Single-fraction Stereotactic Radiosurgery Outcomes for Brain Metastases with Frameless Gamma Knife ICON Radiosurgery: An Update

Abstract Aims Stereotactic radiosurgery (SRS) using the Leksell Gamma Knife system is a commonly used modality for the treatment of brain metastases (BMs). As the size of the target volume (TV) increases, so too does the dose of radiation delivered to surrounding healthy tissue. Large BMs are therefore a contraindication to the use of SRS. Critical organs adjacent to the TV may also be a contraindication to SRS. Staged SRS was proposed as a novel method of delivering three SRS treatments at a reduced radiation dose with a gap of two weeks between each session as a way of shrinking the TV. This allows treatment of TVs otherwise considered untreatable with standard, single-fraction SRS. Little data exists in the literature as to its efficacy. The objective of this study was to evaluate the efficacy of this novel approach and to identify factors which may predict treatment failure. Method A retrospective analysis was undertaken at a single, tertiary Gamma Knife centre. All patients who underwent treatment of their BMs with three-staged Gamma Knife SRS from January 2014 to December 2020 were identified and included. Patient demographics and primary cancer status was ascertained. SRS treatment details for each lesion were collected, including TV, dose and dosimetric data. The percentage reduction in volume of the TVs between the first and second stage, the second and third stage and the first and third stage were calculated. Follow-up data was collected to include follow-up imaging, further intracranial treatments received and survival status. The percentage reduction in volume between each stage was demonstrated on box-and-whisker plots. Statistical significance in reduction in TV between each stage was ascertained by paired samples T-tests. Correlation between initial TV size and percentage reduction post-SRS was determined by a correlation coefficient. Differences were deemed significant with p-values <0.05. Results 12 patients with 14 staged BMs were identified and included. The median age was 61.5 (range 45-79). Seven had a primary malignancy of breast cancer, five non-small cell lung cancer, one melanoma and one colorectal. Median follow-up was 140.5 days (range 10-821). Median TV was 7.44cc (range 1.14-21.53). All TVs received 10Gy at each stage. The median percentage reduction in size of the TV was 7.41% between 1st-2nd stage (range -16.0-42.49%, p-value 0.06), 19.47% between 2nd-3rd stage (range -5.38-53.53%, p-value <0.01) and 24.25% between 1st-3rd stage (range 10.69-68.67%, p-value <0.01). The correlation coefficient between initial TV size and percentage reduction post-SRS was -0.41 (p-value 0.07). 13/14 lesions showed a partial response on first follow-up scan post-SRS, 1/14 lesions showed a mixed response. One patient died 184 days from completion of treatment but without intracranial progression. Two patients had salvage intracranial surgery, 154 and 536 days from completion of treatment respectively. Conclusion Three-staged Gamma Knife is shown to be effective at shrinking the TV and can therefore be used to treat lesions otherwise considered unsuitable for SRS. The presence of extra-cranial metastases did not predict for poor outcomes. Though local control with SRS is thought to diminish with increasing TV size, all staged lesions showed a reduction in size between first and last treatment, and no significant effect was seen between initial TV size and percentage reduction in TV. No patients experienced disease progression on first follow up scan, with 13 of 14 lesions showing disease response. There were only two cases of intracranial progression, with one occurring 536 days post-SRS. Though limited by small numbers and short median follow up period, our data demonstrate encouraging results for three-stage SRS for lesions otherwise unsuitable for single fraction treatment, and should lead to further study.

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Single Fraction Frameless Stereotactic Radiosurgery on the Gamma Knife Icon for Patients with Brain Metastases: Time to Abandon the Frame?

Advances in Radiation Oncology ◽

10.1016/j.adro.2021.100736 ◽

2021 ◽

pp. 100736

Author(s):

Rodney E. Wegner ◽

Zachary D. Horne ◽

Yun Liang ◽

Matthew Goss ◽

Alexander Yu ◽

...

Keyword(s):

Brain Metastases ◽

Stereotactic Radiosurgery ◽

Gamma Knife ◽

Single Fraction

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Changing practice patterns of Gamma Knife versus linear accelerator-based stereotactic radiosurgery for brain metastases in the US

Journal of Neurosurgery ◽

10.3171/2015.4.jns1573 ◽

2016 ◽

Vol 124 (4) ◽

pp. 1018-1024 ◽

Cited By ~ 28

Author(s):

Henry S. Park ◽

Elyn H. Wang ◽

Charles E. Rutter ◽

Christopher D. Corso ◽

Veronica L. Chiang ◽

...

Keyword(s):

Brain Metastases ◽

Stereotactic Radiosurgery ◽

Gamma Knife ◽

Linear Accelerator ◽

Multivariable Analysis ◽

Multivariable Logistic Regression Analysis ◽

Single Fraction ◽

Cancer Data ◽

The Us ◽

The Impact

OBJECT Single-fraction stereotactic radiosurgery (SRS) is a crucial component in the management of limited brain metastases from non-small cell lung cancer (NSCLC). Intracranial SRS has traditionally been delivered using a frame-based Gamma Knife (GK) platform, but stereotactic modifications to the linear accelerator (LINAC) have made an alternative approach possible. In the absence of definitive prospective trials comparing the efficacy and toxicities of treatment between the 2 techniques, nonclinical factors (such as technology accessibility, costs, and efficiency) may play a larger role in determining which radiosurgery system a facility may choose to install. To the authors’ knowledge, this study is the first to investigate national patterns of GK SRS versus LINAC SRS use and to determine which factors may be associated with the adoption of these radiosurgery systems. METHODS The National Cancer Data Base was used to identify patients > 18 years old with NSCLC who were treated with single-fraction SRS to the brain between 2003 and 2011. Patients who received “SRS not otherwise specified” or who did not receive a radiotherapy dose within the range of 12–24 Gy were excluded to reduce the potential for misclassification. The chi-square test, t-test, and multivariable logistic regression analysis were used to compare potential demographic, clinicopathologic, and health care system predictors of GK versus LINAC SRS use, when appropriate. RESULTS This study included 1780 patients, among whom 1371 (77.0%) received GK SRS and 409 (23.0%) underwent LINAC SRS. Over time, the proportion of patients undergoing LINAC SRS steadily increased, from 3.2% in 2003 to 30.8% in 2011 (p < 0.001). LINAC SRS was adopted more rapidly by community versus academic facilities (overall 29.2% vs 17.2%, p < 0.001). On multivariable analysis, 4 independent predictors of increased LINAC SRS use emerged, including year of diagnosis in 2008–2011 versus 2003–2007 (adjusted OR [AOR] 2.04, 95% CI 1.52–2.73, p < 0.001), community versus academic facility type (AOR 2.04, 95% CI 1.60–2.60, p < 0.001), non-West versus West geographic location (AOR 4.50, 95% CI 2.87–7.09, p < 0.001), and distance from cancer reporting facility of < 20 versus ≥ 20 miles (AOR 1.57, 95% CI 1.21–2.04, p = 0.001). CONCLUSIONS GK remains the most commonly used single-fraction SRS modality for NSCLC brain metastases in the US. However, LINAC-based SRS has been rapidly disseminating in the past decade, especially in the community setting. Wide geographic variation persists in the distribution of GK and LINAC SRS cases. Further comparative effectiveness research will be needed to evaluate the impact of these shifts on SRS-related toxicities, local control, and survival, as well as treatment costs and efficiency.

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Intracranial Metastatic Neuroblastoma Treated with Gamma Knife Stereotactic Radiosurgery: Report of Two Novel Cases

Case Reports in Neurological Medicine ◽

10.1155/2012/690548 ◽

2012 ◽

Vol 2012 ◽

pp. 1-4 ◽

Cited By ~ 1

Author(s):

Nathan C. Rowland ◽

Jennifer Andrews ◽

Daxa Patel ◽

David V. LaBorde ◽

Adam Nowlan ◽

...

Keyword(s):

Stereotactic Radiosurgery ◽

Gamma Knife ◽

Treatment Options ◽

Tumor Burden ◽

Poor Survival ◽

Intracranial Metastasis ◽

Temporary Reduction ◽

Single Fraction ◽

Curative Therapy ◽

Gamma Knife Stereotactic Radiosurgery

Intracranial metastasis of neuroblastoma (IMN) is associated with poor survival. No curative therapy for the treatment of IMN currently exists. Unfractionated radiotherapy may be beneficial in the treatment of IMN given the known radiosensitivity of neuroblastoma as well as its proclivity to metastasize as discrete lesions. We present two patients with IMN treated with Gamma Knife stereotactic radiosurgery (SRS). Single-fraction radiotherapy yielded temporary reduction of tumor burden and stability of disease in both patients. SRS may be a useful palliative tool in the treatment of IMN and expands the overall treatment options for this disease.

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Comparison of Fractionated Stereotactic Radiosurgery and Single-Fraction Stereotactic Radiosurgery for the Treatment of Brain Metastases

International Journal of Radiation Oncology*Biology*Physics ◽

10.1016/j.ijrobp.2014.05.1061 ◽

2014 ◽

Vol 90 (1) ◽

pp. S319-S320

Author(s):

G. Savir ◽

D.K. Ebner ◽

J. Chan ◽

P. Rava ◽

D. Cielo ◽

...

Keyword(s):

Brain Metastases ◽

Stereotactic Radiosurgery ◽

Single Fraction ◽

Fractionated Stereotactic Radiosurgery

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MLTI-15. A CASE SERIES OF PRE-OPERATIVE GAMMA-KNIFE RADIOSURGERY FOR RESECTABLE BRAIN METASTASES

Neuro-Oncology Advances ◽

10.1093/noajnl/vdz014.074 ◽

2019 ◽

Vol 1 (Supplement_1) ◽

pp. i17-i17

Author(s):

Tatsuya Takezaki ◽

Haruaki Yamamoto ◽

Naoki Shinojima ◽

Jun-ichiro Kuroda ◽

Shigeo Yamashiro ◽

...

Keyword(s):

Brain Metastases ◽

Stereotactic Radiosurgery ◽

Gamma Knife ◽

Systemic Treatment ◽

Radiation Necrosis ◽

Gamma Knife Radiosurgery ◽

Case Series ◽

Phase 3 ◽

Optimal Sequence ◽

Median Margin

Abstract Recent advances in the systemic treatment of various cancers have resulted in longer survival and higher incidence of brain metastases. Phase 3 trials in north America and in Japan have demonstrated that stereotactic radiosurgery will be a standard adjuvant modality following surgery for resectable brain metastases. However, we don’t know the optimal sequence of this combination therapy. We hypothesized that pre-operative stereotactic radiosurgery for resectable brain metastases provides favorable rates of local control, overall survival, leptomeningeal dissemination and symptomatic radiation necrosis. We have experienced 4 cases of resected brain metastases within 1–7 days after Gamma-knife surgery (median margin dose:22Gy) and have been following their clinical course. We will show the repressive cases.

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