TY - JOUR A1 - Breun, Maria A1 - Monoranu, Camelia M. A1 - Kessler, Almuth F. A1 - Matthies, Cordula A1 - Löhr, Mario A1 - Hagemann, Carsten A1 - Schirbel, Andreas A1 - Rowe, Steven P. A1 - Pomper, Martin G. A1 - Buck, Andreas K. A1 - Wester, Hans-Jürgen A1 - Ernestus, Ralf-Ingo A1 - Lapa, Constantin T1 - [\(^{68}\)Ga]-Pentixafor PET/CT for CXCR4-mediated imaging of vestibular schwannomas JF - Frontiers in Oncology N2 - We have recently demonstrated CXCR4 overexpression in vestibular schwannomas (VS). This study investigated the feasibility of CXCR4-directed positron emission tomography/computed tomography (PET/CT) imaging of VS using the radiolabeled chemokine ligand [\(^{68}\)Ga]Pentixafor. Methods: 4 patients with 6 primarily diagnosed or pre-treated/observed VS were enrolled. All subjects underwent [\(^{68}\)Ga]Pentixafor PET/CT prior to surgical resection. Images were analyzed visually and semi-quantitatively for CXCR4 expression including calculation of tumor-to-background ratios (TBR). Immunohistochemistry served as standard of reference in three patients. Results: [\(^{68}\)Ga]Pentixafor PET/CT was visually positive in all cases. SUV\(_{mean}\) and SUV\(_{max}\) were 3.0 ± 0.3 and 3.8 ± 0.4 and TBR\(_{mean}\) and TBR\(_{max}\) were 4.0 ± 1.4 and 5.0 ± 1.7, respectively. Histological analysis confirmed CXCR4 expression in tumors. Conclusion: Non-invasive imaging of CXCR4 expression using [\(^{68}\)Ga]Pentixafor PET/CT of VS is feasible and could prove useful for in vivo assessment of CXCR4 expression. KW - vestibular schwannoma KW - CXCR4 KW - PET/CT KW - molecular imaging KW - Pentixafor Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-201863 VL - 9 IS - 503 ER - TY - JOUR A1 - Gugel, Isabel A1 - Grimm, Florian A1 - Hartjen, Philip A1 - Breun, Maria A1 - Zipfel, Julian A1 - Liebsch, Marina A1 - Löwenheim, Hubert A1 - Ernemann, Ulrike A1 - Kluwe, Lan A1 - Mautner, Victor-Felix A1 - Tatagiba, Marcos A1 - Schuhmann, Martin Ulrich T1 - Risk stratification for immediate postoperative hearing loss by preoperative BAER (brainstem auditory evoked response) and audiometry in NF2-associated vestibular schwannomas JF - Cancers N2 - Both brainstem auditory evoked potentials (BAEP) and audiometry play a crucial role in neuro-oncological treatment decisions in Neurofibromatosis Type 2 associated (NF2) vestibular schwannoma (VS) as hearing preservation is the major goal. In this study, we investigated the risk of immediate postoperative hearing deterioration (>15 dB and/or 15% loss in pure-tone average [PTA]/ speech discrimination score [SDS] in a cohort of 100 operated VS (ears) in 72 NF2 patients by retrospective analysis of pre- and postoperative hearing data (PTA, SDS, American Association of Otolaryngology–Head and Neck Surgery [AAO-HNS], and brainstem auditory evoked potential [BAEP] class) taking into account relevant influencing factors, particularly preoperative audiometry and BAEP status and the extent of resection. Immediately after surgery, the hearing was preserved in 73% of ears and approximately ~60% of ears kept their hearing classes. Preoperative BAEP (p = 0.015) and resection amount (p = 0.048) significantly influenced postoperative hearing outcome. The prediction model for postoperative hearing deterioration/loss between preoperative BAEP and AAO-HNS class showed increased risk by increasing BAEP class. Twenty-one tumors/ears were identified with large BAEP and AAO-HNS class discrepancies (≥2 points) and were associated with a high (48–100%) risk of deafness after surgery in ears with preoperative available hearing. Overall, the results were heterogeneous but the better both BAEP and audiometry class before surgery, the higher the chance of hearing maintenance afterwards. Large resection amounts (e.g., 100% risk in near-total resections) exhibit a significant (p < 0.05) higher risk compared to smaller amounts (e.g., 10/20% in laser-coagulated/partially resected tumors). Our results emphasized the indispensable role of both hearing monitoring in form of audiometry and neurophysiology (BAEP) in the pre-and perioperative monitoring of NF2-associated VS. Both BAEP and audiometry are good prognostic markers for the postoperative hearing outcome. The extent of resection should be strictly guided by and adjusted to the intraoperative neurophysiological monitoring. KW - hearing preservation KW - neurofibromatosis type 2 KW - vestibular schwannoma KW - audiometry KW - brainstem auditory evoked potentials Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-234165 SN - 2072-6694 VL - 13 IS - 6 ER - TY - JOUR A1 - Matthies, Cordula A1 - Brill, Stefan A1 - Kaga, Kimitaka A1 - Morita, Akio A1 - Kumakawa, Kozo A1 - Skarzynski, Henryk A1 - Claassen, Andre A1 - Hui, Yau A1 - Chiong, Charlotte A1 - Müller, Joachim A1 - Behr, Robert T1 - Auditory Brainstem Implantation Improves Speech Recognition in Neurofibromatosis Type II Patients JF - ORL N2 - This prospective study aimed to determine speech understanding in neurofibromatosis type II (NF2) patients following implantation of a MED-EL COMBI 40+ auditory brainstem implant (ABI). Patients (n = 32) were enrolled postsurgically. Nonauditory side effects were evaluated at fitting and audiological performance was determined using the Sound Effects Recognition Test (SERT), Monosyllable-Trochee-Polysyllable (MTP) test and open-set sentence tests. Subjective benefits were determined by questionnaire. ABI activation was documented in 27 patients, 2 patients were too ill for testing and 3 patients were without any auditory perception. SERT and MTP outcomes under auditory-only conditions improved significantly between first fitting and 12-month follow-up. Open-set sentence recognition improved from 5% at first fitting to 37% after 12 months. The number of active electrodes had no significant effect on performance. All questionnaire respondents were ‘satisfied' to ‘very satisfied' with their ABI. An ABI is an effective treatment option in NF2 patients with the potential to provide open-set speech recognition and subjective benefits. To our knowledge, the data presented herein is exceptional in terms of the open-set speech perception achieved in NF2 patients. KW - acoustic neuroma KW - auditory brainstem implant KW - nonauditory side effects KW - open-set sentence recognition KW - subjective benefits KW - vestibular schwannoma Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196383 SN - 0301-1569 SN - 1423-0275 N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. VL - 75 IS - 5 ER - TY - JOUR A1 - Nattmann, Anja A1 - Breun, Maria A1 - Monoranu, Camelia M. A1 - Matthies, Cordula A1 - Ernestus, Ralf-Ingo A1 - Löhr, Mario A1 - Hagemann, Carsten T1 - Analysis of ADAM9 regulation and function in vestibular schwannoma primary cells JF - BMC Research Notes N2 - Objective Recently, we described a disintegrin and metalloproteinase 9 (ADAM9) overexpression by Schwann cells of vestibular schwannoma (VS) and suggested that it might be a marker for VS tumor growth and invasiveness. This research note provides additional data utilizing a small cohort of VS primary cultures and tissue samples. We examined whether reconstitution of Merlin expression in VS cells regulates ADAM9 protein expression and performed lentiviral ADAM9 knock down to investigate possible effects on VS cells numbers. Moreover, the co-localization of ADAM9 and Integrins α6 and α2β1, respectively, was examined by immunofluorescence double staining. Results ADAM9 expression was not regulated by Merlin in VS. However, ADAM9 knock down led to 58% reduction in cell numbers in VS primary cell cultures (p < 0.0001). While ADAM9 and Integrin α2β1 were co-localized in only 22% (2 of 9) of VS, ADAM9 and Integrin α6 were co-localized in 91% (10 of 11) of VS. Therefore, we provide first observations on possible regulatory functions of ADAM9 expression in VS. KW - vestibular schwannoma KW - pathogenesis KW - ADAM9 KW - knock down KW - integrin KW - immunofuorescence double staining KW - Merlin KW - primary cell culture Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-231213 VL - 13 ER -