Glomus Jugulare Tumors Research Articles

Vascular Blush Size Reduction, Technical Success and Safety of Intra-Arterial Embolization for Glomus Jugular Tumors: A Retrospective Cohort Study

Background: Glomus jugulare tumors are slow-growing neuroendocrine paragangliomas located in the temporal bone. Surgical excision, the standard treatment option, carries a high risk of intraoperative bleeding due to the vascular nature of these lesions. To mitigate this risk, current practice involves performing intra-arterial embolization prior to surgery. Objectives: The objectives of this study were to assess postintervention safety, technical success, and the rate of vascular blush size reduction in a group of patients with Glomus jugulare tumors who were planned for surgery and underwent pre-surgical intra-arterial embolization of the lesion. Patients and Methods: In this retrospective cohort study, all patients who underwent intravascular embolization for Glomus jugulare tumors from 2017 onwards were included. The study comprised 61 patients scheduled for surgery following embolization. All embolizations were completed in one session and were primarily performed via external carotid artery branches using polyvinyl alcohol (PVA). The size of the vascular blush was measured before and after embolization in coronal, supero-inferior sagittal, and antero-posterior sagittal planes, and the rate of blush size reduction was calculated. Procedure complications, including post-embolization pain, were recorded. In the statistical analysis, vascular blush size was compared between pre- and post-embolization times. Results: Pain after embolization was reported in 11 patients (18%). There were no other complications among the patients, indicating a high level of safety. All procedures were technically successful. The mean pre-embolization vascular blush diameter in the coronal plane was 29.1 ± 13.3 mm, which decreased to 16.8 ± 7.1 mm after embolization, representing an average diameter reduction of 38.5% (P < 0.001). Conclusion: The findings of this retrospective cohort study suggest that intra-arterial embolization for Glomus jugulare tumors is safe, technically successful, and effective in reducing vascular blush before surgery.

Lymphatic Vessels in the Inner Ear of Patients With Meniere Disease: A Novel Pathological Finding.

Meniere disease, characterized by intermittent episodes of vertigo, fluctuating sensorineural hearing loss, tinnitus, and aural pressure, is a common cause of vertigo in humans. The pathogenesis of Meniere disease remains unknown. The current study aimed to describe a novel pathological change discovered in the inner ears of patients with Meniere disease who underwent labyrinthectomy. This retrospective case-control study was conducted with 21 patients with MD who underwent labyrinthectomy. A total of 15 patients diagnosed with acoustic neuroma or glomus jugular tumor were review over the same period of time as control. The clinical information of the patients and the pathological features of the membrane are described. The new pathological tissue was a morbid membrane structure sealing the round window, characterized by the formation of lymphatic capillaries. Histochemical and immunofluorescent staining was positive for D2-40, LYVE-1, podoplanin, and PROX1, which are the classical markers of the lymphatic vessels. Transmission electron microscopy revealed that the lymph capillaries lacked a typical basement membrane and that their ends were blind, composed of a single layer of endothelial cells with valval connection structures between adjacent capillary epithelial cells. This is the first report of lymphatic vessels in the human inner ear, and this pathological structure is a completely new discovery. The lymphatic vessels may develop due to inflammation or decompensation of pressure in the inner ear, suggesting that the inner ear can reactively form lymphatic vessels in some inflammation and fluid flow-dependent pathological conditions. The current findings help in improving our understanding of the pathogenesis of Meniere disease.

Efficacy and Safety of Preoperative Embolization in Glomus Jugulare Tumors: A Systematic Review and Meta-analysis of Clinical Outcomes and Complications.

This study aims to provide a comprehensive review of the clinical benefits, complications, and safety profile associated with preoperative embolization in Glomus jugulare tumors (GJTs). A comprehensive search in PubMed, Embase, and Web of Science was conducted for English articles published up to March 2023, focusing on GJTs and preoperative embolization. Included studies involved patients over 18 with GJTs. We excluded studies that explored embolization methods other than the standard endovascular approach, as well as studies involving paragangliomas that did not provide specific data related to GJTs. Key variables such as hemorrhage volume and surgical time, as well as clinical outcomes, were analyzed. Data were analyzed using a random-effects model meta-analysis, assessing heterogeneity with the I2 statistic. This review encompasses 19 studies with a total of 328 patients. The studies incorporated into our meta-analysis display considerable differences and inconsistencies in their data. The findings of the meta-analysis show a mean hemorrhage volume of 636ml (95% confidence interval (CI) 473-799) following preoperative embolization, and a mean surgical duration of 487min (95% CI 350-624). The study also notes potential complications: facial nerve deficits occurred in 20% of cases (95% CI 11-32%), and vagal nerve deficits in 22% (95% CI 13-31%). This study suggests that preoperative embolization could decrease surgery duration and blood loss, but emphasizes the importance of evaluating risks like nerve damage. However, the generalizability of these findings is restricted due to the diversity of available data.

Gamma Knife radiosurgery for the management of glomus jugulare tumors: A systematic review and report of the experience of a radioneurosurgery unit in Latin America.

Glomus jugulare tumors (GJTs) are rare and mainly affect women between the 5th and 6th decades of life. Its localization and anatomic relationships make conventional surgical treatment difficult and with a considerable risk of complications. This manuscript aims to describe the results of Gamma Knife radiosurgery (GKR) in patients with GJT treated in a single center in Latin America, as well as to systematically review the literature to determine the clinical and radiological effectiveness of this technique. A search of information from January 1995 to June 2023 was performed. Twenty-two articles reporting 721 GJT patients treated with GKR were included in the study. Variables such as symptomatic control, control of tumor size, and complications were evaluated. These variables were described using measures of central tendency and proportions. For the institutional experience, 77 patients with GJT tumors were included in the study. Pre-treatment clinical variables and follow-up data were collected from medical charts and phone interviews. The Short Form-36 scale was applied to assess the quality of life. The data were analyzed using the statistical program STATA17.0. A total of 721 patients were considered. The median of patients included in these studies was 18.5. The mean age was 58.4 years. The median of symptom control was 89%, and the median of imaging control was 95.7%. In our institution, 77 patients were included in the study. The mean age was 53.2 years. The median hospital stay was 4.92 hours. For the clinical follow-up, information on 47 patients was obtained. An improvement in pre-treatment symptoms was described in 58%, with general symptomatic control of 97%. The tumor-control rate was 95%, and there were statistically significant differences in six of the nine Short Form-36 scale domains. GKR is an effective, safe, and cost-effective technique that offers a high degree of symptomatic and tumor size control in patients with GJT.

Dose-Painting Linear Accelerator Radiosurgery of Glomus Jugulare With Dosimetric Comparison to Gamma Knife.

Objectives In this study, we outline our rationale for delivering a dose of ≥15 Gy in stereotactic radiosurgery (SRS) of glomus jugulare tumor (GJT) while ensuring the avoidance of complications associated with doses >13 Gy to the facial nerve. To avoid such complications, we initially utilized the Gamma Knife Perfexion (GK) system (Elekta Instrument AB, Stockholm, Sweden) at our institution but encountered challenges related to lengthy treatment times and difficulty in sculpting doses to minimize doses to spare the facial nerve. As a potential solution, we propose the use of HyperArc (Varian Medical Systems, Palo Alto, CA), a newly developed automated delivery platform for linear accelerator (LINAC)-based SRS. HyperArc offers the potential for faster treatment and more complex shaping of the radiotherapy dose with multiple arcs and multi-leaf collimators. Methods We retrospectively reviewed nine cases of patients with GJT treated with HyperArc. Patients' demographic and treatment data were collected. Additionally, simulated GK treatment plans were created and compared with HyperArc plans to assess time savings, PTV coverage, and plan quality. Results One male and eight female patients, with a mean age of 63.9 years, were included. Treatments were delivered on average in 29 minutes, achieving 95-100% of the tumor while limiting the facial nerve to <13 Gy. Treatments replanned using our GK system could achieve only 92-99% tumor coverage while respecting facial nerve constraints, with average treatment times of 180 minutes. Comparable plan quality parameters were attained with both modalities. Conclusions The HyperArc system provides a qualitatively satisfactory and rapid treatment delivery of a highly sculpted radiotherapy dose to maximize tumor coverage and minimize facial nerve complications.

FRI369 SDHB Hereditary Pheochromocytoma Paraganglioma Syndrome With Biochemically Silent Pheochromocytoma

Abstract Disclosure: A.M. Skariah: None. C.C. Zacharia: None. Background: Paragangliomas are rare neuroendocrine tumors arising from extra-adrenal autonomic paraganglia. Majority of cases are sporadic but 30-50% are associated with genetic mutations. Patients with SDHB mutations can present with pheochromocytoma, paragangliomas or both. Lesions are usually extra-adrenal and typically secrete norepinephrine and occasionally dopamine. These cases are often associated with higher malignancy rates (up to 79%) compared to other SDH-x associated mutation cases. Clinical Case: Our patient is a 64-year-old female with history of secondary adrenal insufficiency, hypothyroidism, osteoporosis, GAD who presented in 2005 with left occipital headache and dysphagia. Workup was notable for a glomus tumor. She underwent tumor embolization, resection, radical neck dissection and radiation therapy. Genetic testing was not performed at the time of diagnosis. Routine biochemical surveillance was done postoperatively. In 2018, the patient was found to have a mild elevation of normetanephrine 248 pg/ml (&amp;lt;148 pg/ml) and total metanephrine 297 pg/ml (&amp;lt;205 pg/ml) levels. Subsequent plasma, urinary metanephrine/catecholamine studies were negative. In 2021, her brother was diagnosed with pheochromocytoma. Genetic testing was then pursued in the patient, and she was found to have a pathogenic mutation c.724C&amp;gt;A (p.R242S) in the SDHB gene. In June 2022, CT chest, abdomen and pelvis with contrast was ordered, and she was found to have a homogeneously enhancing 1.3 x 1.1x 1.4 cm left adrenal nodule with indeterminate imaging characteristics. Following this CT, DOTATATE PET CT scan was done and demonstrated somatostatin avidity in the region of previously resected left glomus jugular tumor, right adrenal gland nodule and left inferior pubic ramus sclerotic lesion. Repeat biochemical testing remained negative for catecholamine excess. Despite being asymptomatic, there was concern for a biochemically silent pheochromocytoma. Alpha blockade was completed prior to right adrenalectomy in November 2022 and surgical pathology confirmed pheochromocytoma. The patient remains clinically stable, and she is now undergoing radiation therapy of her left pubic ramus lesion. Conclusion: It is important to have genetic evaluation early in the workup for a newly diagnosed PPGL. Additionally, suspicion for biochemically silent pheochromocytoma should be present even in the setting of negative biochemical workup and positive SDHB mutation. Presentation: Friday, June 16, 2023

Metastatic Malignant Glomus Jugulare Tumor: A Rare Case Report with Clinical Manifestations and Treatment Approach.

BACKGROUND Paragangliomas are neuroendocrine neoplasms derived from paraganglia of the sympathetic and parasympathetic nervous systems. Parasympathetic ganglia-derived tumors, also called non-chromaffin, are located almost exclusively in the neck and skull base and are usually non-secretory and inactive. A case of malignant glomus jugulare with a metastatic cervical lymph node is described here. CASE REPORT A 24-year-old woman was referred to an otolaryngology clinic for concern of voice change for 1 month, which was associated with right progressive hearing loss, pulsating tinnitus, and right facial weakness. A clinical examination revealed a reddish mass in the right ear behind an intact tympanic membrane with right facial weakness of House-Brackmann grade VI. A bedside flexible nasopharyngoscopy revealed an immobile right vocal fold. A computed tomography scan of the brain revealed a destructive lesion within the right jugular foramen. The patient underwent embolization followed by glomus tumor resection via infra-temporal fossa with Fisch type A approach. Pathology revealed that the tumor was an infiltrative epithelioid tumor with a spindle and nesting pattern separated by fibrovascular stroma. The submitted lateral neck lymph node revealed a metastatic tumor. CONCLUSIONS Glomus jugulare tumors are uncommon paragangliomas, and malignant behavior with metastasis is extremely rare. Metastatic tumors are often associated with facial and vagal nerves palsy. There are no histological features that distinguish malignant glomus jugulare tumors. Malignant neoplasms are characterized by the presence of metastases. Tumors of the glomus jugulare that are malignant are treated with surgery, radiotherapy, or both. However, our search of the literature revealed no clear guidelines, given the scarcity of cases. Moreover, the presence of metastasis increases the risk of death.

Glomus jugulare tumor presenting as papilledema – A rare case report

A 54-year-old male presented with headache and blurring of vision in both eyes for 2 months. Ocular examination showed bilateral lateral rectus palsy with papilledema, suggestive of raised intra-cranial pressure. A computed tomography scan of the brain revealed an expansile infiltrating soft tissue lesion causing lysis of the right petrous and jugular fossa, suggestive of a Jugular fossa tumor. The patient’s blood pressure was high at all times despite regular medications because of the glomus tumor’s supposed release of catecholamines. Elective surgery was planned; however, the patient developed a fatal tumor rupture within 4 months of diagnosis, for which emergency neurosurgical intervention and intensive care support were given, but he succumbed to death. Tumors obstructing the jugular outflow can cause increased intra-cranial pressure and vision loss, requiring prompt neurosurgical intervention.

Early extubation of a patient in the operating room after prolonged glomus jugulare tumor surgical resection: a case report

The excision of glomus jugulare tumor as an infrequently highly vascular tumor has many risks and problems for anesthesiologists. Early extubation causes short length of hospitalization and less complications. As there are scant articles about early extubation for it, this encouraged us to report early extubation after prolonged anesthesia for glomus jugulare tumor excision. General anesthesia was performed with the combined use of intravenous anesthetic agents and isoflurane in a convulsive female. After 13 hours and 40 minutes of surgery, she was successfully extubated in the operative room. Therefore, early extubation in selected patient is possible after such a prolonged surgery.

Genotype-phenotype associations in paragangliomas of the temporal bone in a multi-ethnic cohort

Background Temporal bone paragangliomas are rare tumours with variable presentation that can be hereditary. Identification of clinical and genetic factors of aggressive tumour behaviour is important. Objective To determine the underlying genetic mutations and genotype/phenotype correlations in a multi-ethnic population of South Florida with sporadic temporal bone paragangliomas. Methods In a cohort of glomus tympanicum (GT) and glomus jugulare (GJ) cases, we assessed the frequency of pathogenic single nucleotide variants, insertions, deletions, and duplications in coding exons of genes that have been associated with paragangliomas (SDHB, SDHC, SDHD, SDHA, SDHAF2, RET, NF1, VHL, TMEM127, and MAX). Results None of the 12 GT cases had mutations. Among 13 GJ cases, we identified four mutation carriers (31%); two in SDHC, one in SDHB, and one in SDHD. All patients with pathogenic mutations were of Hispanic ethnicity, presented at a younger age (mean 27.5 versus 52.11 years), and with more advanced disease when compared to mutation-negative GJ cases. Conclusions and Significance: Mutations in the SDH genes are found in 31% of sporadic GJ. SDH-associated GJ had advanced disease and a 50% risk of metastasis. Our data supports emerging recommendations for genetic screening in all populations with GJ tumours as the genetic status informs management.

Gamma Knife Radiosurgery as a Dependable, Effective Option for Glomus Jagulare Tumors: A Single Institution Long-Term Experience and Review of the Literature

Objective: Glomus jugulare tumors (GJTs) are benign, slowly growing tumors, highly vascular, with the potential to infiltrate neurovascular structures. Surgical treatment is usually associated with high morbidity and even death. Gamma Knife radiosurgery (GKRS) has been established as an effective treatment option. This retrospective study aims to report and confirm GKRS.'s long-term effectiveness and safety for GJT patients. Methods: A total of 65 patients with GJTs were treated with GKRS, at the authors' center from 2005 to 2020, with a mean follow-up period of 87.7 months. The mean treated GJT volume was 5.4cc with a median prescription dose of 15Gy and a median maximum dose of 42.9Gy. Results: Most patients were females (77%), and the median age at presentation was 48 years. The overall tumor growth control was 93.8% (61 patients) 39% of them achieved tumor size reduction. The overall clinical control was 90.8% (59 patients), and 40.7% achieved clinical improvement. The Actuarial tumor rate free of progression was 100% at 3 years, 91.5% at 5 years, and 86% at 10 years of follow-up. Conclusions: GKRS for GJTs typically results in high long-term tumor control and lower neurological morbidity than those associated with microsurgical resection, therefore should be consider as a dependable effective treatment option.

Trends and Impact of Treatment Modalities (Surgery and Radiation Therapy) on Health Care Utilization in Patients With Glomus Jugulare Tumors (GJTs): An Inverse Probability of Treatment Weight Analysis

The trend of practice pattern and impact on health care utilization for surgery and radiation therapy (RT) in patients with glomus jugulare tumors (GJTs) is not well defined. The IBM (Armonk, NY) MarketScan database was queried using the ICD-9/10 and CPT 4th edition, 2000-2020. We included patients ≥18 years of age who underwent either surgery or RT with at-least 1-year follow-up. We compared the health care utilization at 3-month, 6-month, and 1-year follow up using the inverse probability of treatment weight technique. A cohort of 333 patients was identified. Of these, 72.7% (n= 242) underwent RT and 27.3% (n= 91) underwent surgery. RT use increased from 2002-2004 (50%) to 2017-2019 (91%). Patients in the surgery cohort were younger (median age 49 vs. 56 years, P < 0.0001) and had a higher 3+ comorbidity index (34% vs. 30%, P= 0.43) compared with patients in the RT cohort. Patients who underwent surgery had higher complications at index hospitalization (22% vs. 6%, P < 0.0001) and at 30 days (14% vs. 5%, P= 0.0042). No difference in combined index and 6- or 12-month payments were noted (6-months: surgery, $66m108, RT: $43m509, P= 0.1034; 12-months: surgery, $73,259, RT: $51,576, P= 0.1817). Only 4% of patients who had initial RT underwent RT and none underwent surgery at 12 months, whereas 6% of patients who had initial surgery underwent RT and 2% underwent surgery at 12 months. RT plays an increasingly important role in the treatment for patients with GJTs, with fewer complications and a comparable health care utilization at 1 year.

Glomus jugulare tumors treatment by gamma knife radiosurgery: A single center study.

Glomus jugulare tumor are benign vascular tumors and surgical resection is almost impossible. We have treated these tumors by Gamma knife radiosurgery and share our experience. This study was conducted at the Neurospinal and Cancer Care Institute, Karachi from January 2010 to May 2020. Thirty-four patients with glomus jugulare tumors treated with gamma knife radiosurgery were included in the study. The comprehensive clinical and demographic characteristics of all patients were collected through a manually designed questionnaire. Computed tomography, digital subtraction angiography and magnetic resonance imaging were used to make the diagnosis. Data was incorporated and analyzed by SPSS version 26. A total of 34 patients were included in the study of which 16(47%) were males and 18(53%) were females with first follow up after 6-month up to two year clinical and radiological follow-up. The mean age of the patients was 42.5±13.5 with a minimum age of 20 years and maximum age of 65 years. The KPS scale was 2.09±0.45 and the volume of the tumor was 33.8±22.5 cm3. The improvement was shown in 27 patients of which 14 were males and 13 were females showing insignificance post radiation change. Of all 34 patients, the outcome was recorded as 3(9%) for excellent, 22(64%) for good, 6(17%) for fair and 3(9%) were poor results. Gamma Knife radiosurgery is a safe and effective primary therapy and salvage therapy for residual and recurrent cases of glomus jugulare and tympanicum tumors.

Pencil-beam scanning proton therapy for the treatment of glomus jugulare tumours.

Glomus jugulare tumours (GJT) are benign tumours that arise locally and destructively in the base of the skull and can be successfully treated with radiotherapy. Patients have a long-life expectancy and the late effects of radiotherapy can be serious. Proton radiotherapy reduces doses to critical organs and can reduce late side effects of radiotherapy. The aim of this study was to report feasibility and early clinical results of 12 patients treated using proton therapy. Between December 2013 and June 2019, 12 patients (pts) with GJT (median volume 20.4 cm3 ; range 8.5-41 cm3 ) were treated with intensity modulated proton therapy (IMPT). Median dose was 54 GyE (Gray Equivalents) (50-60 GyE) with daily fractions of 2 GyE. Twelve patients were analysed with a median follow-up time of 42.2 months (11.3-86.7). Feasibility, dosimetric parameters, acute and late toxicity and local effect on tumour were evaluated in this retrospective study. All patients finished treatment without interruption, with excellent dosimetric parameters and mild acute toxicity. Stabilisation of tumour size was detected on MRI in all patients. No changes in symptoms were observed in comparison with pre-treatment conditions. No late effects of radiotherapy were observed. Pencil-beam scanning proton radiotherapy is highly feasible in the treatment of large GJT with mild acute toxicity and promising short-term results. Longer follow-up and larger patient cohorts are required to further identify the role of pencil-beam scanning (PBS) for this indication.

Multimodal treatment of glomus jugular tumours

Glomus jugulare tumours are extremely rare, slow-growing, hypervascular tumours that arise within the jugular foramen of the temporal bone and frequently involve the lower cranial nerves. We performed a retrospective study for patients treated between January 2005 and December 2019, reviewing clinical and radiological data for 91 cases of glomus jugulare tumours. Data were available for 91 patients presenting with 96 tumours. Surgery was 1st intention of treatment for 13 cases, the endovascular approach was 1st intention for 6 cases and GKRS was primarily performed in 72 cases. Combined treatment options were used in 19 cases. The median age at the time of treatment was of 57 years. The tumour volume varied between 0.5 and 73.4 cm3 with a median value of 8.3 cm3. For the cases treated with GKRS, the peripheral dose ranged between 8 and 35 Gy on the 35% to 65% isodose, with a median of 14 Gy on the 45% isodose. The average follow-up was 38 months with a maximum of 94 and consisted of contrast-enhanced MRI every six months in the first year after the procedure and every 1 to 2 years afterwards. The overall tumour control rate was 95.6% using multimodal treatment options for glomus jugulare tumours. Multimodal treatment for glomus jugulare tumours offers the patient the chance for the best possible outcome and long-term survivability. An individual treatment approach for this kind of very rare head and neck tumour (0,6% of all head and neck tumours) is recommended to choose the best risk-versus-benefit treatment option.

Multimodal treatment of glomus jugular tumours

Glomus jugulare tumours are extremely rare, slow-growing, hypervascular tumours that arise within the jugular foramen of the temporal bone and frequently involve the lower cranial nerves. We performed a retrospective study for patients treated between January 2005 and December 2019, reviewing clinical and radiological data for 91 cases of glomus jugulare tumours. Data were available for 91 patients presenting with 96 tumours. Surgery was 1st intention of treatment for 13 cases, the endovascular approach was 1st intention for 6 cases and GKRS was primarily performed in 72 cases. Combined treatment options were used in 19 cases. The median age at the time of treatment was of 57 years. The tumour volume varied between 0.5 and 73.4 cm3 with a median value of 8.3 cm3. For the cases treated with GKRS, the peripheral dose ranged between 8 and 35 Gy on the 35% to 65% isodose, with a median of 14 Gy on the 45% isodose. The average follow-up was 38 months with a maximum of 94 and consisted of contrast-enhanced MRI every six months in the first year after the procedure and every 1 to 2 years afterwards. Overall tumour control rate was of 95.6% using multimodal treatment options for glomus jugulare tumours. Multimodal treatment for glomus jugulare tumours offers the patient the chance for the best possible outcome and long-term survivability. Individual treatment approach for this kind of very rare head and neck tumour (0,6% of all head and neck tumours) is recommended to choose the best risk-versus-benefit treatment option.

Recurrent Glomus Jugulare Tumor Invading the Cerebellum on 68Ga-DOTATATE PET/CT.

Glomus tumors are rare, slow-growing extra-adrenal paragangliomas of the head and neck. Treatment and prevention of neurological deficits become more difficult as these tumors aggressively grow in size and infiltrate adjacent anatomical structures. Because glomus tumors are paragangliomas of neuroendocrine origin, 68Ga-DOTATATE PET/CT can be used as imaging method in the diagnosis and follow-up. In this case, we presented a recurrent glomus jugulare tumor that invaded to the cerebellum on 68Ga-DOTATATE PET/CT imaging.

Stereotactic Radiosurgery for Glomus Jugulare Tumors: Systematic Review and Meta-Analysis

Glomus jugulare tumors (GJTs) are benign paragangliomas of the jugular foramen. Traditional management of these tumors involves surgical resection; however, considering the proximity of these tumors to important neurovasculature, stereotactic radiosurgery (SRS) may be an appropriate noninvasive treatment to consider. The aim of this meta-analysis was to evaluate SRS as a treatment option for GJTs. An online search using PubMed, Web of Science, Scopus, and Cochrane databases was performed in March 2019 for articles on radiosurgery treatment of GJTs. The screening process followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The final analysis comprised 23 studies including 460 patients. Average rates of tinnitus, hearing loss, and lower cranial nerve deficit as presenting symptoms were 56% (95% confidence interval [CI], 46%-66%), 56% (95% CI, 44%-68%), and 42% (95% CI, 31%-54%), respectively. Overall clinical status improvement rate after treatment was 47% (95% CI, 37%-57%). Rates of tinnitus, hearing loss, and lower cranial nerve improvement after treatment were 54% (95% CI, 44%-63%), 28% (95% CI, 19%-40%), and 22% (95% CI, 11%-39%), respectively. The mean follow-up time across studies was 47 months (range, 4-268 months). The aggregate tumor control rate at the time of follow-up was 95% (95% CI, 93%-97%). The tumor control rate of 95% and 47% symptomatic improvement suggest that SRS may be a suitable treatment modality for these hypervascular skull base tumors. Future studies are warranted to further evaluate the potential role of SRS in management of GJTs.

Three-Corridors Procedure to Operate in the Infralabyrinthine Cervico-Jugulo-Carotico-Tympanic Area

Introduction: The aim of the study was to present the results of our experience in three-corridors procedures applied for the tumors and inflammatory lesions of the infralabyrinthine cervico-jugulo-carotico-tympanic area. Methods: The lesions located in the infralabyrinthine cervico-jugulo-carotico-tympanic area were operated in 13 patients using the 3-corridors technique. The anatomical and functional integrity of the external and middle ears and the facial nerve (FN) could be preserved. Results: The diagnoses were glomus jugulare, infralabyrinthine petrous bone cholesteatoma, jugular foramen schwannoma, and giant-cell tumor. The follow-up duration ranged from 2 to 24 months. No tumor recurrence or growth was encountered in the follow-up. The operations were uneventful. Total surgical excision could be achieved in 10 patients. A second-stage retrosigmoid approach was performed for the total removal of the intracranial tumor remnant in two patients. A wait-and-scan policy has been considered in one patient who had partial resection for a glomus jugulare tumor. Conclusion: Three-corridors procedure seems to be a useful technique to operate in the infralabyrinthine, cervico-jugulo-carotico-tympanic area as it takes the advantage of hearing preservation, preservation of the anatomic and functional integrity of the external and middle ear structures as well as the FN.

Feasibility Study of Stereotactic Radiosurgery Treatment of Glomus Jugulare Tumors via HyperArc VMAT.

This study aims to report on the clinical validation and feasibility of utilizing a novel fully automated treatment planning and delivery system, HyperArc VMAT stereotactic radiosurgery (SRS) for glomus jugulare tumors (GJT). Independent dose verification of the HyperArc module via the MD Anderson's SRS head phantom irradiation and credentialing results showed compliance with the SRS treatment requirements per IROC MD Anderson's standard. Following the Alliance clinical trial, AAPM, RTOG protocols, and QUANTEC requirements, utilizing selected three-partial arc geometry of HyperArc module on TrueBeam Linac with 6MV-FFF beam, GJT SRS plans were generated for nine previously treated Gamma Knife (GK) radiosurgery patients using advanced Acuros-based algorithm to account for tissue inhomogeneity corrections and frameless immobilization with Q-fix mask and Encompass device insert. HyperArc VMAT produced highly conformal SRS dose distributions to GJT, a steep dose gradient around the GJT, and spared adjacent critical organs including the spinal cord (< 3.0 Gy). Due to faster patient setup and less MLC modulation through the target (average beam-on time, 6.2 minutes), the HyperArc VMAT plan can deliver a single high-dose of 18 Gy to the GJT in less than 15 minutes overall treatment time, significantly improving patient comfort and clinic workflow. Pretreatment portal dosimetry quality assurance results and independent dose verification via Monte Carlo-based physics second check met our clinical SRS protocol's requirements for treatment. Due to the highly conformal dose distribution, rapid dose fall-off, excellent sparing of adjacent critical organs, and highly precise and accurate treatment, clinical implementation of frameless HyperArc VMAT for GJT patients who may not have access to nor tolerate frame-based GK SRS treatment are underway.