Should Koos I Vestibular Schwannomas Be Treated Early with Gamma Knife Surgery? A Prospective Series of 42 Consecutive Cases

Détails

ID Serval
serval:BIB_4BE37608285E
Type
Actes de conférence (partie): contribution originale à la littérature scientifique, publiée à l'occasion de conférences scientifiques, dans un ouvrage de compte-rendu (proceedings), ou dans l'édition spéciale d'un journal reconnu (conference proceedings).
Sous-type
Abstract (résumé de présentation): article court qui reprend les éléments essentiels présentés à l'occasion d'une conférence scientifique dans un poster ou lors d'une intervention orale.
Collection
Publications
Institution
Titre
Should Koos I Vestibular Schwannomas Be Treated Early with Gamma Knife Surgery? A Prospective Series of 42 Consecutive Cases
Titre de la conférence
journal of Neurological Surgery Part A: Central European Neurosurgery
Auteur⸱e⸱s
Levivier M., Tuleasca C., Mercy G., Schiappacasse L., Faouzi M., Zeverino M., Maire R.
Organisation
Joint Annual Meeting 2015: Swiss Society of Neurosurgery and Swiss Society of Neuroradiology, Together with IG-NOPPS, Lucerne, Switzerland, 10-11 September 2015
ISBN
2193-6315 (Print)
2193-6323 (Electronic)
Statut éditorial
Publié
Date de publication
2015
Volume
76
Pages
1-2
Langue
anglais
Résumé
Background: Gamma Knife surgery (GKS) for vestibular schwannomas (VS) has a long-term clinical and scientific track record. After a period of de-escalation of dose prescription, results show a high rate of tumor control with improvement of clinical outcome (less than 1% facial palsy, 50-70% hearing preservation). Currently, there is controversial data about the active early treatment of intracanalicular (Koos I) VS. Methods: We prospectively analyzed 208 VS, focusing on 42 Koos I patients treated with GKS as first intention in Lausanne University Hospital, between July 2010 and February 2015. We concentrated on patient, tumor, and dosimetric characteristics. Special attention was given on the dose to the cochlea and its impact in maintaining serviceable hearing. Results: The mean follow-up period was 1.7 years (range 0.6-4.2). Twenty-six (61.9%) were females and 16 (38.1%) males. Preoperative serviceable hearing was present in 33 (78.57%) patients. The mean maximal diameter was 7.7 (5-10). The median target volume at the moment of GKS was 90 mm3 (range 17-317). The median prescription isodose volume was 118 mm3 (range 37-603). The median marginal dose administrated was 12 Gy (range 11-12). The median number of shots was 2 (range 1-9). The median isodose prescription was 50% (range 45-80%). The median maximal dose received by the cochlea in patients in GR class 1 and 2 was 4.2 Gy (mean 4.4 Gy, range 1.8-7.6). Our preliminary results showed 98% tumor control, with 30% shrinkage on MRI. The actuarial probability of keeping the same audition class for those with functional hearing at GKS was 80% at 3 years; the probability of keeping a functional hearing was more than 90%. A paraclinical evolution (on MRI and/or audiometry) at the time diagnosis, before GKS, was associated with a less good prognosis (p < 0.05). Conclusions: Our preliminary data suggest that Koos I patients should be treated early with GKS, before tumor growth, and/or hearing deterioration, as they have the highest probability of hearing preservation. The results in terms of functional outcome seemed comparable to, or even better than, the other Koos classes (i.e., larger lesions).
Création de la notice
20/10/2015 9:43
Dernière modification de la notice
20/08/2019 15:00
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