Hypo-Fractionated Stereotactic Radiosurgery for the Management of Brain Metastases

The increasing prevalence of brain metastases in cancer patients due to longer life expectancy and improvements in neuroimaging highlights the need for effective local treatments. Despite advancements in systemic targeted therapies, their low blood–brain barrier (BBB) penetrance limits their intracranial efficacy. Stereotactic radiosurgery (SRS) has largely supplanted whole-brain radiation therapy (WBRT) for patients with up to 10 brain lesions due to superior neurocognitive outcomes and high local control. While single-fraction SRS provides low radiation toxicity with smaller lesions, high-volume metastases necessitate doses above tolerance limits to achieve comparable local control. As tumor volume increases, the number of tumor cells also increases, requiring higher doses of radiation than the maximum tolerated doses reported in the RTOG 9005 study to achieve tumor control. Hypo-fractionated SRS (HySRS) permits the delivery of high radiation doses over 2–5 fractions, thus mitigating the risk of radiation toxicity while maintaining high local control. This review presents the available evidence and ongoing clinical trials on HySRS for the management of brain metastases

EXTH-57. INVESTIGATION OF THE TUMORICIDAL EFFECTS OF SONODYNAMIC THERAPY IN MALIGNANT GLIOBLASTOMA BRAIN TUMORS

Abstract OBJECTIVE Glioblastoma is the most common primary brain tumor; survival is typically 12–18 months after diagnosis. We sought to study the effects of sonodynamic therapy (SDT) using 5-Aminolevulinic acid hydrochloride (5-ALA) and high frequency focused ultrasound (FUS) on 2 glioblastoma cell lines. PROCEDURE Rat C6 and human U87 glioblastoma cells were studied under the following conditions: 1mM 5-ALA (5-ALA); Focused ultrasound (FUS); 5-ALA and focused ultrasound (SDT); control. Studied responses included cell viability using an MTT assay, microscopic changes using phase contract microscopy, apoptotic induction through a caspase-3 assay, and apoptosis staining to quantify cell death. RESULTS SDT led to a marked decrease in cell extension and reduction in cell size. For C6, the MTT assay showed reductions in cell viability for 5-ALA, FUS, and SDT groups of 5%, 16%, and 47%, respectively compared to control (p&amp;lt; 0.05). Caspase 3 induction in C6 cells relative to control showed increases of 109%, 110%, and 278% for 5-ALA, FUS, and SDT groups, respectively (p&amp;lt; 0.05). For the C6 cells, caspase 3 staining positivity was 2.1%, 6.7%, 11.2%, and 39.8% for control, 5-ALA, FUS, and SDT groups, respectively. C6 Parp-1 staining positivity was 1.9%, 6.5%, 9.0%, and 37.8% for control, 5-ALA, FUS, and SDT groups, respectively. U87 cells showed similar responses to the treatments. CONCLUSIONS Sonodynamic therapy resulted in appreciable glioblastoma cell death as compared to 5-ALA or FUS alone. The approach couples two already FDA approved techniques in a novel way to treat the most aggressive and malignant of brain tumors. Further study of this promising technique is planned using glioma and also brain metastasis models. </jats:sec

Evaluating and reducing xerosis in competitive swimmers: an in vitro study and randomized controlled clinical trial

Introduction: Xerosis is a common problem with significant sequelae in competitive swimmers, and it results from transepidermal water loss. This study evaluates moisture barriers for reducing xerosis in competitive swimmers. Methods: An artificial skin model was used to evaluate five products. Models were measured for changes in thickness and weight over 7 days. The optimal barrier was tested in a randomized controlled trial (RCT) of 20 swimmers. Skin moisture content was serially measured. Skin micrographs were scored in a blinded fashion. Results: The moisture barrier #1 treated skin model at day 7 maintained a mean thickness of 7.08 mm versus 2.38 mm for control (p = .0001). The mean weights of group 1 treated and control groups at day 7 were 40.1 and 8.65 g (p = .03). In the RCT, the group treated with moisture barrier #1 and the controls exhibited low moisture content and moderate xerosis scores at baseline. At week 3, moisture measurements for treated and control groups were 28.6% and 18.2% (p = .003). The mean xerosis scores for the treated and control groups were 8.5 and 12.9 (p = .0008). Conclusions: Artificial skin preservation varied for five commercially available moisture barriers. Moisture barrier application improved moisture content and reduced xerosis in competitive swimmers.</p

Effect of Prior Embolization on Outcomes After Stereotactic Radiosurgery for Pediatric Brain Arteriovenous Malformations: An International Multicenter Study

BACKGROUND: Pediatric brain arteriovenous malformations (AVMs) are a significant cause of morbidity but the role of multimodal therapy in the treatment of these lesions is not well understood. OBJECTIVE: To compare the outcomes of stereotactic radiosurgery (SRS) with and without prior embolization for pediatric AVMs. METHODS: We retrospectively evaluated the International Radiosurgery Research Foundation pediatric AVM database. AVMs were categorized, based on use of preembolization (E+ SRS) or lack thereof (SRS-only). Outcomes were compared in unadjusted and inverse probability weight (IPW)-adjusted models. Favorable outcome was defined as obliteration without post-SRS hemorrhage or permanent radiation-induced changes (RIC). RESULTS: The E+ SRS and SRS-only cohorts comprised 91 and 448 patients, respectively. In unadjusted models, the SRS-only cohort had higher rates of obliteration (68.5% vs 43.3%, P<.001) and favorable outcome (61.2% vs 36.3%, P<.001) but a lower rate of symptomatic RIC (9.0% vs 16.7%, P=.031). The IPW-adjusted rates of every outcomewere similar between the 2 cohorts. However, cumulative obliteration rates at 3, 5, 8, and 10 yr remained higher in the absence of prior embolization (46.3%, 64.6%, 72.6%, and 77.4% for SRS-only vs 24.4%, 37.2%, 44.1%, and 48.7% for E+ SRS cohorts, respectively; SHR= 0.449 [0.238-0.846], P=.013). CONCLUSION: Embolization appears to decrease cumulative obliteration rates after SRS for pediatric AVMs without affecting the risk of post-treatment hemorrhage or adverse radiation effects arguing against the routine use of pre-SRS embolization. While endovascular therapy can be considered for occlusion of high-risk angioarchitectural features prior to SRS, future studies are necessary to clarify its role