Exploring Tumor Size as a Predictor of Treatment Success/Failure Following Stereotactic Radiosurgery in Vestibular Schwannoma

Exploring Tumor Size as a Predictor of Treatment Success/Failure Following Stereotactic Radiosurgery in Vestibular Schwannoma | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Exploring Tumor Size as a Predictor of Treatment Success/Failure Following Stereotactic Radiosurgery in Vestibular Schwannoma Sophie Shih-Yüng Wang, Georgios Naros, Albertus van Eck, Marcos Tatagiba, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7441380/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Objective: Stereotactic radiosurgery (SRS) achieves high tumour control in vestibular schwannoma (VS), yet treatment failure occurs in a subset of patients. Tumour size is a proposed predictor, but prior studies show conflicting results and are often limited by small cohorts or short follow-up. We evaluated its prognostic value in a large, single-centre cohort with consistent treatment and long-term follow-up. Methods: This is a retrospective cohort study. The patient collective was identified by a prospectively kept registry. Only solitary VSs were included, VSs associated with schwannomatosis were systematically excluded. Patients with radiographic follow-up of less than two years were systematically excluded to rule out the known phenomenon of pseudoprogression. Volumetric measures were carried out in gadolinium enhanced magnetic resonance imaging. KOOS Classification was used additionally to classify tumour size. Clinical data were collected retrospectively. Results: The study cohort included N =928 VS patients treated with SRS between 1998 and 2019, who met the above-mentioned inclusion criteria. Mean follow-up time was 6.37 (±3.96) years. The rate of treatment failure was different in the different KOOS-subgroups with the lowest rate in KOOS I at 4%, 10% in KOOS II, the highest in KOOS III with 13% and 10% in KOOS IV. Mean time toprogression was 4.49 (±2.64) years overall, with the longest mean time to progression in KOOS I at 5.46 (±4.14) years, 4.97 (±2.85) years in KOOS II, 4.52 (±2.70) years in KOOS III, and 4.75 (±4.50) years in KOOS IV. Paddick Conformity Index (PCI) increased with increasing tumour size, but showed a worse predictive performance compared to smaller tumours. Conclusions: There is a correlation of treatment success/failure to tumour volume: The rate of treatment success decreases with increasing tumour size after SRS in VS. Paddick Conformity Index’s performance to predict treatment failure decreased in increasing tumour size. SRS treatment strategy for large VS for should be adapted in order to improve treatment response. vestibular schwannoma acoustic neuroma stereotactic radiosurgery Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7441380","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":509213128,"identity":"e4761a1e-c153-4aad-ac5a-7b897018e4b6","order_by":0,"name":"Sophie Shih-Yüng Wang","email":"data:image/png;base64,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","orcid":"","institution":"Eberhard Karls University","correspondingAuthor":true,"prefix":"","firstName":"Sophie","middleName":"Shih-Yüng","lastName":"Wang","suffix":""},{"id":509213129,"identity":"481a6bbf-e8eb-40f8-85d6-d9cef7729566","order_by":1,"name":"Georgios Naros","email":"","orcid":"","institution":"Eberhard Karls University","correspondingAuthor":false,"prefix":"","firstName":"Georgios","middleName":"","lastName":"Naros","suffix":""},{"id":509213130,"identity":"c291f1a2-9f13-457e-a798-8d6b0b67614e","order_by":2,"name":"Albertus van Eck","email":"","orcid":"","institution":"Gamma Knife Center Krefeld","correspondingAuthor":false,"prefix":"","firstName":"Albertus","middleName":"van","lastName":"Eck","suffix":""},{"id":509213131,"identity":"c50aa4a4-bd32-4883-966c-0b578d5d0e5a","order_by":3,"name":"Marcos Tatagiba","email":"","orcid":"","institution":"Eberhard Karls University","correspondingAuthor":false,"prefix":"","firstName":"Marcos","middleName":"","lastName":"Tatagiba","suffix":""},{"id":509213132,"identity":"17a08b7f-2f01-4764-8161-e1985f84a035","order_by":4,"name":"Gerhard Horstmann","email":"","orcid":"","institution":"Gamma Knife Center Krefeld","correspondingAuthor":false,"prefix":"","firstName":"Gerhard","middleName":"","lastName":"Horstmann","suffix":""}],"badges":[],"createdAt":"2025-08-23 12:53:11","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7441380/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7441380/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":91900371,"identity":"c76a0735-4506-4aa3-a048-d8226b3a07bc","added_by":"auto","created_at":"2025-09-22 20:46:13","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":845592,"visible":true,"origin":"","legend":"","description":"","filename":"EXPLORINGTUMOURSIZEVSWANG.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7441380/v1_covered_8bc37758-5fbd-4b80-a35a-a66714ae7548.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eExploring Tumor Size as a Predictor of Treatment Success/Failure Following Stereotactic Radiosurgery in Vestibular Schwannoma\u003c/p\u003e","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"vestibular schwannoma, acoustic neuroma, stereotactic radiosurgery","lastPublishedDoi":"10.21203/rs.3.rs-7441380/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7441380/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cu\u003eObjective:\u003c/u\u003e\u003c/p\u003e\n\u003cp\u003eStereotactic radiosurgery (SRS) achieves high tumour control in vestibular schwannoma (VS), yet treatment failure occurs in a subset of patients. Tumour size is a proposed predictor, but prior studies show conflicting results and are often limited by small cohorts or short follow-up. We evaluated its prognostic value in a large, single-centre cohort with consistent treatment and long-term follow-up.\u003c/p\u003e\n\u003cp\u003e\u003cu\u003eMethods:\u003c/u\u003e\u003c/p\u003e\n\u003cp\u003eThis is a retrospective cohort study. The patient collective was identified by a prospectively kept registry. Only solitary VSs were included, VSs associated with schwannomatosis were systematically excluded. Patients with radiographic follow-up of less than two years were systematically excluded to rule out the known phenomenon of pseudoprogression. Volumetric measures were carried out in gadolinium enhanced magnetic resonance imaging. KOOS Classification was used additionally to classify tumour size. Clinical data were collected retrospectively.\u003c/p\u003e\n\u003cp\u003e\u003cu\u003eResults:\u003c/u\u003e\u003c/p\u003e\n\u003cp\u003eThe study cohort included \u003cem\u003eN\u003c/em\u003e=928 VS patients treated with SRS between 1998 and 2019, who met the above-mentioned inclusion criteria. Mean follow-up time was 6.37 (±3.96) years. The rate of treatment failure was different in the different KOOS-subgroups with the lowest rate in KOOS I at 4%, 10% in KOOS II, the highest in KOOS III with 13% and 10% in KOOS IV. Mean time toprogression was 4.49 (±2.64) years overall, with the longest mean time to progression in KOOS I at 5.46 (±4.14) years, 4.97 (±2.85) years in KOOS II, 4.52 (±2.70) years in KOOS III, and 4.75 (±4.50) years in KOOS IV. Paddick Conformity Index (PCI) increased with increasing tumour size, but showed a worse predictive performance compared to smaller tumours.\u003c/p\u003e\n\u003cp\u003e\u003cu\u003eConclusions:\u003c/u\u003e\u003c/p\u003e\n\u003cp\u003eThere is a correlation of treatment success/failure to tumour volume: The rate of treatment success decreases with increasing tumour size after SRS in VS. Paddick Conformity Index’s performance to predict treatment failure decreased in increasing tumour size. SRS treatment strategy for large VS for should be adapted in order to improve treatment response.\u003c/p\u003e","manuscriptTitle":"Exploring Tumor Size as a Predictor of Treatment Success/Failure Following Stereotactic Radiosurgery in Vestibular Schwannoma","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-09-04 14:08:02","doi":"10.21203/rs.3.rs-7441380/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"6ff84700-b3dc-42bb-ba3d-1184ef6e2454","owner":[],"postedDate":"September 4th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-09-22T20:38:06+00:00","versionOfRecord":[],"versionCreatedAt":"2025-09-04 14:08:02","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7441380","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7441380","identity":"rs-7441380","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}