Simultaneous Treatment of Petroclival Meningiomas and the Trigeminal Nerve with Gamma Knife Radiosurgery for Tumor-Related Trigeminal Neuralgia

Some petroclival meningiomas cause trigeminal nerve compression, leading to disabling trigeminal neuralgia (TN). Tumor resection and nerve decompression can offer pain relief but might not be feasible in all patients. Simultaneous stereotactic radiosurgery (SRS) to the tumor and nerve is another option. SRS is an effective means of treating meningiomas and TN separately, but data on the efficacy and outcomes of their concomitant treatment are limited. We report a series of 4 patients who presented with TN secondary to a petroclival mass causing compression of the trigeminal nerve. All patients underwent SRS to both the petroclival mass and trigeminal nerve in a single session. The average margin tumor dose was 12.25 Gy (range, 12-12.5 Gy), and the average maximum trigeminal nerve dose was 80 Gy (range, 75-85 Gy). In all patients, before intervention, the Barrow Neurologic Institute (BNI) pain intensity score was grade IV or V. At last follow-up (average, 29.8 months), all patients were pain-free (BNI I or IIIA). Two patients experienced reduced facial sensation in 1 or all 3 distributions. No brainstem edema was seen. This series highlights the benefits and safety of simultaneous treatment of petroclival tumors and the trigeminal nerve in a single session for patients affected by tumor-related TN

RADI-28. UP-FRONT SINGLE SESSION RADIOSURGERY FOR LARGE BRAIN METASTASES - VOLUMETRIC RESPONSES AND OUTCOMES

OBJECTIVE: Patients presenting with large brain metastases (LBM), described in the literature as ≥2.5 cm in maximum diameter or ≥10cm 3 in volume, pose a management challenge. For patients not compromised by mass effect, corticosteroid therapy followed by SRS allows for efficient, minimal access care that facilitates immediate institution of systemic therapy. METHODS: We performed a volumetric-based analysis in order to determine the efficacy of single-session SRS in the treatment of LBM in comparison to other treatment modalities. Thirty patients over the age of 18 with systemic cancer and brain metastases (≥2.7cm in greatest diameter or ≥10cm 3 in volume) who underwent single session SRS were included. Serial tumor volumes, clinical outcomes, and medication requirements were studied. RESULTS: Among 30 patients, 70% of patients had either lung, melanoma, or breast cancer. Median initial tumor size (maximum diameter) was 32mm (range 28–43) and median initial tumor volume was 9.32cm 3 (range 1.09–25.31). Median marginal dose was 16Gy (range 12–18). Average percent decrease in tumor volume was 50% on imaging at 4–8 weeks, 60% at 4–6 months, 48% at 6–8 months, and 67% at >8 months compared to initial imaging. Only one patient required a subsequent craniotomy 4 years after SRS for an enlarging cyst which was granulation tissue consistent with radiation effects on pathology. There were no adverse events immediately following SRS. Median corticosteroid use after SRS was 21 days. There was no statistically significant difference in KPS score between treatment day and last follow up, suggesting relative safety and maintenance of function. CONCLUSION: Initial high dose corticosteroid therapy followed by prompt single session SRS is a safe and efficacious method of managing patients with large brain metastases (defined in our study as ≥2.7cm or ≥10cm 3 ), if the clinical condition of the patient is acceptable at presentation

RADI-27. ROLE OF STEREOTACTIC RADIOSURGERY IN THE CARE OF PATIENTS WITH >/= 25 CUMULATIVE BRAIN METASTASES

INTRODUCTION: Stereotactic radiosurgery (SRS) is an accepted treatment for multiple brain metastases. However, the upper limit of the number of brain metastases over the course of care suitable for this approach is controversial. METHODS: From a review of our prospective registry, 48 patients treated with SRS for ≥ 25 brain metastases in either single or multiple sessions between 2013 and 2019 were identified. Patient, tumor, and treatments characteristics were evaluated. Clinical outcomes and overall survival (OS) were analyzed. RESULTS: Thirty-one females (64.6%) and 17 males (35.4%) with a median age of 56 years (25–91) were included. Primary diagnoses included lung (n=23, 47.9%), breast (n=13, 27.1%), melanoma (n=8, 16.7%), and other (n=4, 8.33%). Initial median GPA index was 2 (0.5–3). Nine patients (18.8%) had received whole brain radiation therapy (WBRT) prior to first SRS treatment, with a median dose of 35Gy (30–40.5Gy). Ten patients (20.8%) received WBRT after initial SRS, with a median dose of 30Gy (20-30Gy). Thus, only 19 patients (40%) ever received WBRT. Median number of radiosurgeries per patient was 3 (1–12). Median number of cumulative tumors irradiated was 31 (25–110). Median number of tumors irradiated at first SRS was 10 (1–35). Median marginal dose for the largest tumor per session was 16Gy (10-21Gy). Median SRS total tumor volume was 6.8cc (0.8–23.4). Median follow-up since initial SRS was 16 months (1–71). At present, 21 (43.7%) are alive. Median OS from the diagnosis of brain metastases was 31 months (2–97), and OS from the time of first SRS, 22 months (1–70). Median KPS at first SRS and last follow-up was the same (90). Sixty-three percent did not require a corticosteroid course. CONCLUSION: In selected patients with a large number of cumulative brain metastases ( ≥ 25), SRS is effective and safe. Therefore, WBRT may not be required in this population

Up-front single-session radiosurgery for large brain metastases-volumetric responses and outcomes

BackgroundPatients presenting with large brain metastases (LBM) pose a management challenge to the multidisciplinary neuro-oncologic team. Treatment options include surgery, whole-brain or large-field radiation therapy (WBRT), stereotactic radiosurgery (SRS), or a combination of these.ObjectiveTo determine if corticosteroid therapy followed by SRS allows for efficient minimally invasive care in patients with LBMs not compromised by mass effect.MethodsWe analyzed the change in tumor volume to determine the efficacy of single-session SRS in the treatment of LBM in comparison to other treatment modalities. Twenty-nine patients with systemic cancer and brain metastasis (>= 2.7 cm in greatest diameter) who underwent single-session SRS were included.ResultsAmong 29 patients, 69% of patients had either lung, melanoma, or breast cancer. The median initial tumor size (maximal diameter) was 32 mm (range 28-43), and the median initial tumor volume was 9.56 cm(3) (range 1.56-25.31). The median margin dose was 16 Gy (range 12-18). The average percent decrease in tumor volume compared to pre-SRS volume was 55% on imaging at 1-2 months, 58% at 3-5 months, 64% at 6-8 months, and 57% at > 8 months. There were no adverse events immediately following SRS. Median corticosteroid use after SRS was 21 days. Median survival after radiosurgery was 15 months.ConclusionInitial high-dose corticosteroid therapy followed by prompt single-stage SRS is a safe and efficacious method to manage patients with LBMs (defined as >= 2.7 cm)

Survival and outcomes in patients with ≥ 25 cumulative brain metastases treated with stereotactic radiosurgery

OBJECTIVE In the era in which more patients with greater numbers of brain metastases (BMs) are being treated with stereotactic radiosurgery (SRS) alone, it is critical to understand how patient, tumor, and treatment factors affect functional status and overall survival (OS). The authors examined the survival outcomes and dosimetry to critical structures in patients treated with Gamma Knife radiosurgery (GKRS) for ≥ 25 metastases in a single session or cumulatively over the course of their disease. METHODS A retrospective analysis was conducted at a single institution. The institution’s prospective Gamma Knife (GK) SRS registry was queried to identify patients treated with GKRS for ≥ 25 cumulative BMs between June 2013 and April 2020. Ninety-five patients were identified, and their data were used for analysis. Treatment plans for dosimetric analysis were available for 89 patients. Patient, tumor, and treatment characteristics were identified, and outcomes and OS were evaluated. RESULTS The authors identified 1132 patients with BMs in their institutional registry. Ninety-five patients were treated for ≥ 25 cumulative metastases, resulting in a total of 3596 tumors treated during 373 separate treatment sessions. The median number of SRS sessions per patient was 3 (range 1–12 SRS sessions), with nearly all patients (n = 93, 98%) having > 1 session. On univariate analysis, factors affecting OS in a statistically significant manner included histology, tumor volume, tumor number, diagnosis-specific graded prognostic assessment (DS-GPA), brain metastasis velocity (BMV), and need for subsequent whole-brain radiation therapy (WBRT). The median of the mean WB dose was 4.07 Gy (range 1.39–10.15 Gy). In the top quartile for both the highest cumulative number and highest cumulative volume of treated metastases, the median of the mean WB dose was 6.14 Gy (range 4.02–10.15 Gy). Seventy-nine patients (83%) had all treated tumors controlled at last follow-up, reflecting the high and durable control rate. Corticosteroids for tumor- or treatment-related effects were prescribed in just over one-quarter of the patients. Of the patients with radiographically proven adverse radiation effects (AREs; 15%), 4 were symptomatic. Four patients required subsequent craniotomy for hemorrhage, progression, or AREs. CONCLUSIONS In selected patients with a large number of cumulative BMs, multiple courses of SRS are feasible and safe. Together with new systemic therapies, the study results demonstrate that the achieved survival rates compare favorably to those of larger contemporary cohorts, while avoiding WBRT in the majority of patients. Therefore, along with the findings of other series, this study supports SRS as a standard practice in selected patients with larger numbers of BMs

A Novel Variant of the Aortic Arch Great Vessels

Congenital variants of the aortic arch are important to recognize not only for their association with congenital heart disease, vascular rings, and chromosomal abnormalities but also for the purposes of neurointerventional angiography. While many different variants have been reported in the literature, we present two rare cases of an aortic arch variant that, to the best of our knowledge, has not yet been described in the literature- an anteriorly-directed, independent common origin of both carotid arteries from the ascending aorta, with separate subclavian artery trunks originating from the arch

Hippocampal sparing in patients receiving radiosurgery for ≥25 brain metastases

•89 patients treated with stereotactic radiosurgery for ≥25 brain metastases.•More than half had tumors within the hippocampal avoidance region.•Patients with tumors involving the hippocampus had the highest median Dmin.•Even with tumors in the hippocampal avoidance regions, stereotactic affords hippocampal sparing. To report our dosimetric analysis of the hippocampi (HC) and the incidence of perihippocampal tumor location in patients with ≥25 brain metastases who received stereotactic radiosurgery (SRS) in single or multiple sessions. Analysis of our prospective registry identified 89 patients treated with SRS for ≥25 brain metastases. HC avoidance regions (HA-region) were created on treatment planning MRIs by 5 mm expansion of HC. Doses from each session were summed to calculate HC dose. The distribution of metastases relative to the HA-region and the HC was analyzed. Median number of tumors irradiated per patient was 33 (range 25–116) in a median of 3 (range1–12) sessions. Median bilateral HC Dmin (D100), D40, D50, Dmax, and Dmean (Gy) was 1.88, 3.94, 3.62, 16.6, and 3.97 for all patients, and 1.43, 2.99, 2.88, 5.64, and 3.07 for patients with tumors outside the HA-region. Multivariate linear regression showed that the median HC D40, D50, and Dmin were significantly correlated with the tumor number and tumor volume (p < 0.001). Of the total 3059 treated tumors, 83 (2.7%) were located in the HA-region in 57% evaluable patients; 38 tumors (1.2%) abutted or involved the HC itself. Hippocampal dose is higher in patients with tumors in the HA-region; however, even for patients with a high burden of intracranial disease and tumors located in the HA-regions, SRS affords hippocampal sparing. This is particularly relevant in light of our finding of eventual perihippocampal metastases in more than half of our patients