for patients with more than four brain metastases, despite evidence showing an increased rate of intracranial relapse compared with WBRT. In light of the evolving use of SRS, this review will examine the available reports on institutional trials and outcomes for patients with more than four brain metastases treated with SRS alone as first-line therapy.

Stereotactic radiosurgery for patients with multiple brain metastases: a case-matched study comparing treatment results for patients with 2-9 versus 10 or more tumors

OBJECT

Although stereotactic radiosurgery (SRS) alone is not a standard treatment for patients with 4-5 tumors or more, a recent trend has been for patients with 5 or more, or even 10 or more, tumors to undergo SRS alone. The aim of this study was to reappraise whether the treatment results for SRS alone for patients with 10 or more tumors differ from those for patients with 2-9 tumors.

METHODS

This was an institutional review board-approved, retrospective cohort study that gathered data from the Katsuta Hospital Mito GammaHouse prospectively accumulated database. Data were collected for 2553 patients who consecutively had undergone Gamma Knife SRS alone, without whole-brain radiotherapy (WBRT), for newly diagnosed (mostly) or recurrent (uncommonly) brain metastases during 1998-2011. Of these 2553 patients, 739 (28.9%) with a single tumor were excluded, leaving 1814 with multiple metastases in the study. These 1814 patients were divided into 2 groups: those with 2-9 tumors (Group A, 1254 patients) and those with 10 or more tumors (Group B, 560 patients). Because of considerable bias in pre-SRS clinical factors between groups A and B, a case-matched study, which used the propensity score matching method, was conducted for clinical factors (i.e., age, sex, primary tumor state, extracerebral metastases, Karnofsky Performance Status, neurological symptoms, prior procedures [surgery and WBRT], volume of the largest tumor, and peripheral doses). Ultimately, 720 patients (360 in each group) were selected. The standard Kaplan-Meier method was used to determine post-SRS survival times and post-SRS neurological death-free survival times. Competing risk analysis was applied to estimate cumulative incidence for local recurrence, repeat SRS for new lesions, neurological deterioration, and SRS-induced complications.

RESULTS

Post-SRS median survival times did not differ significantly between the 2 groups (6.8 months for Group A vs 6.0 months for Group B; hazard ratio [HR] 1.133, 95% CI 0.974-1.319, p = 0.10). Furthermore, rates of neurological death were very similar: 10.0% for group A and 9.4% for group B (p = 0.89); neurological death-free survival times did not differ significantly between the 2 groups (HR 1.073, 95% CI 0.649-1.771, p = 0.78). The cumulative incidence of local recurrence (HR 0.425, 95% CI 0.0.181-0.990, p = 0.04) and repeat SRS for new lesions (HR 0.732, 95% CI 0.554-0.870, p = 0.03) were significantly lower for Group B than for Group A patients. No significant differences between the groups were found for cumulative incidence for neurological deterioration (HR 0.994, 95% CI 0.607-1.469, p = 0.80) or SRS-related complications (HR 0.541, 95% CI 0.138-2.112, p = 0.38).

CONCLUSIONS

Post-SRS treatment results (i.e., median survival time; neurological death-free survival times; and cumulative incidence for local recurrence, repeat SRS for new lesions, neurological deterioration, and SRS-related complications) were not inferior (neither less effective nor less safe) for patients in Group B than for those in Group A. We conclude that carefully selected patients with 10 or more tumors are not unfavorable candidates for SRS alone. A randomized controlled trial should be conducted to test this hypothesis.

Stereotactic radiosurgery for multiple brain metastases

Stereotactic radiosurgery (SRS) alone has become one of the treatment options for patients with 1-4 metastases as the detrimental effects of whole brain radiation therapy on neurocognition and quality of life are becoming well known. Multiple randomized control trials also failed to show overall survival benefit of adding whole brain radiation therapy to SRS. However, the role of SRS in multiple brain metastases, especially those with ≥ 4 tumors, remains controversial. The literature is emerging, and the limited evidence suggests that the local control benefit is independent of the number of metastases, and that patients with more than four brain metastases have similar overall survival compared to those with 2-4 tumors. This review aims at summarizing the current evidence of SRS for multiple brain metastases, divided into limited (2-3) and multiple (≥ 4) lesions. It also reviews the technical aspects and cost-effectiveness of SRS.

Stereotactic radiosurgery for patients with multiple brain metastases (JLGK0901): a multi-institutional prospective observational study

BACKGROUND

We aimed to examine whether stereotactic radiosurgery without whole-brain radiotherapy (WBRT) as the initial treatment for patients with five to ten brain metastases is non-inferior to that for patients with two to four brain metastases in terms of overall survival.

METHODS

This prospective observational study enrolled patients with one to ten newly diagnosed brain metastases (largest tumour <10 mL in volume and <3 cm in longest diameter; total cumulative volume ≤15 mL) and a Karnofsky performance status score of 70 or higher from 23 facilities in Japan. Standard stereotactic radiosurgery procedures were used in all patients; tumour volumes smaller than 4 mL were irradiated with 22 Gy at the lesion periphery and those that were 4-10 mL with 20 Gy. The primary endpoint was overall survival, for which the non-inferiority margin for the comparison of outcomes in patients with two to four brain metastases with those of patients with five to ten brain metastases was set as the value of the upper 95% CI for a hazard ratio (HR) of 1·30, and all data were analysed by intention to treat. The study was finalised on Dec 31, 2012, for analysis of the primary endpoint; however, monitoring of stereotactic radiosurgery-induced complications and neurocognitive function assessment will continue for the censored subset until the end of 2014. This study is registered with the University Medical Information Network Clinical Trial Registry, number 000001812.

FINDINGS

We enrolled 1194 eligible patients between March 1, 2009, and Feb 15, 2012. Median overall survival after stereotactic radiosurgery was 13·9 months [95% CI 12·0-15·6] in the 455 patients with one tumour, 10·8 months [9·4-12·4] in the 531 patients with two to four tumours, and 10·8 months [9·1-12·7] in the 208 patients with five to ten tumours. Overall survival did not differ between the patients with two to four tumours and those with five to ten (HR 0·97, 95% CI 0·81-1·18 [less than non-inferiority margin], p=0·78; pnon-inferiority<0·0001). Stereotactic radiosurgery-induced adverse events occurred in 101 (8%) patients; nine (2%) patients with one tumour had one or more grade 3-4 event compared with 13 (2%) patients with two to four tumours and six (3%) patients with five to ten tumours. The proportion of patients who had one or more treatment-related adverse event of any grade did not differ significantly between the two groups of patients with multiple tumours (50 [9%] patients with two to four tumours vs 18 [9%] with five to ten; p=0·89). Four patients died, mainly of complications relating to stereotactic radiosurgery (two with one tumour and one each in the other two groups).

INTERPRETATION

Our results suggest that stereotactic radiosurgery without WBRT in patients with five to ten brain metastases is non-inferior to that in patients with two to four brain metastases. Considering the minimal invasiveness of stereotactic radiosurgery and the fewer side-effects than with WBRT, stereotactic radiosurgery might be a suitable alternative for patients with up to ten brain metastases.

FUNDING

Japan Brain Foundation.

Survival among patients with 10 or more brain metastases treated with stereotactic radiosurgery

Object

The goal of this study was to evaluate outcomes in patients with ≥ 10 CNS metastases treated with Gamma Knife stereotactic radiosurgery (GK-SRS).

Methods

Patients with ≥ 10 brain metastases treated using GK-SRS during the period between 2004 and 2010 were identified. Overall survival and local and regional control as well as necrosis rates were determined. The influence of age, sex, histological type, extracranial metastases, whole-brain radiation therapy, and number of brain metastases was analyzed using the Kaplan-Meier method. Univariate (log-rank) analyses were performed, with a p value of < 0.05 considered significant.

Results

Fifty-three patients with ≥ 10 brain metastases were treated between 2004 and 2010. All had a Karnofsky Performance Status score of ≥ 70. Seventy-two percent had either non–small cell lung cancer (38%) or breast cancer (34%); melanoma, small cell lung cancer, renal cell carcinoma, and testicular, colon, and ovarian cancer contributed the remaining 28%. On average, 10.9 lesions were treated in a single session. Sixty-four percent of patients received prior whole-brain radiation therapy. The median survival was 6.5 months. One-year overall survival was 42% versus 14% when comparing breast cancer and other histological types, respectively (p = 0.074). Age, extracranial metastases, number of brain metastases, and previous CNS radiation therapy were not significant prognostic factors. Although the median time to local failure was not reached, the median time to regional failure was 3 months. Female sex was associated with longer time to regional failure (p = 0.004), as was breast cancer histological type (p = 0.089). No patient experienced symptomatic necrosis.

Conclusions

Patients with ≥ 10 brain metastases who received prior CNS radiation can safely undergo repeat treatment with GK-SRS. With median survival exceeding 6 months, aggressive local treatment remains an option; however, rapid CNS failure is to be expected. Although numbers are limited, patients with breast cancer represent one group of individuals who would benefit most, with prolonged survival and extended time to CNS recurrence.

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

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

A case-matched study of stereotactic radiosurgery for patients with multiple brain metastases: comparing treatment results for 1–4 vs ≥ 5 tumors

Object

Although stereotactic radiosurgery (SRS) alone for patients with 4–5 or more tumors is not a standard treatment, a trend for patients with 5 or more tumors to undergo SRS alone is already apparent. The authors' aim in the present study was to reappraise whether SRS results for ≥ 5 tumors differ from those for 1–4 tumors.

Methods

This institutional review board–approved retrospective cohort study used the authors' database of prospectively accumulated data that included 2553 consecutive patients who underwent SRS, not in combination with concurrent whole-brain radiotherapy, for brain metastases (METs) between 1998 and 2011. These 2553 patients were divided into 2 groups: 1553 with tumor numbers of 1–4 (Group A) and 1000 with ≥ 5 tumors (Group B). Because there was considerable bias in pre-SRS clinical factors between Groups A and B, a case-matched study was conducted. Ultimately, 1096 patients (548 each in Groups A and B) were selected. The standard Kaplan-Meier method was used to determine post-SRS survival and the post-SRS neurological death–free survival times. Competing risk analysis was applied to estimate cumulative incidences of local recurrence, repeat SRS for new lesions, neurological deterioration, and SRS-induced complications.

Results

The post-SRS median survival time was significantly longer in the 548 Group A patients (7.9 months, 95% CI 7.0–8.9 months) than in the 548 Group B patients (7.0 months 95% [CI 6.2–7.8 months], HR 1.176 [95% CI 1.039–1.331], p = 0.01). However, incidences of neurological death were very similar: 10.6% in Group A and 8.2% in Group B (p = 0.21). There was no significant difference between the groups in neurological death–free survival intervals (HR 0.945, 95% CI 0.636–1.394, p = 0.77). Furthermore, competing risk analyses showed that there were no significant differences between the groups in cumulative incidences of local recurrence (HR 0.577, 95% CI 0.312–1.069, p = 0.08), repeat SRS (HR 1.133, 95% CI 0.910–1.409, p = 0.26), neurological deterioration (HR 1.868, 95% CI 0.608–1.240, p = 0.44), and major SRS-related complications (HR 1.105, 95% CI 0.490–2.496, p = 0.81).

In the authors' cohort, age ≤ 65 years, female sex, a Karnofsky Performance Scale score ≥ 80%, cumulative tumor volume ≤ 10 cm3, controlled primary cancer, no extracerebral METs, and neurologically asymptomatic status were significant factors favoring longer survival equally in both groups.

Conclusions

This retrospective study suggests that increased tumor number is an unfavorable factor for longer survival. However, the post-SRS median survival time difference, 0.9 months, between the two groups is not clinically meaningful. Furthermore, patients with 5 or more METs have noninferior results compared to patients with 1–4 tumors, in terms of neurological death, local recurrence, repeat SRS, maintenance of good neurological state, and SRS-related complications. A randomized controlled trial should be conducted to test this hypothesis.

Gamma Knife surgery for the treatment of 5 to 15 metastases to the brain: clinical article

OBJECT

It has been generally accepted that Gamma Knife surgery (GKS) is an effective primary or adjunct treatment for patients with 1-4 metastases to the brain. The number of studies detailing the use of GKS for 5 or more brain metastases, however, remains minimal. The aim of the current retrospective study was to elucidate the utility of GKS in patients with 5-15 brain metastases.

METHODS

Patients were chosen for GKS based on prior MRI of these metastatic lesions and a known primary cancer diagnosis. Magnetic resonance imaging was used post-GKS to assess tumor control; patients were also followed up clinically. Overall survival (OS) from the date of GKS was used as the primary end point. Statistical analysis was performed to identify prognostic factors related to OS.

RESULTS

Between 2003 and 2012, 96 patients were treated for a total of 704 metastatic brain lesions. The histology of these lesions varied among non-small cell lung cancer (NSCLC), breast cancer, melanoma, renal cancer, and other more rare carcinomas. At the initial treatment, 18 of the patients (18.8%) were categorized in Recursive Partitioning Analysis (RPA) Class 1 and 77 (80.2%) in RPA Class 2; none were in RPA Class 3. The median number of treated lesions was 7 (mean 7.13), and the median planned treatment volume was 6.12 cm(3) (range 0.42-57.83 cm(3)) per patient. The median clinical follow-up was 4.1 months (range 0.1-40.70 months). Actuarial tumor control was calculated to be 92.4% at 6 months, 84.8% at 12 months, and 74.9% at 24 months post-GKS. The median OS was found to be 4.73 months (range 0.4-41.8 months). Multivariate analysis demonstrated that RPA class was a significant predictor of death (HR = 2.263, p = 0.038). Number of lesions, tumor histology, Graded Prognostic Assessment score, prior whole-brain radiation therapy, prior resection, prior chemotherapy, patient age, patient sex, controlled primary tumor, extracranial metastases, and planned treatment volume were not significant predictors of OS.

CONCLUSIONS

In patients with 5-15 brain metastases at presentation, the number of lesions did not predict survival after GKS; however, the RPA class was predictive of OS in this group of patients. Gamma Knife surgery for such patients offers an excellent rate of local tumor control.

Stereotactic radiosurgery using the Leksell Gamma Knife Perfexion unit in the management of patients with 10 or more brain metastases

OBJECT

To better establish the role of stereotactic radiosurgery (SRS) in treating patients with 10 or more intracranial metastases, the authors assessed clinical outcomes and identified prognostic factors associated with survival and tumor control in patients who underwent radiosurgery using the Leksell Gamma Knife Perfexion (LGK PFX) unit.

METHODS

The authors retrospectively reviewed data in all patients who had undergone LGK PFX surgery to treat 10 or more brain metastases in a single session at the University of Pittsburgh. Posttreatment imaging studies were used to assess tumor response, and patient records were reviewed for clinical follow-up data. All data were collected by a neurosurgeon who had not participated in patient care.

RESULTS

Sixty-one patients with 10 or more brain metastases underwent SRS for the treatment of 806 tumors (mean 13.2 lesions). Seven patients (11.5%) had no previous therapy. Stereotactic radiosurgery was the sole prior treatment modality in 8 patients (13.1%), 22 (36.1%) underwent whole-brain radiation therapy (WBRT) only, and 16 (26.2%) had prior SRS and WBRT. The total treated tumor volume ranged from 0.14 to 40.21 cm(3), and the median radiation dose to the tumor margin was 16 Gy. The median survival following SRS for 10 or more brain metastases was 4 months, with improved survival in patients with fewer than 14 brain metastases, a nonmelanomatous primary tumor, controlled systemic disease, a better Karnofsky Performance Scale score, and a lower recursive partitioning analysis (RPA) class. Prior cerebral treatment did not influence survival. The median survival for a patient with fewer than 14 brain metastases, a nonmelanomatous primary tumor, and controlled systemic disease was 21.0 months. Sustained local tumor control was achieved in 81% of patients. Prior WBRT predicted the development of new adverse radiation effects.

CONCLUSIONS

Stereotactic radiosurgery safely and effectively treats intracranial disease with a high rate of local control in patients with 10 or more brain metastases. In patients with fewer metastases, a nonmelanomatous primary lesion, controlled systemic disease, and a low RPA class, SRS may be most valuable. In selected patients, it can be considered as first-line treatment.

Stereotactic radiosurgery with or without whole-brain radiotherapy for brain metastases: an update

Brain metastases are unfortunately a common occurrence in patients with cancer. Whole-brain radiation therapy (WBRT) is still considered the standard of care in the treatment of brain metastases. Stereotactic radiosurgery (SRS) offers the additional ability to treat tumors with relative sparing of normal brain tissue in a single fraction. While the addition of SRS to WBRT has been shown to improve survival and local tumor control in selected patients, the idea of deferring WBRT in order to avoid its effects on normal tissues and using SRS alone continues to generate significant discussion and interest. Three recent randomized trials from Japan, Europe and the MD Anderson Cancer Center (TX, USA) have attempted to address this issue. In this article, we update a previous review by discussing these trials to compare the outcomes for SRS alone versus SRS plus WBRT for limited metastases. We also discuss recent nonrandomized evidence for the use of SRS alone for oligometastatic disease.

Therapeutic effect of gamma knife radiosurgery for multiple brain metastases

OBJECTIVE

The aim of this study is to evaluate the therapeutic effects of gamma knife radiosurgery (GKRS) in patients with multiple brain metastases and to investigate prognostic factors related to treatment outcome.

METHODS

We retrospectively reviewed clinico-radiological and dosimetric data of 36 patients with 4-14 brain metastases who underwent GKRS for 264 lesions between August 2008 and April 2011. The most common primary tumor site was the lung (n=22), followed by breast (n=7). At GKRS, the median Karnofsky performance scale score was 90 and the mean tumor volume was 1.2 cc (0.002-12.6). The mean prescription dose of 17.8 Gy was delivered to the mean 61.1% isodose line. Among 264 metastases, 175 lesions were assessed for treatment response by at least one imaging follow-up.

RESULTS

The overall median survival after GKRS was 9.1±1.7 months. Among various factors, primary tumor control was a significant prognostic factor (11.1±1.3 months vs. 3.3±2.4 months, p=0.031). The calculated local tumor control rate at 6 and 9 months after GKRS were 87.9% and 84.2%, respectively. Paddick's conformity index (>0.75) was significantly related to local tumor control. The actuarial peritumoral edema reduction rate was 22.4% at 6 months.

CONCLUSION

According to our results, GKRS can provide beneficial effect for the patients with multiple (4 or more) brain metastases, when systemic cancer is controlled. And, careful dosimetry is essential for local tumor control. Therefore, GKRS can be considered as one of the treatment modalities for multiple brain metastase.

Role of stereotactic radiosurgery for multiple (>4) brain metastases

Stereotactic radiosurgery (SRS) is a very important treatment option for patients with brain metastases. Prospective data supports the use of SRS for patients with 1-4 brain metastases. Although whole brain radiation therapy (WBRT) has been an effective adjunct to SRS and surgery and has also provided effective palliation for many patients with brain metastases, the potential side effects especially neurocognitive function decline has increased the use of SRS alone even for patients with multiple (>4) brain metastases despite data that suggests that tumor progression is worse than the potential neurocognitive effects of WBRT. In addition, current stereotactic radiosurgery machines and techniques allow the delivery of SRS to multiple lesions in an efficient manner. As a result, the optimal management of multiple brain metastases (>4) is becoming more contentious given the lack of prospective data. Until further data is available, a multidisciplinary team of neurosurgeons, radiation oncologists, medical oncologists and medical physicists should work closely together to implement individualized treatment for patients with multiple brain metastases. This paper will review some of the institutional, multi-institutional and randomized trials of SRS for patients with brain metastases, and review the outcomes for patients with multiple (>4) brain metastases treated by SRS and the associated costs.

Single-isocenter frameless intensity-modulated stereotactic radiosurgery for simultaneous treatment of multiple brain metastases: clinical experience

PURPOSE

To describe our clinical experience using a unique single-isocenter technique for frameless intensity-modulated stereotactic radiosurgery (IM-SRS) to treat multiple brain metastases.

METHODS AND MATERIALS

Twenty-six patients with a median of 5 metastases (range, 2-13) underwent optically guided frameless IM-SRS using a single, centrally located isocenter. Median prescription dose was 18 Gy (range, 14-25). Follow-up magnetic resonance imaging (MRI) and clinical examination occurred every 2-4 months.

RESULTS

Median follow-up for all patients was 3.3 months (range, 0.2-21.3), with 20 of 26 patients (77%) followed up until their death. For the remaining 6 patients alive at the time of analysis, median follow-up was 14.6 months (range, 9.3-18.0). Total treatment time ranged from 9.0 to 38.9 minutes (median, 21.0). Actuarial 6- and 12-month overall survivals were 50% (95% confidence interval [C.I.], 31-70%) and 38% (95% C.I., 19-56%), respectively. Actuarial 6- and 12-month local control (LC) rates were 97% (95% C.I., 93-100%) and 83% (95% C.I., 71-96%), respectively. Tumors <or=1.5 cm had a better 6-month LC than those >1.5 cm (98% vs. 90%, p = 0.008). New intracranial metastatic disease occurring outside of the treatment volume was observed in 7 patients. Grade >or=3 toxicity occurred in 2 patients (8%).

CONCLUSION

Frameless IM-SRS using a single-isocenter approach for treating multiple intracranial metastases can produce clinical outcomes that compare favorably with those of conventional SRS in a much shorter treatment time (<40 minutes). Given its faster treatment time, this technique is appealing to both patients and personnel in busy clinics.