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:IntroductionDue to the neurocognitive side effects of whole brain radiation therapy (WBRT), stereotactic radiosurgery (SRS) is being used with increasing frequency. The use of SRS is expanding for patients with multiple (>4) brain metastases (BM). This study summarizes our institutional experience with single-fraction, linear-accelerator-based SRS for multiple BM.Methods and materialsAll patients who were treated between January 1, 2013, and September 30, 2015, with single-fraction SRS for ≥4 BM were included in this institutional review board-approved, retrospective, single-institution study. Patients were treated with linear accelerator-based image guided SRS.ResultsA total of 59 patients with ≥4 BM were treated with single-fraction SRS. The median follow-up was 15.2 months, and the median overall survival for the entire cohort was 5.8 months. The median number of treated lesions per patient was 5 (range, 4-23). Per patient, the median planning target volume (PTV) was 4.8 cc (range, 0.7-28.8 cc). The prescribed dose across all 380 BM for the 59 patients ranged from 7 to 20 Gy. The median of the mean dose to the total PTV was 19.5 Gy. Although the number of treated lesions (4-5 vs ≥6) did not influence survival, better survival was noted for a total PTV <10 cc versus ≥10 cc (7.1 vs 4.2 months, respectively; P = .0001). A mean dose of ≥19 Gy to the entire PTV was also associated with increased survival (6.6 vs 5.0 months, respectively; P = .0172). Patients receiving a dose of >12 Gy to ≥10 cc of normal brain had worse survival (5.1 vs 8.6 months, respectively; P = .0028).ConclusionIn single-fraction SRS for patients with multiple BM, smaller total tumor volume, higher total dose, and lower volume of normal brain receiving >12 Gy were associated with increased survival. These data suggest that using SRS for the treatment of multiple BM is efficacious and that outcomes may be affected more by total tumor volume than by the number of lesions.
Project description:BackgroundStereotactic radiosurgery (SRS) is a frequently chosen treatment for patients with brain metastases and the number of long-term survivors is increasing. Brain necrosis (e.g. radionecrosis) is the most important long-term side effect of the treatment. Retrospective studies show a lower risk of radionecrosis and local tumor recurrence after fractionated stereotactic radiosurgery (fSRS, e.g. five fractions) compared with stereotactic radiosurgery in one or three fractions. This is especially true for patients with large brain metastases. As such, the 2022 ASTRO guideline of radiotherapy for brain metastases recommends more research to fSRS to reduce the risk of radionecrosis. This multicenter prospective randomized study aims to determine whether the incidence of adverse local events (either local failure or radionecrosis) can be reduced using fSRS versus SRS in one or three fractions in patients with brain metastases.MethodsPatients are eligible with one or more brain metastases from a solid primary tumor, age of 18 years or older, and a Karnofsky Performance Status ≥ 70. Exclusion criteria include patients with small cell lung cancer, germinoma or lymphoma, leptomeningeal metastases, a contraindication for MRI, prior inclusion in this study, prior surgery for brain metastases, prior radiotherapy for the same brain metastases (in-field re-irradiation). Participants will be randomized between SRS with a dose of 15-24 Gy in 1 or 3 fractions (standard arm) or fSRS 35 Gy in five fractions (experimental arm). The primary endpoint is the incidence of a local adverse event (local tumor failure or radionecrosis identified on MRI scans) at two years after treatment. Secondary endpoints are salvage treatment and the use of corticosteroids, bevacizumab, or antiepileptic drugs, survival, distant brain recurrences, toxicity, and quality of life.DiscussionCurrently, limiting the risk of adverse events such as radionecrosis is a major challenge in the treatment of brain metastases. fSRS potentially reduces this risk of radionecrosis and local tumor failure.Trial registrationClincalTrials.gov, trial registration number: NCT05346367 , trial registration date: 26 April 2022.
Project description:ObjectiveFor patients with surgically accessible solitary metastases or oligometastatic disease, treatment often involves resection followed by postoperative stereotactic radiosurgery (SRS). This strategy has several potential drawbacks, including irregular target delineation for SRS and potential tumor "seeding" away from the resection cavity during surgery. A neoadjuvant (preoperative) approach to radiation therapy avoids these limitations and offers improved patient convenience. This study assessed the efficacy of neoadjuvant SRS as a new treatment paradigm for patients with brain metastases.MethodsA retrospective review was performed at a single institution to identify patients who had undergone neoadjuvant SRS (specifically, Gamma Knife radiosurgery) followed by resection of a brain metastasis. Kaplan-Meier survival and log-rank analyses were used to evaluate risks of progression and death. Assessments were made of local recurrence and leptomeningeal spread. Additionally, an analysis of the contemporary literature of postoperative and neoadjuvant SRS for metastatic disease was performed.ResultsTwenty-four patients who had undergone neoadjuvant SRS followed by resection of a brain metastasis were identified in the single-institution cohort. The median age was 64 years (range 32-84 years), and the median follow-up time was 16.5 months (range 1 month to 5.7 years). The median radiation dose was 17 Gy prescribed to the 50% isodose. Rates of local disease control were 100% at 6 months, 87.6% at 12 months, and 73.5% at 24 months. In 4 patients who had local treatment failure, salvage therapy included repeat resection, laser interstitial thermal therapy, or repeat SRS. One hundred thirty patients (including the current cohort) were identified in the literature who had been treated with neoadjuvant SRS prior to resection. Overall rates of local control at 1 year after neoadjuvant SRS treatment ranged from 49% to 91%, and rates of leptomeningeal dissemination from 0% to 16%. In comparison, rates of local control 1 year after postoperative SRS ranged from 27% to 91%, with 7% to 28% developing leptomeningeal disease.ConclusionsNeoadjuvant SRS for the treatment of brain metastases is a novel approach that mitigates the shortcomings of postoperative SRS. While additional prospective studies are needed, the current study of 130 patients including the summary of 106 previously published cases supports the safety and potential efficacy of preoperative SRS with potential for improved outcomes compared with postoperative SRS.
Project description:The management of brain metastases (BM) remains an important and complex issue in the treatment of cancer-related neurological complications. BM are particularly common in patients diagnosed with lung, melanoma, or breast cancer. Over the past decade, therapeutic approaches for the majority of BM patients have changed. Considering and addressing the fact that patients with BM are living longer, the need to provide effective local control while preserving quality of life and neurocognition is fundamental. Over the past decade, SRS and SRT have become a more commonly chosen treatment option for BM. Despite significant advances in the treatment of BM, numerous questions remain regarding patient selection and optimal treatment sequencing. Clinical trials are critical to advancing our understanding of BM, especially as more therapeutic alternatives become available. Therefore, it is imperative for interdisciplinary teams to improve their understanding of the latest advances in SRS-SRT. This review aims to comprehensively explore SRS and SRT as treatments for BM, covering clinical considerations in their application (e.g., patient selection and eligibility), managing limited and multiple intact BM, addressing brainstem metastases, exploring combination therapies with systemic treatments, and considering the health economic perspective.
Project description:BackgroundBrain metastases (BM) pose a significant problem in patients with metastatic renal-cell carcinoma (mRCC). Local and systemic therapies including stereotactic radiosurgery (SRS) are rapidly evolving, necessitating reassessments of outcomes for modern patient management.Patients and methodsThe mRCC patients with BM treated with SRS were reviewed. Patient demographics, clinical history, and SRS treatment parameters were identified.ResultsAmong 268 patients with mRCC treated between 2006 and 2015, 38 patients were identified with BM. A total of 243 BM were treated with SRS with 1 to 26 BMs treated per SRS session (median, 2 BMs). The median (range) BM size was 0.6 (0.2-3.1) cm and median (range) SRS treatment dose was 18 (12-24) Gy. Treated BM local control rates at 1 and 2 years were 91.8% (95% confidence interval, 85.7-95.4) and 86.1% (95% confidence interval, 77.1-91.7), respectively. BM control declined for larger tumors. Survival after 1-year was 57.5% (95% CI 40.2-71.4) for all patients. Survival was not statistically different between patients with < 5 BM versus ≥ 5 BM. Survival was prognostic based on International Metastatic Renal Cell Carcinoma Database (IMDC) risk groups in patients with < 5 BM. Two patients experienced grade 3 radiation necrosis requiring surgical intervention.ConclusionSRS is effective in controlling BM in patients with mRCC. Over half of treated patients survive past a year, and no differences in survival were noted in patients with > 5 metastases. Prognostic risk categories based on systemic disease (IMDC) are predictive of survival in this BM population, with limited rates of symptomatic radiation necrosis.
Project description:Brain metastasis (BM) represents a common complication of cancer, and in the modern era requires multi-modal management approaches and multi-disciplinary care. Traditionally, due to the limited efficacy of cytotoxic chemotherapy, treatment strategies are focused on local treatments alone, such as whole-brain radiotherapy (WBRT), stereotactic radiosurgery (SRS), and resection. However, the increased availability of molecular-based therapies with central nervous system (CNS) penetration now permits the individualized selection of tailored systemic therapies to be used alongside local treatments. Moreover, the introduction of immune checkpoint inhibitors (ICIs), with demonstrated CNS activity has further revolutionized the management of BM patients. The rapid introduction of these cancer therapeutics into clinical practice, however, has led to a significant dearth in the published literature about the optimal timing, sequencing, and combination of these systemic therapies along with SRS. This manuscript reviews the impact of tumor biology and molecular profiles on the management paradigm for BM patients and critically analyzes the current landscape of SRS, with a specific focus on integration with systemic therapy. We also discuss emerging treatment strategies combining SRS and ICIs, the impact of timing and the sequencing of these therapies around SRS, the effect of corticosteroids, and review post-treatment imaging findings, including pseudo-progression and radiation necrosis.
Project description:Stereotactic radiosurgery (SRS) is the delivery of a high dose ionizing radiation in a highly conformal manner, which allows for significant sparing of nearby healthy tissues. It is typically delivered in 1-5 sessions and has demonstrated safety and efficacy across multiple intracranial neoplasms and functional disorders. In the setting of brain metastases, postoperative and definitive SRS has demonstrated favorable rates of tumor control and improved cognitive preservation compared to conventional whole brain radiation therapy. However, the risk of local failure and treatment-related complications (e.g. radiation necrosis) markedly increases with larger postoperative treatment volumes. Additionally, the risk of leptomeningeal disease is significantly higher in patients treated with postoperative SRS. In the setting of high grade glioma, preclinical reports have suggested that preoperative SRS may enhance anti-tumor immunity as compared to postoperative radiotherapy. In addition to potentially permitting smaller target volumes, tissue analysis may permit characterization of DNA repair pathways and tumor microenvironment changes in response to SRS, which may be used to further tailor therapy and identify novel therapeutic targets. Building on the work from preoperative SRS for brain metastases and preclinical work for high grade gliomas, further exploration of this treatment paradigm in the latter is warranted. Presently, there are prospective early phase clinical trials underway investigating the role of preoperative SRS in the management of high grade gliomas. In the forthcoming sections, we review the biologic rationale for preoperative SRS, as well as pertinent preclinical and clinical data, including ongoing and planned prospective clinical trials.
Project description:Solid tumors metastasizing to the brain are a frequent occurrence with an estimated incidence of approximately 30% of all cases. The longstanding conventional standard of care comprises surgical resection and whole-brain radiotherapy (WBRT); however, this approach is associated with limited long-term survival and local control outcomes. Consequently, stereotactic radiosurgery (SRS) has emerged as a potential alternative approach. The primary aim of SRS has been to improve long-term control rates. Nevertheless, rare observations of abscopal or out-of-field effects have sparked interest in the potential to elicit antitumor immunity via the administration of high-dose radiation. The blood-brain barrier (BBB) has traditionally posed a significant challenge to the efficacy of systemic therapy in managing intracranial metastasis. However, recent insights into the immune-brain interface and the development of immunotherapeutic agents have shown promise in preclinical and early-phase clinical trials. Researchers have investigated combining immunotherapy with SRS to enhance treatment outcomes in patients with brain metastasis. The combination approach aims to optimize long-term control and overall survival (OS) outcomes by leveraging the synergistic effects of both therapies. Initial findings have been encouraging in the management of various intracranial metastases, while further studies are required to determine the optimal order of administration, radiation doses, and fractionation regimens that have the potential for the best tumor response. Currently, several clinical trials are underway to assess the safety and efficacy of administering immunotherapeutic agents concurrently or consecutively with SRS. In this review, we conduct a comprehensive analysis of the advantages and drawbacks of integrating immunotherapy into conventional SRS protocols for the treatment of intracranial metastasis.