Efficacy and safety of a third stereotactic radiosurgery for recurrent trigeminal neuralgia: an international, multicenter study.

BACKGROUND AND OBJECTIVES: 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: 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.

Comparative analysis of stereotactic radiosurgery outcomes for supratentorial hemangioblastomas in von hippel-lindau disease and sporadic cases: A multi-center international study.

BACKGROUND: Hemangioblastomas (HBs) are rare, benign central nervous system (CNS) neoplasms that rarely occur in the supratentorial. Resection with the goal of gross total resection (GTR) is often considered the primary treatment. Stereotactic radiosurgery (SRS) has been utilized more commonly in unresectable or partially resected cases. In this study, we aimed to evaluate SRS's effectiveness and clinical outcomes in supratentorial HBs. METHODS: A retrospective analysis of multi-centers from 1993 to 2022 was conducted on patients with supratentorial HB treated with SRS. RESULTS: The study included 13 patients with 30 supratentorial HBs (24 von Hippel-Lindau (VHL), 6 sporadic). Median age was 26 years. Most tumors were solid (86.2 %). SRS was primary treatment in 86.7 % of cases and adjuvant in 13.3 %. VHL lesions were significantly smaller than sporadic ones (0.2 vs. 3.7 cc, p = 0.009). Median margin dose was higher in VHL cases (17 vs. 13.0 Gy, P = 0.031). For VHL cases, local control (LC) was 100 % at 6 months, 96 % (95 % CI: 88 %, 100 %) from 12 to 60 months post-SRS. For sporadic cases, LC was 100 % at 6 months, 80 % (95 % CI: 52 %, 100 %) from 12 to 60 months post-SRS (p = 0.39). No adverse radiation events or mortality occurred. CONCLUSION: SRS demonstrated a promising role in the clinical course of supratentorial HBs. It can be considered an effective alternative to surgical resection and even a first-line therapeutic option in appropriately selected cases.

Comparison of Repeat Versus Initial Stereotactic Radiosurgery for Intracranial Arteriovenous Malformations: A Retrospective Multicenter Matched Cohort Study.

BACKGROUND AND OBJECTIVES: 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: 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.

Stereotactic radiosurgery for brain metastases from human epidermal receptor 2 positive breast Cancer: an international, multi-center study.

PURPOSE: To report patient outcomes and local tumor control rates in a cohort of patients with biopsy-proven HER-2 positive breast cancer treated with stereotactic radiosurgery (SRS) for brain metastases (BM). METHODS: This international, retrospective, multicenter study, included 195 female patients with 1706 SRS-treated BM. Radiologic and clinical outcomes after SRS were determined and prognostic factors identified. RESULTS: At SRS, median patient age was 55 years [interquartile range (IQR) 47.6-62.0], and 156 (80%) patients had KPS ≥ 80. The median tumor volume was 0.1 cm3 (IQR 0.1-0.5) and the median prescription dose was 16 Gy (IQR 16-18). Local tumor control (LTC) rate was 98%, 94%, 93%, 90%, and 88% at six-, 12-, 24-, 36- and 60-months post-SRS, respectively. On multivariate analysis, tumor volume (p = < 0.001) and concurrent pertuzumab (p = 0.02) improved LTC. Overall survival (OS) rates at six-, 12-, 24-, 36-, 48-, and 60-months were 90%, 69%, 46%, 27%, 22%, and 18%, respectively. Concurrent pertuzumab improved OS (p = 0.032). In this patient subgroup, GPA scores ≥ 2.5 (p = 0.038 and p = 0.003) and rare primary tumor histologies (p = 0.01) were associated with increased and decreased OS, respectively. Asymptomatic adverse radiation events (ARE) occurred in 27 (14.0%) and symptomatic ARE in five (2.6%) patients. Invasive lobular carcinoma primary (p = 0.042) and concurrent pertuzumab (p < 0.001) conferred an increased risk for overall but not for symptomatic ARE. CONCLUSION: SRS affords effective LTC for selected patients with BM from HER-2 positive breast cancer. Concurrent pertuzumab improved LTC and OS but at the same time increased the risk for overall, but not symptomatic, ARE.

Transient Ageusia and Dysgeusia Following Thalamic Cyst Drainage.

Taste consists of sensation and perception. Specific neural structures transmit a stimulus from the taste buds to the gustatory cortex to generate taste sensation. Any disruption of this pathway, whether it affects sensation or perception, can result in taste disorders. Stereotactic procedures involving the thalamus may result in gustatory complications. A 41-year-old female patient who underwent stereotactic drainage of a thalamic cyst suffered transient ageusia. Subsequently, she developed metallic taste perception. When her stereotactic plan was re-evaluated, it was noted that the posteromedial ventral thalamus nucleus was in the path of the needle tract and the needle had passed through it. Follow-up was recommended and her symptoms completely resolved within 2 months following surgery. Modern imaging techniques allow for the visualization of neural structures related to the sense of taste. Additionally, care must be taken when planning stereotactic procedures for such lesions.

Gamma Knife radiosurgery for multiple sclerosis-associated trigeminal neuralgia.

BACKGROUND: Gamma Knife radiosurgery (GKRS) has well-known efficacy in the treatment of idiopathic trigeminal neuralgia (TN). However, few studies have evaluated the effects of GKRS in the treatment of multiple sclerosis (MS)-related TN. This study analyzed the efficacy and complications of GKRS for MS-related TN. METHODS: This retrospective study included 28 MS-related TN patients who underwent GKRS with a median follow-up of 27 (range, 12-181) months. The cisternal segment of the trigeminal nerve was targeted with a median radiation dose of 80 (80-90) Gy. Pain intensity was assessed using Barrow Neurological Institute (BNI)-Pain Intensity Scores (BNI-PIS). Before GKRS, all patients suffered from BNI pain levels of 4 or 5. A reduction in pain to BNI 3b or below was deemed as adequate pain relief. RESULTS: The initial proportion of patients who experienced adequate pain relief was 71.4%, with a median interval of 21 (1-45) days. At the final follow-up, 50% of patients had achieved adequate pain relief. Ten patients (35.7%) suffered from complications, including four with facial sensorial dysfunctions, four with a decline in their corneal reflexes, and two with jaw weakness. Among the 20 initial responders, six (30%) patients suffered pain recurrence after a median interval of 35 (12-180) months. CONCLUSIONS: GKRS is an effective means of pain relief in MS-related TN, but has side effects that are relevant to other ablative treatments. The benefits and risks of GKRS should be discussed with patients who wish to avoid surgery or when previous treatments fail.

Gamma Knife Radiosurgery for Hypothalamic Hamartoma: A Multi-Institutional Retrospective Study on Safety, Efficacy, and Complication Profile.

BACKGROUND AND OBJECTIVES: Gamma knife radiosurgery (GKRS) is a safe and effective treatment option for hypothalamic hamartomas (HH), but there is no consensus opinion on its timing, dosage, and follow-up. The aim of this study was to define the safety, efficacy, outcome, and complication profile of GKRS in this patient population. METHODS: This retrospective multicentric study involved 39 patients with the mean age of 16 ± 14.84 years. Early seizures resulted in an earlier age of diagnosis in 97% of patients. At baseline, no endocrine abnormalities were seen in 75% of patients while 18.9% showed precocious puberty (PP). The median target volume was 0.55 cc (0.1-10.00 cc), and a median margin dose of 16 Gy (8.1-20.0 Gy) was delivered in a single session. All patients were evaluated for clinical, endocrinological, and radiological outcomes. RESULTS: The median follow-up was 5 (0.1-15) years. The median target volume of the cohort was 0.55 (0.35-1.77) cc. The largest HH was of 10 cc. 24/39 (61.5%) were small HH (Regis I-III). At presentation, 94.8% patients suffered from seizures (87.18% with gelastic seizures). 7/39 patients (17.9%) were presented with both PP and epilepsy. Only one (2.6%) patient presented with PP alone. 29 patients had more than 3-year follow-up. All received ≥16 Gy targeting complete HH. 28% of patients showed regression in HH volume. Patients with Regis grade I-III and longer follow-up (>75 months) showed gradual improvement in seizures. 16/29 patients (55.2%) achieved good seizure control (Engel I/II) while 13 (44.8%) were in Engel III/IV status. Nine patients needed adjuvant treatment because of poor seizure control. Eight patients suffered from transient increase in seizures. One patient developed poikilothermia, and 2 patients developed new onset hormonal deficiency. CONCLUSION: GKRS is a safe and effective modality for treatment of HH with significant improvement in seizure control with minimal disruption of endocrine profile. It provides an excellent safety, efficacy, and complication profile, especially for small HH. Latency of results and its adjuvant nature remain the areas of research and breakthroughs among contemporary treatment options.

Risk of new tumor, carotid stenosis, and stroke after Stereotactic Radiosurgery for Pituitary Tumor: A multicenter study of 2254 patients with imaging follow-up.

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: 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.

Pleomorphic Xanthoastrocytoma: Multi-Institutional Evaluation of Stereotactic Radiosurgery.

BACKGROUND AND OBJECTIVES: Pleomorphic xanthoastrocytoma (PXA) is a rare low-grade glial tumor primarily affecting young individuals. Surgery is the primary treatment option; however, managing residual/recurrent tumors remains uncertain. This international multi-institutional study retrospectively assessed the use of stereotactic radiosurgery (SRS) for PXA. METHODS: A total of 36 PXA patients (53 tumors) treated at 11 institutions between 1996 and 2023 were analyzed. Data included demographics, clinical variables, SRS parameters, tumor control, and clinical outcomes. Kaplan-Meier estimates summarized the local control (LC), progression-free survival, and overall survival (OS). Secondary end points addressed adverse radiation effects and the risk of malignant transformation. Cox regression analysis was used. RESULTS: A total of 38 tumors were grade 2, and 15 tumors were grade 3. Nine patients underwent initial gross total resection, and 10 received adjuvant therapy. The main reason for SRS was residual tumors (41.5%). The median follow-up was 34 months (range, 2-324 months). LC was achieved in 77.4% of tumors, with 6-month, 1-year, and 2-year LC estimates at 86.7%, 82.3%, and 77.8%, respectively. Younger age at SRS (hazard ratios [HR] 3.164), absence of peritumoral edema (HR 4.685), and higher marginal dose (HR 6.190) were significantly associated with better LC. OS estimates at 1, 2, and 5 years were 86%, 74%, and 49.3%, respectively, with a median OS of 44 months. Four patients died due to disease progression. Radiological adverse radiation effects included edema (n = 8) and hemorrhagic change (n = 1). One grade 3 PXA transformed into glioblastoma 13 months after SRS. CONCLUSION: SRS offers promising outcomes for PXA management, providing effective LC, reasonable progression-free survival, and minimal adverse events.

Stereotactic radiosurgery for brain metastasis from cholangiocarcinoma.

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.

Vestibular Schwannoma International Study of Active Surveillance Versus Stereotactic Radiosurgery: The VISAS Study.

PURPOSE: The present study assesses the safety and efficacy of stereotactic radiosurgery (SRS) versus observation for Koos grade 1 and 2 vestibular schwannoma (VS), benign tumors affecting hearing and neurological function. METHODS AND MATERIALS: This multicenter study analyzed data from Koos grade 1 and 2 VS patients managed with SRS (SRS group) or observation (observation group). Propensity score matching balanced patient demographics, tumor volume, and audiometry. Outcomes measured were tumor control, serviceable hearing preservation, and neurological outcomes. RESULTS: In 125 matched patients in each group with a 36-month median follow-up (P = .49), SRS yielded superior 5- and 10-year tumor control rates (99% CI, 97.1%-100%, and 91.9% CI, 79.4%-100%) versus observation (45.8% CI, 36.8%-57.2%, and 22% CI, 13.2%-36.7%; P < .001). Serviceable hearing preservation rates at 5 and 9 years were comparable (SRS 60.4% CI, 49.9%-73%, vs observation 51.4% CI, 41.3%-63.9%, and SRS 27% CI, 14.5%-50.5%, vs observation 30% CI, 17.2%-52.2%; P = .53). SRS were associated with lower odds of tinnitus (OR = 0.39, P = .01), vestibular dysfunction (OR = 0.11, P = .004), and any cranial nerve palsy (OR = 0.36, P = .003), with no change in cranial nerves 5 or 7 (P > .05). Composite endpoints of tumor progression and/or any of the previous outcomes showed significant lower odds associated with SRS compared with observation alone (P < .001). CONCLUSIONS: SRS management in matched cohorts of Koos grade 1 and 2 VS patients demonstrated superior tumor control, comparable hearing preservation rates, and significantly lower odds of experiencing neurological deficits. These findings delineate the safety and efficacy of SRS in the management of this patient population.

Adaptive treatment strategy for a vestibular schwannoma in a patient with vascular Eagle syndrome: illustrative case.

BACKGROUND: Eagle syndrome, an uncommon condition, causes symptoms due to neural and/or vascular compression from an elongated styloid process or calcified stylohyoid ligament and can also complicate other planned surgical procedures. OBSERVATIONS: A 42-year-old female with loss of balance, dizziness, and ataxic gait underwent cranial magnetic resonance imaging (MRI), revealing a right-sided Koos grade IV vestibular schwannoma. Initially, a retrosigmoid craniotomy for tumor resection was planned. However, preoperative MRI and computed tomography (CT) showed a dilated right-sided mastoid emissary vein, tortuous scalp and paraspinal veins, and bilateral elongated styloid processes. CT angiography and digital subtraction angiography indicated Eagle syndrome-related compression of both internal jugular veins and concurrent occlusion of the left internal jugular vein at the jugular foramen. Consequently, given the risk of damaging venous structures, Gamma Knife radiosurgery was chosen over resection. LESSONS: This case highlights the importance of adapting treatment plans based on patient-specific anatomical and pathological factors. In situations in which traditional surgery poses risks to sensitive structures such as the venous system, alternative approaches like radiosurgery offer safer yet effective options. Comprehensive risk-benefit evaluations are crucial for such decisions.

Assessing the impact of distortion correction on Gamma Knife radiosurgery for multiple metastasis: Volumetric and dosimetric analysis.

Introduction: Magnetic resonance imaging (MRI) is a robust neuroimaging technique and is the preferred method for stereotactic radiosurgery (SRS) planning. However, MRI data always contain distortions caused by hardware and patient factors. Research question: Can these distortions potentially compromise the effectiveness and safety of SRS treatments? Material and methods: Twenty-six MR datasets with multiple metastatic brain tumors (METs) used for Gamma Knife radiosurgery (GKRS) were retrospectively evaluated. A commercially available software was used for distortion correction. Geometrical agreement between corrected and uncorrected tumor volumes was evaluated using MacDonald criteria, Euclidian distance, and Dice similarity coefficient (DSC). SRS plans were generated using uncorrected tumor volumes, which were assessed to determine their coverage of the corrected tumor volumes. Results: The median target volume was 0.38 cm3 (range,0.01-12.38 cm3). A maximum displacement of METs of up to 2.87 mm and a median displacement of 0.55 mm (range,0.1-2.87 mm) were noted. The median DSC between uncorrected and corrected MRI was 0.92, and the most concerning case had a DSC of 0.46. Although all plans met the optimization criterion of at least 98% of the uncorrected tumor volume (median 99.55%, range 98.1-100%) receiving at least 100% of the prescription dose, the percent of the corrected tumor volume receiving the total prescription dose was a median of 95.45% (range,23.1-99.5%). Discussion and conclusion: MRI distortion, though visually subtle, has significant implications for SRS planning. Regular utilization of corrected MRI is recommended for SRS planning as distortion is sometimes enough to cause a volumetric miss of SRS targets.

Comparative analysis of the spatial distribution of brain metastases across several primary cancers using machine learning and deep learning models.

OBJECTIVE: Brain metastases (BM) are associated with poor prognosis and increased mortality rates, making them a significant clinical challenge. Studying BMs can aid in improving early detection and monitoring. Systematic comparisons of anatomical distributions of BM from different primary cancers, however, remain largely unavailable. METHODS: To test the hypothesis that anatomical BM distributions differ based on primary cancer type, we analyze the spatial coordinates of BMs for five different primary cancer types along principal component (PC) axes. The dataset includes 3949 intracranial metastases, labeled by primary cancer types and with six features. We employ PC coordinates to highlight the distinctions between various cancer types. We utilized different Machine Learning (ML) algorithms (RF, SVM, TabNet DL) models to establish the relationship between primary cancer diagnosis, spatial coordinates of BMs, age, and target volume. RESULTS: Our findings revealed that PC1 aligns most with the Y axis, followed by the Z axis, and has minimal correlation with the X axis. Based on PC1 versus PC2 plots, we identified notable differences in anatomical spreading patterns between Breast and Lung cancer, as well as Breast and Renal cancer. In contrast, Renal and Lung cancer, as well as Lung and Melanoma, showed similar patterns. Our ML and DL results demonstrated high accuracy in distinguishing BM distribution for different primary cancers, with the SVM algorithm achieving 97% accuracy using a polynomial kernel and TabNet achieving 96%. The RF algorithm ranked PC1 as the most important discriminating feature. CONCLUSIONS: In summary, our results support accurate multiclass ML classification regarding brain metastases distribution.

Long-term radiographic and endocrinological outcomes of stereotactic radiosurgery for recurrent or residual nonfunctioning pituitary adenomas.

OBJECTIVE: Stereotactic radiosurgery (SRS) is used for the treatment of residual/recurrent nonfunctional pituitary adenoma (NFPA). The aim of this study was to evaluate the factors related to long-term tumor control and delayed endocrinopathies following SRS. METHODS: This retrospective, multicenter study included patients with recurrent/residual NFPA treated with single-fraction SRS; they were then divided into two arms. The first arm included patients with at least 5 years of radiographic follow-up and all patients with local tumor progression. The second arm included patients with at least 5 years of endocrinological follow-up and all patients who developed endocrinopathy. Study endpoints were tumor control and new or worsening hypopituitarism after SRS and were analyzed using Cox regression and Kaplan-Meier methodology. RESULTS: There were 360 patients in the tumor control arm (median age 52.7 [IQR 42.9-61] years, 193 [53.6%] males) and 351 patients in the hypopituitarism arm (median age 52.5 [IQR 43-61] years, 186 [53.0%] males). The median follow-up in the tumor control evaluation group was 7.95 (IQR 5.7-10.5) years. Tumor control rates at 5, 8, 10, and 15 years were 93% (95% CI 90%-95%), 87% (95% CI 83%-91%), 86% (95% CI 82%-90%), and 69% (95% CI 59%-81%), respectively. The median follow-up in the endocrinopathy evaluation group was 8 (IQR 5.9-10.7) years. Pituitary function preservation rates at 5, 8, 10, and 15 years were 83% (95% CI 80%-87%), 81% (95% CI 77%-85%), 78% (95% CI 74%-83%), and 71% (95% CI 63%-79%), respectively. A margin dose > 15 Gy (HR 0.8, 95% CI 0.7-0.9; p < 0.001) and a delay from last resection to SRS > 1 year (HR 0.9, 95% CI 0.7-0.9; p = 0.04) were significant factors related to tumor control in multivariable analysis. A maximum dose to the pituitary stalk ≤ 10 Gy (HR 1.1, 95% CI 1.09-1.2; p < 0.001) was associated with pituitary function preservation. New visual deficits after SRS occurred in 7 (1.94%) patients in the tumor control group and 8 (2.3%) patients in the endocrinopathy group. Other new cranial nerve deficits post-SRS occurred in 4 of 160 patients with data in the tumor control group and 3 of 140 patients with data in the endocrinopathy group. CONCLUSIONS: SRS affords favorable and durable tumor control for the vast majority of NFPAs. Post-SRS hypopituitarism occurs in a minority of patients, but this risk increases with time and warrants long-term follow-up.

Long-term outcomes of Gamma Knife radiosurgery in treating glossopharyngeal neuralgia.

Glossopharyngeal neuralgia (GPN) is an unusual disorder causing severe, brief pain episodes in the areas supplied by the glossopharyngeal nerve. Initial treatment involves medications like carbamazepine, but if these are ineffective or cause side effects, interventional pain management techniques or surgery may be considered. Gamma Knife radiosurgery is becoming popular in managing GPN due to its lower risk of complications than surgical interventions like microvascular decompression or rhizotomy. In this retrospective case series, we examined the outcomes of Gamma Knife radiosurgery in eight patients with GPN. The decision to utilize Gamma Knife radiosurgery was made following specific criteria, including failed surgical interventions, patient preference against surgery, or contraindications to surgical procedures. Patients were administered radiation doses within the range of 80 to 90 Gy, targeting either the cisternal glossopharyngeal nerve or glossopharyngeal meatus of the jugular foramen. Evaluations were conducted before the Gamma Knife radiosurgery; at 3, 6, and 12 months after Gamma Knife radiosurgery; and annually thereafter. Pain severity was assessed using the modified Barrow Neurological Institute scale grades, with patients achieving grade I-IIIa considered to have a good treatment outcome and grade IV-V to have a poor treatment outcome. Pain control and absence of radiosurgery-related complications were primary endpoints. The median age of the patients was 46.5 years, varying from 8 to 72 years. The median duration of pain was 32 months (range, 12-120 months). All patients, except one, were on polydrug therapy. All cases exhibited preoperative grade V pain. The median follow-up duration after Gamma Knife radiosurgery was 54.5 months, varying from 14 to 90 months. The overall clinical assessments revealed a gradual neurological improvement, particularly within the first 8.5 weeks (range, 1-12 weeks). The immediate outcomes at 3 months revealed that all patients (8/8, 100%) experienced pain relief, with 25% (2/8) achieving a medication-free status (Grade I). Three patients (37%) experienced a recurrence during the follow-up and were managed with repeat Gamma Knife radiosurgery (n = 2) and radiofrequency rhizotomy (n = 1). At the last follow-up, 88% (7/8) of patients had pain relief (Grades I-IIIa), with three (37%) achieving a medication-free status (Grade I). No adverse events or neurological complications occurred. The patient who underwent radiofrequency rhizotomy continued to experience inadequately controlled pain despite medication (Grade IV). Gamma Knife radiosurgery is a non-invasive, efficacious treatment option for idiopathic GPN, offering short- and long-term relief without permanent complications.