Current Volumetric Models Overestimate Vestibular Schwannoma Size Following Stereotactic Radiosurgery.
Otol Neurotol
; 41(2): e262-e267, 2020 02.
Article
en En
| MEDLINE
| ID: mdl-31789797
ABSTRACT
OBJECTIVE:
Accurate volume assessment is essential for the management of vestibular schwannoma after stereotactic radiosurgery (SRS). A cuboidal approximation for volume is the standard surveillance method; however, this may overestimate tumor volume. We sought to evaluate several volumetric models and their suitability for post-SRS surveillance. STUDYDESIGN:
Retrospective cohort study.SETTING:
Tertiary referral center. PATIENTS We evaluated 54 patients with vestibular schwannoma before and after SRS. INTERVENTION(S) Gold-standard volumes were obtained by a radiation oncologist using contouring software. Volume was also calculated by cuboidal, ellipsoidal, and spherical formulae using tumor diameters obtained by a neuroradiologist. MAIN OUTCOME MEASURE(S) Percent error (PE) and absolute percent error (APE) were calculated. Paired t test evaluated bias, and the Bland-Altman method evaluated reproducibility. Linear regression evaluated predictors of model error.RESULTS:
All models overestimated volume compared with the gold standard. The cuboidal model was not reproducible before SRS (pâ<â0.001), and no model was reproducible after SRS (cuboidal pâ<â0.001; ellipsoidal pâ=â0.02; spherical pâ=â0.02). Significant bias was present before SRS for the cuboidal model (pâ<â0.001), and post-SRS for all models [cuboidal (pâ<â0.001), ellipsoidal (pâ<â0.02), and spherical (pâ=â0.005)]. Model error was negatively associated with pretreatment volume for the cuboidal (PE pâ=â0.03; APE pâ=â0.03), ellipsoidal (PE pâ=â0.03; APE pâ=â0.04), and spherical (PE pâ=â0.02; APE pâ=â0.03) methods and lost linearity post-SRS.CONCLUSIONS:
The standard cuboidal practice for following vestibular schwannoma tumor volume after SRS overestimates size. Ellipsoidal and spherical estimations have improved performance but also overestimate volume and lack reliability post-SRS. The development of other volumetric models or application of contouring software should be investigated.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Neuroma Acústico
/
Radiocirugia
Tipo de estudio:
Observational_studies
/
Prognostic_studies
/
Risk_factors_studies
Límite:
Humans
Idioma:
En
Revista:
Otol Neurotol
Asunto de la revista:
NEUROLOGIA
/
OTORRINOLARINGOLOGIA
Año:
2020
Tipo del documento:
Article