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 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.

Outcome Evaluation of Repeat Stereotactic Radiosurgery for Cerebral Arteriovenous Malformations.

BACKGROUND: Repeat stereotactic radiosurgery (SRS) for persistent cerebral arteriovenous malformation (AVM) has generally favorable patient outcomes. However, reporting studies are limited by small patient numbers and single-institution biases. The purpose of this study was to provide the combined experience of multiple centers, in an effort to fully define the role of repeat SRS for patients with arteriovenous malformation. METHODS: This multicenter, retrospective cohort study included patients treated with repeat, single-fraction SRS between 1987 and 2022. Follow-up began at repeat SRS. The primary outcome was a favorable patient outcome, defined as a composite of nidus obliteration in the absence of hemorrhage or radiation-induced neurological deterioration. Secondary outcomes were obliteration, hemorrhage risk, and symptomatic radiation-induced changes. Competing risk analysis was performed to compute yearly rates and identify predictors for each outcome. RESULTS: The cohort comprised 505 patients (254 [50.3%] males; median [interquartile range] age, 34 [15] years) from 14 centers. The median clinical and magnetic resonance imaging follow-up was 52 (interquartile range, 61) and 47 (interquartile range, 52) months, respectively. At last follow-up, favorable outcome was achieved by 268 (53.1%) patients (5-year probability, 50% [95% CI, 45%-55%]) and obliteration by 300 (59.4%) patients (5-year probability, 56% [95% CI, 51%-61%]). Twenty-eight patients (5.6%) experienced post-SRS hemorrhage with an annual incidence rate of 1.38 per 100 patient-years. Symptomatic radiation-induced changes were evident in 28 (5.6%) patients, with most occurring in the first 3 years. Larger nidus volumes (between 2 and 4 cm3, subdistribution hazard, 0.61 [95% CI, 0.44-0.86]; P=0.005; >4 cm3, subdistribution hazard, 0.47 [95% CI, 0.32-0.7]; P<0.001) and brainstem/basal ganglia involvement (subdistribution hazard, 0.6 [95% CI, 0.45-0.81]; P<0.001) were associated with reduced probability of favorable outcome. CONCLUSIONS: Repeat SRS confers reasonable obliteration rates with a low complication risk. With most complications occurring in the first 3 years, extending the latency period to 5 years generally increases the rate of favorable patient outcomes and reduces the necessity of a third intervention.

Stereotactic radiosurgery for Koos grade IV vestibular schwannoma in patients ≥ 65 years old: a multi-institutional retrospective study.

BACKGROUND: Surgery is the preferred treatment for large vestibular schwannomas (VS). Good tumor control and cranial nerve outcomes were described in selected Koos IV VS after single-session stereotactic radiosurgery (SRS), but outcomes in elderly patients have never been specifically studied. The aim of this study is to report clinical and radiological outcomes after single-session SRS for Koos IV VS in patients ≥ 65 years old. METHOD: This multicenter, retrospective study included patients ≥ 65 years old, treated with primary, single-session SRS for a Koos IV VS, and at least 12 months of follow-up. Patients with life-threatening or incapacitating symptoms were excluded. Tumor control rate, hearing, trigeminal, and facial nerve function were studied at last follow-up. RESULTS: One-hundred and fifty patients (median age of 71.0 (IQR 9.0) years old with a median tumor volume of 8.3 cc (IQR 4.4)) were included. The median prescription dose was 12.0 Gy (IQR 1.4). The local tumor control rate was 96.0% and 86.2% at 5 and 10 years, respectively. Early tumor expansion occurred in 6.7% and was symptomatic in 40% of cases. A serviceable hearing was present in 16.1% prior to SRS and in 7.4% at a last follow-up of 46.5 months (IQR 55.8). The actuarial serviceable hearing preservation rate was 69.3% and 50.9% at 5 and 10 years, respectively. Facial nerve function preservation or improvement rates at 5 and 10 years were 98.7% and 91.0%, respectively. At last follow-up, the trigeminal nerve function was improved in 14.0%, stable in 80.7%, and worsened in 5.3% of the patients. ARE were noted in 12.7%. New hydrocephalus was seen in 8.0% of patients. CONCLUSION: SRS can be a safe alternative to surgery for selected Koos IV VS in patients ≥ 65 years old. Further follow-up is warranted.

Stereotactic radiosurgery versus active surveillance for asymptomatic, skull-based meningiomas: an international, multicenter matched cohort study.

OBJECTIVE: The optimal management of asymptomatic, skull-based meningiomas is not well defined. The aim of this study is to compare the imaging and clinical outcomes of patients with asymptomatic, skull-based meningiomas managed either with upfront stereotactic radiosurgery (SRS) or active surveillance. METHODS: This retrospective, multicenter study involved patients with asymptomatic, skull-based meningiomas. The study end-points included local tumor control and the development of new neurological deficits attributable to the tumor. Factors associated with tumor progression and neurological morbidity were also analyzed. RESULTS: The combined unmatched cohort included 417 patients. Following propensity score matching for age, tumor volume, and follow-up 110 patients remained in each cohort. Tumor control was achieved in 98.2% and 61.8% of the SRS and active surveillance cohorts, respectively. SRS was associated with superior local tumor control (p < 0.001, HR = 0.01, 95% CI = 0.002-0.13) compared to active surveillance. Three patients (2.7%) in the SRS cohort and six (5.5%) in the active surveillance cohort exhibited neurological deterioration. One (0.9%) patient in the SRS-treated and 11 (10%) patients in the active surveillance cohort required surgical management of their meningioma during follow-up. CONCLUSIONS: SRS is associated with superior local control of asymptomatic, skull-based meningiomas as compared to active surveillance and does so with low morbidity rates. SRS should be offered as an alternative to active surveillance as the initial management of asymptomatic skull base meningiomas. Active surveillance policies do not currently specify the optimal time to intervention when meningioma growth is noted. Our results indicate that if active surveillance is the initial management of choice, SRS should be recommended when radiologic tumor progression is noted and prior to clinical progression.

Stereotactic radiosurgery versus active surveillance for incidental, convexity meningiomas: a matched cohort analysis from the IMPASSE study.

BACKGROUND: The optimal treatment strategy of asymptomatic, convexity meningiomas, remains unclear. OBJECTIVE: The purpose of this study was to define the safety and efficacy of stereotactic radiosurgery (SRS) in the management of patients with asymptomatic convexity meningiomas. METHODS: Data of SRS-treated patients from 14 participating centers and patients managed conservatively for an asymptomatic, convexity-located meningioma were compared. Local tumor control rate and development of new neurologic deficits were evaluated in the active surveillance and in the SRS-treated cohorts. RESULTS: In the unmatched cohorts, there were 99 SRS-treated patients and 140 patients managed conservatively for an asymptomatic, convexity meningioma. Following propensity score matching for age, there were 98 patients in each cohort. In the matched cohorts, tumor control was achieved in 99% of SRS-treated, and in 69.4% of conservatively managed patients (p < 0.001). New neurological deficits occurred in 2.0% of patients in each of the matched cohorts (p = 1.00). Increasing age was predictive of tumor growth [(OR 1.1; 95% CI (1.04 - 1.2), (p < 0.001)]. CONCLUSION: This is one of the first reports to suggest that SRS is a low risk and effective treatment strategy for asymptomatic incidentally discovered convexity meningiomas. In this study, tumor control was achieved in significantly more patients after radiosurgery compared to those managed with active surveillance. SRS may be offered at diagnosis of an asymptomatic convexity meningioma and should be recommended when meningioma growth is noted on follow-up.

Stereotactic radiosurgery for Koos grade IV vestibular schwannoma in young patients: a multi-institutional study.

PURPOSE: Surgery is the treatment of choice for large vestibular schwannomas (VS). Stereotactic radiosurgery (SRS) has been suggested as an alternative to resection in selected patients. However, the safety and efficacy of SRS in Koos grade IV patients ≤ 45 years old has not been evaluated. The aim of this study is to describe the clinical and radiological outcomes of Koos grade IV in young patient managed with a single-session SRS. METHODS: This retrospective, multicenter analysis included SRS-treated patients, ≤ 45 years old presenting with non-life threatening or incapacitating symptoms due to a Koos Grade IV VS and with follow-up ≥ 12 months. Tumor control and neurological outcomes were evaluated. RESULTS: 176 patients [median age of 36.0 (IQR 9) and median tumor volume of 9.3 cm3 (IQR 4.7)] were included. The median prescription dose was 12 Gy (IQR 0.5). Median follow-up period was 37.5 (IQR 53.5) months. The 5- and 10-year progression-free survival was 90.9% and 86.7%. Early tumor enlargement occurred in 10.9% of cases and was associated with tumor progression at the last follow-up. The probability of serviceable hearing preservation at 5- and 10-years was 56.8% and 45.2%, respectively. The probability of improvement or preservation of facial nerve function was 95.7% at 5 and 10-years. Adverse radiation effects were noted in 19.9%. New-onset hydrocephalus occurred in 4.0%. CONCLUSION: Single-session SRS is a safe and effective alternative to surgical resection in selected patients ≤ 45 years old particularly those with medical co-morbidities and those who decline resection. Longer term follow up is warranted.

Management of pediatric cerebral cavernous malformations with gamma knife radiosurgery: a report of 46 cases.

INTRODUCTION: Pediatric cerebral cavernous malformations (CCMs) are commonly treated vascular anomalies with different clinical characteristics than their adult counterparts. Outcomes of Gamma Knife Radiosurgery (GKRS) for pediatric CCMs have not explicitly been reported. This paper reports our experience in managing pediatric CCMs with GKRS. METHODS: We retrospectively reviewed the clinical features, GKRS parameters, and clinical and radiological outcomes of 46 children with 64 CCMs. RESULTS: A total of 46 children, including 19 girls and 27 boys, with a median age of 16 years (3-17 years), were enrolled in the study. The median age at first CCM diagnosis was 13 years (range, 2-17 years). Twenty-two patients (47.8%) had more than one neurological symptom at the time of diagnosis, and the most common presenting symptom was seizure (28.3%). The most common location was supratentorial superficial (53.1%), and 17.4% of patients had multiple CCMs. A developmental venous anomaly was detected in 5 patients (10.9%). During a total of 52.4 retrospective patient-years in patients with > 1 hemorrhage episode, the calculated annual hemorrhage rate was 40.1%. The median post-GKRS follow-up was 79 months (range, 19-175 months), with an overall 306.2 prospective patient years. The annual hemorrhage rate (AHR) during the first 2 years after GKRS and after the initial 2 years was 1.11% and 0.46%, respectively. Regarding clinical factors and GKRS parameters, univariate analysis revealed a significant association with post-GKRS AHR and volume (p = 0.023) only. Patients with pre-GKRS seizures showed favorable seizure control (Engel class I and II) in 8 children (61.5%). There was no mortality in our series. CONCLUSION: Low AHR following GKRS with no radiation-induced toxicity makes GKRS a therapeutic alternative for pediatric CCMs.

Gamma Knife radiosurgery for tuberculum sellae meningiomas: a series of 78 consecutive patients.

Outcomes of Gamma Knife radiosurgery (GKRS) for tuberculum sellae meningiomas (TSMs) have not been reported explicitly within any meningioma series. We present the first and largest TSM series with clinical, radiosurgical, and outcome features for 78 consecutive patients managed with GKRS. Patients who underwent GKRS for TSMs between 2005 and 2021 and had a minimum of 6 months of follow-up were included. Medical records, imaging studies, and follow-up examinations were evaluated retrospectively. A total of 78 patients with a median age of 50.5 years were included. SRS was conducted as an upfront treatment for 38 patients (48.7%). The median target volume was 1.7 cm3 (range, 0.1-14.6). During a median follow-up of 78.5 months, the cumulative PFS rates of the whole cohort at 1, 5, and 10 years by Kaplan-Meier analysis were 100%, 97.9%, and 94.5%, respectively. Of 47 patients with impaired vision, improvement and/or preservation of visual acuity, and visual field were achieved in 55.3% and 42.6%, respectively. No new-onset hormonal deficits were observed. Based on our data, SRS represents an effective and safe modality for unresected or recurrent/residual TSMs. SRS should be offered to patients who are not willing or not ideal candidates for surgery.

Long-term results of upfront, single-session Gamma Knife radiosurgery for large cystic vestibular schwannomas.

Anecdotally, cystic vestibular schwannomas (cVSs) are regarded to have unpredictable biologic activity with poorer clinical results, and most studies showed a less favorable prognosis following surgery. While stereotactic radiosurgery (SRS) is a well-established therapeutic option for small- to medium-sized VSs, cVSs are often larger, thus making upfront SRS more complicated. The purpose of this retrospective study was to assess the efficacy and safety of upfront SRS for large cVSs. The authors reviewed the data of 54 patients who received upfront, single-session Gamma Knife radiosurgery (GKRS) with a diagnosis of large cVS (> 4 cm3). Patients with neurofibromatosis type 2, multiple VSs, or recurrent VSs and < 24 months of clinical and neuroimaging follow-up were excluded. Hearing loss (48.1%) was the primary presenting symptom. The majority of cVSs were Koos grade IV (66.7%), and the most prevalent cyst pattern was "mixed pattern of small and big cysts" (46.3%). The median time between diagnosis and GKRS was 12 months (range, 1-147 months). At GKRS, the median cVS volume was 6.95 cm3 (range, 4.1-22 cm3). The median marginal dose was 12 Gy (range, 10-12 Gy). The mean radiological and clinical follow-up periods were 62.2 ± 34.04 months (range, 24-169 months) and 94.9 ± 45.41 months (range, 24-175 months), respectively. At 2, 6, and 12 years, the tumor control rates were 100%, 95.7%, and 85.0%, respectively. Tumor shrinkage occurred in 92.6% of patients (n = 50), tumor volume remained stable in 5.6% of patients (n = 3), and tumor growth occurred in 1.9% of patients (n = 1). At a median follow-up of 53.5 months, the pre-GKRS tumor volume significantly decreased to 2.35 cm3 (p < 0.001). While Koos grade 3 patients had a greater possibility of attaining higher volume reduction, "multiple small thick-walled cyst pattern" and smaller tumor volumes decreased the likelihood of achieving higher volume reduction. Serviceable hearing (Gardner-Robertson Scale I-II) was present in 16.7% of patients prior to GKRS and it was preserved in all of these patients following GKRS. After GKRS, 1.9% of patients (n = 1) had new-onset trigeminal neuralgia. There was no new-onset facial palsy, hemifacial spasm, or hydrocephalus. Contrary to what was believed, our findings suggest that upfront GKRS seems to be a safe and effective treatment option for large cVSs.

Stereotactic radiosurgery for the treatment of hypoglossal schwannoma: a multi-institutional retrospective study.

BACKGROUND: Surgical removal has been performed as the first line treatment for symptomatic or enlarging hypoglossal schwannomas (HS). Stereotactic radiosurgery (SRS) offers a minimally invasive approach that may afford long-term tumor control for patients with HS particularly those who refuse or are unfit for surgery. This study evaluates outcomes after SRS performed for both newly diagnosed and residual tumors after incomplete resection. METHODS: This retrospective, multi-institutional study involved patients treated with adjuvant or primary SRS for HS. The study end-points included local tumor response, clinical outcomes, and procedure-related complications. All the patients had Gamma Knife SRS. RESULTS: The cohort included 12 patients (five females), median age at SRS 49.5 years (range, 37-76)]. The median tumor target volume was 5.9 cm3 (range, 0.7-27.23). At median imaging follow-up of 37 months (range, 6-153), tumor control was achieved in 11 patients. Tumor enlargement that was managed with surgical resection was noted at the 6-month follow-up in one patient. At median clinical follow-up of 30.5 months (range, 6-157), stability, or improvement of all pre-SRS signs and symptoms was noted in nine patients. Two patients experienced worsening of at least one pre-existing symptoms or sign. New-onset trapezius weakness was noted in one patient and tongue atrophy in two patients. CONCLUSION: Single-fraction SRS appears to be a safe and effective upfront and adjuvant treatment option for HS. SRS may be recommended as an alternative to surgery for patients presenting with HS or as an adjuvant treatment following subtotal resection and at HS recurrence.

Stereotactic radiosurgery for asymptomatic petroclival region meningiomas: a focused analysis from the IMPASSE study.

BACKGROUND: The optimal management of asymptomatic, petroclival meningiomas remains incompletely defined. The purpose of this study was to evaluate the safety and efficacy of upfront stereotactic radiosurgery (SRS) for patients with asymptomatic, petroclival region meningiomas. METHODS: This retrospective, international, multicenter study involved patients treated with SRS for an asymptomatic, petroclival region meningioma. Study endpoints included local tumor control rate, procedural complications, and the emergence of new neurological deficits. RESULTS: There were 72 patients (22 males, mean age 59.53 years (SD ± 11.9)) with an asymptomatic meningioma located in the petroclival region who were treated with upfront SRS. Mean margin dose and maximum dose were 13.26 (SD ± 2.72) Gy and 26.14 (SD ± 6.75) Gy respectively. Median radiological and clinical follow-up periods post-SRS were 52.5 (IQR 61.75) and 47.5 months (IQR 69.75) respectively. At last follow-up, tumor control was achieved in all patients. SRS-related complications occurred in 6 (8.33%) patients, with 3 of them (4.17%) exhibiting new neurological deficits. CONCLUSIONS: Upfront SRS for asymptomatic, petroclival region meningiomas affords excellent local tumor control and does so with a relatively low risk of SRS-related complications. SRS can be considered at diagnosis of an asymptomatic petroclival region meningioma. If active surveillance is initially chosen, SRS should be recommended when growth is noted during radiological follow-up.

Dosimetric comparison of volumetric modulated arc therapy with TrueBeam LINAC and hypofractionated radiosurgery with gamma knife ICON for large (>10 cm3) skull base meningiomas.

BACKGROUND: Multi Fractionated stereotactic radiosurgery (MF-SRS) of Linac has an essential role in the treatment of skull base meningiomas (sbMNG). However, Gamma Knife Icon (GK) allows MF-SRS using mask immobilization with onboard image guidance. OBJECTIVE: This dosimetric study aims to investigate whether equivalent plan quality can be achieved with Volumetric Modulated Arc Therapy (VMAT) in patients with large sbMNG (>10 cm3) previously treated with GK. METHODS: Twenty patients with the median target volume of 19.7cm3 are re-planned by using VMAT with 20 Gy in 5 fractions. Plan qualities are compared to tumor coverage, paddick conformity index (PCI), gradient index (GI), V4 Gy, V10 Gy, V12 Gy, optic chiasm V20 Gy, brainstem V23 Gy, optic nerve V25 Gy volumes, and maximum doses for all. Additionally, beam-on time and approximate planning time are also analyzed and compared. RESULTS: All plans provide adequate clinical requirements. First, the CI is comparable for the GK and VMAT (0.99±0.01 vs. 1.13±0.20; p = 0.18). Second, VMAT has a significantly higher GI than GK (3.81±0.35 vs. 2.63±0.09; p < 0.001). Third, the PCI is significantly higher in GK than VMAT (0.76±0.05 vs. 0.70±0.07; p < 0.001). The lower GI of the GK also results in significantly lower V4 Gy (156.1±43.8 vs. 207.5±40.1 cm3, p < 0.001) and V10 Gy (26.1±9.0 vs. 28.9±7.7 cm3, p < 0.001) compared to VMAT. Last, the VMAT reduces beam-on time (4.8±0.5 vs. 19±1.1 min.; p < 0.001). CONCLUSION: Although both systems have succeeded in creating effective plans in clinical practice, the GK reveals more effective lower normal brain tissue doses. However, the shorter treatment time with LINAC, excluding the total procedure time, can be considered advantageous over GK.

Stereotactic radiosurgery for IDH wild type glioblastoma: an international, multicenter study.

OBJECTIVE: Isocitrate dehydrogenase (IDH) mutation status is recommended used for diagnosis and prognostication of glioblastoma patients. We studied efficacy and safety of stereotactic radiosurgery (SRS) for patients with recurrent IDH-wt glioblastoma. METHODS: Consecutive patients treated with SRS for IDH-wt glioblastoma were pooled for this retrospective observational international multi-institutional study from institutions participating in the International Radiosurgery Research Foundation. RESULTS: Sixty patients (median age 61 years) underwent SRS (median dose 15 Gy and median treatment volume: 7.01 cm3) for IDH-wt glioblastoma. All patients had histories of surgery and chemotherapy with temozolomide, and 98% underwent fractionated radiation therapy. MGMT status was available for 42 patients, of which half of patients had MGMT mutant glioblastomas. During median post-SRS imaging follow-up of 6 months, 52% of patients experienced tumor progression. Median post-SRS progression free survival was 4 months. SRS prescription dose of > 14 Gy predicted longer progression free survival [HR 0.357 95% (0.164-0.777) p = 0.009]. Fifty-percent of patients died during post-SRS clinical follow-up that ranged from 1 to 33 months. SRS treatment volume of > 5 cc emerged as an independent predictor of shorter post-SRS overall survival [HR 2.802 95% CI (1.219-6.444) p = 0.02]. Adverse radiation events (ARE) suggestive of radiation necrosis were diagnosed in 6/55 (10%) patients and were managed conservatively in the majority of patients. CONCLUSIONS: SRS prescription dose of > 14 Gy is associated with longer progression free survival while tumor volume of > 5 cc is associated with shorter overall survival after SRS for IDH-wt glioblastomas. AREs are rare and are typically managed conservatively.

Gamma Knife radiosurgery for the treatment of central neurocytoma: a single-institution experience of 25 patients.

Central neurocytomas (CNs) are extremely rare tumors that account for 0.1-0.5% of all intracranial neoplasms. Recently, Gamma Knife radiosurgery (GKRS) has become a treatment option in patients with CN. We aimed to evaluate the efficacy and safety of GKRS in 25 CN patients and review the results along with relevant literature. GKRS patient database was searched, and 25 patients who underwent GKRS for CN between 2009 and 2018, were evaluated retrospectively. The study cohort included 15 female and ten male patients with a median age of 32 years (range, 5-60). The most common presenting symptom was headache (88%). The neurological examination was unremarkable in all patients, except for one patient with decreased vision. Twenty patients (80%) had a history of surgical resection. Most of the tumors (92%) were located in the ventricles, and the median tumor volume was 4.8 cm3 (range, 0.8-28.1). The median marginal dose was 14 Gy (range, 12-15) to a median isodose of 50% (range, 40-50). Following a median follow-up of 80 months (range, 36-138), local tumor control was achieved in 100% of patients. Distant recurrence was observed in one patient (4%). No adverse radiation effect was observed. Regarding non-specific post-GKRS symptoms, one patient experienced a prolonged headache, and one epileptic patient experienced a brief partial seizure. In our patient cohort, GKRS yielded favorable local tumor control (100%) during a median follow-up of 6.6 years. Our series demonstrates that GKRS is an effective and safe treatment option for patients with primary or residual CNs.

Long-term results of gamma knife radiosurgery for foramen magnum meningiomas.

Outcomes of 37 patients of foramen magnum meningioma (FMM) were evaluated, and the related literature was reviewed to determine the efficacy of Gamma Knife radiosurgery (GKRS) for treating patients with FMM. We present the largest series reported from a single institution with the longest follow-up to date. The database of patients who underwent GKRS for FMM between 2007 and 2019 was evaluated retrospectively. A total of 37 patients with radiological and pathological features consistent with FMM were included in this series. Thirty-three patients were female, and 4 were male. The median age was 58 years (range, 23-74 years). The most common symptom at diagnosis was headache (64.9%). Twelve patients had a history of microsurgical resection. The median duration from the initial onset of symptoms to GKRS was 12 months (range 1-140 months). Among the 37 tumors, eight (21.6%) were located ventrally, 24 (64.9%) laterally, and five (13.5%) dorsally. The median target volume was 3.30 cm3 (range, 0.6-17.6 cm3). Thirty-five patients (95%) were treated with single fraction GKRS, and two patients (5%) were treated with hypofractionated GKRS. The median clinical follow-up was 80 months (range, 18-151 months), while the median radiological follow-up was 84 months (range, 18-144 months). At the last clinical follow-up after GKRS, 27 patients (73%) had improved symptoms, and none had worsened pre-GKRS symptoms. At the last radiological follow-up after GKRS, 23 tumors (62.2%) remained stable, 13 (35.1%) decreased in size, and 1 (2.7%) increased in size. Tumor control, including stable and regressed tumors, was achieved in 97.3% of patients. Our cohort demonstrates that GKRS is an effective and safe treatment for patients with either primary or recurrent/residual FMM.

Hormonal and radiologic outcomes after gamma knife radiosurgery for nonfunctioning pituitary adenomas.

BACKGROUND: Gamma knife radiosurgery (GKRS) is an established treatment option for residual and recurrent nonfunctioning pituitary adenoma (NFPA). This investigation assessed hormonal and radiologic outcomes after adjuvant and primary GKRS for NFPAs. METHODS: This retrospective study included 252 patients with NFPA who underwent GKRS at a single center between 2005 and 2016. GKRS was performed as adjuvant procedure in 216 (85.8%) patients and as primary procedure in 36 (14.2%) patients. Characteristics of these two groups were compared. RESULTS: Mean age was comparable between adjuvant and primary GKRS groups (48.3 ± 12.6 vs. 52.2 ± 13.2 years, respectively, p > 0.05). Adjuvant GKRS and primary GKRS groups were similar in terms of the mean prescribed radiation dose and tumor volume (15.1 ± 2.7 vs. 15.3 ± 1.9 Gy and 4.2 ± 3.6 vs. 3.1 ± 2.5 cm3, respectively, p > 0.05 for both). The rate of endocrine deficiency during 5-year follow-up showed similar trend in adjuvant and primary GKRS groups (3.7%, 8.7%, and 14.8% vs. 5.6%, 13.9%, and 27.8% at first, third, and fifth year time points, respectively). Tumor control rates were also similar (98.6%, 96.3%, and 93% vs. 100%, 97.3%, and 94.5% at first, third, and fifth year time points, respectively). In both groups, tumor volume >5 cm3 was associated with higher rate of hypopituitarism and tumor progression. CONCLUSIONS: GKRS was effective both as adjuvant and primary procedure in patients with NFPA. Radiation dose of ≤13.5 Gy was associated with lower tumor control rate and tumor volume >5 cm3 was associated with higher rates of hypopituitarism and tumor progression.

Integration of arterial spin labeling into stereotactic radiosurgery planning of cerebral arteriovenous malformations.

PURPOSE: To test whether the combined use of 4D arterial spin labeling angiography (4D ASL) and contrast-enhanced magnetic resonance angiography (4D CE-MRA) can work as a prospective alternative to digital subtraction angiography (DSA) for the delineation of the arteriovenous malformation (AVM) nidus in stereotactic radiosurgery (SRS) planning. MATERIALS AND METHODS: A custom 4D ASL sequence and a proof-of-concept software tool to integrate 4D ASL data to SRS planning were implemented. Ten AVM patients were scanned at 3T. Two observers independently contoured niduses in two separate sessions. Reference niduses were contoured using DSA, 4D ASL, and 4D CE-MRA. Test niduses were contoured using 4D ASL and 4D CE-MRA only. Reference and test niduses from both observers were compared in terms of volume, distance between centers of volumes (dCOV), and the Jaccard index (JI). RESULTS: In volume comparisons, excellent intraobserver and interobserver agreements were obtained (intraclass correlation coefficients: 0.99 and 0.98, respectively). Median dCOV, JIs between reference and test niduses were 0.55 mm, 0.78 for Observer 1 and were 0.6 mm, 0.78 for Observer 2. None of the dCOV and JI parameters varied significantly among the delineation methods or the observers (P = 0.84, P = 0.39). CONCLUSION: Our preliminary results indicate that reproducibility of the target volumes with high agreement levels is achievable without using DSA. The combined use of high temporal resolution 4D ASL and high spatial resolution and vessel-to-background contrast 4D CE-MRA provided sufficient spatiotemporal angiographic information for the delineation of AVM niduses. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2017;46:1718-1727.

Alexithymia and depression may predict treatment failure in patients undergoing Gamma Knife radiosurgery for trigeminal neuralgia: the potential contribution of colored pain drawings.

OBJECTIVE: Gamma Knife radiosurgery (GKRS) effectively achieves high rates of pain control in trigeminal neuralgia (TN); however, psychological factors can also impact how individuals perceive pain and respond to treatment. The authors aimed to measure the effects of alexithymia and depression on GKRS outcomes, as well as the potential role of colored pain drawings (CPDs) in identifying patients who require additional psychological support. METHODS: Seventy-three medically intractable, typical patients with TN were included. Participants completed a visual analog scale (VAS), the Toronto Alexithymia Scale (TAS-20), and the Turkish version of the Beck Depression Inventory-II (BDI-II). Participants used colored pens to draw their pain patterns on standardized face charts and CPDs were categorized as expected or unexpected. Based on the Barrow Neurological Institute pain scale, patients were categorized as responders or nonresponders. RESULTS: Most patients (63%) were female, and the median age was 60 (range 27-88) years. Of 73 patients, 56 (76.7%) were responders and 17 (23.3%) were nonresponders. Forty-nine patients (67.1%) had expected CPDs, whereas 24 (32.9%) had unexpected CPDs. Responder and nonresponder groups had similar ages, genders, education, comorbidities, and initial VAS scores. Both groups preferred the colors red and black to describe intense pain (79.2% vs 67.3%, p = 0.411). Significantly better pain relief was observed in patients with expected CPDs than in those with unexpected CPDs (87.8% vs 54.2%, p = 0.003). The unexpected CPD group had significantly more alexithymia (58.3% vs 32.7%, p = 0.045). The mean BDI-II score of the cohort was 26 (range 15-37) and was significantly higher in the unexpected group (28.3 vs 24.8, p = 0.028). Unexpected CPD (OR 12.540) and higher TAS-20 score (OR 3.22) increased treatment failure risk. CONCLUSIONS: The outcomes of TN treatment can be influenced by psychological factors, and patients with TN with higher total TAS-20 and BDI-II scores, along with unexpected CPDs, had an increased likelihood of treatment failure. CPDs can be accessed quickly and may allow the physician to screen out most patients with unfavorable psychometrics and proceed with the necessary treatment with appropriate psychological support.

Unveiling the Efficacy of Gamma Knife Radiosurgery for Tectal Plate Gliomas.

BACKGROUND AND OBJECTIVES: Tectal plate gliomas (TPGs) are midbrain tumors that grow slowly and have a benign clinical course. Most TPGs are low-grade astrocytomas, but they can encompass various histological tumor types. Gamma Knife radiosurgery (GKRS) is being explored as a potentially safe and effective treatment option for TPGs, although research in this area is limited. This study aims to evaluate GKRS's efficacy and safety in patients with TPG and provide a comprehensive review of existing literature on the topic. METHODS: This retrospective, single-center study included 48 patients with consecutive TPG who underwent GKRS between September 2005 and June 2022. Patients diagnosed with TPGs based on radiological or tissue-based criteria and who had a minimum follow-up period of 12 months were eligible for inclusion. The primary end points were local control and the absence of GKRS-associated or tumor-associated mortality and morbidity. RESULTS: During a median follow-up of 28.5 months (range, 12-128), the radiological assessment showed tumor control in all cases, with 16.7% achieving a complete response and 68.8% achieving a partial response. Pseudoprogression occurred in 6.2% of cases, with onset ranging from 3 to 8 months. Clinical outcomes revealed no permanent neurological deterioration, with symptoms improving in 14.6% of patients and remaining stable in the others. One patient in the pseudoprogression group experienced transient Parinaud syndrome. One patient died during follow-up because of unrelated causes. The mean survival time after GKRS was 123.7 months. None of the clinical, radiological, or radiosurgical variables showed a correlation with partial/complete response, clinical improvement, or overall survival. CONCLUSION: There is limited research available on the management of TPGs, and this study presents the largest patient cohort treated with GKRS, along with a substantial follow-up duration. Despite its limitations, this study demonstrates the efficacy and low-risk profile of GKRS for TPGs.