Project description:Stereotactic radiosurgery (SRS) has been shown to be efficacious for treatment of limited brain metastasis (BM), however, the effects of SRS on human brain metastases have yet to be studied. We performed genomic analysis of resected brain metastases from patients whose resected lesion was previously treated with SRS. Our analyses demonstrated for the first time that patients possess a distinct genomic signature based on type of treatment failure including local failure, leptomeningeal spread, and radio-necrosis. Examination of the center and peripheral edge of the tumors treated with SRS indicated differential DNA damage distribution and an enrichment for tumor suppressor mutations and DNA damage repair pathways along the peripheral edge. Furthermore, the two clinical modalities used to deliver SRS, LINAC and GK, demonstrated differential effects on the tumor landscape even between controlled primary sites. Our study provides, in humans, biological evidence of differential effects of SRS across BM’s.
Project description:Stereotactic radiosurgery (SRS) has been shown to be efficacious for treatment of limited brain metastasis (BM), however, the effects of SRS on human brain metastases have yet to be studied. We performed genomic analysis of resected brain metastases from patients whose resected lesion was previously treated with SRS. Our analyses demonstrated for the first time that patients possess a distinct genomic signature based on type of treatment failure including local failure, leptomeningeal spread, and radio-necrosis. Examination of the center and peripheral edge of the tumors treated with SRS indicated differential DNA damage distribution and an enrichment for tumor suppressor mutations and DNA damage repair pathways along the peripheral edge. Furthermore, the two clinical modalities used to deliver SRS, LINAC and GK, demonstrated differential effects on the tumor landscape even between controlled primary sites. Our study provides, in humans, biological evidence of differential effects of SRS across BM’s.
Project description:Genomic Analysis of Human Brain Metastases Treated with Stereotactic Radiosurgery Reveals Unique Signature Based on Treatment Failure.
Project description:Genomic Analysis of Human Brain Metastases Treated with Stereotactic Radiosurgery Reveals Unique Signature Based on Treatment Failure. [WES]
Project description:Genomic Analysis of Human Brain Metastases Treated with Stereotactic Radiosurgery Reveals Unique Signature Based on Treatment Failure. [RNA-Seq]
Project description:Stereotactic radiosurgery (SRS) and hypofractionated stereotactic radiotherapy (HFSRT) have become important treatment modalities for brain metastases. While effective, there are still areas of extensive debate on its appropriate use in patients with life-limiting diseases. This review provides an overview of the indications and challenges of SRS and HFSRT in the management of brain metastases.
Project description:Background and purposeCranial irradiation is associated with significant neurocognitive sequelae, secondary to radiation-induced damage to hippocampal cells. It has been shown that hippocampal-sparing (HS) leads to modest benefit in neurocognitive function in patients with brain metastases, but further improvement is possible. We hypothesized that improved benefits could be seen using HS in patients treated with stereotactic radiation (HS-SRS). Our study evaluated whether the hippocampal dose could be significantly reduced in the treatment of brain metastases using SRS, while maintaining target coverage.Materials and methodsSixty SRS plans were re-planned to minimize dose to the hippocampus while maintaining target coverage. Patients with metastases within 5 mm of the hippocampus were excluded. Minimum, mean, maximum and dose to 40% (mean equivalent dose in 2 Gy per fraction, EQD2 to the hippocampus) were compared between SRS and HS-SRS plans. Median number of brain metastases was two.ResultsCompared to baseline SRS plans, hippocampal-sparing plans demonstrated Dmin was reduced by 35%, from 0.4 Gy to 0.3 Gy (p-value 0.02). Similarly, Dmax was reduced by 55%, from 8.2 Gy to 3.6 Gy, Dmean by 52%, from 1.6 Gy to 0.5 Gy, and D40 by 50%, from 1.8 Gy to 0.9 Gy (p-values <0.001).ConclusionsOur study demonstrated that further reduction of hippocampal doses of more than 50% is possible in the treatment of brain metastases with SRS using dose optimization. This could result in significantly improved neurocognitive outcomes for patients treated for brain metastases.
Project description:Background and purposePatients with brain metastases (BMs) are surviving longer and returning for multiple courses of stereotactic radiosurgery. BMs are monitored after radiation with follow-up magnetic resonance (MR) imaging every 2-3 months. This study investigated whether it is possible to automatically track BMs on longitudinal imaging and quantify the tumor response after radiotherapy.MethodsThe METRO process (MEtastasis Tracking with Repeated Observations was developed to automatically process patient data and track BMs. A longitudinal intrapatient registration method for T1 MR post-Gd was conceived and validated on 20 patients. Detections and volumetric measurements of BMs were obtained from a deep learning model. BM tracking was validated on 32 separate patients by comparing results with manual measurements of BM response and radiologists' assessments of new BMs. Linear regression and residual analysis were used to assess accuracy in determining tumor response and size change.ResultsA total of 123 irradiated BMs and 38 new BMs were successfully tracked. 66 irradiated BMs were visible on follow-up imaging 3-9 months after radiotherapy. Comparing their longest diameter changes measured manually vs. METRO, the Pearson correlation coefficient was 0.88 (p < 0.001); the mean residual error was -8 ± 17%. The mean registration error was 1.5 ± 0.2 mm.ConclusionsAutomatic, longitudinal tracking of BMs using deep learning methods is feasible. In particular, the software system METRO fulfills a need to automatically track and quantify volumetric changes of BMs prior to, and in response to, radiation therapy.
Project description:PurposeStereotactic radiosurgery (SRS) in combination with immunotherapy (IMT) or targeted therapy is increasingly being used in the setting of melanoma brain metastases (MBMs). The synergistic properties of combination therapy are not well understood. We compared the distant intracranial failure rates of intact MBMs treated with SRS, SRS + IMT, and SRS + targeted therapy.Methods and materialsCombination therapy was defined as delivery of SRS within 3 months of IMT (anti-CTLA-4 /anti-PD-1 therapy) or targeted therapy (BRAF/MEK inhibitors). The primary endpoint was distant intracranial failure after SRS, which was defined as any new MBM identified on brain magnetic resonance imaging. Outcomes were evaluated using the Kaplan Meier method and Cox proportional hazards.ResultsA total of 72 patients with melanoma with 233 MBMs were treated between April 2006 and April 2016. The number of MBMs within each treatment group was as follows: SRS: 121; SRS + IMT: 48; and SRS + targeted therapy: 64. The median follow-up was 8.9 months. One-year distant intracranial control rates for SRS, SRS + IMT, and SRS + targeted therapy were 11.5%, 60%, and 10%, respectively (P < .001). On multivariate analysis, after adjusting for steroid use and number of MBMs, SRS + IMT remained associated with a significant reduction in distant intracranial failure compared with SRS (hazard ratio [HR], 0.48; 95% confidence interval [CI], 0.29-0.80; P = .003) and compared with SRS + targeted therapy (HR, 0.41; 95% CI, 0.25-0.68; P = .001).One-year local control for SRS, SRS + IMT, and SRS + targeted therapy was 66%, 85%, and 72%, respectively (P = .044). On multivariate analysis, after adjusting for dose, SRS + IMT remained associated with a significant reduction in local failure compared with SRS alone (HR, 0.37; 95% CI, 0.14-0.95; P = .04).ConclusionsSRS with immunotherapy is associated with decreased distant and local intracranial failure compared with SRS alone. Prospective studies are warranted to validate this result.