Gamma Knife Surgery Research Articles

QLTI-13. A REVIEW OF THE BEST TREATMENT STRATEGY FOR NEUROFIBROMATOSIS TYPE 2 PATIENTS THROUGH A SINGLE-CENTER RETROSPECTIVE STUDY: HOW TO ORCHESTRATE MULTIMODAL TREATMENT OPTIONS

Abstract PURPOSE Neurofibromatosis type 2(NF2) is an autosomal-dominant tumor predisposition syndrome that affects the whole neuro-axis and causes various neurological symptoms decreasing the quality of life throughout the patient’s lifespan. However, due to the diversity of related diseases and the complexity of treatment, there are many cases in which only partial treatments are performed, the timing of the treatment is missed, and inappropriate treatment modality selection is made despite the intervention of many clinicians. Therefore, to increase the overall understanding of the disease, the single-institution experience was analyzed. MATERIALS AND METHODS Between 1998 and 2022, a total of 80 patients who clinically suspected NF2 visited our Brain Tumor Center. After excluding the patients with follow-up loss, the remaining 48 patients were finally analyzed. The patient’s symptoms, diagnosis process, treatment process, and outcomes were analyzed. RESULTS The average age at the time of symptom onset was 31.0(2-63) year-old. Hearing impairment was the major primary symptom(46.8%) among the patients. Five patients(10.9%) had family history of NF2. Thirty-five patients(76.1%) was clinically diagnosed as a NF2 for the bilateral vestibular schwannomas, and 34 patients(73.9%) had intracranial meningiomas, and 37 patients(80.4%) had spinal lesions at the time of diagnosis. Eleven patients were genetically confirmed as NF2. For vestibular schwannomas, 16 patients had surgical resection and 20 patients took gamma-knife surgery as a primary or secondary treatment. For intracranial meningiomas, 16 patients had surgical resection, 13 patients took gamma-knife surgery, and 15 patients took conventional radiation therapy as a primary or secondary treatment. Ventriculo-peritoneal shunt due to increased intracranial pressure was performed in 4 patients(8.7%). For spinal lesions, 16 patients had surgical resection. CONCLUSION NF2 is a disease group requiring a multidisciplinary team approach. The key to treatment is to set and implement a treatment sequence and method tailored to each patient. For this, an overall understanding of the disease and the treatment options is essential.

EXTH-81. A RARE CASE OF RELENTLESSLY PROGRESSIVE METASTATIC PINEOCYTOMA MANAGED WITH SEQUENTIAL MULTIMODAL THERAPY

Abstract BACKGROUND Pineocytoma is a rare pineal parenchymal WHO grade 1 tumor, typically well-managed with surgical resection alone. With gross total resection (GTR), 91% 1-year and 84% 5-year survival rates have been reported. Recurrent pineocytoma is rare and optimal management in that setting is unknown, in part owing to the rarity of the condition. METHODS We report an atypical course of pineocytoma in a 58-year-old male involving metastatic disease. RESULTS A pineal mass was identified upon MRI of the brain obtained for vision changes. Patient underwent GTR, pathology was consistent with pineocytoma, WHO grade 1. Ki-67 labeling index was low at 1-2%. Despite low-grade pathology, two years later, surveillance imaging demonstrated recurrence in the pineal region and a second lesion in the right thalamus. The patient underwent gamma knife surgery (GKRS) to both lesions. Three years later, he developed three new lesions in the right cerebellum and again underwent GKRS. Subsequent surveillance imaging identified new lesions in the right cerebellum and along ventricular walls, treated with further GKRS. Nine years after initial diagnosis, focal nodular leptomeningeal metastases were discovered, along with progression at the primary tumor site. Patient was treated with GKRS to the nodular deposits followed by pembrolizumab. Further disease progression as noted despite immunotherapy. Patient was treated with 6 cycles of temozolomide chemotherapy and at further progression 3 cycles of lomustine. Upon additional progression, further radiation therapy was administered with bevacizumab to reduce risk of radiation necrosis. Patient remains on surveillance 13 years after initial diagnosis with visual changes and mild headache representing only clinical issues. CONCLUSIONS Although exceedingly rare, pineocytoma is capable of metastasizing to brain parenchyma and the leptomeninges, as demonstrated in our patient. However, our case demonstrates prolonged survival is possible even in the setting of relentlessly progressive metastatic disease with utilization of multimodality treatment.

Radiosurgical biologically effective dose on trigeminal root division and section for outcomes of idiopathic trigeminal neuralgia type 1: a multicentre retrospective cohort study

The wide variability in the efficacy of Gamma Knife surgery (GKS) treating trigeminal neuralgia type 1 (TN1) has not been completely elucidated. We aimed to investigate the association between outcomes of TN1 and the radiosurgical biologically effective dose (BED) on the specific part of the trigeminal root. We performed a multicentre retrospective cohort study for 548 patients with refractory TN1 treated by GKS. BED-volume histogram was formed for the trigeminal root, responsible division within the trigeminal root affected by TN1 (RD), trigeminal root section adjacent to the root entry zone (S1) and brainstem to generate the maximum BED (DMaxBED), and the volume percentage enclosed by iso-BED 1000 Gy2.47 (V%BED1000) as plan quality metrics. The outcomes included pain relief, recurrence, and complications. Logistic regression and Cox proportional hazards models were used to analyse BED parameters. There were 344 (62.77%), 144 (26.28%), and 54 (9.85%) patients with Barrow Neurological Institute (BNI) pain relief class III within 1 month, recurrence, and facial hypoesthesia. Patient-level analysis screened V%BED1000 of the trigeminal root associated with BNI class III within 1 month and recurrence. DMaxBED of the brainstem + V%BED1000 of the S1 significantly predicted facial hypoesthesia. Division-level analysis showed that DMaxBED + V%BED1000 of the RD significantly predicted BNI class III within 1 month and recurrence. The efficacy and safety of GKS treating TN1 may depend on the sufficient coverage of high BED on the division affected by pain and tolerated BED on the root entry zone.

Gamma knife radiosurgery clinical efficacy for brain stem glioma: The institutional experience

Objective: In the past, brain stem was treated with surgery or placement of shunt in Pakistan. Gamma Knife surgery is currently an alternative to surgery for deep brain lesions. In the current study, we show the clinical experience of our Centre treated with Gamma Knife surgery. Methods: This is a descriptive study conducted between February 2016 and October 2021. We had total 47 patients presented with focal brainstem gliomas which were selected for Gamma knife radiosurgery at the Neurospinal and Cancer Care Institute Karachi. Results: Clinical Response was observed among them 20 (42.55%) patients improved, 22(46.80%) were stable, while 05 (10.63%) got worse The mean duration of symptoms was 31.9(SD10.5± 3months). Karnofsky Performance Status (KPS) scores during Gamma knife radiosurgery were 90 in 24 patients (51%), 80 in 21 patients (44.6%), and 70 in two patients (4.2%). Four patients (10.6%) had received conventional radiotherapy before Gamma knife radiosurgery. Conclusion: Among the diverse gliomas, their peril varies not just by type but also by their intricate location within the brain. The efficacy of gamma knife radiation is excellent particularly when tackling high-grade tumors, exhibiting its prowess in both adult and pediatric cases. doi: https://doi.org/10.12669/pjms.40.10.9658 How to cite this: Kalhoro A, Ahmed K, Hashim ASM. Gamma knife radiosurgery clinical efficacy for brain stem glioma: The institutional experience. Pak J Med Sci. 2024;40(10):2176-2180. doi: https://doi.org/10.12669/pjms.40.10.9658 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Subtotal resection of vestibular schwannoma with subsequent Gamma Knife irradiation - tumor growth control, facial and cochlear nerve outcome - preliminary results.

<b>Introduction:</b> The choice of treatment of vestibular schwannoma (VS) depends on several factors, including the tumor size, the patient's age and overall health, and the presence and severity of symptoms.<b>Aim:</b> The aim of the study was to assess the effectiveness of intentional subtotal resection (STR) of tumor followed by Gamma Knife surgery (GKS) in patients with larger VS (Koos 3 and 4).<b>Materials and methods:</b> The retrospective analysis was performed on 18 patients. Data of VS volumes measured in MRI, the facial nerve function assessed in the House-Brackmann scoring system (HB), and the results of audiological examination expressed on the Gardner-Robertson scale (GR) were collected preoperatively, postoperatively, and post-GKS.<b>Results:</b> Preoperatively, the main symptom was hearing loss observed in 13 out of 18 patients. The facial nerve function was assessed as HB 1 in 16, whereas HB 2 in 2 patients. The mean volume of the tumor in the initial MRI amounted to 16.81 cm<sup>3</sup> . Postoperatively, the facial nerve was assessed as HB 1 or 2 in 16, whereas HB 3 in 2 patients. Serviceable hearing was presented by only 4 persons. The Mean diameter of the tumor after subtotal surgery amounted to 3.16 cm<sup>3</sup> , 1.83 cm<sup>3</sup> after GKS, and 1.58 cm<sup>3</sup> at the last follow-up. The facial nerve function and hearing level remained the same as before GKS in all patients.<b>Conclusions:</b> STR followed by GKS can be a safe and effective method of treatment of large VS concerning the functional outcome of the facial nerve and the tumor volume growth control.

Characteristics of Patients With Intractable Obsessive-Compulsive Disorder With High/Low Responsiveness to Gamma Knife Surgery.

Obsessive-compulsive disorder (OCD) is a psychiatric condition that causes significant distress and social costs and often follows a chronic course with frequent relapses. Approximately 20% of patients do not respond to medication or cognitive behavioral therapy; gamma knife surgery (GKS) has been proposed as a treatment option for these patients. However, research on GKS for OCD patients is rare. In this study, 10 patients with treatment-resistant OCD underwent GKS, and the treatment response and side effects were assessed. The improvement in patients' obsessive-compulsive symptoms was evaluated using the Yale-Brown Obsessive Compulsive Scale (YBOCS) scores following GKS. Additionally, the characteristics distinguishing the groups with favorable responses to GKS from those with less favorable responses were examined. GKS was well tolerated, and patients demonstrated a statistically significant reduction in YBOCS scores before and after GKS (p=0.016). Patients that responded to GKS exhibited distinct characteristics from those who did not respond. Patients who responded poorly tended to present an earlier age of onset, a longer duration of illness, more frequent hospitalizations, poorer social functioning, and a greater incidence of suicide attempts/thoughts. This study not only demonstrated that GKS is a safe and effective treatment method for intractable OCD but also revealed characteristics distinguishing patients who respond well to GKS from those who do not. These results may aid in the selection of patients for future application of GKS.

A chronic encapsulated expanding hematoma that developed 20 years after gamma knife surgery for a cerebral epilepsy

Background:We report a patient diagnosed with epilepsy 20 years ago who developed a chronic encapsulated expanding hematoma after gamma knife surgery. Case presentation:A 49-year-old middle-aged female was admitted to our department due to headaches accompanied by left-sided limb weakness for 2 months. Cranial computed tomography (CT) and magnetic resonance imaging (MRI) scans revealed a giant cystic-solid mass in the right frontal-temporal lobe, accompanied by compression and edema of the surrounding brain parenchyma. After completion of relevant preoperative examinations upon admission, she underwent microsurgical evacuation of the chronic encapsulated expanding intracerebral hematoma. Postoperatively, the patient improved and recovered well. Conclusion:Chronic encapsulated expanding hematoma is a rare complication after gamma knife surgery therapy. It's essential for individuals experiencing symptoms or complications related to a hematoma to seek medical attention for proper evaluation and management.

160 Gamme Knife Radio Surgery for Cerebral Arteriovenous Malformation (AVM) in Children: A Systematic Review and Meta-analysis of Clinical Outcomes

INTRODUCTION: As radiosurgical devices are becoming more commonly used and applied to treat cerebral arteriovenous malformations (cAVMs), there is a growing concern about whether the outcomes of radiosurgery might differ between children, adolescents, and adults due to the distinct characteristics of cAVMs in these age groups. METHODS: Search: A search for RCT, not RCT, prospective and retrospective cohort studies in PUBMED; SCOPUS; Central Cochrane Registry ofControlled Trials (The Cochrane Library); MEDLINE; EMBASE (Ovid); CINAHL. The search strategy include subject headings (MeSH) and text words connected with Booleans term. Population: Children (younger than 18 years old) with Cerebral Arterio-venous Malformation (AVMs). Intervention: Gamma Knife radiosurgery (GKS). Outcomes: Primary Outcome: Mortality to end of Follow-up and Surgery successfull determined by the percentage of obliterated AVMs. Secondary Outcome: New Neurological deterioration and Post-Radiosurgery intracranial hemorrhage. RESULTS: 21 studies with 2142 children who had Gamma knife surgery for cerebral arteriovenous malformations were found for this systematic review. For children with cerebral AVMs treat with GKS, the death rate was 0.725% (95% CI 0.411%-1.126%; I2 = 0%) while the success rate of gamma knife radiosurgery was 71.74% (95% CI 65.716%-77.211%; I2 = 88.13). The rate of complications, such as the rate of new neurological deficits, was 2.57% (1.43% to 3.89%; I2 = 66.78%), and the postoperative intracranial bleeding rate was 2.463% (1.348% to 3.9%; I2 = 70.14%). CONCLUSIONS: Gamma Knife radiosurgery is a safe and effective treatment option for cerebral arteriovenous malformations, with high surgical success rates, low mortality, and low complication rates. However, further high-quality case-control studies are needed to evaluate its long-term efficacy and safety.

Is Gamma Knife surgery, omitting adjunct whole brain radiation treatment, feasible for patients with 20 or more brain metastases?

The importance of the number of brain metastases (BM) when deciding between whole brain radiation treatment (WBRT) and radiosurgery is controversial. We hypothesized that the number of BM is of limited importance when deciding radiation strategy, and offered Gamma Knife surgery (GKS) also for selected patients with 20 or more BM. The outcome following single session GKS for 75 consecutive patients harboring 20 or more (20+) BM was analyzed. Data was collected both retro- and prospectively. The median survival time was 9 months. Two grade 3 complications occurred, 1 resolved and 1 did not. Sex and clinical condition at the time of GKS (ECOG value) were the only parameters significantly related to survival time. Eighteen patients developed leptomeningeal dissemination with or without distant recurrences (DR), and another 32 patients developed DR a total of 73 times. DR was managed with GKS 24 times, with WBRT 3 times and with systemic treatment or best supportive care 46 times. The median time to developing DR was unrelated to the number of BM, but significantly longer for patients older than 65 years, as well as for patients with NSCLC. GKS is a reasonable treatment option for selected patients with 20 or more BM. It is better to decide the optimal management of post-GKS intracranial disease progression once it occurs rather than trying to prevent it by using adjunct WBRT.

Hearing Outcomes from Gamma Knife Treatment for Intracanalicular Vestibular Schwannomas with Good Initial Hearing.

Background: The objective of this study was to describe the long-term hearing outcomes of gamma knife treatment for unilateral progressing vestibular schwannomas (VS) presenting with good initial hearing using audiologic data. Methods: A retrospective review was performed between 2010 and 2020 to select patients with progressing unilateral VS and good hearing (AAO-HNS class A) treated with stereotactic gamma knife surgery (GKS). Their audiograms were analyzed along with treatment metrics and patient data. Results: Hearing outcomes with a median follow-up of 5 years post-treatment showed statistically significant loss of serviceable hearing: 34.1% of patients maintained good hearing (AAO-HNS class A), and 56.1% maintained serviceable hearing (AAO-HNS class A and B). Non-hearing outcomes are favorable with excellent tumor control and low facial nerve morbidity. Conclusions: Hearing declines over time in intracanalicular VS treated with GKS, with a significant loss of serviceable hearing after 5 years. The mean cochlear dose and the presence of cochlear aperture obliteration by the tumor are the main statistically significant factors involved in the hearing outcomes.

Is two-staged gamma knife surgery a reasonable management option for very large cerebellar metastases? A case series of three patients.

Two-staged gamma knife surgery (GKS) is a method that may extend the upper tumor volume limit for using GKS in the management of brain metastases. However, the safety of treating very large posterior fossa lesions with this technique has not been well demonstrated. Therefore, we analyzed our experience in treating cerebellar metastases larger than 12 cm3 with two-staged GKS. Four consecutive patients harboring 12 to 30 cm3 cerebellar metastases scheduled two-staged GKS were included in the study, and all but one patient completed the treatment. The treatment doses were 10-13Gy. All patients were followed with regular MR imaging and clinical assessments, and the tumor volumes were measured on all treatment and follow-up images. Tumor progression was not demonstrated in any of the patients. Tumor volumes decreased by, on average, more than half between the two stages. The median survival was 22months, and no patient died due to intracranial tumor progression. Peritumoral edema at the first GKS resolved in all patients, replaced by asymptomatic mild T2 changes in two of them not requiring any treatment. No radiation-induced complication has developed thus far. Staged GKS seems to be a feasible management option for very large cerebellar metastases.

Long‐Term Quality of Life in Patients with Intracanalicular Vestibular Schwannomas after Gamma Knife Surgery Treatment: A Follow‐Up Study

Introduction. Our previous research showed that the gamma knife surgery (GKS) is a highly effective treatment for intracanalicular vestibular schwannomas (IVS). In the current study, we aimed to evaluate long‐term quality of life (QoL) as a follow‐up to the assessment of baseline clinical and demographic parameters in the original study. Moreover, QoL outcomes were compared with norms for the general population and for patients who underwent different ear, nose, and throat (ENT) procedures. Materials and Methods. The follow‐up study included 92 patients (59 women and 33 men; mean age, 61.71 ± 12.55 years; range: 32‐85 years) with unilateral IVS who underwent GKS. Patients completed the Assessment of Quality of Life, Penn Acoustic Neuroma Quality‐of‐Life, Glasgow Benefit Inventory, and WHO‐5 Well‐being Index questionnaires as well as a demographic survey. Neurosurgical parameters were assessed using the Koos and House‐Brackmann scales and the results of audiological examinations. Results and Conclusions. QoL scores were within or above the norm in 38% of patients. There were significant differences in terms of comorbidities and emotional well‐being between patients with QoL scores within or above the norm and patients with QoL scores below the norm. Comorbidities were more common in patients with QoL scores below the norm, and they influenced reported QoL (p = 0.009). Patients with QoL scores within or above the norm reported better emotional well‐being than those with QoL scores below the norm. Long‐term QoL outcomes were satisfactory, consistent with the results of the original study. Although GKS is a complex procedure, patients reported higher QoL than those using hearing aids and the same QoL as those after ENT surgery or reassurance. However, they reported a slightly lower QoL than patients taking ENT medications. GKS appears to be a promising treatment option for patients with IVS.

Microsurgery of Brainstem Cavernoma: Challenges and Outcomes

Cavernous malformation of brainstem is at increased risk of hemorrhage compared to supratentorial cavernomas. Increased morbidity associated with brainstem cavernoma (BCs) is defined by the inherent eloquence of the surrounding structures. At present watchful waiting, microsurgical resection and gamma knife surgery are the treatment modalities for symptomatic brainstem cavernoma. However, in the resource limited settings microsurgical excision by selecting an appropriate corridor can help in gross total removal in the meantime improving the neurological deficit and patient satisfaction. In this case series we have reviewed cavernomas of midbrain and pons, the technical difficulty with its management and its outcomes.

Neurosurgical treatment and outcome patterns in patients with meningioma in South Moravian region-a population-based study.

Meningiomas are usually slow-growing tumours, constituting about one third of all primary intracranial tumours. They occur more frequently in women. Clinical manifestation of meningiomas depends on their location, tumour size and growth rate. In most cases, surgical treatment is the procedure of choice. The success of this treatment is, however, associated with the radicality of the resection. Radiotherapy represents an additional or alternative treatment modality. Gamma knife surgery is another notable treatment method, especially in small and/or slow-growing tumours in eloquent areas or in elderly patients. Authors describe their experience with the diagnosis, treatment and outcome of the patients with meningioma (n = 857). Furthermore, they also assess the postoperative morbidity/mortality and recurrence rate. In view of the benign histology of meningiomas, the success of the treatment largely depends (besides the tumour grading) on the radicality of the resection. The emphasis is also put on appropriate follow-up of the patients. In certain patients, the watch and wait strategy should be also considered as a suitable treatment method.

Natural History and Histopathology of Expanding Cysts and Hematomas After Stereotactic Radiosurgery for Arteriovenous Malformations of the Brain: A Case Series

We reviewed the clinical course and histopathologic findings for cases involving the formation of expanding cysts and/or hematomas after gamma knife surgery (GKS) for arteriovenous malformations (AVMs). We report a single-center retrospective review of 18 patients who presented with cyst and/or hematoma expansion after GKS for AVMs between 1993 and 2023. Expanding cysts and hematomas were defined as well-demarcated cavities filled with fluid or well-marginated heterogenous hematomas presenting with expansion proximal to or in the location of the original AVM, respectively. Patient demographics, AVM characteristics, history of interventions and surgeries, and imaging and histopathologic features of expanding cysts and hematomas were collected for analysis. Among 1072 AVM patients treated using GKS, 18 presented with expanding cysts or hematomas during a total follow-up period of 16,757 patient-years (0.11 case/100 persons/patient-year). The time to cyst or hematoma identification was 4-13 years after initial GKS, with a mean duration of 8.6 years. Among the patients examined, 7 (38.9%) presented mainly with hematoma, 10 (55.6%) presented mainly with cysts, and 1 presented with approximately equal components of both. Among the 18 patients, 13 (72.2%) underwent craniotomy to treat cyst or hematoma expansion. All the specimens had similar histopathologic characteristics, including organizing hematoma with fresh and old hemorrhage, fibrinoid necrosis of the vessels, gliosis of normal brain tissue, infiltration of hemosiderin-laden histiocytes, and extravascular protein leakage. Our findings suggest that the formation of these 2 complications can be attributed to a common mechanism involving radiation-induced vascular damage in brain tissue adjacent to the AVM and subsequent chronic inflammation and capillary dilatation.

Surgical salvage for recurrent vestibular schwannoma after primary stereotactic radiosurgery

Background: The management of vestibular schwannoma has evolved over the past hundred years. In the last decades, surgery has been gradually replaced by radiation therapy as a primary treatment modality, particularly for small tumors, due to the less invasive nature and the compared reported outcomes in tumor control and hearing preservation. However, irradiation sometimes fails to stop tumor growth. In a long-term follow-up after primary fractionated stereotactic radiotherapy, the rate of treatment failure was reported as 3% and needed surgical salvage. For single-fraction modality, Hasegawa et al. reported salvage treatment after primary Gamma Knife radiosurgery in 8%, where 90% of these underwent surgery and 50% of those who were treated with a second gamma knife surgery required surgical intervention later. An increase in tumor volume by more than 10–20%, tumor growth after three years, and no return to pretreatment volume after transient swelling have been considered as tumor recurrence rather than pseudoprogression, a transient increase in tumor volume after radiotherapy that occurs up to 30% of cases. It has been reported that microsurgery after radiotherapy is more difficult, with most authors reporting a loss of defined arachnoid planes and worse cranial nerve outcomes, especially for hearing and facial nerve function. Case Description: A 43-year-old female patient was incidentally (asymptomatic) diagnosed on a magnetic resonance imaging (MRI) scan harboring a left vestibular schwannoma, grade T2 (Hannover classification), in 2015. Neurologic examination was unremarkable, and audiometry testing was normal. She was initially treated with observation. Three years later, in 2018, the lesion had enlarged, becoming a grade T3a and reaching the cistern of the cerebellopontine angle. The tumor was then treated with fractionated stereotactic radiosurgery (5 sessions of 5 Gy). MRI scans in 2019 and 2020 showed slight tumor growth. This enlargement was attributed to a pseudoprogression after radiosurgery, and only observation was advocated. In 2022, 4 years later, after radiosurgery, the tumor was still growing, and the patient began to suffer from hearing loss. A failure treatment was considered, and microsurgery was indicated. The patient was counseled about the risk of functional nerve impairment, and surgical consent was obtained. A retro sigmoid approach was planned. A gross total resection was attempted due to the clear subperineural plane during tumor dissection and because it was the only option that would provide a cure for the patient. The adjacent neurovascular structures were firmly adhered to the tumor capsule, which represented a major challenge for microdissection. The tumor was soft, without significant bleeding. A total resection was achieved, and the facial nerve was anatomically preserved. The patient developed facial paresis (House-Brackmann III) in the immediate postoperative period, which improved at the 6-month follow-up. Hearing loss did not improve. Postoperative MRI showed total resection. Conclusion: Microsurgery after radiotherapy for vestibular schwannoma is challenging in terms of indication, when to indicate, resection target, difficulty in dissection due to local changes, and outcome. Gross total resection may be considered, as it is the only treatment that may provide a cure for the patient. However, the patient should be counseled about the risks.

Changing trends in gamma knife surgery to linear accelerator brain stereotactic radiotherapy in Japan: a survey based on the nationwide claims database

PurposeThis study evaluated the trends in the platform for stereotactic radiotherapy to the brain (SRT), utilizing the open data of the National Database published by the Ministry of Health, Labour, and Welfare.Materials and methodsThis study analyzed data from FY2014 to FY2021. The practices included in the study were gamma knife surgery (GKS) and SRT with a linear accelerator (LINAC). The total number of outpatient and inpatient cases in each SRT system was evaluated annually.ResultsFrom April 2014 to March 2022, the study included 212,016 cases (102,691 GKS and 109,325 LINAC) of the registered 1,996,540 radiotherapy cases. In the first year, 13,117 (54.1%) cases were GKS, and 11,128 (45.9%) were LINAC; after that, GKS decreased, and LINAC increased, reaching the same rate in FY2017. Compared to the first year, the final year showed 11,702 GKS (− 1415 or − 10.8%) and 17,169 LINAC (+ 6041 or + 54.3%), with an increase of 4626 total SRT cases to 28,871 (+ 19.1%). The percentage of outpatient treatment also increased from 4.6 to 11.8% for GKS and from 44.7 to 57.9% for LINAC.ConclusionThe study found a gradual decrease in the selection of GKS, an increasing trend in the selection of LINAC, and an increase in the overall number of stereotactic irradiations. In particular, the proportion of outpatient treatment increased, indicating that more than half of LINAC was selected for outpatient treatment.

Association between Sarcopenia and Survival in Patients Undergoing Gamma Knife Surgery for Brain Metastasis from Breast Cancer: A Retrospective Single-centre Cohort Study

AimsMany recent studies related to cancer surgery have reported that sarcopenia influences mortality in surgical patients. However, few comprehensive studies have examined the associations between sarcopenia and short- and long-term surgical outcomes of metastatic cancer, especially breast cancer with brain metastasis. In the present study, we investigated the association between sarcopenia and mortality in patients who underwent gamma knife radiosurgery (GKRS) for brain metastasis with breast cancer. Materials and methodsThis retrospective study analysed 157 patients who underwent GKRS for brain metastasis with breast cancer between January 2014 and December 2018. A Cox regression analysis was carried out to evaluate the association between sarcopenia and mortality at 90 days, 180 days, 1 year, 3 years and the overall period. ResultsIn the Cox regression analysis, sarcopenia was significantly associated with high 90-day mortality (adjusted hazard ratio 3.46, 95% confidence interval 1.24–9.67, P = 0.018), 180-day mortality (adjusted hazard ratio 2.67, 95% confidence interval 1.37–5.22, P = 0.004), 1-year mortality (adjusted hazard ratio 2.39, 95% confidence interval 1.42–4.02, P = 0.001), 3-year mortality (adjusted hazard ratio 2.39, 95% confidence interval 1.53–3.74, P < 0.001) and overall mortality (adjusted hazard ratio 2.11, 95% confidence interval 1.37–3.26, P < 0.001). ConclusionSarcopenia could be a risk factor for short- and long-term mortality in patients undergoing GKRS for brain metastasis from breast cancer.

NCMP-07. HEADACHE PRESENTATION AND MANAGEMENT IN VON HIPPEL-LINDAU (VHL)-ASSOCIATED HEMANGIOBLASTOMAS

Abstract BACKGROUND Hemangioblastomas are the most common brain tumors among patients with Von Hippel-Lindau (VHL) disease. Common characteristics of these benign tumors, such as tumor growth, peritumoral edema, and cystic expansion, may lead to neurologic morbidity and/or mortality. Thus, early diagnosis based on symptom presentation and appropriate treatment is paramount to VHL-associated hemangioblastoma management. METHODS We conducted a systematic review of PubMed, Scopus, Cochrane, Embase, and Web of Science databases using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We identified studies reporting pre-diagnostic symptoms and post-diagnostic treatments among patients with VHL-associated hemangioblastomas. RESULTS Data from 150 patients were analyzed. The average age at presentation was 35.3 years (range: 18-75) and 52.7% of patients were female. Headache was the most common presenting symptom (73.3%). Other presenting symptoms included balance or gait disturbances (42%), ataxia (41.3%), nausea (24.3%), emesis (24.3%), dysmetria (15.5%), swallowing difficulties (11.3%), and singultus (10.7%). Anatomically, 98.7% of tumors were in the posterior fossa, specifically 69% in the cerebellum and 30% in the brainstem. Approximately 62.8% of patients had tumor associated cysts. A majority of the patients (98.7%) underwent gross-total resection of the tumor and cyst drainage as needed. Other common treatments included radiotherapy, gamma-knife surgery, and ventriculoperitoneal shunt placement. CONCLUSION Patients with VHL-associated hemangioblastomas commonly presented with headaches, balance or gait difficulties, and ataxia. Tumors were generally found in the posterior fossa and were associated with cysts. Gross-total resection was the main treatment offered to patients with these tumors.

Neuroepithelial tumor with EWSR1::PATZ1 fusion: A literature review.

We present the clinicopathological and molecular genetic characteristics of a neuroepithelial tumor (NET), EWSR1::PATZ1 fusion-positive with a literature review. This fusion has recently been discovered in rare central nervous system tumors and soft tissue sarcomas and was not included in the fifth edition of the WHO classifications. We identified this fusion in 2 NETs. The first case involved a 7-year-old girl and the second case occurred in a 53-year-old man; both presented with headaches and vomiting. The pediatric case initially showed an intermediate grade of the tumor, but upon recurrences, it transformed into a high-grade tumor with 2 relapses in 8.3 years. This case exhibited high mitotic activity (20/10 high-power fields), and a high Ki-67 index (21%). The TERT promoter (TERTp) mutation was present in both initial and recurrent tumors. In contrast, the adult case was a low-grade tumor with no mitotic activity or recurrence over 13.5 months after subtotal resection and gamma knife surgery. Interestingly, the pediatric case demonstrated a longer survival time compared to conventional glioblastoma. The TERTp mutation, similar to being a molecular signature in adult-type glioblastoma, could also be an indicator of high-grade behavior in PATZ1 fusion NET.