Current strategies in management of intracanalicular vestibular schwannoma

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

PURPOSE

The present study assesses the safety and efficacy of stereotactic radiosurgery (SRS) versus observation for Koos grade 1 and 2 vestibular schwannoma (VS), benign tumors affecting hearing and neurological function.

METHODS AND MATERIALS

This multicenter study analyzed data from Koos grade 1 and 2 VS patients managed with SRS (SRS group) or observation (observation group). Propensity score matching balanced patient demographics, tumor volume, and audiometry. Outcomes measured were tumor control, serviceable hearing preservation, and neurological outcomes.

RESULTS

In 125 matched patients in each group with a 36-month median follow-up (P = .49), SRS yielded superior 5- and 10-year tumor control rates (99% CI, 97.1%-100%, and 91.9% CI, 79.4%-100%) versus observation (45.8% CI, 36.8%-57.2%, and 22% CI, 13.2%-36.7%; P < .001). Serviceable hearing preservation rates at 5 and 9 years were comparable (SRS 60.4% CI, 49.9%-73%, vs observation 51.4% CI, 41.3%-63.9%, and SRS 27% CI, 14.5%-50.5%, vs observation 30% CI, 17.2%-52.2%; P = .53). SRS were associated with lower odds of tinnitus (OR = 0.39, P = .01), vestibular dysfunction (OR = 0.11, P = .004), and any cranial nerve palsy (OR = 0.36, P = .003), with no change in cranial nerves 5 or 7 (P > .05). Composite endpoints of tumor progression and/or any of the previous outcomes showed significant lower odds associated with SRS compared with observation alone (P < .001).

CONCLUSIONS

SRS management in matched cohorts of Koos grade 1 and 2 VS patients demonstrated superior tumor control, comparable hearing preservation rates, and significantly lower odds of experiencing neurological deficits. These findings delineate the safety and efficacy of SRS in the management of this patient population.

Management of sporadic intracanalicular vestibular schwannomas: A critical review and International Stereotactic Radiosurgery Society (ISRS) practice guidelines

BACKGROUND

The choice of an appropriate strategy for intracanalicular vestibular schwannoma (ICVS) is still debated. We conducted a systematic review and meta-analysis with the aim to compare treatment outcomes amongst management strategies (conservative surveillance (CS), microsurgical resection (MR), or stereotactic radiosurgery (SRS)) aiming to inform guideline recommendations on behalf of the International Stereotactic Radiosurgery Society (ISRS).

METHODS

Using PRISMA guidelines, we reviewed manuscripts published between January 1990 and October 2021 referenced in PubMed or Embase. Inclusion criteria were peer-reviewed clinical studies or case series reporting a cohort of ICVS managed with CS, MR, or SRS. Primary outcome measures included tumor control, the need for additional treatment, hearing outcomes, and posttreatment neurological deficits. These were pooled using meta-analytical techniques and compared using meta-regression with random effect.

RESULTS

Forty studies were included (2371 patients). The weighted pooled estimates for tumor control were 96% and 65% in SRS and CS series, respectively (P < .001). Need for further treatment was reported in 1%, 2%, and 25% for SRS, MR, and CS, respectively (P = .001). Hearing preservation was reported in 67%, 68%, and 55% for SRS, MR, and CS, respectively (P = .21). Persistent facial nerve deficit was reported in 0.1% and 10% for SRS and MR series, respectively (P = .01).

CONCLUSIONS

SRS is a noninvasive treatment with at least equivalent rates of tumor control and hearing preservation as compared to MR, with the caveat of better facial nerve preservation. As compared to CS, upfront SRS is an effective treatment in achieving tumor control with similar rates of hearing preservation.

Wait and Scan Management of Intra-canalicular Vestibular Schwannomas: Analysis of Growth and Hearing Outcome

OBJECTIVE

To report on the results of intracanalicular vestibular schwannomas (ICVS) that were managed by wait and scan and to analyze the possible predictors of tumor growth and hearing deterioration throughout the observation period.

STUDY DESIGN

A retrospective case series.

SETTING

Quaternary referral center for skull base pathologies.

PATIENTS

Patients with sporadic ICVS managed by wait and scan.

INTERVENTION

Serial resonance imaging (MRI) with size measurement and serial audiological evaluation.

MAIN OUTCOME MEASURE

Tumor growth defined as 2 mm increase of maximal tumor diameter, further treatment, and hearing preservation either maintain initial modified Sanna hearing class, or maintain initial serviceable hearing (class A/B).

RESULTS

339 patients were enrolled. The mean follow-up was 36.5±31.7 months with a median of 24 months. Tumor growth occurred in 141 patients (40.6%) either as slow growth (SG) in 26.3% of cases or fast growth (FG) in 15.3% of cases. Intervention was performed in only 64 cases (18.8%). Out of 271 patients who underwent hearing analysis, 86 patients (33.5%) showed hearing deterioration to a lower hearing class of the modified Sanna classification. Tumor growth and older age were predictors of hearing deterioration. Of the 125 cases with initial serviceable hearing (Class A/B), 91 cases (72.8%) maintained serviceable hearing at last follow-up. Tumor growth and a worse initial pure tone average (PTA) were predictors of hearing deterioration.

CONCLUSIONS

Wait and scan management of ICVS is a viable option and only 18.8% of patients needed further treatment. Hearing tends to deteriorate over time.

Endoscopic-Assisted Keyhole Middle Cranial Fossa Approach for Small Vestibular Schwannomas

The classical middle cranial fossa approach (MCFA) for vestibular schwannoma (VS) removal often requires a large incision and craniotomy, excessive temporal lobe manipulation, and a longer recovery. We describe a keyhole MCFA (KMCFA) with endoscopic assistance that allows for adequate access with minimal temporal lobe manipulation, resulting in a fast recovery and an invisible scar. Eight sides of four cadaveric heads were dissected through the endoscopic-assisted KMCFA to access the internal auditory canal (IAC). Furthermore, five patients with intracanalicular VS underwent tumor removal with the endoscopic-assisted KMCFA. During the endoscopic-assisted KMCFA with fine instruments, a 3-cm supra-auricular incision and a 2-cm diameter keyhole craniotomy achieved exposure of the entire length of the IAC in all cadaveric dissections without unintended violation of the cochlea, semicircular canal, and facial nerve. The gross tumor was totally removed in five patients with no major postoperative complications. The surgical time was reduced, the hearing outcomes were similar to those of the classical MCFA, and the scar was invisible 1 month after the surgery. The endoscopic-assisted KMCFA permits intracanalicular VS removal in a safe, efficient, and cosmetic way. For small intracanalicular VSs, this approach can replace the classical MCFA when indicated.

Intracanalicular Vestibular Schwannoma: A Systematic Review and Meta-analysis of Therapeutics Outcomes

OBJECTIVE

To perform a systematic review and meta-analysis summarizing the current evidence on the management of intracanalicular vestibular schwannoma.

DATA SOURCES

Embase (1947-), Medline (1946-), Cochrane library (1947-), Scopus (2010-), and CINAHL (1961-) were searched from 1969 to October 5, 2019 (50 years).

STUDY SELECTION

A search strategy was performed to identify patients with vestibular schwannoma confined to the internal auditory canal without extension to the cerebellopontine angle. Studies with patients aged less than 18, Neurofibromatosis type 2, revision cases, and non-English language were excluded.

DATA EXTRACTION

A standardized collection sheet was used for the extracted data and a quality assessment was performed using the Newcastle-Ottawa Scale with the comparability criterion omitted.

DATA SYNTHESIS

Seventy-one studies were included with 24 on observation, 14 on radiotherapy, and 34 on surgery. The primary outcome was serviceable hearing preservation. Secondary outcomes were preservation of facial nerve function, growth, involution, and dizziness. Sub-analysis on the type of surgery and type of radiotherapy were performed. Excel 2016 with MIX 2.0 Pro add-on package was used to analyze the data and create forest plots. Data were presented in proportion with a 95% confidence interval.

CONCLUSIONS

Serviceable hearing was observed in 31% of patients after observation, 56% after radiotherapy, and 51% after surgical treatment with mean follow-up time of 4.04 years, 4.92 years, and 2.23 years, respectively. Facial nerve function was found to be best preserved in both observation and radiotherapy groups. Vestibular schwannoma growth occurred in 33% of patients under observation. Involution occurred in 2% of patients under observation and in 38% after radiotherapy.

The Role of Magnetic Resonance Imaging (MRI) in Diagnostics of Acoustic Schwannoma

Background:

Acoustic neuromas are also called vestibular schwannoma, acoustic neurinoma, vestibular neuroma, and acoustic neurofibroma. These are tumors that evolve from Schwann cell sheath and can be either intracranial or extra-axial. They usually occur adjacent to the cochlear or vestibular nerve. Anatomically, acoustic neuromas tend to occupy the cerebellopontine angle. About 20% of internal carotid artery (ICA) tumors are meningiomas and may occur elsewhere in the brain. Bilateral acoustic neuromas also tend to be exclusively in individuals with type 2 neurofibromatosis.

Objective:

The aim was to asses the role of MRI in evaluation of cerebellopontine angle acoustic schwannomas, the role of the cyber knife treatment in eliminating the tumor with a maximum protection of healthy tissue.

Methods:

MRI, GE 1.5 Tesla unit and standard protocol: Pre-contrast MRI images of the temporal bones and posterior fossa were obtained using Ax 3D Fiesta T2W Hi-resolution; Ax 3D T1 Fat-Suppressed, Thin-slice (2mm) Coronal T2W, Sag 3D FiestaT2W Hi-resolution images. Post-contrast images were obtained using Ax 3D T1 Fat-Suppressed Cor 3D T1 Fat-suppressed sequences. FLAIR sequence axial).

Case report:

A woman 62 years of age, reported sudden tinnitus, dizziness, hearing loss in her left ear. After one years she began to experience vertigo, headache.

Results:

MRI of brain temporal bone with contrast show acoustic schwannoma measuring 20x9 mm on the left cerebellopontine angle extending into and enlarging the left IAC, solid enhancing component is seen the acoustic meatus and peripheral contrast cystic component in the left cerebellopontine angle, after cyber knife treatment MRI result was the solid component of the mass, filling the left internal acoustic canal shows marked post-contrast enhancement and is measured 10x5x4mm, cystic component of it filling the left cerebellopontine angle cistern is enlarged to 25x19x12mm), it extends down till the left lateral aspect of medullary cistern, abutting the CN-XII at its entrance to left hypoglossal canal. After 5 month control show, a 15mm long and 5mm thick neoplastic soft-tissue in the left internal acoustic canal, with post-contrast enhancement, measured up to 12mm at the level of porus acusticus but cystic component of the mass in left cerebellopontine angle cistern is no longer visible in this MRI exam.

Conclusion:

The sensitivity of MRI for correctly diagnosing acoustic schwannoma was 100 % and specificity was 92.86 % with a positive predictive value of 94.12 % and accuracy of 96.67 %. MRI is considered as an excellent noninvasive investigation for pontocerebral angle Schwannoma’s.

Gamma knife surgery in the treatment of intracanalicular vestibular schwannomas

OBJECTIVE

According to the literature, gamma knife surgery (GKS) is a promising method for intracanalicular vestibular schwannoma (IVS) management, providing excellent tumor growth control rates (91%-100%) and good hearing preservation rates (41%-76%), but this evidence originates primarily from a small series of patients. The aim of this study was to present the outcomes of GKS in the largest group of patients with IVS studied to date, with particular emphasis on the long-term outcomes of treatment.

METHODS

The study included 136 consecutive patients with unilateral IVS, who underwent GKS in 2011-2015. Mean age of the patients was 54 ± 12.6 years. All patients were operated on with a 192-source cobalt-60 gamma knife unit. All patients had complete follow-up documentation and the mean duration of the follow-up was 52 ± 13.8 months (6-83 months). Neurological status (facial and trigeminal nerve), hearing and instability/dizziness presence were determined prior to GKS, immediately after the procedure, and during the follow-up visits.

RESULTS

Tumor growth control was obtained in 124/136 (~91.2%) patients. Hearing improvement was observed in 32/136 (23.5%) patients, and there was a distinct cluster of 9 patients (6.6%) regaining serviceable hearing after GKS, whereas in 36 patients (26.5%) was stable. Four patients developed facial nerve dysfunction, including 3 periodic hemifacial spasm and 1 partial paresis, which resolved spontaneously within 12 months of GKS. None of the operated patients showed new, debilitating neurological deficits, including trigeminal sensory disturbances or hydrocephalus.

CONCLUSIONS

GKS is a highly effective treatment for IVS, associated with low morbidity and good tumor growth control.

Imaging Features Differentiating Vestibular Ganglion from Intracanalicular Schwannoma on Single-Sequence Non-Contrast Magnetic Resonance Imaging Study

Introduction: This study aimed to identify imaging features on single-sequence noncontrast magnetic resonance imaging (MRI) that differentiate the vestibular ganglion from small intracanalicular schwannomas. Materials and Methods: Ninety patients (42 men and 48 women; age: 24‒87 years old) with 102 internal auditory canal (IAC) nodules (59 vestibular ganglia and 43 intracanalicular schwannoma) who underwent both singlesequence T2-weighted (T2W) non-contrast enhanced MRI studies and contrast-enhanced T1-weighted (T1W) MRI studies between May 2012 and April 2017 were evaluated. The length, width, distance to the IAC fundus and length/width ratios for all lesions were obtained and compared among groups. Diagnostic performance and cutoff values of the parameters were evaluated with receiver operating characteristics curve analysis. Area under the curve (AUC) value was calculated. Results: Vestibular ganglia have significantly smaller lengths and widths compared to intracanalicular vestibular schwannomas (1.7 ± 0.4 mm and 1.0 ± 0.2 mm versus 5.6 ± 3.0 mm and 3.7 ± 1.5 mm). They are more fusiform in shape compared to vestibular schwannomas (length/width ratio: 1.8 ± 0.4 versus 1.5 ± 0.4). The lesion width demonstrated the highest diagnostic performance (AUC: 0.998). Using a cutoff width of <1.3 mm, the sensitivity, specificity and overall accuracy for diagnosing vestibular ganglia were 97% (57/59), 100% (43/43) and 98% (100/102), respectively. Conclusion: Vestibular ganglia may mimic intracanalicular vestibular schwannomas on a single-sequence T2W MRI. However, a fusiform shape and width <1.3 mm increases confidence in the diagnosis of ganglia. Identifying the vestibular ganglion on single-sequence T2W MRI studies may obviate the need for a contrast-enhanced MRI, reducing the risks of contrast administration, additional scanning time and cost. Key words: Acoustic neuroma, Internal auditory canal, Vestibulocochlear nerve

Stereotactic radiotherapy in three weekly fractions for the management of vestibular schwannomas

PURPOSE

This study evaluates the rates of tumor control, hearing preservation and cranial nerve toxicity with the use of CyberKnife stereotactic radiotherapy consisting of 2100 cGy to the 80% isodose line delivered in three weekly fractions to treat vestibular schwannomas.

MATERIALS AND METHODS

Retrospective chart review of vestibular schwannoma patients treated with CyberKnife stereotactic radiotherapy or undergoing watchful waiting between 2006 and 2017 was performed. For inclusion, patients receiving CyberKnife stereotactic radiotherapy must have had pretreatment magnetic resonance imaging and audiography, and 2 follow-up magnetic resonance imaging and audiograms. Watchful waiting patients must have had a minimum of 2 magnetic resonance imaging and 2 audiograms.

RESULTS

Forty patients met inclusion criteria. Twenty-two underwent CyberKnife stereotactic radiotherapy. Eighteen remain in watchful waiting. Crude tumor control was 86.4% at mean radiographic follow-up of 52.3 months. Kaplan-Meier progression-free survival was 76.9% at 5 years. Kaplan-Meier survival from radiographic growth was 61.5% at 5 years. Kaplan-Meier hearing preservation was 17.5% at 5 years. All patients undergoing watchful waiting presenting with serviceable hearing maintained serviceable hearing. Serviceable hearing among CyberKnife stereotactic radiotherapy patients was 42.9% prior to treatment and 14.2% through mean follow-up of 53.7 months. One patient experienced trigeminal nerve toxicity 45 months after SRT. 95.5% of CyberKnife stereotactic radiotherapy patients were complication-free.

CONCLUSIONS

Our fractionation regimen provides tumor control consistent with current literature. Hearing outcomes, however, should be discussed with patients prior to CyberKnife stereotactic radiotherapy.

National Trends in Vestibular Schwannoma Surgery: Influence of Patient Characteristics on Outcomes

Objective To characterize current vestibular schwannoma (VS) surgery outcomes with a nationwide database and identify factors associated with increased complications and prolonged hospital course. Study Design Retrospective review utilizing the University HealthSystem Consortium national inpatient database. Setting US academic health centers. Subjects and Methods Data from patients undergoing VS surgery were analyzed over a 3-year time span (October 2012 to September 2015). Surgical outcomes, such as length of stay (LOS), complications, and mortality, were analyzed on the basis of race, sex, age, and comorbidities during the 30-day postoperative period. Results A total of 3697 VS surgical cases were identified. The overall mortality rate was 0.38%, and the overall complication rate was 5.3%. Advanced age significantly affected intensive care unit LOS, mortality, and complications ( P = .04). Comorbidities, including hypertension, obesity, and depression, also significantly increased complication rates ( P = .02). Sixty-eight patients (1.8%) had a history of irradiation, and they had a significantly increased LOS ( P = .03). Conclusion Modern VS surgery has a low mortality rate and a relatively low rate of complications. Several factors contribute to high complication rates, including age and comorbidities. These data will help providers in counseling patients on which treatment course might be best suited for them.

Postoperative Complications and Readmission Rates Following Surgery for Cerebellopontine Angle Schwannomas

OBJECTIVE

To investigate the 30-day postoperative complication, readmission, and reoperation rates following surgery for cerebellopontine angle (CPA) schwannomas.

STUDY DESIGN

Cross-sectional analysis.

SETTING

National surgical quality improvement program dataset (NSQIP) 2009 through 2013.

PATIENTS

All surgical cases with an International Classification of Diseases, 9th edition, Clinical Modification (ICD-9-CM) diagnosis code of 225.1, benign neoplasms of cranial nerves, and one of the following current procedural terminology (CPT) codes, were included: 61616, 61526, 61530, and 61520.

INTERVENTION(S)

Surgical resection as indicated by the CPT codes above.

MAIN OUTCOME MEASURE(S)

Demographics, comorbidities, 30-day postoperative complications, readmission rate, and reoperation rate.

RESULTS

Overall, 404 cases were identified, of which 42.6% were men. The average age was 51 years. Comorbidities were present in 45.3%. NSQIP-tracked complications occurred in 9.7% of patients. Most common complications were wound infections including surgical-site infection and wound dehiscence (11 patients, 2.7%), sepsis (10 patients, 2.5%), blood loss (nine patients, 2.2%), and deep vein thrombosis (DVT; seven patients, 1.7%). Mortality occurred in four patients (1.0%). The complication rate was statistically higher in patients with comorbidities versus those without (10.2% versus 4.1%, p = 0.04). Patients with complications were more likely to undergo reoperation (2.5% with versus 4.1% without, p = 0.001). Unplanned readmissions occurred in 41 cases (10.1%) and reoperations occurred in 23 patients (5.7%).

CONCLUSIONS

Most common NSQIP-tracked complications in excision of CPA neoplasms are infections, sepsis, blood loss, and deep vein thrombosis (DVT). Further, investigation of patients with unplanned readmission and reoperation are warranted. Neurotologists need to take an active role in the data to be gathered in the NSQIP database as it relates to vestibular schwannomas.

Long-term follow-up after stereotactic radiosurgery of intracanalicular acoustic neurinoma

Background

The management of solely intracanalicular acoustic neurinoma (iAN) includes observation, microsurgical resection and radiation therapy. Treatment goals are long-term tumor control, hearing preservation and concurrently low side-effects. Stereotactic radiosurgery (SRS) has evolved as an alternative first-line treatment for small AN. Here we report about the long-term follow-up of a unique cohort of patients with iAN after LINAC or Cyberknife® based SRS.

Methods

In this single center retrospective analysis, we included all patients with iAN who underwent single session LINAC or Cyberknife® based SRS between 1993 and 2015, and who had a minimum follow-up period of six weeks. Patient data were analyzed in terms of radiological and clinical tumor control (no further treatment necessary), subjective preservation of serviceable hearing, objective change in pure tone averages (PTA), and adverse events rated by the Common Terminology Criteria for Adverse Events (CTCAE; v4.03).

Results

Forty-nine patients (f/m = 21/28, median age 54 ± 12, range 20–77 years) were identified. Mean tumor volumes were 0.24 ± 0.12 cm³ (range, 0.1–0.68 cm³), the mean marginal dose was 12.6 ± 0.6 Gy (range, 11.0–14.0 Gy) and the prescription isodose was 75 ± 7.4% (range, 47–86%). Mean follow-up time was 65 months (range, 4–239 months).

Radiological tumor control was 100% during further follow-up. 17 (35%) out of 49 patients had lost serviceable hearing prior to SRS. Those with preserved serviceable hearing remained stable in 78% (n = 25/32) at the last follow-up (LFU). The median PTA (n = 16) increased from 25.6 dB prior to SRS to 43.8 dB at LFU.

Mild adverse events were observed temporarily in two patients (4%): one with CTCAE grade 1 facial nerve disorder after 3 months, resolving three months later, and one with CTCAE grade 2 facial muscle weakness resolving after 12 months. Three patients described permanent mild symptoms CTCAE grade 1 without limiting daily life (facial weakness n = 1, vertigo n = 2).

Conclusion

SRS for iAN shows long-term reliable tumor control with a high rate of hearing preservation without considerable permanent side effects, and can be proposed as a safe and effective treatment alternative to microsurgical resection.

Surgical outcomes of middle fossa approach in intracanalicular vestibular schwannoma

CONCLUSION

Middle fossa approach (MFA) shows a hearing preservation rate of 86% and facial nerve function was preserved with HB grade I or II in 93%. MFA is a good treatment option for intra-canalicular vestibular schwannomas when surgical excision is needed.

BACKGROUND

Surgical outcomes of vestibular schwannoma have progressively improved with the advancement of microsurgical instruments. MFA is known to have better chances to preserve hearing, while it has limited access to the posterior fossa, limitation of tumor size, and higher risk of post-operative facial nerve weakness.

OBJECTIVES

To investigate surgical outcomes and clinical efficiency of MFA in vestibular schwannoma.

METHODS

A retrospective study was done in 14 patients who underwent MFA for vestibular schwannoma in Asan Medical Center.

RESULTS

The median age at diagnosis was 46.3 years. At initial presentation, 57% of the patients had vertigo, 43% hearing disturbance, and 64% tinnitus. The mean tumor size was 9.7 mm. The tumors were completely resected in 86% of the patients. Hearing was post-operatively preserved in 12 patients and two patients lost their hearing following surgery. Facial nerve function post-operatively remained unchanged in 12 patients (86%).

Vestibular Schwannomas Treated with Cyberknife®: Clinical Outcomes

Purpose

Fractionated stereotactic radiotherapy (FSR) is a recognized treatment for vestibular schwannomas (VS). This study's aim is to present clinical outcomes and local control (LC) results for patients with VS treated with FSR using the Cyberknife® (CK) in 2 French cancer centers.

Methods

Patients treated with FSR for VS between 2007 and 2012 were retrospectively analyzed. Local control was determined using follow-up MRI. The hearing preservation (HP) rate was determined by analyzing pretreatment and posttreatment audiograms.

Results

Forty patients were treated for VS with the CK in both centers. The mean maximal VS dimension was 18.3 mm (range 3–30). The median follow-up was 36 months and the LC was 97% at 3 years of follow-up and 89% after 5 years. The HP rate was 83% and no facial nerve impairment was reported.

Conclusions

Our results in terms of LC and HP rate are congruent with similar studies that use the CK to treat VS. It appears that the CK is safe and efficient in VS management even for large lesions. Further studies with larger cohorts are warranted.

[Computer-controlled high-precision radiation]

The irradiation of tumors in the brain is challenging due to the proximity of radiation sensitive critical structures and the tumors to be treated. In addition, irradiation above a certain level can cause irreversible damage to nerve tissue. The irradiation of benign and malignant brain tumors requires precise techniques to preserve critical structures while simultaneously administering a high radiation dose for maximum effectiveness. Therefore, stereotaxy, as a subspecialty of neurosurgery, has developed various irradiation techniques, e. g., intracerebral application of interstitial brachytherapy (SBT; stereotactic brachytherapy) and stereotactic radiosurgery (SRS). Due to the development of computer-controlled radiation techniques (e. g., Cyberknife) over the last 20 years, SRS has gained increasing importance.

Isolated lymphoma of the optic nerve, chiasm and tract: A case report

The current study reports the case of a 68-year-old, previously healthy female who presented with progressive visual impairment leading to blindness bilaterally. Brain imaging features were suggestive of malignant glioma of the anterior visual pathway. Postoperative examination indicated a diagnosis of diffuse malignant lymphoma type B. As no evidence of extracranial lymphoma was observed, the final diagnosis was primary central nervous system lymphoma (PCNSL). Following treatment with surgery and radiotherapy, the patient's symptoms went into remission. At a follow-up examination 12 months after diagnosis, the patient demonstrated no evidence of recurrence. To the best of our knowledge, PCNSL isolated to the optic chiasm has been reported only three times in immunocompetent patients. Therefore, the present case of the lymphoma involving the optic nerve, optic chiasm and optic tract in an immunocompetent patient is unusual. The present case emphasizes the importance of considering the diagnosis of lymphoma in this setting.

Vestibular Schwannoma Excision in Sporadic versus Neurofibromatosis Type 2 Populations

OBJECTIVE

To understand the differences in characteristics of neurofibromatosis type 2 (NF2) and sporadic patients with surgically excised vestibular schwannomas in the state of California.

STUDY DESIGN

Cross-sectional.

SETTING, SUBJECTS, AND METHODS

The records of all patients who underwent vestibular schwannoma excision between 1997 and 2011 were extracted from the California Hospital Inpatient Discharge Databases (CHIDD). NF2 cases were identified using ICD-9-CM diagnosis code 237.72, neurofibromatosis, type 2. All other cases were recoded as sporadic. Trends in total number and population-adjusted rates (per 1 million California residents) of surgery, demographics, hospital case volume, state of residency, complications, length of stay, total charges, expected source of payment, and disposition were examined.

RESULTS

Vestibular schwannoma (VS) excision was performed on 7017 patients, of which 464 patients (6.6%) had NF2. The population-adjusted surgery rate declined from 11.8 to 6.2 (P < .001) for sporadic cases and from 0.3 to 0.2 (P = .01) for NF2 cases over the study period. NF2 was associated with younger age (mean, 32.9 vs 51.3), higher rate of other complications (8.8% vs 4.4%) and facial nerve complications (32.3% vs 16.8%), higher total charges (median $70,106 vs $46,395), longer stay (median 5 vs 4), and high volume hospitals (80.4% vs 48.8%) (all P < .001).

CONCLUSION

The surgery rates for vestibular schwannoma excision for both sporadic and NF2 patients have declined, but the decline is more prominent for sporadic cases. NF2 patients tend to be younger and have a longer hospitalization and possibly higher corresponding hospital charges compared to patients with sporadic VS.

Clinical evaluation of CyberKnife in the treatment of vestibular schwannomas

Objective. This study assessed the posttreatment tumor control and auditory function of vestibular schwannoma (VS) patients after CyberKnife (CK) and analyzed the possible prognostic factors of hearing loss. Methods. We retrospectively studied 117 VS patients, with Gardner-Robertson (GR) classification grades I to IV, who underwent CK between 2006 and 2012. Data including radiosurgery treatment parameters, pre- and postoperative tumor size, and auditory function were collected and examined. Results. With CK, 117 patients had excellent tumor control rates (99.1%), with a mean imaging followup of 61.1 months. Excluding 52 patients (GR III-IV pretreatment), 53 (81.5%) of the remaining 65 patients (initial GR I-II) maintained GR I or II hearing after CK, with a mean audiometric followup of 64.5 months. Twelve patients experienced hearing degradation (91.6% were GR II pretreatment); they appeared to have significantly larger tumor sizes, significantly smaller cochlear sizes, and higher prescribed cochlear doses, compared to the patients with preserved hearing. Conclusion. Our data showed that CK treatment provided an excellent tumor control rate and a comparable hearing preservation rate in VS patients. Patients with pretreatment GR II hearing levels, larger tumor volumes, smaller cochlear sizes, and higher prescribed cochlear doses may have poor hearing prognoses.

Trends in Demographics, Charges, and Outcomes of Patients Undergoing Excision of Sporadic Vestibular Schwannoma

Objective

To assess demographics, charges, and outcome measures by temporal and volume analysis in the treatment of vestibular schwannoma.

Design

Cross-sectional analysis.

Setting, Subjects, and Methods

The California Hospital Inpatient Discharge Databases from 1996 to 2010.

Results

A total of 6545 cases from 1996 to 2010 were identified. Of these, 86.2% occurred at high-volume centers (HVCs), and the number of annual cases decreased by 28.5%. Patients presenting for surgery were increasingly younger, non-Caucasian, and likely to have comorbidities. Total charges significantly increased over time ( P < .001), with the median total charge in 2006-2010 being $91,338 compared with $38,607.92 in 1996-2000 after adjusting for inflation. Routine discharges (home or residence) were more likely at HVCs (odds ratio [OR] 5.48, P < .001) and less likely if patients had Medicaid (Medi-Cal; OR 0.51, P = .002) or Medicare (OR 0.55, P = .022), were 65 years or older (OR 0.56, P = .025), or had comorbidities (OR 0.54, P < .001). Shorter hospital stays were more likely at HVCs (OR 3.77, P < .001) and less likely if patients had Medicaid (OR 0.36, P < .001) or comorbidities (OR 0.61, P < .001). Lesser total charges were more likely at HVCs (OR 2.12, P = .002) and less likely if patients had comorbidities (OR 0.70, P < .001). Mortality was less likely at HVCs (OR 0.10, P = .011).

Conclusion

The profile of patients undergoing vestibular neuroma excision is changing. Surgical volume is decreasing, suggesting a trend toward more conservative management or stereotactic radiation. Patients are best served at HVCs, where routine discharges, shorter length of stay, decreased mortality, and lower total charges are more likely.