My name is Akiyoshi Ogino. I am a Japanese neurosurgeon and research fellow at UPMS. Today's title is Useful Hearing Preservation is Improved in Base-Brush 1 Patients who Undergo Stereotactic Radiotherapy for their Hearing Deterioration Ensurance. The purpose of this study is to evaluate whether hearing deterioration during observation before radiotherapy, reduce serviceable hearing preservation rate after radiotherapy, in base-brush 1 patients with normal hearing. In 1,447 base-brush 1 patients, we identified 100 patients who had gotten a 101 hearing at initial diagnosis but were observed without surgery or radiosurgery. This is flow diagram. At first, we excluded the patients of Neurofibromatosis 2 and who had prior surgery and prior radiosurgery. We identified 275 patients who had observed after diagnosis. Next, we excluded the patients who had Gardner-Watson grade 2 to 5 at diagnosis and who had grade 3 to 5 at radiosurgery. Finally, we identified 100 patients. I divide my talk into two parts. First, we compare the two groups. One group is Hearing Maintenance Group and the other group is Hearing Deterioration Group. The Hearing Maintenance Group was defined as hearing had maintained Gardner-Watson grade 1 from diagnosis to radiosurgery. We set it HM group. And Hearing Deterioration Group was defined as hearing from grade 1 at diagnosis to grade 2 at radiosurgery. We set it HD group. Second, we investigated relationship changing degree in fetal average and speech discrimination score before radiosurgery and hearing preservation after radiosurgery. First, we compared HM group to HD group. This is patient characteristics. Age, sex, genetics, speech discrimination score at diagnosis, target volume, margin dose, maximum dose, interval between diagnosis and radiosurgery were not significantly different in these two groups, but were particular. HD group was higher incidence than HM group. But peertone average at diagnosis, HD group was higher than HM group. And its close classification. The most common class in HM group was class 1, but HD group was class 2. This is a Kaplan-Meier plot demonstrating tumor control rate. Tumor control rate was 95% at 5 years. This is comparing tumor control rate of HM group and HD group. Tumor control rate was no different between the two groups. This is a Kaplan-Meier plot demonstrating serviceable hearing preservation rate. The rate was 53% at 5 years. This table is univariate and multivariate analysis for serviceable hearing status after radiosurgery. In univariate analysis, younger age peertone average at diagnosis and HM group were significantly associated with improved serviceable hearing preservation rate. And in multivariate analysis, younger age and HM group were significantly associated. This is a Kaplan-Meier plot comparing serviceable hearing preservation rate of HM group and HD group. The rate of HM group was 63% at 5 years. But HD group was only 33% at 5 years. This table shows the change of Gardner-Robertson grade at the time of initial diagnosis, radiosurgery, and last follow-up. In the HM group, 42 patients maintained serviceable hearing at the last follow-up. But in the HD group, only 8 patients maintained. During observation after initial diagnosis, if the patients become worse of hearing, maintaining serviceable hearing after radiosurgery becomes very difficult. Next, this is second part from here. We investigated the relationship between hearing change before radiosurgery and serviceable hearing preservation after radiosurgery. This is Kaplan-Meier plot comparing serviceable hearing preservation rate of patient with increased peertone average of 15 dB or more of HM group. Increased peertone average of 15 dB or more and less than 15 dB. Increased peertone average less than 15 dB was significantly associated with higher serviceable hearing preservation rate. Similarly, we compared about speech discrimination score. Decreased speech discrimination score less than 10% was significantly associated with higher serviceable hearing preservation rate. Next, we investigated the relationship between hearing change before radiation surgery and probability of maintaining Gardner-Robertson grade 1 after radiosurgery. This is Kaplan-Meier plot comparing probability of maintaining Gardner-Robertson grade 1 of patient with increased peertone average of 6 dB or greater and less than 6 dB. Increased peertone average less than 6 dB was significantly associated with higher probability of maintaining Gardner-Robertson grade 1. Similarly, we compared about speech discrimination score. Decreased speech discrimination score less than 5% was significantly associated with higher probability of maintaining Gardner-Robertson grade 1. Let me summarize the point of our presentation. First, the serviceable hearing preservation rate of HM group was 63% at 5 years, but HD group was only 33% at 5 years. HM group was significantly associated with improved serviceable hearing preservation rate. Second, increased peertone average less than 15 dB or decreased speech discrimination score less than 10% before radiosurgery elevated serviceable hearing preservation rate after radiosurgery. Third, increased peertone average less than 6 dB or decreased speech discrimination score less than 5% before radiosurgery elevated probability of maintaining Gardner-Robertson grade 1 after radiosurgery. Radiosurgery before hearing deterioration improved serviceable hearing preservation in basebrain schwannoma patient with Gardner-Robertson grade 1 at initial diagnosis. Radiosurgery before hearing deterioration ensures can optimize hearing preservation. Thank you for your attention.

Akiyoshi Ogino

neurosurgeon

study

hearing preservation

radiosurgery