Management of vestibular schwannoma in the modern era: Early clinical outcomes

Siddhartha Nanda; Amitima Mehta; Papuji Meher; Rakesh Kumar Gupta

doi:10.25259/ASJO_22_2026

View/Download PDF

Buy Reprints

PDF

Translate this page into:

Original Article

2026

:12;

doi:

10.25259/ASJO_22_2026

Management of vestibular schwannoma in the modern era: Early clinical outcomes

Siddhartha Nanda¹_{MD, DNB}, Amitima Mehta¹_MBBS, Papuji Meher^1,_{MBBS, MD}, Rakesh Kumar Gupta²_{MD, DNB}

1Department of Radiation Oncology, All India Institute of Medical Sciences, Raipur, Chhattisgarh, India

2Department of Pathology and Lab Medicine, All India Institute of Medical Sciences, Raipur, Chhattisgarh, India

*Corresponding author: Papuji Meher, Department of Radiation Oncology, All India Institute of Medical Sciences, Tati Bandh, Raipur, 492099, Chhattisgarh, India. papuji.meher@gmail.com

Received: 2026-02-20, Accepted: 2026-04-23, Published: 2026-06-11

Licence

This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-Share Alike 4.0 License, which allows others to remix, transform, and build upon the work non-commercially, as long as the author is credited and the new creations are licensed under the identical terms.

How to cite this article: Nanda S, Mehta A, Meher P, Gupta RK. Management of vestibular schwannoma in the modern era: Early clinical outcomes. Asian J Oncol. 2026;12:15. doi: 10.25259/ASJO_22_2026

Abstract

Objectives:

To evaluate clinical characteristics, treatment approaches, dosimetrist parameters, and early outcomes in patients with vestibular schwannoma treated with radiotherapy.

Material and Methods:

This retrospective observational study analyzed patients with vestibular schwannoma treated with radiotherapy between 2022 and 2025. Demographic, clinical, radiological, audiometric, and dosimetrist parameters were evaluated. Treatment outcomes, including radiologic response, hearing outcomes, and treatment-related toxicity, were also reviewed. Descriptive statistics and exploratory non-parametric analyses were performed.

Results:

Ten patients were included, with a median age of 32 years. fractionated stereotactic radiotherapy (FSRT) and volumetric modulated arc therapy (VMAT) were used in five patients each. At a median follow-up of 10.5 months, no radiologic progression was observed in any patient. Three patients (30%) demonstrated complete radiologic response, while seven (70%) showed stable disease. Hearing preservation was achieved in only one patient. Treatment was well tolerated, with no Grade 3 or 4 toxicities and no life-threatening adverse events.

Conclusion:

Precision radiotherapy using FSRT or VMAT provides excellent tumor control with acceptable toxicity in vestibular schwannoma. Larger studies with longer follow-up are required to evaluate long-term functional outcomes.

Keywords

Hearing preservation

Radiotherapy

Stereotactic

Vestibular schwannoma

Volumetric modulated arc therapy

Show Related Articles from PubMed

INTRODUCTION

CVestibular schwannoma is a benign tumor that arises from the Schwann cells of the vestibulocochlear nerve and represents one of the most common tumors in the cerebellopontine (CP) angle. Improvements in magnetic resonance imaging (MRI) have enabled early diagnosis, resulting in increased detection of small and moderately sized tumors. Although microsurgical resection remains an established treatment modality, concerns regarding cranial nerve morbidity have led to increased utilization of radiotherapy as a primary treatment strategy.^[1–3]

Modern radiotherapy techniques, including fractionated stereotactic radiotherapy (FSRT) and stereotactic radiosurgery (SRS), have demonstrated high local control rates exceeding 90%, with reduced risk of neurological complications compared with surgery in appropriately selected patients.^[3–5] Fractionated stereotactic approaches are particularly advantageous for larger tumors or lesions located near critical structures such as the cochlea and brainstem. Despite encouraging oncologic outcomes, functional preservation, particularly hearing, remains variable.

This study presents a retrospective institutional experience evaluating clinical characteristics, treatment approaches, dosimetrist parameters, and early outcomes in patients with vestibular schwannoma treated with radiotherapy. Given the rarity of this disease and limited regional data from central India, this study is intended as a descriptive analysis providing real-world institutional experience.

MATERIAL AND METHODS

Study design and ethics

This retrospective observational study was conducted in accordance with institutional ethical standards. Patient confidentiality was maintained throughout the study.

Patient selection

Patients treated with radiotherapy for radiologically or histologically confirmed vestibular schwannoma between 2022 and 2025 were included [Figure 1]. Eligibility criteria included patients treated with FSRT or conventionally fractionated conformal radiotherapy. Patients with incomplete follow-up imaging or missing treatment records were excluded.

22-year-old male with left CP (cerebellopontine) angle vestibular schwannoma who presented with headache and left ear hearing loss and underwent subtotal excision of the lesion. Low power (4X) histopathologic photograph of the excised specimen stained with hematoxylin and eosin, showing prominent Vero cay bodies with Antoni A areas and hypocellular Antoni B regions.

Data collection

Demographic, clinical, radiological, audiometric, and treatment-related data were retrieved from institutional records. Variables recorded included age, sex, presenting symptoms, symptom duration, baseline cranial nerve examination, and pure-tone audiometry (PTA) results. Tumor characteristics, including laterality, maximum tumor diameter, and Koos grade, were documented from MRI scans [Figure 2].

46-year-old male with left CP (cerebellopontine) angle vestibular schwannoma who presented with left ear hearing reduction and underwent subtotal excision of the lesion. Axial T1-weighted post-contrast (gadolinium-enhanced) MRI (magnetic resonance imaging ) of the brain shows a residual enhancing lesion in the left cerebellopontine angle region. (Gross tumor delineated in purple outline)

Radiotherapy parameters included treatment technique, total dose, fractionation schedule, and dosimetrist parameters of organs at risk, particularly the cochlea and brainstem.

Treatment planning and delivery

Two distinct treatment approaches were used: fractionated stereotactic radiotherapy (FSRT) in four patients (40%) and volumetric modulated arc therapy (VMAT) in six patients (60%). Treatment modality selection was individualized. FSRT was generally preferred for smaller tumors or those in proximity to critical structures such as the cochlea and brainstem, where hypofractionation was considered beneficial. VMAT-based conventional fractionation was more commonly used for larger tumors. Additional factors included prior surgery, residual disease status, and overall patient condition.

All patients underwent computed tomography (CT) simulation using individualized immobilization devices. A three-clamp thermoplastic mask was employed for VMAT treatments, while a double-shell immobilization mask was used for FSRT cases to ensure sub-millimeter reproducibility [Figure 3]. Planning CT images were acquired with 0.625 mm (for FSRT cases) and 2.5 mm slice thickness (for VMAT cases) and co-registered with contrast-enhanced MRI for target and organ at risk (OAR) delineation [Figure 4]. Gross tumor volume (GTV) was delineated based on MRI findings. A planning target volume (PTV) margin of 1–2 mm was applied depending on immobilization technique and image guidance accuracy. Treatment plans were optimized to ensure that at least 95% of the PTV received the prescribed dose. Treatment planning was performed using the Monaco® (version 6.1.2.0) treatment planning system (Elekta AB, Stockholm, Sweden). Organ-at-risk constraints were prioritized during planning. For FSRT, the cochlear dose was evaluated using Dmax, while for VMAT plans, Dmean was used due to fractionation differences. Brainstem dose constraints were assessed using Dmax in all cases. Image-guided radiotherapy using cone-beam CT was employed for treatment verification [Figure 5].

A 30-year-old male with a right cerebellopontine (CP) angle vestibular schwannoma presented with right ear hearing loss and underwent subtotal excision of the lesion, being planned for fractionated stereotactic radiotherapy for the residual tumor. Patient positioned for fractionated stereotactic radiotherapy (FSRT) using a double-shell thermoplastic immobilization mask system. (Clinical photograph used with written informed consent from the patient)

44-year-old woman with right CP angle vestibular schwannoma who presented with right ear hearing reduction and tinnitus, being planned for VMAT-based radiotherapy for the residual lesion. Axial T1-weighted post-contrast (gadolinium-enhanced) MRI co-registered with planning CT scan for target and OAR delineation. CP: Cerebellopontine, VMAT: Volumetric modulated arc therapy, MRI: Magnetic resonance imaging, OAR: Organs at risk

34-year-old male with left CP angle vestibular schwannoma who presented with headache and left ear hearing loss, and underwent subtotal excision of the lesion, being planned for FRST for the residual lesion. CBCT image acquired prior to FSRT demonstrating image-guided setup verification. On-board CBCT is registered with the planning dataset to confirm target alignment and assess translational and rotational deviations, ensuring accurate repositioning before treatment delivery. CP: Cerebellopontine, FSRT: Fractionated stereotactic radiotherapy, CBCT: Cone-beam computed tomography

The FSRT group received 25 Gy in 5 fractions of 5 Gy each, delivered over one week, while VMAT-based treatments were prescribed to total doses ranging from 50.4 Gy to 54 Gy in 28–30 daily fractions of 1.8 Gy each delivered over six weeks.

Follow-up and outcome assessment

Patients underwent clinical and radiologic follow-up at three and six months following treatment and subsequently at every six months. Local control was defined as the absence of radiologic progression on serial imaging. Audiometric outcomes were evaluated with PTA at every follow-up visit.

Statistical analysis

All data were compiled and analyzed descriptively. Continuous variables were summarized using mean, standard deviation, median, and interquartile range. Exploratory comparisons between treatment techniques were performed using the Mann– Whitney U test and Fisher’s exact test. Correlation between tumor size and Koos grade was assessed using the Spearman correlation coefficient. Statistical analyses were exploratory and descriptive in nature, given the small sample size and rarity of the disease. The study was not powered for hypothesis testing, and non-parametric methods were used appropriately.

RESULTS

Patient and tumor characteristics

Ten patients were included in the analysis. The median age was 32.0 years (interquartile range [IQR] 22.5–44.0), with a mean age of 34.3 ± 13.8 years (range 18–60). Six patients were male, and four were female. Seven patients had unilateral tumors, while three had bilateral lesions associated with neurofibromatosis type 2.

The median tumor size was 2.5 cm (IQR 2.3–3.5), with a mean of 2.89 ± 0.99 cm. Koos grade II tumors were observed in three patients, grade III in three patients, and grade IV in four patients. Tumor size demonstrated a strong correlation with Koos grade (Spearman rho = 0.94, p = 0.0001).

The most common presenting symptom was hearing loss (90%), followed by headache (60%) and imbalance or vertigo (30%) [Table 1].

Table 1: Baseline patient and tumor characteristics

Case No.	Age (years)	Gender	Presenting symptoms	Duration of symptoms	Baseline PTA	Baseline cranial nerve findings	Tumor laterality	Maximum size (cm)	Koos grade
1	22	M	Headache, ipsilateral hearing loss, facial weakness	11 months	Left mild SNHL	Left VII palsy, VIII dysfunction, ataxia	Left	1.7	II
2	46	M	Headache, ipsilateral hearing loss	51 months	Left SNHL	Left VIII dysfunction	Left	3.5	IV
3	24	M	Headache, right hearing loss, blurred vision	Since childhood ( ↑ 1 month)	Right SNHL, left mild SNHL	Bilateral VIII dysfunction	Bilateral (NF2)	1.7	II
4	30	M	Headache, ipsilateral hearing loss	15 months	Right SNHL	Right VIII dysfunction	Right	2.5	III
5	44	F	Otalgia, tinnitus	28 months	Right severe SNHL	Right VIII dysfunction	Right	4.5 (4.2 recurrent)	III
6	34	M	Headache, ipsilateral hearing loss, imbalance, facial weakness	12 months	Left severe SNHL	Left VII palsy, VIII dysfunction, ataxia	Left	2.5	III
7	18	F	Headache, dizziness, bilateral hearing loss, and imbalance	5 months	Bilateral mild SNHL	Bilateral VIII palsy, cerebellar signs	Bilateral (NF2)	4.0 (right)	IV
8	21	M	Headache, bilateral ear tingling, hearing loss	22 months	Bilateral severe SNHL	Bilateral VIII dysfunction	Bilateral (NF2)	3.3 (R), 3.6 (L)	IV
9	60	F	Left facial pain, ipsilateral hearing loss	1 month (+ recurrent at 2 years)	Left mild SNHL	Left VII palsy, hearing reduction	Left	3.5	IV
10	44	F	Headache, vomiting	3 months	Right SNHL	Right VII palsy, hearing reduction	Right	2.3	III

M: Male, F: Female, PTA: Pure tone audiometry, SNHL: Sensorineural hearing loss; NF2: neurofibromatosis type 2, VII – Facial nerve; VIII – Vestibulocochlear nerve.

Treatment characteristics

Five patients underwent FSRT, and five received VMAT-based radiotherapy [Figure 6a and 6b]. Tumors treated with FSRT were generally smaller (median 2.3 cm) compared with those treated using VMAT (median 3.6 cm), although this difference did not reach statistical significance (Mann– Whitney U test, p = 0.084).

(a) 46-year-old male with left CP angle vestibular schwannoma who presented with left ear hearing reduction and underwent subtotal excision of the lesion. Axial planning CT image demonstrating VMAT plan. PTV is delineated in cyan blue, encompassed by the 95% isodose color wash. OARS, including the brainstem and surrounding normal brain parenchyma, are also contoured and spared, (b) 22-year-old male with left CP angle vestibular schwannoma who presented with headache and left ear hearing loss and underwent subtotal excision of the lesion. Axial planning CT image showing FSRT plan. The GTV is contoured in red, the PTV is shown in cyan blue, and adjacent OARs are delineated. The isodose distribution and beam arrangement demonstrate conformal target coverage while sparing surrounding critical brainstem and inner ear structures. CP: Control point, VMAT: Volumetric modulated arc therapy, MRI: Magnetic resonance imaging, OAR: Organs at risk

All patients completed treatment without interruption. Dosimetrist constraints for the cochlea and brainstem were maintained within acceptable limits for all plans [Table 2 and Figure 7].

Table 2: Radiotherapy treatment details and OAR dosimetry

Case no.	Treatment technique	Total dose/fractionation	Cochlea dose	Brainstem dose
1	FSRT	25 Gy / 5 fractions @ 5 Gy	Dmax 19 Gy (Left)	Dmax 25 Gy
2	FSRT	25 Gy / 5 fractions @ 5 Gy	Dmax 24 Gy (Left)	Dmax 24 Gy
3	FSRT (right side lesion)	25 Gy / 5 fractions @ 5 Gy	Dmax 14 Gy (Right)	Dmax 24 Gy
4	VMAT	54 Gy / 30 fractions @ 1.8 Gy	Dmean 44 Gy (Right)	Dmax 52 Gy
5	VMAT	54 Gy / 30 fractions @ 1.8 Gy	Dmean 39 Gy (Right)	Dmax 53 Gy
6	FSRT	25 Gy / 5 fractions @ 5 Gy	Dmax 24 Gy (Left)	Dmax 24 Gy
7	VMAT (right side lesion)	50.4 Gy / 28 fractions @ 1.8 Gy	Dmean 45 Gy (Right)	Dmax 50 Gy
8	VMAT (bilateral lesions)	54 Gy / 30 fractions @ 1.8 Gy	Dmean 44 Gy (Right), 40 Gy (Left)	Dmax 48 Gy
9	VMAT	54 Gy / 30 fractions @ 1.8 Gy	Dmean 41 Gy (Left)	Dmax 55 Gy (V54 = 2 cc)
10	FSRT	25 Gy / 5 fractions @ 5 Gy	Dmax 17 Gy (Right)	Dmax 25 Gy

LINAC: Linear accelerator, Dmax: Maximum dose, Dmean: Mean dose, Gray: Gy. FSRT: Fractionated stereotactic radiotherapy, VMAT: Volumetric modulated arc therapy

44-year-old woman with right CP angle vestibular schwannoma who presented with headache and vomiting, and underwent subtotal excision of the lesion, being planned for FRST for the residual lesion. Cumulative dose–volume histogram (DVH) demonstrating the PTV (represented in cyan-blue) with adequate high-dose coverage, the right temporal lobe (depicted in purple), the brainstem (yellow), and the left temporal lobe (red), illustrating dose constraints and relative volume exposure to surrounding critical structures. CP: Control point, FRST: Fraction, PTV: Planning target volume

Radiologic outcomes

At a median follow-up of 10.5 months (range 6–18 months), no patient demonstrated radiologic progression. Three patients (30%) showed complete radiologic resolution, while seven (70%) demonstrated stable residual disease [Table 3]. Complete response was observed in three patients treated with FSRT, while no complete responses were seen in the VMAT group; however, these observations are descriptive and not intended for comparative inference.

Table 3: Follow-up, radiologic and audiologic outcomes, and treatment toxicity

Case no.	Follow-up duration (months)	MRI outcome at 6 months	Hearing outcome (at 6 months)
1	6	No residual disease	Persistent ipsilateral SNHL
2	8	No residual disease	Persistent ipsilateral SNHL
3	10	Stable residual disease	Persistent right SNHL
4	15	Stable residual disease	Persistent right SNHL
5	10	Stable residual disease	Persistent right SNHL
6	8	No residual disease	Persistent left SNHL
7	13	Stable residual disease	Hearing preserved bilaterally
8	18	Stable residual disease	Persistent bilateral SNHL
9	11	Stable residual disease	Persistent left SNHL
10	11	Stable residual disease	Persistent right SNHL

SNHL: Sensorineural hearing loss, MRI: Magnetic resonance imaging

Audiologic outcomes

At the last follow-up, hearing preservation was observed in one patient (10%), while nine patients demonstrated persistent sensorineural hearing loss. No patient experienced new contralateral hearing loss following treatment.

Treatment toxicity

Treatment was generally well tolerated. No cases of Grade 3 or 4 toxicity, radiation necrosis, or new cranial nerve deficits were observed.

DISCUSSION

This study describes early institutional experience with radiotherapy in the management of vestibular schwannoma using contemporary conformal radiotherapy techniques. The primary findings of this study include excellent short-term radiologic control across the cohort, acceptable treatment tolerance, and low incidence of high-grade toxicity. These findings represent early outcomes, as long-term tumor control and functional preservation in vestibular schwannoma require extended follow-up.

Radiologic control was achieved in all patients during the observed follow-up period, with either complete response or stable disease documented on serial imaging. These results are consistent with previously published series reporting tumor control rates exceeding 90% following stereotactic radiotherapy.^[1–4] The absence of progression in the present cohort likely reflects both the benign biological behavior of vestibular schwannoma and the precision achievable with modern image-guided radiotherapy techniques. Although a higher proportion of complete radiologic response was observed in patients treated with fractionated stereotactic radiotherapy, this finding should be interpreted cautiously, given the small sample size and the tendency for smaller tumors to be selected for stereotactic treatment.

The strong association observed between tumor size and Koos grade is expected and reflects the anatomical progression of disease. This observation reinforces the clinical importance of early detection and timely intervention before the development of advanced disease or brainstem compression. In the present cohort, larger tumors were more frequently treated using conventionally fractionated VMAT, reflecting a pragmatic clinical approach aimed at maintaining organ-at-risk dose constraints while ensuring adequate target coverage.

Functional outcomes remain an important challenge in vestibular schwannoma management. Hearing preservation in this study was limited (10%), which is lower than that reported in most published series. Similar findings have been reported in the literature, where baseline auditory function and pre-existing nerve damage appear to be major determinants of post-treatment hearing outcomes.^[1,4,6] This is likely attributable to poor baseline auditory function in the majority of patients, with many presenting with moderate-to-severe sensorineural hearing loss, as well as the high proportion of advanced tumors and inclusion of NF2-associated bilateral cases. These factors are known to adversely impact functional outcomes.

Treatment-related toxicity in our cohort was minimal. This safety profile is comparable with other institutional experiences, demonstrating low rates of significant neurotoxicity following stereotactic or conformal radiotherapy.^[3–5] The use of MRI-based target delineation, image guidance, and strict adherence to organ-at-risk constraints likely contributed to the favorable outcomes observed.

This study has several limitations. The retrospective design, small sample size, and relatively short follow-up duration limit assessment of long-term tumor control and delayed toxicity. The limited sample size reflects the low incidence of vestibular schwannoma and challenges in case accrual in a resource-constrained regional setting, and thus, findings should be interpreted as preliminary institutional experience rather than definitive comparative evidence. Nevertheless, the study reflects real-world clinical practice and provides early outcome data from a tertiary care setting where both FSRT and VMAT techniques are routinely employed.

Future studies with larger patient populations, longer follow-up, and standardized assessment of functional outcomes are required to better define predictors of hearing preservation and to refine optimal dose constraints for critical structures. Multi-institutional collaboration may further help establish consensus regarding technique selection and fractionation strategies in vestibular schwannoma management.

CONCLUSION

This institutional experience demonstrates that precision radiotherapy using FSRT and VMAT provides effective short-term tumor control with acceptable toxicity in patients with vestibular schwannoma. While radiologic outcomes were favorable, functional preservation, particularly hearing outcomes, remains variable. These findings represent early outcomes, and longer follow-up is essential to evaluate long-term tumor control and functional preservation. Ongoing follow-up of this cohort is planned.

Author contributions:

SN: Contributed to manuscript review, literature review and supervised the study; AM: Contributed to data acquisition, analysis, manuscript drafting and editing; PM: Conceptualized the study and contributed to treatment planning oversight; RKG: Rontributed to histopathological evaluation and manuscript review. All authors approved the final manuscript.

Ethical approval:

The Institutional Review Board not required as retrospective nature of the study the ethical approval was waived by the institution as per institutional policy.

Declaration of patient consent:

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given consent for their images and other clinical information to be reported in the journal. The patient understand that the patient’s names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Conflicts of interest:

There are no conflicts of interest.

Use of artificial intelligence (AI)-assisted technology for manuscript preparation:

The authors confirm that there was no use of artificial intelligence (AI)-assisted technology for assisting in the writing or editing of the manuscript, and no images were manipulated using AI.

Financial support and sponsorship: Nil.

References

Brun L, Mom T, Guillemin F, Puechmaille M, Khalil T, Biau J. The recent management of vestibular schwannoma radiotherapy: A narrative review of the literature. J Clin Med. 2024;13:1611.
[CrossRef] [PubMed] [Google Scholar]
Tos M, Stangerup SE, Caye-Thomasen P, Tos T, Thomsen J. What is the real incidence of vestibular schwannoma? Arch Otolaryngol Head Neck Surg. 2004;130:216-20.
[CrossRef] [PubMed] [Google Scholar]
Apicella G, Paolini M, Deantonio L, Masini L, Krengli M. Radiotherapy for vestibular schwannoma: Review of recent literature results. Rep Pract Oncol Radiother. 2016;21:399-406.
[CrossRef] [PubMed] [Google Scholar]
Pialat PM, Fieux M, Tringali S, Beldjoudi G, Pommier P, Tanguy R. Vestibular schwannoma: Results of hypofractionated stereotactic radiation therapy. Adv Radiat Oncol. 2021;6:100694.
[CrossRef] [PubMed] [Google Scholar]
Ammirati M, Colasanti R, Lamki T, Tailor AR, Kalnin A, Slone W, et al. A retrospective case series on the usefulness of fractionated stereotactic radiotherapy for benign intracranial tumors. Interdiscip Neurosurg. 2019;16:100447.
[CrossRef] [Google Scholar]
Kano H, Kondziolka D, Khan A, Flickinger JC, Lunsford LD. Predictors of hearing preservation after stereotactic radiosurgery for acoustic neuroma. J Neurosurg. 2015;123:463-70.
[Google Scholar]