GAMMA KNIFE RADIOSURGERY FORGLOMUS JUGULARE TUMORS

Clinical consensus guideline on the management of phaeochromocytoma and paraganglioma in patients harbouring germline SDHD pathogenic variants

Patients with germline SDHD pathogenic variants (encoding succinate dehydrogenase subunit D; ie, paraganglioma 1 syndrome) are predominantly affected by head and neck paragangliomas, which, in almost 20% of patients, might coexist with paragangliomas arising from other locations (eg, adrenal medulla, para-aortic, cardiac or thoracic, and pelvic). Given the higher risk of tumour multifocality and bilaterality for phaeochromocytomas and paragangliomas (PPGLs) because of SDHD pathogenic variants than for their sporadic and other genotypic counterparts, the management of patients with SDHD PPGLs is clinically complex in terms of imaging, treatment, and management options. Furthermore, locally aggressive disease can be discovered at a young age or late in the disease course, which presents challenges in balancing surgical intervention with various medical and radiotherapeutic approaches. The axiom-first, do no harm-should always be considered and an initial period of observation (ie, watchful waiting) is often appropriate to characterise tumour behaviour in patients with these pathogenic variants. These patients should be referred to specialised high-volume medical centres. This consensus guideline aims to help physicians with the clinical decision-making process when caring for patients with SDHD PPGLs.

Giant carotid chemodectoma treated with a combination of surgery and CyberKnife radiotherapy: a case report and review of the literature

Background

Paragangliomas are rare vascular neuroendocrine tumors that develop in the extra-adrenal paraganglion tissue. They occur most commonly at the carotid bifurcation, where they are known as carotid body tumors. Most paragangliomas are benign, locally aggressive, infiltrative tumors. Approximately 10% of patients with paragangliomas develop distant metastases, 10% present with multiple or bilateral tumors (mostly carotid body tumors), and 10% have a family history of paragangliomas. The malignant transformation of carotid body tumors has been reported in 6% of cases.

Case presentation

We present the case of a 64 year-old Caucasian woman with a gigantic glomic tumor mass in the neck. Twenty years before the consultation, the patient had undergone an unsuccessful attempt to remove the mass. Over the last 3 years, the patient had felt enlargement of the mass at an increased rate, almost doubling the prior size. Angio magnetic resonance imaging showed a 9 cm paratracheal mass on the left cervical side that laterally displaced the sternocleidomastoid muscle and 2 c m of the trachea. Due to the change in the tumor behavior, the maxillofacial team at Ruber International Hospital decided to remove the tumor surgically after embolization. During the surgery the tumor was gently dissected from the carotid an removed from the carotid bifurcation uneventfully. Two small nodes adhering tightly to the internal carotid adventitia and the posterior torn hole were left in place to avoid any potentially life-threatening complications. The final biopsy confirmed the initial diagnosis of carotid body paraganglioma and showed a Ki-67 expression of 19%. Due to the aggressive growth behavior and high Ki-67 expression of the tumor, the patient was referred to the CyberKnife Unit of Ruber International Hospital for treatment of the remaining nodes.

Conclusions

The management of cervical paragangliomas is difficult and remains a challenge. Although the likelihood of tumor control is high with surgical or radiotherapeutic treatments, we currently lack consensus regarding the best treatment option. Nevertheless, in selected complex cases, such as the case we present, the combination of surgery and radiosurgery may allow complete local tumor control with minimal morbidity.

Less common extracerebral tumors

This chapter examines the results of GKNS on a variety of extraparenchymal skull base tumors some benign and some malignant. For the benign tumors there is good evidence on the effectiveness of the method for pretty much all diagnoses. For malignant extraparenchymal tumors the results are more limited and GKNS only has a supportive role in these lesions.

Long-Term Results of Gamma Knife Radiosurgery for Glomus Tumors: An Analysis of 32 Patients

Background Glomus jugulare tumors are rare slow-growing hypervascular tumors that arise from the paraganglia of the chemoreceptor system within the jugulare foramen of the temporal lobe. The historical standard treatment has been surgical resection, but because of their high vascularity and involvement with cranial nerves (CNs), Gamma Knife radiosurgery (GKRS) has been advocated as an alternative. The goal of this study is to update and report long-term results of GKRS to achieve local control and symptomatic improvement and to reduce morbidity and mortality when treating glomus jugulare tumors. Materials and Methods This study retrospectively collected and reviewed clinical and radiographic data of 32 patients with glomus jugulare tumors treated with GKRS at the Miami Neuroscience Center, South Miami, FL, from 1995 to 2019. For the 32 patients, the mean volume treated was 13.9 cc (0.23 to 40.0 cc), with an average of 8.6 isocenters. The median prescription dose was 12.84 Gy ± 2.07 Gy (range: 10-20 Gy). Follow-up data were available for 29 out of 32 patients, with a median clinical follow-up time of 37.3 months (range: 4.3-169.1 months). At follow-up, patients were evaluated for neurological signs and symptoms and radiographic evidence of progression of disease. Results The median age of the cohort treated with GKRS was 60 years (range: 14-83 years). There were three males and 27 females. Presenting symptomatology was available for 30 out of 32 patients. The most common presenting symptom was hearing loss (21/30) and the most common CN deficit was in CN VIII (19/30). Out of 29 of the patients followed up, 28 patients had improvement (20/29) or resolution (8/29) of symptoms. At the most recent evaluation or contact, patients were without symptomatic progression of CN deficits. Radiographic tumor control was achieved in 28 out of 29 patients. One patient had a recurrence seven years after GKRS, which was treated with surgery. There were no complications, radionecrosis, or mortality reported from GKRS. Conclusion These data confirm that GKRS is a reasonable upfront treatment option for glomus jugulare tumors. GKRS should be considered more frequently given its excellent long-term local control with low morbidity and risk of complications.

LINAC radiosurgery for glomus jugulare tumors: retrospective - cohort study of 23 patients

BACKGROUND

Glomus jugulare tumors (GJTs) are uncommon and locally disruptive tumors that usually arise within the jugular foramen of the temporal bone. Surgery was the treatment of choice up until recently. In the last decades, however, radiosurgery has surfaced as a promising alternative treatment by providing excellent tumor control with low risk of cranial nerve injuries. Our aim was to examine the results of radiosurgery specifically, linear accelerator stereotactic radiosurgery (LINAC SRS) for GJT treatment. We hypothesized that radiosurgery will reduce the size of the tumor and improve neurological symptoms.

DESIGN AND METHOD

Between January 1, 1994 and December 31, 2013, 30 patients with GJTs were treated in Sheba Medical Center using LINAC SRS treatment. Comprehensive clinical follow-up was available for 23 patients. Sixteen patients were female and seven males with a median age of 64 years, with a range of 18-87 years. In 19 of the patients, LINAC SRS was the primary treatment, whereas in the remaining four cases, surgery or embolization preceded radiosurgery. The median treated dose to tumor margin was 14 Gy (range 12-27 Gy), and the median tumor volume before treatment was 5 ml (range 0.5-15 ml).

RESULTS

Following the LINAC SRS treatment, 14 of 23 patients (60%) showed improvement of previous neurological deficits, nine patients (40%) remained unchanged. At the end of a follow-up, tumor reduction was seen in 13 patients and a stable volume in eight (91% tumor control rate). Two cases of tumor progression were noted. Three patients (13%) had post- SRS complications during the follow-up, two of which achieved tumor control, while in one the tumor advanced.

CONCLUSIONS

LINAC SRS is a practical treatment option for GJTs, with a high rate of tumor control and satisfactory neurological improvement.

Pathologic Correlation of Cellular Imaging Using Apparent Diffusion Coefficient Quantification in Patients with Brain Metastases After Gamma Knife Radiosurgery

OBJECTIVE

To evaluate the role of apparent diffusion coefficient (ADC) in differentiating radiation necrosis (RN) from recurrent tumor after Gamma Knife radiosurgery (GKRS) for brain metastases (BMs).

METHODS

Forty-one patients with BM who underwent surgical intervention after GKRS at Cleveland Clinic (2006-2017) were included in this retrospective study. The ADC values of the growing lesions and the contralateral hemisphere were calculated using picture archiving and communication system. These values were correlated to the percentage of RN identified on pathologic evaluation of the surgical specimen.

RESULTS

The median age of the patients was 59 years (range, 25-86 years), and lung cancer (63.4%) was the most common malignancy. Median initial (pre-GKRS) target volume of the lesions was 5.4 cc (range, 0.135-45.6 cc), and median GKRS dose was 18.0 Gy. Surgical resection or biopsy was performed at a median of 176 days after GKRS. Two variables were statistically significant predictors of predominate RN (75%-100%) in the surgical specimen: 1) ADC of the lesion on the preresection magnetic resonance imaging (MRI) and 2) initial pre-GKRS target volume. ADC >1.5 × 10^-3 mm²/s within the lesion on MRI predicted significant RN on pathologic evaluation of the lesion (P < 0.05). Similarly, when the target volume before GKRS was large (>10 cc), the risk of identifying significant necrosis in the pathologic specimen was elevated (P < 0.05).

CONCLUSIONS

Our data suggest that the combination of lesion ADC on MRI prior to surgical intervention and the initial target volume can predict RN with reasonable accuracy.

Long-term tumor control following stereotactic radiosurgery for jugular paraganglioma using 3D volumetric segmentation

OBJECTIVE

The morbidity of gross-total resection of jugular paraganglioma (JP) is often unacceptable due to the potential for irreversible lower cranial neuropathy. Stereotactic radiosurgery (SRS) has been used at the authors' institution since 1990 for the treatment of JP and other benign intracranial tumors. Conventional means of assessing tumor progression using linear measurements or elliptical approximations are imprecise due to the irregular shape and insinuating growth pattern of JP. The objective of this study was to assess long-term tumor control in these patients by using slice-by-slice 3D volumetric segmentation of serial MRI data.

METHODS

Radiographic data and clinical records were reviewed retrospectively at a single, tertiary-care academic referral center for patients treated from 1990 to 2017. Volumetric analyses by integration of consecutive tumor cross-sectional areas (tumor segmentation) of serial MRI data were performed. Tumor progression was defined as volumetric growth of 15% or greater over the imaging interval. Primary outcomes analyzed included survival free of radiographic and clinical progression. Secondary outcomes included new or worsened cranial neuropathy.

RESULTS

A total of 85 patients were treated with Gamma Knife radiosurgery (GKRS) for JP at the authors' institution over the last 27 years. Sixty patients had pretreatment and serial posttreatment contrast-enhanced MRI follow-up suitable for volumetric analysis. A total of 214 MR images were analyzed to segment tumor images in a slice-by-slice fashion to calculate integral tumor volume. The median follow-up duration was 66 months (range 7-202 months). At 5 years the tumor progression-free survival rate was 98%. Three tumors exhibited progression more than 10 years after GKRS. Estimated survival free of radiographic progression rates (95% confidence interval [CI]; n = number still at risk) at 5, 10, and 15 years following radiosurgery were 98% (95% CI 94%-100%; n = 34), 94% (95% CI 85%-100%; n = 16), and 74% (95% CI 56%-98%; n = 6), respectively. One patient with tumor progression required treatment intervention using external beam radiation therapy, constituting the only case of clinical progression. Two patients (3%) without preexisting lower cranial nerve dysfunction developed new ipsilateral vocal fold paralysis following radiosurgery.

CONCLUSIONS

SRS achieves excellent long-term tumor control for JP without a high risk for new or worsened cranial neuropathy when used in primary, combined modality, or recurrent settings. Long-term follow-up is critical due to the potential for late radiographic progression (i.e., more than 10 years after SRS). As none of the patients with late progression have required salvage therapy, the clinical implications of this degree of tumor growth have yet to be determined.

Long-Term Outcome Following Stereotactic Radiosurgery for Glomus Jugulare Tumors: A Single Institution Experience of 20 Years

BACKGROUND

Glomus jugulare tumors (GJTs) are rare benign tumors, which pose significant treatment challenges due to proximity to critical structures.

OBJECTIVE

To evaluate the long-term clinical and radiological outcome in patients undergoing stereotactic radiosurgery (SRS) for GJTs through retrospective study.

METHODS

Forty-two patients with 43 GJTs were treated using Gamma Knife radiosurgery (GKRS; Elekta AB, Stockholm, Sweden) at our institute from 1997 to 2016. Clinical, imaging, and radiosurgery data were collected from an institutional review board approved database.

RESULTS

Most patients were females (n = 35, 83.3%) and median age was 61 yr (range 23-88 yr). Median tumor volume and diameter were 5 cc and 3 cm, respectively, with a median follow-up of 62.3 mo (3.4-218.6 mo). Overall, 20 patients (47.6%) improved clinically and 14 (33.3%) remained unchanged at last follow-up. New onset or worsening of hearing loss was noted in 6 patients (17.2%) after SRS. The median prescription dose to the tumor margin was 15 Gy (12-18 Gy). Median reduction in tumor volume and maximum tumor diameter at last follow-up was 33.3% and 11.54%, respectively. The 5-yr and 10-yr tumor control rates were 87% ± 6% and 69% ± 13%, respectively. There was no correlation between maximum or mean dose to the internal acoustic canal and post-GK hearing loss (P > .05).

CONCLUSION

SRS is safe and effective in patients with GJTs and results in durable, long-term control. SRS has lower morbidity than that associated with surgical resection, particularly lower cranial nerve dysfunction, and can be a first-line management option in these patients.

Toxicity of Gamma Knife Radiosurgery May Be Greater in Patients with Lower Cranial Nerve Schwannomas

Objective  Gamma Knife stereotactic radiosurgery (GK-SRS) is a preferred treatment option for tumors of the jugular foramen. We hypothesized that GK-SRS toxicity is higher for lower cranial nerve schwannomas than for glomus jugulare tumors despite anatomically similar locations. Methods  We performed a retrospective review of all patients who received GK-SRS for glomus jugulare tumors and lower cranial nerve schwannomas at our institution between 2006 and 2014. Because of small sample sizes, Fisher's exact tests and logistic regression techniques were employed using SPSS. Result  We identified 20 glomus jugulare tumors and 6 lower cranial nerve schwannoma patients with a median follow-up of 17 months. Median marginal dose was 16 Gy (range 13-18 Gy) and 12.5 Gy (range 12-14 Gy), respectively. All except one patient had tumor control at last follow-up visit. No worsening of pre-existing neurological deficits was observed. There were seven patients who developed any new neurological deficit after GK-SRS, four from the glomus group, and three from the schwannoma group (20 and 50% of each group, respectively). Only two of seven patients had permanent new neurological deficits. Both of them were in the schwannoma group. Univariate analysis showed that only a diagnosis of schwannoma had a greater risk of permanent new cranial nerve complication after GK-SRS compared with diagnosis of glomus jugulare ( p  = 0.046). Conclusion  Although the marginal dose for glomus jugulare is greater, our study suggests that the risk of a new permanent neurological deficit after GK-SRS was higher in the schwannoma group compared with the glomus group.

Long-term effectiveness and safety of stereotactic gamma knife surgery as a primary sole treatment in the management of glomus jagulare tumor

OBJECTIVE

This study aims to report and confirm long-term effectiveness and safety of stereotactic Gamma Knife Surgery as a primary sole treatment in the management of 40 glomus jagulare tumors patients.

PATIENTS AND METHODS

Retrospective analysis of clinical and radiological outcomes of 40 GJTs consecutive patients treated with GKS as primary sole treatment at International Medical Center (IMC), Cairo-Egypt from the beginning of 2005 till the end of 2014,with mean follow-up period of 84 months (range 36-156 months), mean tumor volume was 6.5 cc, and mean peripheral radiation dose of 15 Gy, to mean isodose curve of 38%.

RESULTS

The most common neurological deficit at initial evaluation was bulbar symptoms in 24 patients, followed by pulsatile tinnitus in 22, deterioration of hearing in 20 patients. The overall clinical control achieved in 92.5% of patients, while actuarial tumor size control rate post- GKS was 97.5% at 3 years, 97% at 5 years and 92% at 10 years of follow-up period.

CONCLUSIONS

Gamma knife surgery could be used effectively and safely as a primary sole treatment tool in the management of glomus jugulare tumors.

Hereditary Paraganglioma Syndrome Associated with SDHD Gene Mutations: A Patient with Multicentric Presentation Treated with Radiotherapy. Case Report

Introduction

Extra-adrenal paragangliomas are rare tumors arising from neuroendocrine cells. Sporadic and hereditary forms have been recognized. Among the latter, the PGL1 and PGL4 syndromes are associated with a high risk of multiple localizations. The treatment of choice for paragangliomas is surgical resection, but in some cases surgery can be difficult due to particular or multiple tumor sites or may result in severe neurological deficits. In such cases radiotherapy can be an effective alternative. In this paper we describe the case of a patient affected by hereditary paraganglioma syndrome with multicentric presentation who was treated at our center by external radiotherapy.

Case report

A 55-year-old man presented in April 2008 with multiple paragangliomas: one in the left pontocerebellar angle, two in the middle neck, one mediastinal paraaortic mass, and an abdominal paraaortic lesion. The left pontocerebellar and mediastinal tumors were treated with three-dimensional conformal radiotherapy (3D-CRT) at total doses of 50.40 Gy and 55.80 Gy, respectively. The neck lesions were treated with intensity-modulated radiotherapy (IMRT) at a total dose of 55.80 Gy. The abdominal paraaortic lesion was surgically resected.

Results

No severe acute or late toxicity as evaluated with the EORTC-RTOG scale was observed. Fourteen months after the end of radiotherapy a whole body CT scan showed that the tumor lesions were stable in size and in their relations to contiguous structures. The arterial pressure was controlled by medical therapy and urine catecholamine levels were within the normal range.

Conclusions

We believe that in patients affected by unresectable paragangliomas radiotherapy is a safe and effective alternative to surgery. The use of high-dose conformity techniques such as 3D-CRT and IMRT will allow higher local control rates with relatively few side effects thanks to the possibility of dose escalation and reduction of the amount of irradiated healthy tissues.

Stereotactic Radiosurgical Treatment of Glomus Jugulare Tumors

OBJECTIVE

Determine treatment outcomes of stereotactic radiosurgery (SRS) for glomus jugulare tumors (GJT), focusing on three-dimensional volume change and symptoms before and after SRS, as well as complications related to SRS.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

PATIENTS

Thirty-eight patients treated with SRS between 2000 and 2015.

INTERVENTION

SRS treatment of GJT.

MAIN OUTCOME MEASURES

The tumor volumes on pre- and posttreatment imaging were compared utilizing the Leskell GammaPlan treatment plan software to assess tumor progression. Pre- and posttreatment symptoms, Fisch classification, and complications were recorded.

RESULTS

The mean radiographic follow-up was 39.1 months. The mean dose-to-tumor margin was 13.2 Gy. The mean tumor size at treatment was 5.8 and 5.2 cm at last follow-up. Thirty-three patients had follow-up imaging suitable for analysis. When defining both 10 and 15% tumor size increases as significant, 27 (82%) and 29 (88%) tumors decreased in size or remained stable, respectively. For the seven tumors with documented pre-SRS growth, treatment success was 86%. The mean marginal dose for treatment success and failure were 13.2 and 13.7 Gy, respectively. Patients receiving a higher margin dose had a greater risk of tumor progression (p = 0.0277). Fisch classification did not impact tumor progression rate. Initial tumor volume had no significance on tumor response to SRS.

CONCLUSIONS

SRS is an effective treatment option for GJT. Both initial tumor volume and Fisch classification did not impact tumor progression. There were no significant patient or lesion characteristics that distinguished treatment success and/or failure.

Gamma Knife radiosurgery for glomus jugulare tumors: a single-center series of 75 cases

OBJECTIVE Glomus jugulare tumors are rare indolent tumors that frequently involve the lower cranial nerves (CNs). Complete resection can be difficult and associated with lower CN injury. Gamma Knife radiosurgery (GKRS) has established its role as a noninvasive alternative treatment option for these often formidable lesions. The authors aimed to review their experience at the National Centre for Stereotactic Radiosurgery, Sheffield, United Kingdom, specifically the long-term tumor control rate and complications of GKRS for these lesions. METHODS Clinical and radiological data were retrospectively reviewed for patients treated between March 1994 and December 2010. Data were available for 75 patients harboring 76 tumors. The tumors in 3 patients were treated in 2 stages. Familial and/or hereditary history was noted in 12 patients, 2 of whom had catecholamine-secreting and/or active tumors. Gamma Knife radiosurgery was the primary treatment modality in 47 patients (63%). The median age at the time of treatment was 55 years. The median tumor volume was 7 cm³, and the median radiosurgical dose to the tumor margin was 18 Gy (range 12-25 Gy). The median duration of radiological follow-up was 51.5 months (range 12-230 months), and the median clinical follow-up was 38.5 months (range 6-223 months). RESULTS The overall tumor control rate was 93.4% with low CN morbidity. Improvement of preexisting deficits was noted in 15 patients (20%). A stationary clinical course and no progression of symptoms were noted in 48 patients (64%). Twelve patients (16%) had new symptoms or progression of their preexisting symptoms. The Kaplan-Meier actuarial tumor control rate was 92.2% at 5 years and 86.3% at 10 years. CONCLUSIONS Gamma Knife radiosurgery offers a risk-versus-benefit treatment option with very low CN morbidity and stable long-term results.

An intermediate term benefits and complications of gamma knife surgery in management of glomus jugulare tumor

Glomus tumors are rare skull base slow-growing, hypervascular neoplasms that frequently involve critical neurovascular structures, and delay in diagnosis is frequent. Surgical removal is rarely radical and is usually associated with morbidity or mortality. Gamma knife surgery (GKS) has gained an increasing dependable role in the management of glomus jugulare tumors, with high rate of tumor growth control, preserving or improving clinical status and with limited complications. This study aims to evaluate intermediate term benefits and complications of gamma knife surgery in management of twenty-two patients bearing growing glomus jugulare tumors at the International Medical Center (IMC), Cairo, Egypt, between 2005 and 2011. The mean follow-up period was 56 months (range 36-108 months); there were 3 males, 19 females; mean age was 43.6 years; 15 patients had GKS as the primary treatment; 2 patients had surgical residuals; 2 had previous radiation therapy; and 3 previously underwent endovascular embolization. The average tumor volume was 7.26 cm3, and the mean marginal dose was 14.7 Gy. Post gamma knife surgery through the follow-up period neurological status was improved in 12 patients, 7 showed stable clinical condition and 3 patients developed new moderate deficits. Tumor volume post GKS was unchanged in 13 patients, decreased in 8, and showed tumor regrowth in 1 patient. Tumor progression-free survival in our studied patients was 95.5% at 5 and 7 years of the follow-up period post GKS. Gamma knife surgery could be used safely and effectively with limited complications as a primary management tool in the treatment of glomus jugulare tumors controlling tumor growth with preserving or improving clinical status especially those who do not have significant cranial or cervical extension, elderly, and surgically unfit patients; moreover, it is safe and highly effective as adjuvant therapy as well.

Stereotactic radiosurgery of glomus jugulare tumors: current concepts, recent advances and future perspectives

Stereotactic radiosurgery (SRS), a very highly focused form of therapeutic irradiation, has been widely recognized as a viable treatment option in the management of intracranial pathologies including benign tumors, malign tumors, vascular malformations and functional disorders. The applications of SRS are continuously expanding thanks to the ever-increasing advances and corresponding improvements in neuroimaging, radiation treatment techniques, equipment, treatment planning and delivery systems. In the context of glomus jugulare tumors (GJT), SRS is being more increasingly used both as the upfront management modality or as a complementary or salvage treatment option. As its safety and efficacy is being evident with compiling data from studies with longer follow-up durations, SRS appears to take the lead in the management of most patients with GJT. Herein, we address current concepts, recent advances and future perspectives in SRS of GJT in light of the literature.

Stereotactic radiosurgery in the management of vestibular schwannoma and glomus jugulare: indications, techniques, and results

Gamma Knife stereotactic radiosurgery (GKS) has become an important management strategy for an increasing number of patients with skull base tumors. For select patients with lateral skull base disorders, given the proximity to sensitive critical structures such as the brainstem, cranial nerves, and cochlea, this technology has emerged as a first-line treatment to achieve the paramount goals of long-term tumor control and maintenance of existing neurologic function. This article reviews the indications, technique, and results of GKS for the treatment of vestibular schwannoma and glomus jugulare tumors, and highlights our experience in treating these tumors at the Mayo Clinic.

Leksell Gamma Knife radiosurgery of the jugulotympanic glomus tumor: long-term results

OBJECT

Glomus tumors usually display indolent behavior, and the effectiveness of radiation in stopping their growth can be assessed after long-term follow-up. Currently only midterm results of radiosurgery are available, so the authors included patients treated by Gamma Knife at least 10 years ago in this study to obtain a perspective of long-term results.

METHODS

During the period from 1992 to 2003, the Gamma Knife was used to treat 46 patients with glomus tumors. The age of the patients ranged from 21 to 79 years (median 56 years). Gamma Knife radiosurgery was the primary treatment in 17 patients (37%). Open surgery preceded radiosurgery in 46% of cases, embolization in 17%, and fractionated radiotherapy in 4%. The volume of the tumor ranged from 0.2 to 24.3 cm(3) (median 3.6 cm(3)). The minimal dose to the tumor margin ranged between 10 and 30 Gy (median 20 Gy).

RESULTS

One patient was lost for follow-up after radiosurgery. Clinical follow-up was available in 45 patients and 44 patients were followed with MRI in a follow-up period that ranged from 12 to 217 months (median 118 months). Neurological deficits improved in 19 (42%) of 45 patients and deteriorated in 2 patients (4%). Tumor size decreased in 34 (77%) of 44 patients with imaging follow-up, while an increase in volume was observed in 1 patient (2%) 182 months after radiosurgery and Gamma Knife treatment was repeated. One patient underwent another Gamma Knife treatment for secondary induced meningioma close to the glomus tumor 98 months after initial radiosurgical treatment. Seven patients died 22-96 months after radiosurgery (median 48 months), all for unrelated reasons.

CONCLUSIONS

Radiosurgery has proved to be a safe treatment with a low morbidity rate and a reliable long-term antiproliferative effect.

Jugulotympanic paragangliomas treated with Gamma Knife radiosurgery: a single-center review of 58 cases

OBJECT

Jugulotympanic paragangliomas (JTPs) are rare benign tumors whose surgical treatment is usually associated with partial resection of the lesion, high morbidity, and even death. Gamma Knife radiosurgery (GKRS) has been reported as a useful treatment option. The goal of this retrospective study is to analyze the role of GKRS in tumor volume control and clinical outcomes of these patients.

METHODS

A total of 75 patients with JTPs were treated with GKRS at the authors' center from 1995 to 2012. The authors analyzed those treated during this period to allow for a minimal observation time of 2 years. The MR images and clinical reports of these patients were reviewed to assess clinical and volumetric outcomes of the tumors. The radiological and clinical assessments, along with a group of prognostic factors measured, were analyzed using descriptive methods. The time to volumetric and clinical progression was analyzed using the Kaplan-Meier method. Prognostic factors were identified using log-rank statistics and multivariate Cox regression models.

RESULTS

The mean follow-up was 86.4 months. The authors observed volumetric tumor control in 94.8% of cases. In 67.2% of cases, tumor volume decreased by a mean of 40.1% from the original size. Of patients with previous tinnitus, 54% reported complete recovery. Improvement of other symptoms was observed in 34.5% of cases. Overall, clinical control was achieved in 91.4% of cases. Previous embolization and familial history of paraganglioma were selected as significant prognostic factors for volumetric response to GKRS treatment in the univariate analysis. In multivariate analysis, no factors were significantly correlated with progression-free survival. No patient died of side effects related to GKRS treatment or tumor progression.

CONCLUSIONS

Gamma Knife radiosurgery is an effective, safe, and efficient therapeutic option for the treatment of these tumors as a first-line treatment or in conjunction with traditional surgery, endovascular treatment, or conventional fractionated radiotherapy.

Lower cranial nerves function after surgical treatment of Fisch Class C and D tympanojugular paragangliomas

The aim of this study was to report the postoperative lower cranial nerves (LCNs) function in patients undergoing surgery for tympanojugular paraganglioma (TJP) and to evaluate risk factors for postoperative LCN dysfunction. A retrospective case review of 122 patients having Fisch class C or D TJP, surgically treated from 1988 to 2012, was performed. The follow-up of the series ranged from 12 to 156 months (mean, 39.4 ± 32.6 months). The infratemporal type A approach was the most common surgical procedure. Gross total tumor removal was achieved in 86% of cases. Seventy-two percent of the 54 patients with preoperative LCN deficit had intracranial tumor extension. Intraoperatively, LCNs had to be sacrificed in 63 cases (51.6%) due to tumor infiltration. Sixty-six patients (54.09%) developed a new deficit of one or more of the LCNs. Of those patients who developed new LCN deficits, 23 of them had intradural extension. Postoperative follow-up of at least 1 year showed that the LCN most commonly affected was the CN IX (50%). Logistic regression analysis showed that intracranial transdural tumor extension was correlated with the higher risk of LCN sacrifice (p < 0.05). Despite the advances in skull base surgery, new postoperative LCN deficits still represent a challenge. The morbidity associated with resection of the LCNs is dependent on the tumor's size and intradural tumor extension. Though no recovery of LCN deficits may be expected, on long-term follow-up, patients usually compensate well for their LCNs loss.

The lower cranial nerves: IX, X, XI, XII

The lower cranial nerves innervate the pharynx and larynx by the glossopharyngeal (CN IX) and vagus (CN X) (mixed) nerves, and provide motor innervation of the muscles of the neck by the accessory nerve (CN XI) and the tongue by the hypoglossal nerve (CN XII). The symptomatology provoked by an anomaly is often discrete and rarely in the forefront. As with all cranial nerves, the context and clinical examinations, in case of suspicion of impairment of the lower cranial nerves, are determinant in guiding the imaging. In fact, the impairment may be located in the brain stem, in the peribulbar cisterns, in the foramens or even in the deep spaces of the face. The clinical localization of the probable seat of the lesion helps in choosing the adapted protocol in MRI and eventually completes it with a CT-scan. In the bulb, the intra-axial pathology is dominated by brain ischemia (in particular, with Wallenberg syndrome) and multiple sclerosis. Cisternal pathology is tumoral with two tumors, schwannoma and meningioma. The occurrence is much lower than in the cochleovestibular nerves as well as the leptomeningeal nerves (infectious, inflammatory or tumoral). Finally, foramen pathology is tumoral with, outside of the usual schwannomas and meningiomas, paragangliomas. For radiologists, fairly hesitant to explore these lower cranial pairs, it is necessary to be familiar with (or relearn) the anatomy, master the exploratory technique and be aware of the diagnostic possibilities.

Stereotactic radiosurgery as the primary treatment for new and recurrent paragangliomas: is open surgical resection still the treatment of choice?

OBJECTIVE

Paragangliomas (PGs) or glomus tumors are rare, and publications comparing treatment alternatives are few. We sought to analyze our experience with stereotactic radiosurgery (SRS), review the literature, and develop treatment guidelines.

METHODS

We retrospectively examined the outcomes of 41 PGs in 36 patients treated with SRS at Stanford. Our data from medical records, telephone interviews, and imaging studies were combined with previously reported SRS data and compared to results following other treatments.

RESULTS

With a median clinical follow-up of 4.8 years (3.9 years radiographic), local control was 100%. Complications included increase in preexistent vertigo in one patient and transient cranial neuropathies in two patients. Published surgical series describe a lower local control rate as well as more frequent and severe complications. Published radiation therapy (RT) series document a slightly lower local control rate than SRS, but SRS can be delivered more quickly and conveniently. Open surgery and other combinations of treatments appear to be required for several subpopulations of PG patients.

CONCLUSIONS

We feel that SRS should be the primary treatment for most new and recurrent PGs. Even some very large PGs are appropriate for SRS. RT remains an appropriate option in some centers, especially those where SRS is not available. PGs occurring in the youngest patients, catecholamine secreting PGs, and PGs causing rapidly progressing neurologic deficits may be more appropriate for open resection. Metastatic PGs may benefit from combinations of chemotherapy and SRS or RT. Treatment guidelines are proposed.

Gamma Knife surgery for the management of glomus tumors: a multicenter study

Object

Glomus tumors are rare skull base neoplasms that frequently involve critical cerebrovascular structures and lower cranial nerves. Complete resection is often difficult and may increase cranial nerve deficits. Stereotactic radiosurgery has gained an increasing role in the management of glomus tumors. The authors of this study examine the outcomes after radiosurgery in a large, multicenter patient population.

Methods

Under the auspices of the North American Gamma Knife Consortium, 8 Gamma Knife surgery centers that treat glomus tumors combined their outcome data retrospectively. One hundred thirty-four patient procedures were included in the study (134 procedures in 132 patients, with each procedure being analyzed separately). Prior resection was performed in 51 patients, and prior fractionated external beam radiotherapy was performed in 6 patients. The patients' median age at the time of radiosurgery was 59 years. Forty percent had pulsatile tinnitus at the time of radiosurgery. The median dose to the tumor margin was 15 Gy. The median duration of follow-up was 50.5 months (range 5–220 months).

Results

Overall tumor control was achieved in 93% of patients at last follow-up; actuarial tumor control was 88% at 5 years postradiosurgery. Absence of trigeminal nerve dysfunction at the time of radiosurgery (p = 0.001) and higher number of isocenters (p = 0.005) were statistically associated with tumor progression–free tumor survival. Patients demonstrating new or progressive cranial nerve deficits were also likely to demonstrate tumor progression (p = 0.002). Pulsatile tinnitus improved in 49% of patients who reported it at presentation. New or progressive cranial nerve deficits were noted in 15% of patients; improvement in preexisting cranial nerve deficits was observed in 11% of patients. No patient died as a result of tumor progression.

Conclusions

Gamma Knife surgery was a well-tolerated management strategy that provided a high rate of long-term glomus tumor control. Symptomatic tinnitus improved in almost one-half of the patients. Overall neurological status and cranial nerve function were preserved or improved in the vast majority of patients after radiosurgery.

Jugular and vagal paragangliomas: Systematic study of management with surgery and radiotherapy

BACKGROUND

The definitive treatment for head and neck paraganglioma (PG) is surgical excision. Unfortunately, surgery, particularly of vagal paraganglioma (VPG; "glomus vagale") and foramen jugulare ("glomus jugulare") tumors, may be complicated by injuries to the lower cranial nerves, a high price to pay for treatment for a benign tumor. Alternatively these tumors may be followed without treatment, or irradiated. The purpose of this review was to compare the existing evidence concerning the efficacy and safety of surgery, external beam radiotherapy (EBRT), and stereotactic radiosurgery (SRS), for jugular paragangliomas (JPGs) and VPGs.

METHODS

Relevant articles were reviewed using strict criteria for systematic searches. Forty-one surgical studies met the criteria which included 1310 patients. Twenty articles including 461 patients treated with EBRT, and 14 radiosurgery studies comprising 261 patients were also evaluated. Results were compared between treatment modalities using analysis of variance (ANOVA) tests.

RESULTS

A total of 1084 patients with JPGs and 226 VPGs were treated with different surgical procedures. Long-term control of the disease was achieved in 78.2% and 93.3% of patients, respectively. A total of 715 patients with JPG were treated with radiotherapy: 461 with EBRT and 254 with SRS. Control of the disease with both methods was obtained in 89.1% and 93.7% of the patients, respectively. The treatment outcomes of a JPG treated with surgery or radiotherapy were compared. Tumor control failure, major complication rates, and the number of cranial nerve palsies after treatment were significantly higher in surgical than in radiotherapy series. The results of SRS and EBRT in JPGs were compared and no significant differences were observed in tumor control. Because only 1 article reported on the treatment of 10 VPGs with radiotherapy, no comparisons with surgery could be made. Nevertheless, the vagus nerve was functionally preserved in only 11 of 254 surgically treated patients (4.3%).

CONCLUSION

There is evidence that EBRT and SRS offer a similar chance of tumor control with lower risks of morbidity compared with surgery in patients with JPGs. Although the evidence is based on retrospective studies, these results suggest that surgery should be considered only for selected cases, but the decision should be individual for every patient.

Benefits and limitations of diameter measurement in the conservative management of meningiomas

Background:

Meningiomas are the most common benign brain tumors that are frequently followed-up by neurologists, general practitioners, and neurosurgeons. Some recent studies advocate the accurate volumetric method (VM) over measuring the linear maximum diameter although its clinical significance still remains unknown. The aim of this study is to directly compare the linear method (LM) and VM to delineate the characteristics of both measurements.

Methods:

Between 2003 and 2010, growth analysis using magnetic resonance imaging DICOM files was performed for 189 meningiomas in 161 patients at the Cleveland Clinic. In LM, a minimum increase of 2 mm in maximum diameter was defined as tumor growth. The absolute volume growth (VG, in cm³) was calculated for each tumor.

Results:

Linear growth (LG) was seen in 71 tumors (37.6%) within the median follow-up of 2.0 years. These tumors with LG showed a mean VG of 2.80 cm³. Some large LG-positive tumors can be larger than estimated from LG. In addition, the skull base location was correlated to greater VG. On the other hand, 118 tumors without LG demonstrated the minimal actual volume increase, i.e., mean VG of 0.16 cm³. Although a small subset of these LG-negative tumors might have slightly high VG when they were large, the location of tumor had no correlation to VG.

Conclusions:

Our data demonstrated some important precautions in measuring the tumor growth. We believe that it is mandatory in the conservative management of meningiomas to correctly understand benefits and potential limitations of different measurement methods utilized.

Evolving concepts in the management of jugular paraganglioma: a comparison of radiotherapy and surgery in 88 cases

Surgery for jugular paraganglioma (PGL) tumors often results in the acquisition of neurological deficits where none had been present previously. This has a significant impact on the quality of life. Radiotherapy is a recognized alternative therapy. The aim of this study was to compare the results of radiotherapy and surgery for the management of jugular PGL in terms of function and tumor control to define a treatment algorithm. We conducted a retrospective and comparative analysis of the treatment of 41 patients by conventional radiotherapy and 47 patients by surgery via tertiary referral at an academic medical center. Forty-seven patients with type C and/or D jugular PGLs (mean age, 46 years) underwent surgery after endovascular embolization between 1984 and 1998 using an infratemporal fossa type A approach. The facial nerve was transposed in 18 patients. An adjunctive neurosurgical procedure was required in 14 patients. Mean follow-up was 66 months (range, 17 months to 14 years). Forty-one patients with type C jugular PGLs (mean age, 59.5 years) were treated by external beam or conformational radiotherapy between 1988 and 2003 with a total mean dose of 45 Gy (range, 44 to 50 Gy). Mean follow-up was 50 months (range, 18 months to 13 years). The primary outcome measures were tumor control and cranial nerve status. Surgical resection, total or subtotal, yielded an overall 86% rate of either cure or tumor stabilization. Radiotherapy achieved local control in 96% of patients. For surgery, the main postoperative complications were dysphagia, aspiration, and facial paralysis. Patients treated by radiotherapy developed minor disabilities. We concluded that radiotherapy and surgery achieve similar oncologic outcomes, but the former achieves tumor control with less morbidity. Our data favor radiotherapy as treatment for jugular PGLs, but we acknowledge that the aims of these two treatment modalities are different, namely, eradication of tumor by surgery versus stabilization of tumor with radiotherapy. The search for the better quality of life has to be weighed against the uncertainty of the long-term behavior of the tumor.

Radiosurgery of glomus jugulare tumors: a meta-analysis

PURPOSE

During the past two decades, radiosurgery has arisen as a promising approach to the management of glomus jugulare. In the present study, we report on a systematic review and meta-analysis of the available published data on the radiosurgical management of glomus jugulare tumors.

METHODS AND MATERIALS

To identify eligible studies, systematic searches of all glomus jugulare tumors treated with radiosurgery were conducted in major scientific publication databases. The data search yielded 19 studies, which were included in the meta-analysis. The data from 335 glomus jugulare patients were extracted. The fixed effects pooled proportions were calculated from the data when Cochrane's statistic was statistically insignificant and the inconsistency among studies was <25%. Bias was assessed using the Egger funnel plot test.

RESULTS

Across all studies, 97% of patients achieved tumor control, and 95% of patients achieved clinical control. Eight studies reported a mean or median follow-up time of >36 months. In these studies, 95% of patients achieved clinical control and 96% achieved tumor control. The gamma knife, linear accelerator, and CyberKnife technologies all exhibited high rates of tumor and clinical control.

CONCLUSIONS

The present study reports the results of a meta-analysis for the radiosurgical management of glomus jugulare. Because of its high effectiveness, we suggest considering radiosurgery for the primary management of glomus jugulare tumors.

Recurrent paraganglioma of Meckel's cave: Case report and a review of anatomic origin of paragangliomas

BACKGROUND

Paragangliomas are rare, usually benign tumors of neural crest origin. They account for only 0.6% of all head and neck tumors. In the craniocervical area, they are more common in the carotid body and tympanico-jugular regions. To the authors' knowledge, a case of paraganglioma in Meckel's cave has not yet been reported in the medical literature. The pathogenesis and natural history of paragangliomas are still not well understood. We present a case of recurrent paraganglioma in Meckel's cave.

CASE DESCRIPTION

A 53-year-old woman was diagnosed with trigeminal neuralgia, dysesthesia and hypoesthesia on the left side of the face, hearing disturbance and a history of chronic, persistent temporal headaches. Magnetic resonance imaging (MRI) showed a lesion located in Meckel's cave on the left side, extending to the posterior cranial fossa and compressing the left cerebral peduncle. The lesion was first thought to be a recurrence of an atypical meningioma, as the pathologist described it in the tissue specimen resected 3 years earlier, and a decision for re-operation was made. A lateral suboccipital approach to the lesion was used under neuronavigational guidance. The tumor was removed, and histological examination proved the lesion to be a paraganglioma. Five months later, the follow-up MRI showed local regrowth, which required subsequent surgical intervention.

CONCLUSIONS

A paraganglioma in Meckel's cave is an uncommon tumor in this location. Although ectopic paragangliomas have been described in the literature, a paraganglioma atypically located in Meckel's cave makes a topographic correlation difficult, mainly because paraganglionic cells are usually not found in Meckel's cave. Another peculiarity of the case is the local recurrence of the tumor in a relatively short time despite an attempted, almost gross total resection.

The safety and efficacy of gamma knife surgery in management of glomus jugulare tumor

Background

Glomus jugulare is a slowly growing, locally destructive tumor located in the skull base with difficult surgical access. The operative approach is, complicated by the fact that lesions may be both intra and extradural with engulfment of critical neurovascular structures. The tumor is frequently highly vascular, thus tumor resection entails a great deal of morbidity and not infrequent mortality. At timeslarge residual tumors are left behind. To decrease the morbidity associated with surgical resection of glomus jugulare, gamma knife surgery (GKS) was performed as an alternative in 13 patients to evaluate its safety and efficacy.

Methods

A retrospective review of 13 residual or unresectable glomus jagulare treated with GKS between 2004 and 2008.. Of these, 11 patients underwent GKS as the primary management and one case each was treated for postoperative residual disease and postembolization. The radiosurgical dose to the tumor margin ranged between 12-15 Gy.

Results

Post- gamma knife surgery and during the follow-up period twelve patients demonstrated neurological stability while clinical improvement was achieved in 5 patients. One case developed transient partial 7th nerve palsy that responded to medical treatment. In all patients radiographic MRI follow-up was obtained, the tumor size decreased in two cases and remained stable (local tumor control) in eleven patients.

Conclusions

Gamma knife surgery provids tumor control with a lowering of risk of developing a new cranial nerve injury in early follow-up period. This procedure can be safely used as a primary management tool in patients with glomus jugulare tumors, or in patients with recurrent tumors in this location. If long-term results with GKS are equally effective it will emerge as a good alternative to surgical resection.

Surgical management of glomus jugulare tumors: a proposal for approach selection based on tumor relationships with the facial nerve

Object

The goal of this paper is to analyze the extension and relationships of glomus jugulare tumor with the temporal bone and the results of its surgical treatment aiming at preservation of the facial nerve. Based on the tumor extension and its relationships with the facial nerve, new criteria to be used in the selection of different surgical approaches are proposed.

Methods

Between December 1997 and December 2007, 34 patients (22 female and 12 male) with glomus jugulare tumors were treated. Their mean age was 48 years. The mean follow-up was 52.5 months. Clinical findings included hearing loss in 88%, swallowing disturbance in 50%, and facial nerve palsy in 41%. Magnetic resonance imaging demonstrated a mass in the jugular foramen in all cases, a mass in the middle ear in 97%, a cervical mass in 85%, and an intradural mass in 41%. The tumor was supplied by the external carotid artery in all cases, the internal carotid artery in 44%, and the vertebral artery in 32%. Preoperative embolization was performed in 15 cases. The approach was tailored to each patient, and 4 types of approaches were designed. The infralabyrinthine retrofacial approach (Type A) was used in 32.5%; infralabyrinthine pre- and retrofacial approach without occlusion of the external acoustic meatus (Type B) in 20.5%; infralabyrinthine pre- and retrofacial approach with occlusion of the external acoustic meatus (Type C) in 41%; and the infralabyrinthine approach with transposition of the facial nerve and removal of the middle ear structures (Type D) in 6% of the patients.

Results

Radical removal was achieved in 91% of the cases and partial removal in 9%. Among 20 patients without preoperative facial nerve dysfunction, the nerve was kept in anatomical position in 19 (95%), and facial nerve function was normal during the immediate postoperative period in 17 (85%). Six patients (17.6%) had a new lower cranial nerve deficit, but recovery of swallowing function was adequate in all cases. Voice disturbance remained in all 6 cases. Cerebrospinal fluid leakage occurred in 6 patients (17.6%), with no need for reoperation in any of them. One patient died in the postoperative period due to pulmonary complications. The global recovery, based on the Karnofsky Performance Scale (KPS), was 100% in 15% of the patients, 90% in 45%, 80% in 33%, and 70% in 6%.

Conclusions

Radical removal of glomus jugulare tumor can be achieved without anterior transposition of the facial nerve. The extension of dissection, however, should be tailored to each case based on tumor blood supply, preoperative symptoms, and tumor extension. The operative field provided by the retrofacial infralabyrinthine approach, or the pre- and retrofacial approaches, with or without closure of the external acoustic meatus, allows a wide exposure of the jugular foramen area. Global functional recovery based on the KPS is acceptable in 94% of the patients.

Radiosurgery for glomus jugulare: history and recent progress

In this article the authors review the literature for recent studies of radiosurgical treatment for glomus jugulare. These studies demonstrate that radiosurgery results in similar glomus jugulare tumor control and a superior morbidity profile compared with surgical treatment. In addition, patients treated with radiosurgery usually remain stable clinically or improve. Given the indolent nature of these tumors, however, more follow-up is required to ensure that the immediate benefits are lasting. These preliminary reports demonstrate that the use of radiosurgery as a primary treatment for glomus jugulare should be extended to encompass more of the patients who are currently assigned to microsurgical treatment.

Glomus jugulare tumours: certain clinical and radiological aspects observed following Gamma Knife radiosurgery

INTRODUCTION

Glomus jugulare tumours represent a great therapeutic challenge. Previous papers have documented good results from Gamma Knife surgery (GKS) with these tumours. However, the relationship between clinical improvement and tumour shrinkage has never been assessed.

MATERIALS AND METHODS

There were 14 patients, 9 women and 5 men. The mean follow-up period was 28 months (range 6 to 60 months). All the tumours except one were Fisch type D and the mean volume was 14.2 cm(3) (range 3.7-28.4 cm(3)). The mean prescription dose was 13.6 Gy (range 12-16 Gy).

RESULTS

None of the tumours have continued to grow. Eight are smaller and 6 unchanged in volume. Two patients with bruit have had no improvement in their symptoms. Among the other 12 patients, 5 have had symptomatic improvement of dysphagia, 4 in dysphonia, 3 in facial numbness, 3 in ataxia and 2 in tinnitus. Individual patients have experienced improvement in vomiting, vertigo, tongue fasciculation, hearing, headache, facial palsy and accessory paresis. One patient developed a transient facial palsy. Symptomatic improvement commonly began before any reduction in tumour volume could be detected. The mean time to clinical improvement was 6.5 months whereas the mean time to shrinkage was 13.5 months.

CONCLUSIONS

Gamma Knife treatment of glomus jugulare tumours is associated with a high incidence of clinical improvement with few complications, using the dosimetry recorded here. Clinical improvement would seem to be a more sensitive early indicator of therapeutic success than radiological volume reduction. Further follow-up will be needed.

[Tinnitus treatment: neurosurgical management]

Tinnitus is a very frequent symptom affecting 10% of the general population. It corresponds to the perception of an internal noise that can severely impair the quality of life. Tinnitus management requires a multidisciplinary approach in which neuromodulation and neurosurgery tend to play major roles. Classification of tinnitus separates objective tinnitus (i.e., tinnitus that can be heard or recorded) from the more frequent subjective tinnitus (i.e., tinnitus only perceived by the patient). Objective tinnitus is either pulsatile synchronous with heartbeat or asynchronous. In the former, appropriate radiological testing should search for a vascular abnormality as well as other neurological diseases (intracranial hypertension, Arnold-Chiari malformation, vascular loops, etc.). Asynchronous objective tinnitus generally corresponds to muscular contractions that require specific management. The pathophysiology of subjective tinnitus is more complex, showing strong analogies with postamputation pain syndromes. After peripheral middle ear or inner ear damage, auditory deafferentation could result in hyperactivity and/or functional reorganization within central auditory and nonauditory structures. This could explain the persistence of tinnitus after total hearing amputation (e.g., translabyrinthine approach for vestibular schwannoma) and associated symptoms such as hyperacusis or anxiety and depression. This central model finds strong support in animal experiments and in functional neuroimagery (PET, fMRI, MEG). Since no etiologically based therapies are currently available, severe subjective tinnitus management only targets tinnitus tolerance with sound enrichment or cognitive behavior therapy. However, in the near future better knowledge of tinnitus pathophysiology and innovative therapeutic tools could emerge from neuromodulation techniques such as repeated transcranial magnetic or epidural electric stimulation.

Radiosurgery for glomus jugulare tumors

Results for treating glomus jugulare tumors with radiosurgery have been limited by short follow-up and small number of patients. We report our experience using LINAC or CyberKnife in 21 tumors with a median follow-up of 66 months (Mean follow-up of 60 months). In addition, we have a subset of eight patients that were followed out for more than 10 years. Patients were treated with doses ranging from 1400 cGy to 2700 cGy. We retrospectively assessed patients for efficacy and post treatment side effects. All patients had stable neurological symptoms, and two patients experienced transient ipsilateral tongue weakness and hearing loss, both of which subsequently resolved. One patient experienced transient ipsilateral vocal cord paresis; however, this patient received previous external beam radiotherapy. All tumors remained stable or decreased in size by MRI exam. Our results support radiosurgery as an effective and safe method of treatment for glomus jugulare tumors with low morbidity as evidenced by a larger number of patients and long term follow-up.

VOLUMETRIC FOLLOW-UP OF MENINGIOMAS

OBJECTIVE

The most important treatment options for meningiomas are microsurgery, radiotherapy, and gamma knife radiosurgery (GKRS). The efficacy of GKRS in terms of local tumor control and tumor volume (TV) reduction can best be determined by accurate analysis of changes in tumor size in pre- and post-GKRS images. In this prospective study, we set the focus on evaluating TV changes and treatment outcome of meningiomas using a quantitative volumetric follow-up protocol after GKRS.

METHODS

Consecutive patients with World Health Organization Grade I and II meningiomas were included in this study. Most patients underwent a microsurgical TV reduction before being treated with GKRS. Follow-up examinations were performed according to a standardized protocol and included magnetic resonance imaging and quantitative volumetric tumor analyses as well as thorough neurological examinations.

RESULTS

Complete follow-up data was available for 211 patients (243 tumors) with a mean age of 57.9 years. TVs ranging from 0.1 to 48.3cm3 were treated with GKRS using prescription doses ranging from 10 to 22 Gy. The achieved overall tumor control rate determined with quantitative TV analyses after GKRS was 93.4%; a mean TV reduction of 42.1% was achieved in 74.5% of all treated patients.

CONCLUSION

Results of this study show that a quantitative volumetric follow-up study of meningiomas is a useful method to demonstrate the efficacy of GKRS for meningiomas. Statistically significant TV reductions with a low rate of side effects can be achieved with GKRS.