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Item does not contain fulltext, A 13-year-old patient was referred to the ENT department because of a ring-shaped radiopaque foreign body in her right nasal cavity demonstrated on an orthopantomogram. Her medical history revealed long-standing right-sided rhinorrhea thought to be caused by an inhalation allergy. In case of unilateral rhinorrhea in a child a nasal foreign body has to be excluded.

Item does not contain fulltext, A 13-year-old patient was referred to the ENT department because of a ring-shaped radiopaque foreign body in her right nasal cavity demonstrated on an orthopantomogram. Her medical history revealed long-standing right-sided rhinorrhea thought to be caused by an inhalation allergy. In case of unilateral rhinorrhea in a child a nasal foreign body has to be excluded.

Item does not contain fulltext, A 13-year-old patient was referred to the ENT department because of a ring-shaped radiopaque foreign body in her right nasal cavity demonstrated on an orthopantomogram. Her medical history revealed long-standing right-sided rhinorrhea thought to be caused by an inhalation allergy. In case of unilateral rhinorrhea in a child a nasal foreign body has to be excluded.

1 april 2011, Item does not contain fulltext, The objectives of the study are to assess adverse events and complications of hyoid suspension (HS) as a treatment of obstructive sleep apnea syndrome (OSAS). The study design was cohort. Thirty-nine patients with OSAS and obstruction at tongue base level, as assessed by sleep endoscopy, underwent HS. Information about adverse events and complications were obtained by reviewing charts and patient-completed questionnaires. The mean follow-up period from surgery to last control visit was 13.1 months (range 2-38). The charts demonstrated mainly adverse events. Minor complications occurred in six patients. No major complications were observed. The mean admission duration was 3.3 days (range 2-5). Twenty-six patients (67%) returned their questionnaires. No association was found between completing questionnaires and the success of the intervention (p = 0.73). The questionnaires were completed on average 25.9 months (range 3.5-51.5) after surgery. VAS scores showed a fast decline in complaints regarding taste, speech, swallowing and pain. No significant long-term differences were found, when comparing the postoperative VAS scores with the preoperative VAS scores. Of the 26 evaluable questionnaires, 20 patients (77%) would recommend HS to an acquaintance if they suffered from sleep apnea syndrome, when only taking side effects into consideration. The intention to give a positive recommendation did not seem to be related to the therapeutic success of the intervention. In conclusion, this study demonstrates that the complication rate of HS is low and that the discomfort is very acceptable.

Item does not contain fulltext, OBJECTIVES/HYPOTHESIS: Gamma knife radiosurgery (GKRS) has become an important treatment modality for vestibular schwannomas. The primary aim of this study was to investigate whether tumor growth at the moment of GKRS has any correlation with the outcome. The secondary aim was to identify clinical predictors of radioresistance in vestibular schwannoma patients treated with GKRS. STUDY DESIGN: One hundred vestibular schwannoma patients, treated with GKRS, were divided into two groups: 1) proven tumor growth preceding GKRS; and 2) previous history of growth unknown. GKRS outcome was defined in two ways. According to the first definition, GKRS was said to have failed when additional treatment had taken place. According to the second one, a volume decrease >20% after 2 years marked successful treatment. METHODS: Correlations between outcome and growth status were determined with SPSS software. Furthermore, the study assessed how different variables (patient data, history, tumor characteristics, imaging, and audiovestibular examinations) correlated with the outcome of GKRS. RESULTS: No significant difference regarding success and failure of GKRS was found between the two patient groups. The mean reduction in tumor volume after GKRS was less pronounced in patients in whom tumor growth was demonstrated before treatment, but this finding was not significant. No significant predictors (P < .05) could be identified in this data set. CONCLUSIONS: This study found no indication that growth at the moment of GKRS influences therapeutic outcome, nor did it identify any predictors of the outcome after GKRS in vestibular schwannoma patients.

Radboud Universiteit Nijmegen, 30 november 2011, Promotor : Graamans, K. Co-promotor : Mulder, J.J.S., Contains fulltext : 91391.pdf (publisher's version ) (Open Access)

Item does not contain fulltext, OBJECTIVES: Endolymphatic sac tumors (ELSTs) are rare adenomatous tumors arising in the petrous bone, either spontaneously (isolated) or in association with von Hippel-Lindau (VHL) disease. For 9 patients, this study describes the typical features and management of ELST and the clinical outcome of treatment. Similarities and differences are identified for ELST in isolation and in association with VHL disease. STUDY DESIGN: Case series. SETTING: Tertiary referral center. PATIENTS: The patient database was searched for patients diagnosed with ELST. All other tertiary referral centers in The Netherlands were invited to do likewise. INTERVENTIONS: The patient records were screened for presenting symptoms, hearing, imaging, treatment, and treatment outcome. Histopathologic finding was reviewed by a senior pathologist. RESULTS: Six patients with an isolated ELST and 3 patients with an ELST in association with VHL disease were identified. In the isolated ELST group, 5 patients were treated surgically and 1 patient was administered primary radiotherapy. In the VHL group, 1 patient underwent surgery and 2 patients were treated conservatively after a wait-and-magnetic resonance imaging-scan protocol. All individual treatment outcomes are scrupulously presented in this article. CONCLUSION: This study compiles and describes 9 cases of ELST. In 8 of 9 patients, the ELST could be controlled by surgery, radiotherapy, or a wait-and-scan protocol. The large interpatient differences make it difficult to standardize the management of this disease. The management is strongly influenced by comorbidity and tumor stage.

Item does not contain fulltext

Item does not contain fulltext, OBJECTIVES: Endolymphatic sac tumors (ELSTs) are rare adenomatous tumors arising in the petrous bone, either spontaneously (isolated) or in association with von Hippel-Lindau (VHL) disease. For 9 patients, this study describes the typical features and management of ELST and the clinical outcome of treatment. Similarities and differences are identified for ELST in isolation and in association with VHL disease. STUDY DESIGN: Case series. SETTING: Tertiary referral center. PATIENTS: The patient database was searched for patients diagnosed with ELST. All other tertiary referral centers in The Netherlands were invited to do likewise. INTERVENTIONS: The patient records were screened for presenting symptoms, hearing, imaging, treatment, and treatment outcome. Histopathologic finding was reviewed by a senior pathologist. RESULTS: Six patients with an isolated ELST and 3 patients with an ELST in association with VHL disease were identified. In the isolated ELST group, 5 patients were treated surgically and 1 patient was administered primary radiotherapy. In the VHL group, 1 patient underwent surgery and 2 patients were treated conservatively after a wait-and-magnetic resonance imaging-scan protocol. All individual treatment outcomes are scrupulously presented in this article. CONCLUSION: This study compiles and describes 9 cases of ELST. In 8 of 9 patients, the ELST could be controlled by surgery, radiotherapy, or a wait-and-scan protocol. The large interpatient differences make it difficult to standardize the management of this disease. The management is strongly influenced by comorbidity and tumor stage.

Item does not contain fulltext, OBJECTIVES/HYPOTHESIS: A prospective long-term follow-up study was conducted to evaluate the results of gamma knife radiosurgery (GKRS) for vestibular schwannoma (VS) patients. Both axial and volumetric measurements are used to determine tumor size during follow-up. STUDY DESIGN: Individual prospective cohort study. METHODS: A total of 110 VS patients were referred for radiosurgery between 2002 and 2007. All patients were treated with a Leksell 4C gamma knife. There were 12.5 to 13 Gy prescribed to the isodose covering 90% of the tumor volume. The resulting marginal dose was on average 11.0 Gy (range, 9.3-12.5 Gy). Tumor size and tumor volume were determined before and after gamma knife treatment at regular intervals. The minimal follow-up period was 2 years. RESULTS: There were 100 patients included in the study. Eight patients needed additional treatment after a mean follow-up period of 38 months. One patient experienced a temporary facial nerve deficit. No growth pattern could be recognized for tumor growth after GKRS. Based on the measurements of the largest extrameatal diameter, the tumor size would have decreased or remained stable in 94%. Based on volumetric measurement, the tumor size was decreased or remained stable in 79%. CONCLUSIONS: High tumor control and low complication rates make GKRS a good therapy for VS. If tumor growth occurs after GKRS, a conservative management can be considered because continued tumor growth is uncertain. The extrameatal diameter on axial magnetic resonance imaging seems to be a reliable parameter of the size of a VS. Volumetry is the preferred method to assess the dimensions of a VS, although the consequences of strong volumetric increase, especially in small tumors, can be different depending on individual differences in tumor size.

01 april 2011, Item does not contain fulltext, The objectives of the study are to assess adverse events and complications of hyoid suspension (HS) as a treatment of obstructive sleep apnea syndrome (OSAS). The study design was cohort. Thirty-nine patients with OSAS and obstruction at tongue base level, as assessed by sleep endoscopy, underwent HS. Information about adverse events and complications were obtained by reviewing charts and patient-completed questionnaires. The mean follow-up period from surgery to last control visit was 13.1 months (range 2-38). The charts demonstrated mainly adverse events. Minor complications occurred in six patients. No major complications were observed. The mean admission duration was 3.3 days (range 2-5). Twenty-six patients (67%) returned their questionnaires. No association was found between completing questionnaires and the success of the intervention (p = 0.73). The questionnaires were completed on average 25.9 months (range 3.5-51.5) after surgery. VAS scores showed a fast decline in complaints regarding taste, speech, swallowing and pain. No significant long-term differences were found, when comparing the postoperative VAS scores with the preoperative VAS scores. Of the 26 evaluable questionnaires, 20 patients (77%) would recommend HS to an acquaintance if they suffered from sleep apnea syndrome, when only taking side effects into consideration. The intention to give a positive recommendation did not seem to be related to the therapeutic success of the intervention. In conclusion, this study demonstrates that the complication rate of HS is low and that the discomfort is very acceptable.

Item does not contain fulltext, OBJECTIVES/HYPOTHESIS: Gamma knife radiosurgery (GKRS) has become an important treatment modality for vestibular schwannomas. The primary aim of this study was to investigate whether tumor growth at the moment of GKRS has any correlation with the outcome. The secondary aim was to identify clinical predictors of radioresistance in vestibular schwannoma patients treated with GKRS. STUDY DESIGN: One hundred vestibular schwannoma patients, treated with GKRS, were divided into two groups: 1) proven tumor growth preceding GKRS; and 2) previous history of growth unknown. GKRS outcome was defined in two ways. According to the first definition, GKRS was said to have failed when additional treatment had taken place. According to the second one, a volume decrease >20% after 2 years marked successful treatment. METHODS: Correlations between outcome and growth status were determined with SPSS software. Furthermore, the study assessed how different variables (patient data, history, tumor characteristics, imaging, and audiovestibular examinations) correlated with the outcome of GKRS. RESULTS: No significant difference regarding success and failure of GKRS was found between the two patient groups. The mean reduction in tumor volume after GKRS was less pronounced in patients in whom tumor growth was demonstrated before treatment, but this finding was not significant. No significant predictors (P < .05) could be identified in this data set. CONCLUSIONS: This study found no indication that growth at the moment of GKRS influences therapeutic outcome, nor did it identify any predictors of the outcome after GKRS in vestibular schwannoma patients.

Radboud Universiteit Nijmegen, 30 november 2011, Promotor : Graamans, K. Co-promotor : Mulder, J.J.S., Contains fulltext : 91391.pdf (publisher's version ) (Open Access)

Item does not contain fulltext, OBJECTIVES: Endolymphatic sac tumors (ELSTs) are rare adenomatous tumors arising in the petrous bone, either spontaneously (isolated) or in association with von Hippel-Lindau (VHL) disease. For 9 patients, this study describes the typical features and management of ELST and the clinical outcome of treatment. Similarities and differences are identified for ELST in isolation and in association with VHL disease. STUDY DESIGN: Case series. SETTING: Tertiary referral center. PATIENTS: The patient database was searched for patients diagnosed with ELST. All other tertiary referral centers in The Netherlands were invited to do likewise. INTERVENTIONS: The patient records were screened for presenting symptoms, hearing, imaging, treatment, and treatment outcome. Histopathologic finding was reviewed by a senior pathologist. RESULTS: Six patients with an isolated ELST and 3 patients with an ELST in association with VHL disease were identified. In the isolated ELST group, 5 patients were treated surgically and 1 patient was administered primary radiotherapy. In the VHL group, 1 patient underwent surgery and 2 patients were treated conservatively after a wait-and-magnetic resonance imaging-scan protocol. All individual treatment outcomes are scrupulously presented in this article. CONCLUSION: This study compiles and describes 9 cases of ELST. In 8 of 9 patients, the ELST could be controlled by surgery, radiotherapy, or a wait-and-scan protocol. The large interpatient differences make it difficult to standardize the management of this disease. The management is strongly influenced by comorbidity and tumor stage.

Item does not contain fulltext

Item does not contain fulltext, OBJECTIVES/HYPOTHESIS: A prospective long-term follow-up study was conducted to evaluate the results of gamma knife radiosurgery (GKRS) for vestibular schwannoma (VS) patients. Both axial and volumetric measurements are used to determine tumor size during follow-up. STUDY DESIGN: Individual prospective cohort study. METHODS: A total of 110 VS patients were referred for radiosurgery between 2002 and 2007. All patients were treated with a Leksell 4C gamma knife. There were 12.5 to 13 Gy prescribed to the isodose covering 90% of the tumor volume. The resulting marginal dose was on average 11.0 Gy (range, 9.3-12.5 Gy). Tumor size and tumor volume were determined before and after gamma knife treatment at regular intervals. The minimal follow-up period was 2 years. RESULTS: There were 100 patients included in the study. Eight patients needed additional treatment after a mean follow-up period of 38 months. One patient experienced a temporary facial nerve deficit. No growth pattern could be recognized for tumor growth after GKRS. Based on the measurements of the largest extrameatal diameter, the tumor size would have decreased or remained stable in 94%. Based on volumetric measurement, the tumor size was decreased or remained stable in 79%. CONCLUSIONS: High tumor control and low complication rates make GKRS a good therapy for VS. If tumor growth occurs after GKRS, a conservative management can be considered because continued tumor growth is uncertain. The extrameatal diameter on axial magnetic resonance imaging seems to be a reliable parameter of the size of a VS. Volumetry is the preferred method to assess the dimensions of a VS, although the consequences of strong volumetric increase, especially in small tumors, can be different depending on individual differences in tumor size.

Item does not contain fulltext

Item does not contain fulltext, OBJECTIVES/HYPOTHESIS: A prospective long-term follow-up study was conducted to evaluate the results of gamma knife radiosurgery (GKRS) for vestibular schwannoma (VS) patients. Both axial and volumetric measurements are used to determine tumor size during follow-up. STUDY DESIGN: Individual prospective cohort study. METHODS: A total of 110 VS patients were referred for radiosurgery between 2002 and 2007. All patients were treated with a Leksell 4C gamma knife. There were 12.5 to 13 Gy prescribed to the isodose covering 90% of the tumor volume. The resulting marginal dose was on average 11.0 Gy (range, 9.3-12.5 Gy). Tumor size and tumor volume were determined before and after gamma knife treatment at regular intervals. The minimal follow-up period was 2 years. RESULTS: There were 100 patients included in the study. Eight patients needed additional treatment after a mean follow-up period of 38 months. One patient experienced a temporary facial nerve deficit. No growth pattern could be recognized for tumor growth after GKRS. Based on the measurements of the largest extrameatal diameter, the tumor size would have decreased or remained stable in 94%. Based on volumetric measurement, the tumor size was decreased or remained stable in 79%. CONCLUSIONS: High tumor control and low complication rates make GKRS a good therapy for VS. If tumor growth occurs after GKRS, a conservative management can be considered because continued tumor growth is uncertain. The extrameatal diameter on axial magnetic resonance imaging seems to be a reliable parameter of the size of a VS. Volumetry is the preferred method to assess the dimensions of a VS, although the consequences of strong volumetric increase, especially in small tumors, can be different depending on individual differences in tumor size.

Item does not contain fulltext, OBJECTIVES: Endolymphatic sac tumors (ELSTs) are rare adenomatous tumors arising in the petrous bone, either spontaneously (isolated) or in association with von Hippel-Lindau (VHL) disease. For 9 patients, this study describes the typical features and management of ELST and the clinical outcome of treatment. Similarities and differences are identified for ELST in isolation and in association with VHL disease. STUDY DESIGN: Case series. SETTING: Tertiary referral center. PATIENTS: The patient database was searched for patients diagnosed with ELST. All other tertiary referral centers in The Netherlands were invited to do likewise. INTERVENTIONS: The patient records were screened for presenting symptoms, hearing, imaging, treatment, and treatment outcome. Histopathologic finding was reviewed by a senior pathologist. RESULTS: Six patients with an isolated ELST and 3 patients with an ELST in association with VHL disease were identified. In the isolated ELST group, 5 patients were treated surgically and 1 patient was administered primary radiotherapy. In the VHL group, 1 patient underwent surgery and 2 patients were treated conservatively after a wait-and-magnetic resonance imaging-scan protocol. All individual treatment outcomes are scrupulously presented in this article. CONCLUSION: This study compiles and describes 9 cases of ELST. In 8 of 9 patients, the ELST could be controlled by surgery, radiotherapy, or a wait-and-scan protocol. The large interpatient differences make it difficult to standardize the management of this disease. The management is strongly influenced by comorbidity and tumor stage.

Item does not contain fulltext, OBJECTIVES/HYPOTHESIS: Gamma knife radiosurgery (GKRS) has become an important treatment modality for vestibular schwannomas. The primary aim of this study was to investigate whether tumor growth at the moment of GKRS has any correlation with the outcome. The secondary aim was to identify clinical predictors of radioresistance in vestibular schwannoma patients treated with GKRS. STUDY DESIGN: One hundred vestibular schwannoma patients, treated with GKRS, were divided into two groups: 1) proven tumor growth preceding GKRS; and 2) previous history of growth unknown. GKRS outcome was defined in two ways. According to the first definition, GKRS was said to have failed when additional treatment had taken place. According to the second one, a volume decrease >20% after 2 years marked successful treatment. METHODS: Correlations between outcome and growth status were determined with SPSS software. Furthermore, the study assessed how different variables (patient data, history, tumor characteristics, imaging, and audiovestibular examinations) correlated with the outcome of GKRS. RESULTS: No significant difference regarding success and failure of GKRS was found between the two patient groups. The mean reduction in tumor volume after GKRS was less pronounced in patients in whom tumor growth was demonstrated before treatment, but this finding was not significant. No significant predictors (P < .05) could be identified in this data set. CONCLUSIONS: This study found no indication that growth at the moment of GKRS influences therapeutic outcome, nor did it identify any predictors of the outcome after GKRS in vestibular schwannoma patients.

1 juni 2010, Contains fulltext : 89525timmer.pdf (publisher's version ) (Closed access), This study evaluates the impact of gamma knife radiosurgery (GKRS) on the quality of life (QOL) of patients with a sporadic vestibular schwannoma (VS). This study pertains to 108 VS patients who had GKRS in the years 2003 through 2007. Two different QOL questionnaires were used: medical outcome study short form 36 (SF36) and Glasgow benefit inventory (GBI). Radiosurgery was performed using a Leksell 4C gamma knife. The results of the QOL questionnaires in relation to prospectively and retrospectively gathered data of the VS patients treated by GKRS. Eventually, 97 patients could be included in the study. Their mean tumor size was 17 mm (range 6-39 mm); the mean maximum dose on the tumor was 19.9 Gy (range 16-25.5 Gy) and the mean marginal dose on the tumor was 11.1 (range 9.3-12.5 Gy). SF36 scores showed results comparable to those for a normal Dutch population. GBI showed a marginal decline in QOL. No correlation was found between QOL and gender, age, tumor size, or radiation dose. Increased audiovestibular symptoms after GKRS were correlated with a decreased GBI score, and decreased symptoms were correlated with a higher QOL post-GKRS. In this study shows that GKRS for VS has little impact on the general QOL of the VS patient. However, there is a wide range in individual QOL results. Individual QOL was influenced by the audiovestibular symptoms. No predictive patient, tumor, or treatment factors for QOL outcome after GKRS could be determined. Comparison with microsurgery is difficult because of intra group variability.

01 juni 2010, Contains fulltext : 89525timmer.pdf (publisher's version ) (Closed access), This study evaluates the impact of gamma knife radiosurgery (GKRS) on the quality of life (QOL) of patients with a sporadic vestibular schwannoma (VS). This study pertains to 108 VS patients who had GKRS in the years 2003 through 2007. Two different QOL questionnaires were used: medical outcome study short form 36 (SF36) and Glasgow benefit inventory (GBI). Radiosurgery was performed using a Leksell 4C gamma knife. The results of the QOL questionnaires in relation to prospectively and retrospectively gathered data of the VS patients treated by GKRS. Eventually, 97 patients could be included in the study. Their mean tumor size was 17 mm (range 6-39 mm); the mean maximum dose on the tumor was 19.9 Gy (range 16-25.5 Gy) and the mean marginal dose on the tumor was 11.1 (range 9.3-12.5 Gy). SF36 scores showed results comparable to those for a normal Dutch population. GBI showed a marginal decline in QOL. No correlation was found between QOL and gender, age, tumor size, or radiation dose. Increased audiovestibular symptoms after GKRS were correlated with a decreased GBI score, and decreased symptoms were correlated with a higher QOL post-GKRS. In this study shows that GKRS for VS has little impact on the general QOL of the VS patient. However, there is a wide range in individual QOL results. Individual QOL was influenced by the audiovestibular symptoms. No predictive patient, tumor, or treatment factors for QOL outcome after GKRS could be determined. Comparison with microsurgery is difficult because of intra group variability.

01 juni 2010, Contains fulltext : 89525timmer.pdf (Publisher’s version ) (Closed access), This study evaluates the impact of gamma knife radiosurgery (GKRS) on the quality of life (QOL) of patients with a sporadic vestibular schwannoma (VS). This study pertains to 108 VS patients who had GKRS in the years 2003 through 2007. Two different QOL questionnaires were used: medical outcome study short form 36 (SF36) and Glasgow benefit inventory (GBI). Radiosurgery was performed using a Leksell 4C gamma knife. The results of the QOL questionnaires in relation to prospectively and retrospectively gathered data of the VS patients treated by GKRS. Eventually, 97 patients could be included in the study. Their mean tumor size was 17 mm (range 6-39 mm); the mean maximum dose on the tumor was 19.9 Gy (range 16-25.5 Gy) and the mean marginal dose on the tumor was 11.1 (range 9.3-12.5 Gy). SF36 scores showed results comparable to those for a normal Dutch population. GBI showed a marginal decline in QOL. No correlation was found between QOL and gender, age, tumor size, or radiation dose. Increased audiovestibular symptoms after GKRS were correlated with a decreased GBI score, and decreased symptoms were correlated with a higher QOL post-GKRS. In this study shows that GKRS for VS has little impact on the general QOL of the VS patient. However, there is a wide range in individual QOL results. Individual QOL was influenced by the audiovestibular symptoms. No predictive patient, tumor, or treatment factors for QOL outcome after GKRS could be determined. Comparison with microsurgery is difficult because of intra group variability.

Item does not contain fulltext

Contains fulltext : 81894timmer.pdf (publisher's version ) (Closed access), Management of a sporadic vestibular schwannoma (VS) is still a subject of controversy, mainly due to distinct and unpredictable growth patterns. To embark on an appropriate therapy it is necessary to dispose of a reliable prediction about tumor progression. This study aims to design a risk profile with predictors for VS growth. A total of 234 VS patients who were managed conservatively were included. Data concerning (duration of) symptoms and localization of VS were analyzed with Cox proportional hazards regression models. Predictors for growth are unsteadiness/vertigo, no sudden onset of hearing loss and short duration of hearing loss. High-risk patients have (1) VS with an extrameatal localization, short duration of hearing loss and at least one of the two other predictors (unsteadiness/vertigo or no sudden sensorineural hearing loss) or (2) VS with an intrameatal localization and all three other predictors. Low-risk patients have (1) VS with an extrameatal component and no other predictor or (2) VS with an intrameatal localization and at most one other predictor. High-risk patients have a risk of growth of 36.9% in the first year and 64.6% in the second year. For patients with a low risk this is 2.5 and 12.7%, respectively. Simple data gathered at the moment of diagnosis may provide useful information since they may lead to a risk profile for growth.

Contains fulltext : 80665timmer.pdf (publisher's version ) (Closed access), OBJECTIVES/HYPOTHESIS: This study was designed to evaluate hearing preservation after gamma knife radiosurgery (GKRS) and to determine the relation between hearing preservation and cochlear radiation dose in patients with a sporadic vestibular schwannoma (VS). METHODS: Prospective study involving patients suffering from VS who received GKRS from June 2003 until November 2007. Pure tone and speech audiometry were conducted before and after GKRS. The thresholds at pure tone audiometry were taken as a measure of hearing. Pure tone average (PTA) was defined as the mean threshold at 0.5 kHz, 1.0 kHz, 2.0 kHz, and 4.0 kHz. Hearing was classified according to the 2003 consensus meeting in Tokyo. Stereotactic surgery was performed using a Leksell 4C Gamma Knife (Elekta, Stockholm, Sweden). RESULTS: A total of 69 patients were included in the study. Mean tumor size was 17 mm. Mean marginal dose at the tumor was 11.0 Gy (range, 9.3 Gy-12.3 Gy), mean maximal dose was 19.7 Gy (range, 16 Gy-25.5 Gy). Mean maximal dose at the cochlea was 10.27 Gy (range, 3.1 Gy-16.1 Gy), and mean minimal dose at the cochlea was 2.6 Gy (range, 0.9 Gy-7.4 Gy). Mean PTA before GKRS was 43 dB (standard deviation [SD] 20 dB), mean PTA after GKRS was 63 dB (SD 30 dB). Mean interval between pre-GKRS audiometry and GKRS was 8.0 months. Between GKRS and post-GKRS audiometry, mean interval was 14.2 months. Hearing was considered to be preserved (max +1 class, Tokyo classification) in 52 (75%) of 69 patients. However, only 32 patients had class A, B, or C (serviceable hearing) before GKRS. Within this group, only 13 patients (41%) had a hearing class A, B, or C after GKRS. A significant relation was found between the maximal cochlear dose and the difference in PTA before and after GKRS. CONCLUSIONS: Hearing preservation is correlated to the maximal radiation dose at the cochlea. The purpose of developing GKRS techniques was to avoid collateral damage in healthy tissues. This study emphasizes the need for ex

Item does not contain fulltext

Contains fulltext : 81894timmer.pdf (publisher's version ) (Closed access), Management of a sporadic vestibular schwannoma (VS) is still a subject of controversy, mainly due to distinct and unpredictable growth patterns. To embark on an appropriate therapy it is necessary to dispose of a reliable prediction about tumor progression. This study aims to design a risk profile with predictors for VS growth. A total of 234 VS patients who were managed conservatively were included. Data concerning (duration of) symptoms and localization of VS were analyzed with Cox proportional hazards regression models. Predictors for growth are unsteadiness/vertigo, no sudden onset of hearing loss and short duration of hearing loss. High-risk patients have (1) VS with an extrameatal localization, short duration of hearing loss and at least one of the two other predictors (unsteadiness/vertigo or no sudden sensorineural hearing loss) or (2) VS with an intrameatal localization and all three other predictors. Low-risk patients have (1) VS with an extrameatal component and no other predictor or (2) VS with an intrameatal localization and at most one other predictor. High-risk patients have a risk of growth of 36.9% in the first year and 64.6% in the second year. For patients with a low risk this is 2.5 and 12.7%, respectively. Simple data gathered at the moment of diagnosis may provide useful information since they may lead to a risk profile for growth.

Contains fulltext : 80665timmer.pdf (publisher's version ) (Closed access), OBJECTIVES/HYPOTHESIS: This study was designed to evaluate hearing preservation after gamma knife radiosurgery (GKRS) and to determine the relation between hearing preservation and cochlear radiation dose in patients with a sporadic vestibular schwannoma (VS). METHODS: Prospective study involving patients suffering from VS who received GKRS from June 2003 until November 2007. Pure tone and speech audiometry were conducted before and after GKRS. The thresholds at pure tone audiometry were taken as a measure of hearing. Pure tone average (PTA) was defined as the mean threshold at 0.5 kHz, 1.0 kHz, 2.0 kHz, and 4.0 kHz. Hearing was classified according to the 2003 consensus meeting in Tokyo. Stereotactic surgery was performed using a Leksell 4C Gamma Knife (Elekta, Stockholm, Sweden). RESULTS: A total of 69 patients were included in the study. Mean tumor size was 17 mm. Mean marginal dose at the tumor was 11.0 Gy (range, 9.3 Gy-12.3 Gy), mean maximal dose was 19.7 Gy (range, 16 Gy-25.5 Gy). Mean maximal dose at the cochlea was 10.27 Gy (range, 3.1 Gy-16.1 Gy), and mean minimal dose at the cochlea was 2.6 Gy (range, 0.9 Gy-7.4 Gy). Mean PTA before GKRS was 43 dB (standard deviation [SD] 20 dB), mean PTA after GKRS was 63 dB (SD 30 dB). Mean interval between pre-GKRS audiometry and GKRS was 8.0 months. Between GKRS and post-GKRS audiometry, mean interval was 14.2 months. Hearing was considered to be preserved (max +1 class, Tokyo classification) in 52 (75%) of 69 patients. However, only 32 patients had class A, B, or C (serviceable hearing) before GKRS. Within this group, only 13 patients (41%) had a hearing class A, B, or C after GKRS. A significant relation was found between the maximal cochlear dose and the difference in PTA before and after GKRS. CONCLUSIONS: Hearing preservation is correlated to the maximal radiation dose at the cochlea. The purpose of developing GKRS techniques was to avoid collateral damage in healthy tissues. This study emphasizes the need for ex

Contains fulltext : 81894timmer.pdf (publisher's version ) (Closed access), Management of a sporadic vestibular schwannoma (VS) is still a subject of controversy, mainly due to distinct and unpredictable growth patterns. To embark on an appropriate therapy it is necessary to dispose of a reliable prediction about tumor progression. This study aims to design a risk profile with predictors for VS growth. A total of 234 VS patients who were managed conservatively were included. Data concerning (duration of) symptoms and localization of VS were analyzed with Cox proportional hazards regression models. Predictors for growth are unsteadiness/vertigo, no sudden onset of hearing loss and short duration of hearing loss. High-risk patients have (1) VS with an extrameatal localization, short duration of hearing loss and at least one of the two other predictors (unsteadiness/vertigo or no sudden sensorineural hearing loss) or (2) VS with an intrameatal localization and all three other predictors. Low-risk patients have (1) VS with an extrameatal component and no other predictor or (2) VS with an intrameatal localization and at most one other predictor. High-risk patients have a risk of growth of 36.9% in the first year and 64.6% in the second year. For patients with a low risk this is 2.5 and 12.7%, respectively. Simple data gathered at the moment of diagnosis may provide useful information since they may lead to a risk profile for growth.

Contains fulltext : 80665timmer.pdf (Publisher’s version ) (Closed access), OBJECTIVES/HYPOTHESIS: This study was designed to evaluate hearing preservation after gamma knife radiosurgery (GKRS) and to determine the relation between hearing preservation and cochlear radiation dose in patients with a sporadic vestibular schwannoma (VS). METHODS: Prospective study involving patients suffering from VS who received GKRS from June 2003 until November 2007. Pure tone and speech audiometry were conducted before and after GKRS. The thresholds at pure tone audiometry were taken as a measure of hearing. Pure tone average (PTA) was defined as the mean threshold at 0.5 kHz, 1.0 kHz, 2.0 kHz, and 4.0 kHz. Hearing was classified according to the 2003 consensus meeting in Tokyo. Stereotactic surgery was performed using a Leksell 4C Gamma Knife (Elekta, Stockholm, Sweden). RESULTS: A total of 69 patients were included in the study. Mean tumor size was 17 mm. Mean marginal dose at the tumor was 11.0 Gy (range, 9.3 Gy-12.3 Gy), mean maximal dose was 19.7 Gy (range, 16 Gy-25.5 Gy). Mean maximal dose at the cochlea was 10.27 Gy (range, 3.1 Gy-16.1 Gy), and mean minimal dose at the cochlea was 2.6 Gy (range, 0.9 Gy-7.4 Gy). Mean PTA before GKRS was 43 dB (standard deviation [SD] 20 dB), mean PTA after GKRS was 63 dB (SD 30 dB). Mean interval between pre-GKRS audiometry and GKRS was 8.0 months. Between GKRS and post-GKRS audiometry, mean interval was 14.2 months. Hearing was considered to be preserved (max +1 class, Tokyo classification) in 52 (75%) of 69 patients. However, only 32 patients had class A, B, or C (serviceable hearing) before GKRS. Within this group, only 13 patients (41%) had a hearing class A, B, or C after GKRS. A significant relation was found between the maximal cochlear dose and the difference in PTA before and after GKRS. CONCLUSIONS: Hearing preservation is correlated to the maximal radiation dose at the cochlea. The purpose of developing GKRS techniques was to avoid collateral damage in healthy tissues. This study emphasizes the need for ex

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Contains fulltext : 68925.pdf ( ) (Open Access)

Contains fulltext : 68925.pdf ( ) (Open Access)

Contains fulltext : 68925.pdf ( ) (Open Access)

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