Faculty Bibliography

BACKGROUND AND OBJECTIVES/OBJECTIVE:Trigeminal Neuralgia (TN) is a debilitating facial pain disorder, often necessitating surgical interventions when medication proves insufficient. Stereotactic Radiosurgery (SRS) is an established therapeutic option. Limited studies explored the feasibility of a third SRS procedure. Our study investigates the safety and efficacy of a third SRS procedure for recurrent TN. METHODS:We performed a retrospective analysis across multiple centers using databases collected prospectively. Pain status was evaluated utilizing the BNI Pain Intensity Scales. The Kaplan-Meier method was employed to estimate the time to recurrence, with group comparisons conducted using log-rank tests. Associations were explored using Chi-square and logistic regression models. RESULTS:Ten institutions contributed with a total of 35 patients. A third SRS revealed sustained effectiveness with a pain control rate of 82.7%. The median time to recurrence was 35.5 months. New sensory dysfunction following the third procedure occurred in 22% of patients who had preserved sensory function after the second procedure. When considering those who developed sensory dysfunction after the second procedure, 40% of the entire cohort was affected. There were no significant differences in pain recurrence intervals among the three procedures. A meta-analysis, combining data from previous studies, showed that 89.6% of patients achieved some degree of pain control after a third SRS, with 27.4% experiencing new sensory dysfunction and a median time to recurrence of 31.6 months. CONCLUSION/CONCLUSIONS:Our study, the largest on the topic, affirms the sustained effectiveness of a third SRS for TN, providing comparable pain relief to initial procedures. Notably, an extended pain-free interval after the third SRS session was observed. Facial sensory dysfunction emerged as the primary side effect. Larger studies are warranted to explore correlations with demographics and treatment parameters for a comprehensive understanding of repeat SRS in managing recurrent TN.

OBJECTIVE:Cerebral cavernous malformations (CCMs) are the second most common vascular anomaly affecting the CNS in children. Although stereotactic radiosurgery (SRS) has been proposed as an alternative to microsurgery in the management of selected cases in adults, there is a paucity of studies focusing on pediatric patients. The aim of this study was to present the outcomes and associated risks of SRS in this subgroup of patients. METHODS:This retrospective multicenter study included pediatric patients treated with single-session SRS for CCMs. The annual hemorrhage rate (AHR) was calculated before and after SRS in hemorrhagic lesions. The Engel classification was used to describe post-SRS epileptic control. Adverse radiation effects (AREs) and the occurrence of new neurological deficits were recorded. RESULTS:The study included 50 patients (median age 15.1 [IQR 5.6] years) harboring 62 CCMs. Forty-two (84%) and 22 (44%) patients had a history of hemorrhage or epilepsy prior to SRS, respectively. The AHR from diagnosis to SRS excluding the first hemorrhage was 7.19 per 100 CCM-years, dropping to 3.15 per 100 CCM-years after treatment. The cumulative risk of first hemorrhage after SRS was 7.4% (95% CI 0%-14.3%) at 5 years and 23.6% (95% CI 0%-42.2%) at 10 years. Eight hemorrhagic events involving 6 CCMs in 6 patients were recorded in the post-SRS follow-up period; 4 patients presented with transient symptoms and 4 with permanent symptoms. Of the 22 patients with pre-SRS seizures, 11 were seizure free at the last follow-up (Engel class I), 6 experienced improvement (Engel class II or III), 5 had no improvement (Engel class IVA or IVB), and 1 experienced worsening (Engel class IVC). Radiographic AREs were documented in 14.5% (9/62) of CCMs, with 4 being symptomatic. CONCLUSIONS:Single-session SRS reduces the CCM hemorrhage rate in the pediatric population and provides adequate seizure control.

BACKGROUND:Higher risk of secondary brain tumor, carotid stenosis and stroke has been reported after conventional sella irradiation for pituitary neuroendocrine tumors (PitNET). Stereotactic radiosurgery (SRS), which is a more focused approach, is now increasingly used instead. The aim was to assess the risk of secondary brain tumor, carotid stenosis/occlusion and stroke after SRS. METHODS:In this multicentric retrospective study, 2,254 patients with PitNET were studied, 1,377 in the exposed group and 877 in the control group. RESULTS:There were 9,840.1 patient-years at risk for the SRS and 5,266.5 for the control group. The 15-year cumulative probability of secondary intracranial tumor was 2.3% (95%CI:0.5%, 4.1%) for SRS and 3.7% (95%CI:0%, 8.7%) for the control group (p=0.6), with an incidence rate of 1.32 per 1,000 and 0.95 per 1,000, respectively. SRS was not associated with increased risk of tumorigenesis when stratified by age (HR: 1.59 [95%CI: 0.57, 4.47], p=0.38). The 15-year probability of new carotid stenosis/occlusion was 0.9% (95%CI: 0.2, 1.6) in the SRS and 2% (95%CI: 0, 4.4) in the control group (p=0.8). The 15-year probability of stroke was 2.6% (95%CI: 0.6%, 4.6%) in the SRS and 11.1% (95%CI: 6%, 15.9%) in the control group (p<0.001). In cox multivariate analysis stratified by age, SRS (HR 1.85[95%CI:0.64, 5.35], p=0.26) was not associated with risk of new stroke. CONCLUSION/CONCLUSIONS:No increased risk of long-term secondary brain tumor, new stenosis or occlusion and stroke was demonstrated in SRS group compared to control in this study with imaging surveillance.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Infratentorial arteriovenous malformations (AVMs) harbor different characteristics compared with supratentorial AVMs. This study aims to explore the unique characteristics of pediatric infratentorial AVMs and their response to single session stereotactic radiosurgery (SRS). METHODS:The International Radiosurgery Research Foundation database of pediatric patients with AVM (age <18 years) who underwent SRS was retrospectively reviewed. Baseline demographics, AVM characteristics, outcomes, and complications post-SRS were compared between infratentorial and supratentorial pediatric AVMs. Unfavorable outcome was defined as the absence of AVM obliteration, post-SRS hemorrhage, or permanent radiation-induced changes at last follow-up. RESULTS:A total of 535 pediatric AVMs managed with SRS with a median follow-up of 67 months (IQR 29.0-130.6) were included, with 69 being infratentorial and 466 supratentorial. The infratentorial group had a higher proportion of deep location (58.4% vs 30.3%, P = <.001), deep venous drainage (79.8% vs 61.8%, P = .004), and prior embolization (26.1% vs 15.7%, P = .032). There was a higher proportion of hemorrhagic presentation in the infratentorial group (79.7% vs 71.3%, P = .146). There was no statistically significant difference in the odds of an unfavorable outcome (odds ratio [OR] = 1.36 [0.82-2.28]), AVM obliteration (OR = 0.85 [0.5-1.43]), post-SRS hemorrhage (OR = 0.83 [0.31-2.18]), or radiologic radiation-induced changes (OR = 1.08 [0.63-1.84]) between both cohorts. No statistically significant difference on the rates of outcomes of interest and complications were found in the adjusted model. CONCLUSION/CONCLUSIONS:Despite baseline differences between infratentorial and supratentorial pediatric AVMs, SRS outcomes, including AVM obliteration and post-SRS hemorrhage rates, were comparable amongst both groups. SRS appears to have a similar risk profile and therapeutic benefit to infratentorial pediatric AVMs as it does for those with a supratentorial location.

OBJECTIVE:Accounting for approximately 15% of primary liver cancers and 3% of gastrointestinal malignancies, cholangiocarcinoma (CCA) poses a serious health concern given its high mortality rate. Managing brain metastases (BMs) from CCA is challenging because of their rarity and poor prognosis, with little guidance on treatment from the literature. In this study, the authors aimed to evaluate the safety and efficacy of stereotactic radiosurgery (SRS) in managing BMs from CCA. METHODS:This multicenter retrospective study included 13 CCA patients with 41 BMs treated with SRS from October 2006 to April 2022 at eight institutions affiliated with the International Radiosurgery Research Foundation. Inclusion criteria were a CCA diagnosis, an age over 18 years, no other malignancies, single-fraction SRS treatment for BMs, and at least one follow-up image. Data on demographics, tumor characteristics, treatment details, and outcomes were collected. The primary endpoints were local control (LC), intracranial progression-free survival (PFS), and overall survival (OS). The secondary endpoint was the development of adverse radiation effects (AREs). RESULTS:The median radiological follow-up was 5 months (range 1-18 months). At the last follow-up, LC was achieved in 39 (95.1%) of 41 BMs. New distant metastases were observed in 3 patients (23.1%), and the mean intracranial PFS was 9.4 months (95% CI 6.5-12.3 months). Six-month and 1-year OS rates were 38.5% and 11.5%, respectively, and the median OS was 6 months (95% CI 4.9-7.2 months). Concurrent immunotherapy was associated with a high risk of local failure (HR 29.665, 95% CI 1.799-489.206, p = 0.018), and the absence of systemic chemotherapy before SRS was linked to reduced OS (HR 6.658, 95% CI 1.173-37.776, p = 0.032). Regarding AREs, only 1 patient (7.7%) experienced right hemiparesis and was treated with corticosteroid therapy. CONCLUSIONS:SRS is an effective option for managing BMs in CCA patients, showing promise in LC and a high safety profile.

Objectives To characterize treatment and hearing outcomes for cerebellopontine angle (CPA) meningiomas with inherent risks of hearing loss and identify predictors of hearing loss for surgically treated lesions. Design Retrospective chart review. Setting Tertiary care medical center. Participants Adult patients with CPA meningiomas impinging upon cranial nerve VIII and/or pretreatment hearing loss managed with microsurgery or stereotactic radiosurgery (SRS) with Gamma Knife at our center between 2012 and 2023. Main Outcome Measures Hearing preservation rate was determined from analysis of patients with pretreatment serviceable hearing for whom hearing-preserving treatment was attempted. Surgical patients were further analyzed using multivariable Cox proportional hazards regression models to identify factors predictive of postoperative hearing loss. Results We identified 80 patients with CPA meningiomas meeting inclusion criteria who were managed with either microsurgery (43, 54%) or radiosurgery (37, 46%). Following SRS, hearing was preserved in 88% of cases. Following microsurgery, hearing was preserved in 71% of patients-all patients who lost hearing had tumors involving the internal auditory canal (IAC). Among surgical patients only, multivariable analysis accounting for preoperative hearing, recurrence status, lesion size, and patient age, the preoperative imaging finding that the CPA meningioma surrounded the vestibulocochlear nerve was significantly associated with hearing loss (hazard ratio: 10.3, 95% confidence interval: 1.3-81.4, p = 0.02). Conclusion Most patients with meningiomas of the CPA can experience preservation of hearing, even when there is risk of hearing loss based on pretreatment evaluation. IAC invasion and surrounding of eighth nerve by tumor may portend poorer hearing outcomes in surgically managed patients.

The detection and tracking of metastatic cancer over the lifetime of a patient remains a major challenge in clinical trials and real-world care. Advances in deep learning combined with massive datasets may enable the development of tools that can address this challenge. We present NYUMets-Brain, the world's largest, longitudinal, real-world dataset of cancer consisting of the imaging, clinical follow-up, and medical management of 1,429 patients. Using this dataset we developed Segmentation-Through-Time, a deep neural network which explicitly utilizes the longitudinal structure of the data and obtained state-of-the-art results at small (<10 mm³) metastases detection and segmentation. We also demonstrate that the monthly rate of change of brain metastases over time are strongly predictive of overall survival (HR 1.27, 95%CI 1.18-1.38). We are releasing the dataset, codebase, and model weights for other cancer researchers to build upon these results and to serve as a public benchmark.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Studies comparing neurological and radiographic outcomes of repeat to initial stereotactic radiosurgery (SRS) intracranial arteriovenous malformations are scarce. Our aim was to perform a retrospective matched comparison of patients initially treated with SRS with those undergoing a second radiosurgical procedure. METHODS:We collected data from arteriovenous malformations managed in 21 centers that underwent initial and repeated radiosurgery from 1987 to 2022. Based on arteriovenous malformations volume, margin dose, deep venous drainage, deep, and critical location, we matched 1:1 patients who underwent an initial SRS for treatment-naive arteriovenous malformations and a group with repeated SRS treatment. RESULTS:After the selection process, our sample consisted of 328 patients in each group. Obliteration in the initial SRs group was 35.8% at 3 and 56.7% at 5 years post-SRS, while the repeat SRS group showed obliteration rates of 33.9% at 3 years and 58.6% at 5 years, without statistically significant differences (P = .75 and P = .88, respectively). There were no statistically significant differences between the 2 groups for obliteration rates (hazard ratio = 0.93; 95% CI, 0.77-1.13; P = .5), overall radiation-induced changes (RIC) (OR = 1.1; 95% CI, 0.75-1.6; P = .6), symptomatic RIC (OR = 0.78; 95% CI, 0.4-1.5; P = .4), and post-SRS hemorrhage (OR = 0.68; 95% CI; P = .3). CONCLUSION/CONCLUSIONS:In matched cohort analysis, a second SRS provides comparable outcomes in obliteration and RIC compared with the initial SRS. Dose reduction on repeat SRS may not be warranted.

OBJECTIVE:Concussions can occur at any level of ice hockey. Incidence estimates of concussions in ice hockey vary, and optimal prevention strategies and return-to-play (RTP) considerations have remained in evolution. The authors performed a mixed-methods study with the aim of elucidating the landscape of concussion in ice hockey and catalyzing initiatives to standardize preventative mechanisms and RTP considerations. METHODS:The authors performed a five-part mixed-methods study that includes: 1) an analysis of the impact of concussions on games missed and income for National Hockey League (NHL) players using a publicly available database, 2) a systematic review of the incidence of concussion in ice hockey, 3) a systematic review of preventative strategies, 4) a systematic review of RTP, and 5) a policy review of documents from major governing bodies related to concussions in sports with a focus on ice hockey. The PubMed, Embase, and Scopus databases were used for the systematic reviews and focused on any level of hockey. RESULTS:In the NHL, 689 players had 1054 concussions from the 2000-2001 to 2022-2023 seasons. A concussion led to a mean of 13.77 ± 19.23 (range 1-82) games missed during the same season. After cap hit per game data became available in 2008-2009, players missed 10,024 games due to 668 concussions (mean 15.13 ± 3.81 per concussion, range 8.81-22.60 per concussion), with a cap hit per game missed of $35,880.85 ± $25,010.48 (range $5792.68-$134,146.30). The total cap hit of all missed games was $385,960,790.00, equating to $577,635.91 per concussion and $25,724,052.70 per NHL season. On systematic review, the incidence of concussions was 0.54-1.18 per 1000 athlete-exposures. Prevention mechanisms involved education, behavioral and cognitive interventions, protective equipment, biomechanical studies, and policy/rule changes. Rules prohibiting body checking in youth players were most effective. Determination of RTP was variable. Concussion protocols from both North American governing bodies and two leagues mandated that a player suspected of having a concussion be removed from play and undergo a six-step RTP strategy. The 6th International Conference on Concussion in Sport recommended the use of mouthguards for children and adolescents and disallowing body checking for all children and most levels of adolescents. CONCLUSIONS:Concussions in ice hockey lead to substantial missed time from play. The authors strongly encourage all hockey leagues to adopt and adhere to age-appropriate rules to limit hits to the head, increase compliance in wearing protective equipment, and utilize high-quality concussion protocols.

BACKGROUND:Cerebral cavernous malformations (CCMs) frequently manifest with haemorrhages. Stereotactic radiosurgery (SRS) has been employed for CCM not suitable for resection. Its effect on reducing haemorrhage risk is still controversial. The aim of this study was to expand on the safety and efficacy of SRS for haemorrhagic CCM. METHODS:This retrospective multicentric study included CCM with at least one haemorrhage treated with single-session SRS. The annual haemorrhagic rate (AHR) was calculated before and after SRS. Recurrent event analysis and Cox regression were used to evaluate factors associated with haemorrhage. Adverse radiation effects (AREs) and occurrence of new neurological deficits were recorded. RESULTS:The study included 381 patients (median age: 37.5 years (Q1-Q3: 25.8-51.9) with 414 CCMs. The AHR from diagnosis to SRS excluding the first haemorrhage was 11.08 per 100 CCM-years and was reduced to 2.7 per 100 CCM-years after treatment. In recurrent event analysis, SRS, HR 0.27 (95% CI 0.17 to 0.44), p<0.0001 was associated with a decreased risk of haemorrhage, and the presence of developmental venous anomaly (DVA) with an increased risk, HR 1.60 (95% CI 1.07 to 2.40), p=0.022. The cumulative risk of first haemorrhage after SRS was 9.4% (95% CI 6% to 12.6%) at 5 years and 15.6% (95% CI% 9 to 21.8%) at 10 years. Margin doses> 13 Gy, HR 2.27 (95% CI 1.20 to 4.32), p=0.012 and the presence of DVA, HR 2.08 (95% CI 1.00 to 4.31), p=0.049 were factors associated with higher probability of post-SRS haemorrhage. Post-SRS haemorrhage was symptomatic in 22 out of 381 (5.8%) patients, presenting with transient (15/381) or permanent (7/381) neurological deficit. ARE occurred in 11.1% (46/414) CCM and was responsible for transient neurological deficit in 3.9% (15/381) of the patients and permanent deficit in 1.1% (4/381) of the patients. Margin doses >13 Gy and CCM volume >0.7 cc were associated with increased risk of ARE. CONCLUSION/CONCLUSIONS:Single-session SRS for haemorrhagic CCM is associated with a decrease in haemorrhage rate. Margin doses ≤13 Gy seem advisable.