Management of patients with acoustic neuromas: a Markov decision analysis

Markov models for clinical decision-making in radiation oncology: A systematic review

The intrinsic stochasticity of patients' response to treatment is a major consideration for clinical decision-making in radiation therapy. Markov models are powerful tools to capture this stochasticity and render effective treatment decisions. This paper provides an overview of the Markov models for clinical decision analysis in radiation oncology. A comprehensive literature search was conducted within MEDLINE using PubMed, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Only studies published from 2000 to 2023 were considered. Selected publications were summarized in two categories: (i) studies that compare two (or more) fixed treatment policies using Monte Carlo simulation and (ii) studies that seek an optimal treatment policy through Markov Decision Processes (MDPs). Relevant to the scope of this study, 61 publications were selected for detailed review. The majority of these publications (n = 56) focused on comparative analysis of two or more fixed treatment policies using Monte Carlo simulation. Classifications based on cancer site, utility measures and the type of sensitivity analysis are presented. Five publications considered MDPs with the aim of computing an optimal treatment policy; a detailed statement of the analysis and results is provided for each work. As an extension of Markov model-based simulation analysis, MDP offers a flexible framework to identify an optimal treatment policy among a possibly large set of treatment policies. However, the applications of MDPs to oncological decision-making have been understudied, and the full capacity of this framework to render complex optimal treatment decisions warrants further consideration.

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.

Lifetime Cost and Quality-Adjusted Life-Years Across Management Options for Small- and Medium-Sized Sporadic Vestibular Schwannoma

OBJECTIVE

Despite the growing emphasis on healthcare costs, limited data address this aspect of care within the vestibular schwannoma (VS) literature. We sought to determine which strategy confers the lowest lifetime cost and greatest quality-adjusted life-years (QALYs) for patients with small- to medium-sized sporadic VS tumors.

STUDY DESIGN

A Markov model was created to determine the most cost-effective management algorithm. Tumor characteristics, magnetic resonance imaging surveillance schedule, treatment outcomes, and health-related quality of life values were derived from previously published data. Cost estimates were based on CMS Fee Schedule reimbursement rates.

SETTING

Economic Evaluation Service within the Kern Center for the Science of Healthcare Delivery.

PATIENTS

Patients diagnosed with small- to medium-sized sporadic VS.

INTERVENTIONS

Upfront microsurgery following diagnosis, upfront radiosurgery following diagnosis, observation with microsurgery reserved for observed tumor growth, and observation with radiosurgery reserved for observed tumor growth.

RESULTS

Across patient ages at time of diagnosis ranging from 18 to 70 years, observation with subsequent radiosurgery used for tumor growth was the most cost-effective management algorithm while upfront microsurgery was the least. When presented with a hypothetical 50-year-old patient, the strategy with the lowest lifetime cost and highest QALYs was observation with subsequent radiosurgery reserved for tumor growth ($32,161, 14.11 QALY), followed by observation with microsurgery reserved for tumor growth ($34,503, 13.94 QALY), upfront radiosurgery ($43,456, 14.02 QALY), and lastly, upfront microsurgery ($47,252, 13.60 QALY). Sensitivity analyses varying mortality rates, estimated costs, health-related quality of life, and progression to nonserviceable hearing demonstrated consistent ranking among treatments.

CONCLUSIONS

When considering initial management of small- and medium-sized sporadic VSs, neither lifetime cost nor QALYs support upfront microsurgery or radiosurgery, even for younger patients. Initial observation with serial imaging, reserving radiosurgery or microsurgery for patients exhibiting tumor growth, confers the greatest potential for optimized lifetime healthcare cost and QALY outcomes.

Adherence to Long-Term Follow-up in Patients With Sporadic Vestibular Schwannomas Managed With Serial Observation

Objectives

To examine the long-term adherence to serial imaging of patients with sporadic vestibular schwannoma and analyze factors associated with being lost to follow-up.

Study Design

Retrospective chart review with telephone interview.

Setting

Single tertiary care center.

Methods

Patients with a sporadic vestibular schwannoma and started on observational surveillance management between January 2005 and December 2010 were included. Demographic data, tumor size, hearing and vestibular changes, and follow-up length were recorded. Patient factors were analyzed for association with being lost to follow-up.

Results

In total, 122 patients were included with a median length of follow-up of 5 months (range, 0-146). After initial surveillance, 22.1% (n = 27) of patients had a change in management to either microsurgery or radiosurgery. Of the remaining 77.9% (n = 95), nearly half (44.2%, n = 42) never returned for a second visit, and all but 3 were eventually lost to follow-up. There was no association between sex, race, age at diagnosis, initial tumor size, insurance status, household income, or driving distance to hospital and being lost to follow-up. Of 26 interviewed patients initially lost to follow-up, 11 (42.3%) sought care at another institution, 5 (19.2%) chose to no longer receive care, 1 (3.8%) had transportation difficulties, and 9 (36.4%) had poor understanding of their diagnosis or instructions.

Conclusions

The length of follow-up for patients undergoing surveillance of sporadic vestibular schwannoma varies widely, and patients are commonly lost to follow-up. Further efforts should be made to identify at-risk patients and provide adequate education to improve long-term surveillance.

Surgical Management of Vestibular Schwannoma: Practice Pattern Analysis via NSQIP

Objective:

Characterize current perspectives in the surgical management of vestibular schwannoma (VS) to guide otolaryngologists in understanding United States practice patterns.

Methods:

A retrospective analysis of ACS-NSQIP database was performed to abstract all patients from 2008 to 2016 who underwent VS resection using ICD-9/10 codes 225.1 and D33.3, respectively. The specific surgical approach employed was identified via CPT codes 61520, 61526/61596, and 61591, which represent retrosigmoid (RS), translabyrinthine (TL) and middle cranial fossa (MCF) approaches, respectively. Analyzed outcomes include general surgical complications, total length of stay, and reoperation.

Results:

A total of 1671 VS cases were identified, 1266 (75.7%) were RS, 292 (17.5%) were TL, and 114 (6.8%) were MCF. The annual number of cases increased over the study period from 15 to 375, which is chiefly attributed to increased institutional participation in ACS-NSQIP. Perioperative variables including BMI ( P < .001), ASA class ( P = .004), ethnicity ( P = .008), operative time ( P < .001), and reoperation ( P < .001) were found to be statistically significant between cohorts. Increased utilization of RS approach was consistent over the entire study period, with significantly more RS performed than either TL or MCF. Finally, a statistically significant difference with respect to general surgical complication rates was not noted between surgical approaches.

Conclusions:

There is increased employment of RS approach for the operative management of VS, which likely is the result of increased reliance on both stereotactic radiosurgery and observation as alternative treatment strategies.

Hearing Preservation for Vestibular Schwannomas Treated with Stereotactic Radiosurgery or Fractionated Stereotactic Radiotherapy

BACKGROUND

Vestibular schwannomas (VS) are benign intracranial neoplasms arising from the eighth cranial nerve for which targeted radiation therapy (RT) has proved increasingly successful. However, long-term hearing and related cranial nerve outcomes have been disputed for the 3 current RT modalities.

OBJECTIVE

To determine differences in hearing preservation for patients treated with stereotactic radiosurgery (SRS), fractionated stereotactic radiotherapy (FSRT), or hypofractionated stereotactic radiotherapy (hypoFSRT) for VS.

METHODS

A retrospective electronic chart review was conducted for all patients with unilateral VS treated with primary RT at a single academic medical center between 2000 and 2017. The primary outcome measure was preservation of serviceable hearing status in the affected ear at last follow-up. Secondary outcomes included tinnitus, vertigo, and imbalance.

RESULTS

A total of 33 FSRT cases, 21 SRS cases, and 6 hypoFSRT cases were identified. Postoperative deterioration in serviceable hearing and tinnitus showed significant differences across cohorts. The SRS cohort had a higher baseline incidence of nonserviceable hearing and disequilibrium compared with other cohorts before RT (P = 0.001 and 0.022, respectively); no differences in baseline morbidity were observed for vertigo and tinnitus. The 5-year tumor control rate was 95.2%, 93.9%, and 100% with SRS, FSRT, and hypoFSRT, respectively.

CONCLUSIONS

Our series indicated an excellent tumor control rate in all the modalities. Our SRS cohort showed increased incidence and shorter time to hearing deterioration compared with the FSRT and hypoFSRT cohorts. The FSRT and hypoFSRT cohorts have shown comparable overall outcomes. Onset of post-RT tinnitus was observed only with FSRT.

In search of the most cost-effective monitoring strategy for vestibular schwannoma: A decision analytical modelling study

Objectives

To assess the cost‐effectiveness of frequently used monitoring strategies for vestibular schwannoma (VS).

Design

A state transition model was developed to compare six monitoring strategies for patients with VS: lifelong annual monitoring; annual monitoring for the first 10 years after diagnosis; scanning at 1‐5, 7, 9, 12, 15 years after diagnosis and subsequently every 5 years; a personalised monitoring strategy for small and large tumours; scanning at 1, 2 and 5 years after diagnosis and no monitoring. Input data were derived from literature and expert opinion. Quality‐adjusted life years (QALYs) and healthcare costs of each strategy were modelled over lifetime. Net monetary benefits (NMBs) were calculated to determine which strategy provided most value for money. Sensitivity analyses were performed to address uncertainty.

Results

Omitting monitoring is least effective with 18.23 (95% CI 16.84‐19.37) QALYs per patient, and lifelong annual monitoring is most effective with 18.66 (95% CI 17.42‐19.65) QALYs. Corresponding costs were €6526 (95% CI 5923‐7058) and €9429 (95% CI 9197‐9643) per patient, respectively. Lifelong annual monitoring provided the best value with a NMB of €363 765 (339 040‐383 697), but the overall probability of being most cost‐effective compared to the other strategies was still only 23%. Sensitivity analysis shows that there is large uncertainty in the effectiveness of all strategies, with largely overlapping 95% confidence intervals for all strategies.

Conclusions

Due to the largely overlapping 95% confidence intervals of all monitoring strategies for VS, it is unclear which monitoring strategy provides most value for money at this moment.

Patient Motivation and Long-Term Satisfaction with Treatment Choice in Vestibular Schwannoma

OBJECTIVES

To ascertain primary motivation and long-term satisfaction with treatment selection in patients with vestibular schwannoma.

METHODS

A multicenter, cross-sectional survey was performed. Patients with small- to medium-sized sporadic vestibular schwannoma who underwent stereotactic radiosurgery (SRS; n = 247), microsurgery (n = 144), or observation (n = 148) between 1998 and 2008 were surveyed regarding their motivation behind treatment selection and hindsight satisfaction with their choice of management.

RESULTS

"Physician recommendation" was the most commonly stated reason for modality selection in all 3 groups. The second and third most common reasons for selecting SRS included "less invasive option than surgery" in 80 patients (32%) and "less recovery time than surgery" in 16 patients (6%). The second and third most common reasons for selecting observation included "to avoid side-effects of treatment" in 25 patients (17%) and "symptoms not severe enough to warrant intervention" in 22 patients (15%). The second and third most common reasons for selecting microsurgery included "do not want tumor in head" in 35 patients (24%) and "most definitive treatment" in 15 patients (10%). Overall, 232 patients (96%) treated with SRS, 141 observed patients (97%), and 121 patients (85%) who underwent microsurgical treatment were satisfied with their original decision (P < 0.001).

CONCLUSIONS

Motivation behind treatment selection varies between individuals. Those who select observation and SRS commonly reference less invasiveness and lower risk, whereas those who select microsurgery are commonly motivated by having their tumor physically removed and the more definitive nature of treatment. Posttreatment satisfaction is highest in patients who undergo SRS and observation, although all 3 groups report high levels of satisfaction.

[Surgical indications and complications management in vestibular schwannoma]

BACKGROUND

Recent surgical treatment concepts for patients with vestibular schwannoma (VS) require an interdisciplinary approach as well as recognition and mastering of complications.

OBJECTIVE

This paper provides an overview of indications, as well as possible options for function preservation and management of complications in the surgical resection of these tumors.

METHODS

Up-to-date treatment concepts and surgical indications were differentiated according to size and extent of tumors. The frequency of important complications was extracted from the literature. Technical options to avoid and correct complications were compiled from personal experience and review of the literature.

RESULTS

Complications unrelated to cranial nerves are not infrequent, particularly in older patients. Small and medium-sized tumors that do not reach the fundus and cochlear fossa can be completely removed with good chances of hearing preservation. As long as these tumors do not grow, patients benefit from observation. Large tumors are overrepresented in surgical series compared to their prevalence. Postoperative facial nerve function correlates to tumor volume. Hearing preservation in these tumors is rare. Intraoperative electrophysiological techniques are valuable for attempted preservation of cranial nerve function. Persistent facial palsies can be remedied by dynamic and static interventions for facial rehabilitation.

CONCLUSION

Mortality and morbidity associated with surgical treatment of VS are very acceptable. Surgical concepts should be custom-tailored to the individual patient in order to ensure high quality of life.

Quality of Life in 807 Patients with Vestibular Schwannoma: Comparing Treatment Modalities

Objective In vestibular schwannoma treatment, the choice among treatment modalities is controversial. The first aim of this study was to examine the quality of life of patients with vestibular schwannoma having undergone observation, radiation therapy, or microsurgical resection. The second aim was to examine the relationship between perceived symptoms and quality of life. Last, the association between quality of life and time since treatment was studied. Study Design Cross-sectional study. Setting Tertiary referral center. Subjects and Methods A total of 1208 patients treated for sporadic vestibular schwannoma between 2004 and 2014 were mailed the disease-specific Penn Acoustic Neuroma Quality of Life (PANQOL) questionnaire and additional questions on symptoms associated with vestibular schwannoma. Total and domain scores were calculated and compared among treatment groups. Propensity scores were used, and results were stratified according to tumor size to control for potential confounders. Correlations were calculated to examine the relationship between self-reported symptoms and quality of life, as well as between quality of life and time since treatment. Results Patients with small tumors (≤10 mm) under observation showed a higher PANQOL score when compared with the radiation therapy and microsurgical resection groups. A strong negative correlation was found between self-reported symptoms and quality of life, with balance problems and vertigo having the largest impact. No correlation was found between PANQOL score and time since treatment. Conclusion This study suggests that patients with small vestibular schwannomas experience better quality of life when managed with observation than do patients who have undergone active treatment.

[Vestibular schwannoma - management and microsurgical results]

BACKGROUND

The experience of the medical team, interdisciplinarity, quality of the physician-patient relationship, sensible use of modern technology, and a sound knowledge about the long-term results of observation and interventions all influence treatment quality in patients with vestibular schwannomas.

OBJECTIVES

Compilation of findings regarding the results of observation and microsurgical treatment of patients with these tumors. Deduction of strategies for the medical management from these data.

MATERIALS AND METHODS

Review of the pertinent literature concerning the course of the disease with observational management and microsurgical treatment with respect to tumor growth and symptoms.

RESULTS

Reported annual growth rates of vestibular schwannoma vary between 0.3 and 4.8 mm. Vertigo is the symptom that is most influential on quality of life regardless of the medical management strategy. Up to 75 % of patients are treated within 5 years of the primary diagnosis. Independent of the approach, reported resection rates are higher than 95 %, even with preservation of function as the primary goal. Recurrence rates after subtotal removal are three times higher than after complete removal. Facial nerve preservation is accomplished in more than 90 % of cases. With functional hearing before surgery and small tumors, the chance of hearing preservation exceeds 50 %.

CONCLUSIONS

Quality of life is primarily defined by symptoms caused by the tumor itself and only secondarily by the medical interventions. Treatment should be directed towards the preservation of the patient's quality of life from the beginning. Results of medical treatment should be superior to the natural course of the disease.

Radiotherapy for vestibular schwannoma: Review of recent literature results

BACKGROUND

The management of vestibular schwannoma is still a quite controversial issue and can include wait and see policy, surgery and radiotherapy, mainly with stereotactic technique. The purpose of this study is to review the results of recent clinical series treated by radiotherapy.

MATERIALS AND METHODS

Literature search was performed by Pubmed and Scopus by using the words "vestibular schwannoma, acoustic neuroma, radiotherapy, radiosurgery".

RESULTS

Management options of VS include wait and see, surgery and radiotherapy. In case of small lesions, literature data report local control rates higher than 90% after radiosurgery (SRS) similar those of surgical techniques. Recent literature reviews show favourable functional outcome by using SRS. Several literature data support the use of fractionated stereotactic radiotherapy (FSRT) in case of large inoperable lesions.

CONCLUSION

Radiotherapy plays a relevant role in the treatment of VS. In small-size lesions, SRS can guarantee similar local control and potentially better function outcome compared to surgery. In case of large and irregularly shaped lesions, FSRT can be the used when surgery is not feasible.

How Much Does the Type of Tympanostomy Tube Matter? A Utility-Based Markov Decision Analysis

Objectives

To use a utility-based Markov decision analysis model to compare outcomes of short-term grommet tympanostomy tubes (TTs), intermediate-type tubes, and permanent T-Tubes and to use a detailed sensitivity analysis to determine the most important factors influencing outcomes with one type of TT versus another.

Study Design

Markov decision analysis.

Setting

Hypothetical cohort.

Subjects and Methods

A Markov cohort decision analysis model was created using computer software (TreeAge Software, Inc, Williamstown, Massachusetts) comparing the 3 types of TT. Published data were used to determine key baseline model parameters. The model featured potential complications including eardrum perforation, early TT extrusion/blockage, and the need for possible repeat TT placement after extrusion. Outcomes were quantified using a 0.95 (1 procedure, full recovery) to 0.6 (failed myringoplasty) utility scale. Utility values were discounted over time to incorporate real-life inconvenience.

Results

The intermediate TT accumulated superior total utility in 2-, 4-, and 6-year models (2.48, 3.96, and 5.27 total utility) compared with grommets (2.32, 3.82, 5.18) and T-Tubes (2.42, 3.86, 5.18). Examining a hypothetically otherwise healthy 3000-child cohort, T-Tubes resulted in an increased overall persistent perforation rate (7.9% vs 0.2%, P < .001, χ2). Sensitivity analysis indicated that the rate of repeat TT placement, the utility assigned to having a functional tube in place, and the inconvenience utility discount factor over time were the driving factors of the model.

Conclusion

The intermediate TT may produce optimal outcomes as it combines a balance of a lower perforation rate than T-Tubes and a longer period of ventilation than grommet tubes.

Conservative management, surgery and radiosurgery for treatment of vestibular schwannomas: a model-based approach to cost-effectiveness

OBJECTIVE

To undertake a cost-effectiveness analysis comparing conservative management, surgery and radiosurgery for treating small-to-medium (1-20 mm)-sized vestibular schwannomas.

DESIGN

Model-based economic evaluation using individual-level data from a Birmingham-based longitudinal patient database and from published sources. Both a decision tree and state-transition (Markov) model were developed, from an National Health Service (NHS) perspective. Sensitivity analyses were also carried out.

SETTING

Secondary care treatment for patients with small-to-medium-sized vestibular schwannomas.

PARTICIPANTS

Three hypothetical cohorts of adult patients receiving conservative management, radiosurgery or surgery treatment, aged 58 years as starting age within model.

MAIN OUTCOME MEASURES

Cost-effectiveness based on cost per quality-adjusted life year (QALY).

RESULTS

Conservative management is the preferred strategy for the treatment of small-to-medium-sized vestibular schwannomas. Conservative management is both cheaper (-£ 722 and -£ 2764) and more effective (0.136 and 0.554 quality-adjusted life years) than both radiosurgery and surgery, respectively. A conservative strategy can therefore be considered as highly cost-effective. This result is sensitive to the assumed quality-of-life parameters in the model. Sensitivity analysis suggests that the probability of a conservative strategy being the most cost-effective approach compared with surgery and radiosurgery at a willingness to pay of £ 20 000/quality-adjusted life year gained is 80% and 55%, respectively.

CONCLUSIONS

A conservative approach is the preferred strategy for treatment of small-to-medium vestibular schwannomas. This result is sensitive to quality-of-life values used in the analysis. More research is required to assess the impact of treatment upon patients' health-related quality of life over time.

Diagnostic yield of computed tomography scan for pediatric hearing loss: a systematic review

BACKGROUND

Computed tomography (CT) has been used in the assessment of pediatric hearing loss, but concern regarding radiation risk and increased utilization of magnetic resonance imaging (MRI) have prompted us toward a more quantitative and sophisticated understanding of CT's potential diagnostic yield.

OBJECTIVE

To perform a systematic review to analyze the diagnostic yield of CT for pediatric hearing loss, including subgroup evaluation according to impairment severity and laterality, as well as the specific findings of enlarged vestibular aqueduct and narrow cochlear nerve canal.

DATA SOURCES

PubMed, EMBASE, and the Cochrane Library were assessed from the date of their inception to December 2013. In addition, manual searches of bibliographies were performed and topic experts were contacted.

REVIEW METHODS

Data from studies describing the use of CT in the diagnostic evaluation of pediatric patients with hearing loss of unknown etiology were evaluated, according to a priori inclusion/exclusion criteria. Two independent evaluators corroborated the extracted data. Heterogeneity was evaluated according to the I(2) statistic.

RESULTS

In 50 criteria-meeting studies, the overall diagnostic yield of CT ranged from 7% to 74%, with the strongest and aggregate data demonstrating a point estimate of 30%. This estimate corresponded to a number needed to image of 4 (range, 2-15). The most commonly identified findings were enlarged vestibular aqueduct and cochlear anomalies. The largest studies showed a 4% to 7% yield for narrow cochlear nerve canal.

CONCLUSION

These data, along with similar analyses of radiation risk and risks/benefits of sedated MRI, may be used to help guide the choice of diagnostic imaging.

Cost–utility analysis and otolaryngology

As providers of health care, we face increasing demand on our limited, indeed diminishing, resources. Economic appraisal of our interventions means assessing the trade-off between effectiveness, efficiency and equity. When rationing becomes inevitable, calculation of utility values is a valuable decision-making tool. This paper reviews objective measures of patient benefit, such as quality of life, and focuses on their application within otolaryngology.

An update on unilateral sporadic small vestibular schwannoma

Advances in neuroimaging have increased the detection rate of small vestibular schwannomas (VSs, maximum diameter < 25 mm). Current management modalities include observation with serial imaging, stereotactic radiosurgery, and microsurgical resection. Selecting one approach over another invites speculation, and no standard management consensus has been established. Moreover, there is a distinct clinical heterogeneity among patients harboring small VSs, making standardization of management difficult. The aim of this article is to guide treating physicians toward the most plausible therapeutic option based on etiopathogenesis and the highest level of existing evidence specific to the different cohorts of hypothetical case scenarios. Hypothetical cases were created to represent 5 commonly encountered scenarios involving patients with sporadic unilateral small VSs, and the literature was reviewed with a focus on small VS. The authors extrapolated from the data to the hypothetical case scenarios, and based on the level of evidence, they discuss the most suitable patient-specific treatment strategies. They conclude that observation and imaging, stereotactic radiosurgery, and microsurgery are all important components of the management strategy. Each has unique advantages and disadvantages best suited to certain clinical scenarios. The treatment of small VS should always be tailored to the clinical, personal, and social requirements of an individual patient, and a rigid treatment protocol is not practical.

Current strategies in management of intracanalicular vestibular schwannoma

PURPOSE OF REVIEW

The current practitioner is more often managing intracanalicular vestibular schwannomas than in the past, as improved imaging and heightened awareness leads to earlier diagnosis of these tumors. The role of observation, microsurgery, and radiation treatment in the management of intracanalicular tumors continues to evolve. The goal of this article is to evaluate and summarize recent literature pertaining to the management of intracanalicular vestibular schwannomas.

RECENT FINDINGS

Watchful waiting is an important management option for patients with minimal symptoms. The literature on the natural history of small vestibular schwannomas continues to expand, with particular emphasis on the expected hearing outcomes. Microsurgical techniques also focus on hearing preservation. Presence of fundal fluid and good or normal hearing preoperatively are positive predictors of hearing preservation after surgery. Long-term follow-up after radiation therapy for vestibular schwannomas continues to demonstrate excellent tumor control rates, although hearing preservation rates are modest.

SUMMARY

Multiple factors, including status of hearing, presence of vestibular symptoms, patient age, medical comorbidities, institutional outcomes, and patient preferences, help determine the management strategy for patients with an intracanalicular vestibular schwannoma.

Stereotactic radiation treatment of vestibular schwannoma: indications, limitations, and outcomes

PURPOSE OF REVIEW

Stereotactic radiation treatment is an increasingly performed procedure for patients with vestibular schwannoma and other benign skull base tumors. During the past 30 years, advancements in stereotactic imaging, radiation delivery techniques, and dose planning have improved overall patient outcomes. The specific role of radiation in current management strategies for vestibular schwannoma continues to evolve as long-term outcome data are analyzed and standardized studies are performed. The recent literature regarding the indications, limitations, and outcomes for stereotactic radiation treatment is reviewed.

RECENT FINDINGS

Systematic reviews of the Gamma Knife literature demonstrate improved overall outcomes with radiation doses below 13 Gy. Observation of small vestibular schwannomas is recommended over early radiation or microsurgical intervention. Radiation may be used as adjunctive therapy for large tumors and in certain postradiation treatment failures. Stereotactic radiosurgery and fractionated radiotherapy are equally effective treatment modalities.

SUMMARY

Long-term outcome data will ultimately define future indications and limitations for the use of stereotactic radiation with benign skull base lesions. Current evidence supports its use for small to medium sized primary and recurrent vestibular schwannomas with optimal dosing below 13 Gy. It is also recommended for adjunctive therapy, recurrent tumors, in poor surgical candidates, and for those who do not desire observation or surgery.