Neuroendoscopic transventricular transchoroidal approach for access to the posterior zone of the third ventricle or pineal region.

The endoscopic transventricular transchoroidal approach facilitates entry into the posterior part of the third ventricle, allowing a visualization field from the foramen of Monro to the pineal region through this anatomical corridor. Combined surgery to treat the target lesion and possible endoscopic third ventriculostomy (ETV) can be performed through a single burr hole. A detailed description of this surgical technique is given, and a series of cases from our center is presented. This retrospective study included patients with lesions in the pineal region or posterior zone of the third ventricle who underwent surgery between 2004 and 2022 in our center for tumor biopsy or endoscopic cyst fenestration. In nine cases, the transchoroidal approach was performed. Demographic and clinical variables were collected: sex, age at diagnosis, clinical presentation, characteristics of the lesion, pathological diagnosis, characteristics of the procedure, complications, subsequent treatments, evolution, follow-up time, and degree of success of the endoscopic procedure. The mean and range of the quantitative variables and frequency of the qualitative variables were analyzed, together with the statistical significance (p < 0.05). Surgical planning was carried out by performing a preoperative MRI, calculating the ideal entry point and trajectory for each case. The preoperative planning of the surgical technique is described in detail. Of our sample, 55.6% were women, with a mean age of 35 years (7-78). The most common clinical presentation was intracranial hypertension (55.6%), with or without a focus. Eight patients presented hydrocephalus at diagnosis. The most frequent procedure was endoscopic biopsy with ETV (66.7%). The pathological diagnosis varied widely. Procedure-related complications included one case of self-limited bleeding of the choroidal fissure at its opening and one intraventricular hemorrhage due to tumor bleeding in the postoperative period. Non-procedure-related complications comprised two ETV failures and one case of systemic infection, while late complications included one case of disease progression and one case of radionecrosis. Four patients died, one due to poor neurological evolution after post-surgical tumor bleeding and three due to causes unrelated to the procedure. The rest of the patients had a favorable evolution and were asymptomatic or stable. The transchoroidal approach through a single burr hole is a feasible and safe option for access to the posterior part of the third ventricle. Proper planning of each case is necessary to avoid complications.

Re-ventriculostomía endoscópica de tercer ventrículo. Análisis retrospectivo de una serie de 13 casos / Re-Do endoscopic third ventriculostomy. Retrospective analysis of 13 patients

Objetivos: La indicación de ventriculostomía endoscópica de tercer ventrículo (VET) en el tratamiento de la hidrocefalia no comunicante está extensamente aceptada. Existe controversia respecto a la indicación de un segundo procedimiento (re-VET) cuando el primero ha fallado. El objetivo de este trabajo es recoger los fallos de VET en una serie propia en los que se realizó re-VET y describir los factores relacionados con su pronóstico.MétodoEstudio retrospectivo de pacientes pediátricos con fallo de VET tratados mediante una re-VET entre 2003 y 2018. Se registró género, edad en primera y segunda VET, tiempo hasta fallo de primera VET, etiología de hidrocefalia, presencia previa de DVP, ETV-SS en primera y segunda VET, hallazgos intraoperatorios, éxito del segundo procedimiento y seguimiento. El resultado de ETV-SS se agrupó en puntuación alta (≥80), moderada (50-70) o baja (≤40). Se consideró fallo de procedimiento endoscópico el deterioro clínico o la ausencia de criterios radiológicos de mejoría (reducción de tamaño ventricular o presencia de artefacto de flujo de VET en área premamilar).ResultadosDe 97 VET realizadas en este periodo, se registraron 47 fallos, llevándose a cabo 13 re-VET. De ellas, 8 fueron clasificadas como éxito (61,53%). La re-VET fue exitosa en 4/4 casos cuya etiología fue tumoración tectal o estenosis de acueducto. En el grupo de alta puntuación ETV-SS hubo mayor porcentaje de éxito (75%) que en el grupo de moderada puntuación (40%). Nueve pacientes presentaban DVP previa a la primera VET y en ellos, el éxito fue del 66,6% frente al 50% en el grupo sin DVP previa. Todas las re-VET se llevaron a cabo sin complicaciones. En 11 de los 13 procedimientos se encontró una membrana premamilar cerrada y en los 2 casos restantes una apertura puntiforme. El seguimiento medio tras re-VET fue de 61,23 meses.ConclusiónLa re-VET es un procedimiento seguro y con una tasa de éxito del 61,5% en nuestra serie...(AU)

Objetives: Indication for endoscopic third ventriculostomy (ETV) in the treatment for noncommunicating hydrocephalus is widely accepted. There is controversy regarding the indication of a second procedure (re-ETV) when the first has failed. The objective of this work is to revise ETV failures in a series in which re-ETV was performed and to describe the factors related to its prognosis.MethodRetrospective study of pediatric patients with ETV failure treated by re-ETV between 2003 and 2018. Gender, age in first and second ETV, time to failure of first ETV, etiology of hydrocephalus, previous presence of shunt, ETV-SS in the first and second ETV, intraoperative findings, success of the second procedure and follow-up were collected. The ETV-SS result was grouped into high (≥80), moderate (50-70) or low (≤40) scores. Endoscopic procedure failure was considered clinical worsening or the absence of radiological criteria for improvement (reduction in ventricular size or presence of ETV flow artifact in the floor of third ventricle).ResultsOf 97 ETV carried out in this period, 47 failures were registered, with 13 re-ETV performed. Of these, 8 were classified as successful (61.53%). Re-ETV was successful in 4/4 cases in which etiology was tectal tumor or aqueduct stenosis. In the group with a high ETV-SS score there was a higher rate of success (75%) than in the group with a moderate score (40%). 9 patients presented shunt prior to first ETV and in them, success was 66.6% compared to 50% in the group without prior shunt. All re-ETV were performed without complications. In 11 of the 13 procedures a closed stoma was found and the remaining 2 cases, we found a punctate opening. The mean follow-up after re-ETV was 61.23 months.ConclusionThe selection of patients for re-VET should be cautious. Factors such as age, etiology, and previous shunt (ETV-SS factors) have prognostic influence. However... (AU)

Re-Do endoscopic third ventriculostomy. Retrospective analysis of 13 patients.

OBJETIVES: Indication for endoscopic third ventriculostomy (ETV) in the treatment for noncommunicating hydrocephalus is widely accepted. There is controversy regarding the indication of a second procedure (re-ETV) when the first has failed. The objective of this work is to revise ETV failures in a series in which re-ETV was performed and to describe the factors related to its prognosis. METHOD: Retrospective study of pediatric patients with ETV failure treated by re-ETV between 2003 and 2018. Gender, age in first and second ETV, time to failure of first ETV, etiology of hydrocephalus, previous presence of shunt, ETV-SS in the first and second ETV, intraoperative findings, success of the second procedure and follow-up were collected. The ETV-SS result was grouped into high (≥ 80), moderate (50-70) or low (≤ 40) scores. Endoscopic procedure failure was considered clinical worsening or the absence of radiological criteria for improvement (reduction in ventricular size or presence of ETV flow artifact in the floor of third ventricle). RESULTS: Of 97 ETV carried out in this period, 47 failures were registered, with 13 re-ETV performed. Of these, 8 were classified as successful (61.53%). Re-ETV was successful in 4/4 cases in which etiology was tectal tumor or aqueduct stenosis. In the group with a high ETV-SS score there was a higher rate of success (75%) than in the group with a moderate score (40%). 9 patients presented shunt prior to first ETV and in them, success was 66.6% compared to 50% in the group without prior shunt. All re-ETV were performed without complications. In 11 of the 13 procedures a closed stoma was found and the remaining 2 cases, we found a punctate opening. The mean follow-up after re-ETV was 61.23 months. CONCLUSION: The selection of patients for re-VET should be cautious. Factors such as age, etiology, and previous shunt (ETV-SS factors) have prognostic influence. However, there are specific factors which indicate favorable prognostic for re-VET such as a longer time to failure of the first procedure, the finding of a closed/punctate stoma or the loss of flow artifact in the follow-up MRI.

Re-Do endoscopic third ventriculostomy. Retrospective analysis of 13 patients. / Re-ventriculostomía endoscópica de tercer ventrículo. Análisis retrospectivo de una serie de 13 casos.

OBJETIVES: Indication for endoscopic third ventriculostomy (ETV) in the treatment for noncommunicating hydrocephalus is widely accepted. There is controversy regarding the indication of a second procedure (re-ETV) when the first has failed. The objective of this work is to revise ETV failures in a series in which re-ETV was performed and to describe the factors related to its prognosis. METHOD: Retrospective study of pediatric patients with ETV failure treated by re-ETV between 2003 and 2018. Gender, age in first and second ETV, time to failure of first ETV, etiology of hydrocephalus, previous presence of shunt, ETV-SS in the first and second ETV, intraoperative findings, success of the second procedure and follow-up were collected. The ETV-SS result was grouped into high (≥80), moderate (50-70) or low (≤40) scores. Endoscopic procedure failure was considered clinical worsening or the absence of radiological criteria for improvement (reduction in ventricular size or presence of ETV flow artifact in the floor of third ventricle). RESULTS: Of 97 ETV carried out in this period, 47 failures were registered, with 13 re-ETV performed. Of these, 8 were classified as successful (61.53%). Re-ETV was successful in 4/4 cases in which etiology was tectal tumor or aqueduct stenosis. In the group with a high ETV-SS score there was a higher rate of success (75%) than in the group with a moderate score (40%). 9 patients presented shunt prior to first ETV and in them, success was 66.6% compared to 50% in the group without prior shunt. All re-ETV were performed without complications. In 11 of the 13 procedures a closed stoma was found and the remaining 2 cases, we found a punctate opening. The mean follow-up after re-ETV was 61.23 months. CONCLUSION: The selection of patients for re-VET should be cautious. Factors such as age, etiology, and previous shunt (ETV-SS factors) have prognostic influence. However, there are specific factors which indicate favorable prognostic for re-VET such as a longer time to failure of the first procedure, the finding of a closed/punctate stoma or the loss of flow artifact in the follow-up MRI.

Quality of life in children with hydrocephalus treated with endoscopic third ventriculostomy.

OBJECTIVE: The objectives of this study were to determine the quality of life of a pediatric cohort with hydrocephalus treated by endoscopic third ventriculostomy (ETV), using the Hydrocephalus Outcome Questionnaire-Spanish version (HOQ-Sv), and study the clinical and radiological factors associated with a better or worse functional status. METHODS: This cross-sectional study was undertaken between September 2018 and December 2019. It comprised a series of 40 patients ranging from 5 to 18 years old with hydrocephalus treated by ETV. ETV was considered to be successful if there was no need for surgery for the treatment of hydrocephalus after a minimum follow-up of 6 months. The clinical variables included gender, age at hydrocephalus diagnosis, age at the time of ETV, age at completion of the questionnaire, etiology and type of hydrocephalus (communicating or not), prior shunt, repeat ETV, number of neurosurgical procedures, number of epileptic seizures, presenting signs, and follow-up duration until last office revision. The radiological variables were the Evans Index and the pre- and posttreatment frontooccipital horn ratio. An analysis was conducted of the association between all these variables and the various dimensions on the HOQ-Sv, completed by the parents of the patients via telephone or in the outpatient offices. RESULTS: The mean age of the children at ETV was 7 years (range 7-194 months), and on completing the questionnaire was 12 years (range 60-216 months). The mean HOQ scores were as follows: overall 0.82, physical domain 0.86, social-emotional (SE) domain 0.84, cognitive domain 0.75, and utility score 0.90. A history of epileptic crises was a predictive factor for a worse score overall and in the SE and cognitive domains. Factors related to a worse score in the physical domain were a previous shunt, the number of procedures, and the etiology and type of hydrocephalus. The mean follow-up duration from ETV to the last office visit was 5 years (64.5 months). No association was found between the degree of ventricular reduction and the quality of life. CONCLUSIONS: The factors related to a worse score in the different dimensions of the HOQ were a history of epileptic seizures, the number of procedures, communicating hydrocephalus, and having had a previous valve. No association was found between the reduction in ventricular size and the quality of life as measured on the HOQ-Sv.

Tratamiento neuroendoscópico de quistes aracnoideos en edad pediátrica. Resultados de una serie de 20 pacientes / Neuroendoscopic treatment of arachnoid cysts in the paediatric population. Series results for 20 patient

INTRODUCCIÓN: La neuroendoscopia se ha posicionado como un tratamiento eficaz y seguro en los quistes aracnoideos en la edad pediátrica. Realizamos una revisión de los pacientes pediátricos con quistes aracnoideos tratados mediante neuroendoscopia en nuestro servicio y analizamos los resultados. MATERIAL Y MÉTODOS: Análisis retrospectivo de una serie de 20 pacientes intervenidos entre los años 2005 y 2018. Las variables recogidas son: género, edad, presentación clínica, localización del quiste, presencia de hidrocefalia o colecciones extraaxiales, maniobras endoscópicas realizadas y complicaciones. Se consideró éxito del procedimiento cuando se produjo mejoría de los síntomas y reducción del tamaño del quiste, manteniéndose esta situación hasta final de seguimiento. RESULTADOS: La serie consta de 13 varones y 7 mujeres (edad media: 64,6 meses; rango 4-172 meses). La localización más repetida fue supraselar/prepontina (7), seguida de intraventricular (6), después cuadrigeminales (3), interhemisféricos (2) y silvianos (2). Un 70% (14/20) de pacientes asociaba hidrocefalia en el momento del diagnóstico, elevándose hasta el 85% en quistes supraselares/prepontinos o el 100% en cuadrigeminales. Solo 4/14 pacientes precisaron un sistema de derivación ventriculoperitoneal (mediana de edad al diagnóstico: 12,5 meses). De estos 4, 3 desarrollaron un sobredrenaje valvular grave. Se consideró éxito del procedimiento en 12/20 pacientes (60%) de la serie. Diferenciando por localización: 4/7 en supraselares (57%), 1/3 en cuadrigeminales (33%), 4/6 en intraventriculares (66%), 2/2 en interhemisféricos (100%) y 1/2 en silvianos (50%). Por tanto, se registraron 8 fallos de tratamiento, con un tiempo medio hasta el fallo de 12,12 meses (rango: 0-45). De esos 8 pacientes, en 4 se realizó una nueva neuroendoscopia (éxito de 2/4), en 2 casos se optó por la colocación de derivación ventriculoperitoneal, en un caso por la colocación de derivación cistoperitoneal y en el restante se mantuvo una actitud conservadora. El seguimiento medio fue de 52,45 meses (rango 3-129 meses). CONCLUSIONES: El tratamiento neuroendoscópico es efectivo y seguro en el tratamiento de los quistes aracnoideos en edad pediátrica, permitiendo además en muchos casos el control de la hidrocefalia asociada. El tipo de procedimiento neuroendoscópico y el porcentaje de éxito dependen de la localización del quiste. Se observa una tendencia de mayor dependencia valvular en pacientes de menor edad. En esos casos, sería recomendable la aplicación de medidas de prevención de sobredrenaje

INTRODUCTION: Neuroendoscopy has become an effective and safe treatment for arachnoid cysts in the paediatric population. We review the paediatric patients with arachnoid cysts treated by neuroendoscopy in our hospital and analyse the results. MATERIAL AND METHODS: A retrospective analysis of 20 patients operated on from 2005 to 2018. The variables assessed are: gender, age, clinical presentation, cyst site, presence of hydrocephalus and/or extra-axial collections, endoscopic procedures and complications. Procedure success is defined as an improvement in symptoms and reduction in cyst size until end of follow-up. RESULTS: Our series comprised 13 males and 7 females (mean age: 64.6 months, range: 4-172 months). The most frequent site was suprasellar-prepontine (7), followed by intraventricular (6), quadrigeminal (3), interhemispheric (2) and Sylvian (2). A total of 70% (14/20) of patients had hydrocephalus at diagnosis, which increased to 85% in suprasellar-prepontine cysts and 100% in quadrigeminal cysts. Only 4/14 patients with required a ventriculoperitoneal shunt (median age at diagnosis: 12.5 months). Of these 4 patients, 3 developed severe shunt overdrainage. The procedure was successful in 60% (12/20) of the patients in the series. Success by location was 57% (4/7) in suprasellar cysts, 33% (1/3) in quadrigeminal cysts, 66% (4/6) in intraventricular cysts, 100% (2/2) in interhemispheric cysts and 50% (1/2) in Sylvian cysts. Treatment thus failed in 8 cases, with a mean time to failure of 12.12 months (range: 0-45 months). A new neuroendoscopic procedure was performed in 4 of these 8 cases (success in 2/4), a ventriculoperitoneal shunt was placed in 2 cases, a cystoperitoneal shunt was placed in 1 case and the remaining case was managed conservatively. Mean follow-up time was 52.45 months (range: 3-129 months). CONCLUSIONS: Neuroendoscopy is an effective and safe treatment for arachnoid cysts in paediatric patients that also enables managing associated hydrocephalus in most cases. The choice of neuroendoscopic procedure and success rate depend on cyst location. Younger patients have been found to have a higher shunt dependency rate. In these cases, measures to prevent shunt overdrainage are recommended

Neuroendoscopic biopsy: analysis of a series of 80 patients.

Neuroendoscopy enables diagnostic biopsy of intraventricular and/or paraventricular tumors and the simultaneous treatment of associated hydrocephalus in selected cases. The objective of this paper was to analyze the effectiveness and safety of this procedure. This retrospective study included 80 patients between 2 months and 78 years old diagnosed with intraventricular and/or paraventricular expansive lesion who underwent neuroendoscopic biopsy from 2004 to 2016. Collected variables were gender, age at diagnosis, clinical presentation, tumor location, surgical technique, management of hydrocephalus, pathological findings, procedure-related complications, and follow-up time. Neuroendoscopic biopsy was performed in 80 patients. Mean age at diagnosis was 27 years, and 52.5% were men. According to the Depreitere Classification, 71 were level I (conclusive diagnosis), 1 level III (problematic categorization), and 8 level IV (non-interpretable diagnosis). The most frequent diagnosis was grade I astrocytoma (14%). Diagnostic success per patient was 88.7%. Sixty-nine patients had hydrocephalus at diagnosis, 37 of whom were treated with endoscopic third ventriculostomy (ETV), with septostomy (SPT) in 14, and only SPT in 4. Twenty-eight patients underwent ventricular peritoneal shunt (VPS), with SPT in 20. The ETV success rate was 70.9%. The complication rate per patient was 11%: five patients presented intraventricular hemorrhage, three of whom died; one patient presented cerebrospinal fluid fistula; three presented transient oculomotor impairment. Postoperative follow-up was from 1 month to 12.4 years (mean 45 months). Neuroendoscopy is an effective procedure for the pathological diagnosis of intraventricular and paraventricular tumors, allowing the treatment of associated hydrocephalus. Nevertheless, it is not exempt from serious complications and requires proper training.

Neuroendoscopic treatment of arachnoid cysts in the paediatric population. Series results for 20 patients. / Tratamiento neuroendoscópico de quistes aracnoideos en edad pediátrica. Resultados de una serie de 20 pacientes.

INTRODUCTION: Neuroendoscopy has become an effective and safe treatment for arachnoid cysts in the paediatric population. We review the paediatric patients with arachnoid cysts treated by neuroendoscopy in our hospital and analyse the results. MATERIAL AND METHODS: A retrospective analysis of 20 patients operated on from 2005 to 2018. The variables assessed are: gender, age, clinical presentation, cyst site, presence of hydrocephalus and/or extra-axial collections, endoscopic procedures and complications. Procedure success is defined as an improvement in symptoms and reduction in cyst size until end of follow-up. RESULTS: Our series comprised 13 males and 7 females (mean age: 64.6 months, range: 4-172 months). The most frequent site was suprasellar-prepontine (7), followed by intraventricular (6), quadrigeminal (3), interhemispheric (2) and Sylvian (2). A total of 70% (14/20) of patients had hydrocephalus at diagnosis, which increased to 85% in suprasellar-prepontine cysts and 100% in quadrigeminal cysts. Only 4/14 patients with required a ventriculoperitoneal shunt (median age at diagnosis: 12.5 months). Of these 4 patients, 3 developed severe shunt overdrainage. The procedure was successful in 60% (12/20) of the patients in the series. Success by location was 57% (4/7) in suprasellar cysts, 33% (1/3) in quadrigeminal cysts, 66% (4/6) in intraventricular cysts, 100% (2/2) in interhemispheric cysts and 50% (1/2) in Sylvian cysts. Treatment thus failed in 8 cases, with a mean time to failure of 12.12 months (range: 0-45 months). A new neuroendoscopic procedure was performed in 4 of these 8 cases (success in 2/4), a ventriculoperitoneal shunt was placed in 2 cases, a cystoperitoneal shunt was placed in 1 case and the remaining case was managed conservatively. Mean follow-up time was 52.45 months (range: 3-129 months). CONCLUSIONS: Neuroendoscopy is an effective and safe treatment for arachnoid cysts in paediatric patients that also enables managing associated hydrocephalus in most cases. The choice of neuroendoscopic procedure and success rate depend on cyst location. Younger patients have been found to have a higher shunt dependency rate. In these cases, measures to prevent shunt overdrainage are recommended.

LINAC radiosurgery treatment for vestibular schwannoma / Tratamiento con radiocirugía micromultiláminas de schwannomas vestibulares

Objective: The aims of our study were to evaluate tumour response in a series of patients with vestibular schwannoma (VS) treated with linear accelerator stereotactic radiosurgery (LINAC-RS), to describe the complications and to analyze the variables associated with the response to treatment. Material and methods: This retrospective descriptive study included 64 patients treated from 2010 to 2016 with a minimum follow-up of one year, excluding patients with neurofibromatosis. Clinical-radiological parameters were evaluated. The treatment was performed using LINAC-RS. The prescribed dose was 12Gy at 90% isodose. Results: The mean age at treatment was 53 years, 56% were women. Ninety-eight percent of the patients had hearing loss, 71% with grade III according to the Gardner-Robertson Classification. The mean volume at treatment was 2.92cc and the mean follow-up, 40.95 months. The overall therapeutic success was 90%, reaching 100% at 12 and 24 months, and 86% after 36 months of follow-up. The radiological result was significantly related to the initial tumour volume (p<0.037). In 20 patients there was evidence of transient tumour growth compatible with pseudoprogression. Acute complications were present in 37.5%, and transitory complications in 50%. Chronic complications were found in 20%, with 84% being permanent. The rate of acute complications was lower in patients with regression (p<0.016). Chronic complications were more frequent in the 41-60 year old age group (p<0.040). Conclusions: In our study, the overall tumour control was in accordance with other published series. The radiological result significantly related to the tumour volume at the commencement of treatment. The rate of acute complications was lower in patients with regression

Objetivo: Los objetivos del estudio fueron evaluar la respuesta tumoral en una serie de pacientes con schwannoma vestibular (SV) tratados con radiocirugía (RC) mediante acelerador lineal de electrones (LINAC), describir las complicaciones y analizar las variables relacionadas con la respuesta al tratamiento. Material y métodos: Estudio descriptivo retrospectivo de 64 pacientes tratados entre 2010-2016 con seguimiento mínimo de un año, excluyendo pacientes con neurofibromatosis. Se evaluaron parámetros clínico-radiológicos. El tratamiento se realizó mediante RC-LINAC. La dosis prescrita fue de 12Gy al 90% de isodosis. Resultados: La edad media al tratamiento fue de 53 años, 56% mujeres. El 98% de los pacientes presentaban hipoacusia, el 71% grado iii según la clasificación Gardner-Robertson. El volumen medio al tratamiento fue de 2,92cc, y la media de seguimiento 40,95 meses. El éxito terapéutico global fue del 90% siendo del 100% a los 12 y 24 meses y del 86% a partir de los 36 meses de seguimiento. El resultado radiológico se relacionaba con el volumen tumoral inicial (p<0,037). En 20 pacientes se evidenció un crecimiento tumoral transitorio compatible con seudoprogresión. El 37,5% tuvieron complicaciones agudas siendo transitorias el 50%. Se recogieron complicaciones crónicas en el 20%, siendo permanentes en el 84%. La tasa de complicaciones agudas era menor en pacientes con regresión (p<0,016). Las complicaciones crónicas fueron más frecuentes en el grupo de 41-60 años (p<0,040). Conclusiones: En nuestra serie, el control tumoral global obtenido es acorde con otras series publicadas. El resultado radiológico estaba relacionado con el volumen tumoral inicial al tratamiento. La tasa de complicaciones agudas fue menor en pacientes con regresión

LINAC radiosurgery treatment for vestibular schwannoma.

OBJECTIVE: The aims of our study were to evaluate tumour response in a series of patients with vestibular schwannoma (VS) treated with linear accelerator stereotactic radiosurgery (LINAC-RS), to describe the complications and to analyze the variables associated with the response to treatment. MATERIAL AND METHODS: This retrospective descriptive study included 64 patients treated from 2010 to 2016 with a minimum follow-up of one year, excluding patients with neurofibromatosis. Clinical-radiological parameters were evaluated. The treatment was performed using LINAC-RS. The prescribed dose was 12Gy at 90% isodose. RESULTS: The mean age at treatment was 53 years, 56% were women. Ninety-eight percent of the patients had hearing loss, 71% with grade III according to the Gardner-Robertson Classification. The mean volume at treatment was 2.92cc and the mean follow-up, 40.95 months. The overall therapeutic success was 90%, reaching 100% at 12 and 24 months, and 86% after 36 months of follow-up. The radiological result was significantly related to the initial tumour volume (p<0.037). In 20 patients there was evidence of transient tumour growth compatible with pseudoprogression. Acute complications were present in 37.5%, and transitory complications in 50%. Chronic complications were found in 20%, with 84% being permanent. The rate of acute complications was lower in patients with regression (p<0.016). Chronic complications were more frequent in the 41-60 year old age group (p<0.040). CONCLUSIONS: In our study, the overall tumour control was in accordance with other published series. The radiological result significantly related to the tumour volume at the commencement of treatment. The rate of acute complications was lower in patients with regression.

Atypical Meningiomas: Histologic and Clinical Factors Associated With Recurrence.

BACKGROUND: Atypical meningioma is a heterogeneous group of tumors with an unpredictable behavior. Our objectives were to study patients with atypical meningioma, monitor their follow-up, identify the histologic characteristics, and analyze factors associated with severe outcomes. METHODS: This retrospective study involved 28 patients with atypical meningioma from 1994 to 2014. The histologic samples were reviewed under current criteria. The association with recurrence and survival was analyzed statistically for clinical, therapeutic, histologic, and molecular factors. RESULTS: The average age at the time of diagnosis was 55.5 years (range, 18-83 years) and 57% were female. Total resection (Simpson grade I) was performed in 10 cases (38%). Adjuvant radiotherapy was given to 13 patients. During the 77-month follow-up, 64% had a recurrence or progression. The average time to first recurrence and overall survival were 43.83 months and 149 months, respectively. Recurrence was found in 85% of the patients whose samples presented necrosis. Of the tumors, 84% showed a high mitotic index (4-20 mitoses/10 high-power field). Of the 4 patients with a low mitotic index (<4 mitoses/10 high-power field), the degree of resection was subtotal and 3 experienced disease progression. Of patients with Ki67 >9.9%, 67% had recurrence. The degree of resection was the only variable significantly associated with tumor recurrence. CONCLUSIONS: The high rate of recurrence observed and the short disease-free survival exemplify the unpredictable behavior of atypical meningiomas. Total resection was the only significant factor associated with recurrence. However, the presence of atypical features, such as necrosis or high Ki67, is frequent in patients with disease progression.