4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

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A-0009Frameless robot assisted stereotactic biopsy: an effective and minimallyinvasive technique for pediatric diffuse intrinsic pontine gliomas
RUI ZHAO1
1

Department Of Neurosurgery, Children’s Hospital Of Shanghai, Shanghai, China

Introduction : Diffuse intrinsic pontine gliomas (DIPGs) are prone to high surgical risks, and they
could even lead to death due to their specific sites. To determine the value of frameless robotassisted stereotactic biopsies of DIPGs, when compared it with microsurgical biopsies.
Material & Methods : We conducted a retrospective study of 71 pediatric patients who underwent
biopsies from January 2016 to January 2021. (i) group 1: microsurgical biopsies, and (ii) group2: frameless robot-assisted stereotactic biopsies. Demographic information, neuroimaging
characteristics, pathological diagnoses, operation time, postoperative intensive care unit (ICU)staytime, postoperative hospitalization time, complications, cost, and perioperative mortality rate (POMR)
were collected for analyses.
Results : 32 Cases underwent microsurgical biopsies (group 1) and 39 cases underwent framelessrobot-assisted stereotactic biopsies (group 2). All cases were accurately diagnosed after surgery.
There was no significant difference in gender, age, symptom times and tumor volumes between thetwo groups (p > 0.05); operation time, postoperative ICU, stay time and postoperative hospitalization
time were longer in group 1 than in group 2 (p < 0.001); the intraoperative bleeding volumes andcost were higher in group 1 than in group 2 (p< 0.001). Group 1 patients required more perioperative
blood transfusion than group 2 (p = 0.001), and the new neurological impairments were more
frequent in group 1 than in group 2 (p = 0.003). The POMR was 9.38% (3/32) in group 1 and 0 ingroup 2 (p = 0.087).
Conclusions : Frameless robot-assisted stereotactic biopsy was an effective and minimally invasive
technique for pediatric DIPGs.

14th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

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A-0065
The risk and benefit of early surgery for infants with congenital brain tumors
Jong Seok LEE1, Ji Yeoun LEE1, Kyung Hyun KIM1, Sung-Hye PARK2, Eun Jung KOH1,
Seung-Ki KIM1, Ji Hoon PHI1
1

Neurosurgery, Seoul National University Hospital, Seoul, Korea, Republic of,
Pathology, Seoul National University Hospital, Seoul, Korea, Republic of2

Introduction : Infant brain tumors are known to have different biological features from other pediatricbrain tumors. The present study aimed to evaluate the risk of early surgery in congenital brain tumors
and analyze the clinical outcomes of infant brain tumors.
Material & Methods : We reviewed the clinical presentations, imaging features, intraoperative
findings, and histopathological findings of infant brain tumors at a single institution from January 2008
to June 2023. Outcomes were measured as intraoperative CPR (N = 4) to evaluate the risk of earlysurgery in congenital brain tumors. Recurrence and overall survival were analyzed in infant brain
tumors (N = 69).
Results : Intraoperative CPR occurred in low age and body weight in patients with congenital brain
tumors. Cut-off values of age and body weight were found to be 1.3 months and 5.2 kg (AUC of 96.9
(p<0.001) and 95.8 (p<0.001)) for no CPR. Three patients (30%) had intraoperative CPR in the earlysurgery group, and intraoperative CPR occurred in one patient (7.14%) in the delayed surgery group,
whose tumor was excessively enlarged. Younger age at diagnosis (<3 months of age, HR: 10.0, 95%
CI: 2.12-46.7, p = 0.004) and leptomeningeal seeding (LMS, HR: 27.0, 95% CI: 3.7-197.0, p=0.001)
were significant independent risk factors for high mortality in infant brain tumors.
Conclusions : We suggest delaying surgery until the patient reaches 1.3 months of age and weighsover 5.2 kg with short-term imaging follow-up unless tumors grow rapidly in congenital brain tumors.
Younger ages and LMS are independent risk factors for high mortality in infant brain tumors.

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4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

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A-0093
Multimodality in Pediatric Brain Tumor Surgery -endoscope, exoscope, &navigationKazuhiko KUROZUMI1, Shinichiro KOIZUMI1, Hiroaki NEKI1, Tomoya OISHI1,
Gakuji MARUYAMA1, Tomohiro YAMAZAKI1, Yoshinobu KAMIO1, Tetsuro SAMESHIMA1
1

Department Of Neurosurgery, Hamamatsu University School Of Medicine, Hamamatsu City, Japan

Introduction : Various types of end-or exoscopic surgery are performed in the field of pediatricneurosurgery. In addition, safer and more reliable surgery utilizing various modalities is requiredin cases of brain tumors and hydrocephalus. In this report, we describe our experience using
multimodality in pediatric brain tumor surgery at our hospital.
Material & Methods : From May 2020 to the present, 27 pediatric brain tumor surgery cases under
20 years of age were included in the study. Sixteen were male and 11 were female, ranging in age
from 0 to 20 years (mean 11.8 years). Stealth Station S7 and S8 (Medtronic) navigation systems wereused. Endoscopes were Videoscope (Olympus) and 4KEndoArm (Sony& Olympus). Exoscope was
ORBEYE (Olympus).
Results : Tumors included 6 gliomas, 4 schwannomas, 4 germ cell tumors, 2 meningiomas, 1
ependymoma, 1 pineoblastoma, 1 rhabdomyosarcoma, and 8 others. Endoscopes were used in 8
cases, and navigation systems were used in 27 cases. Endoscopic biopsy was performed in 4 cases,
ETV in 5 cases, and eTSS in 2 cases. Exoscopes were used in 2 cases. The use of intraoperative
navigation helped determine the extent of craniotomy and assist in the precise approach to thelesion. The electromagnetic navigation was particularly useful in confirming the location of the tumor
in the ventricles and determining the biopsy site.
Conclusions : In the surgical field of pediatric brain tumors, navigation and end-or exoscope made it
possible to perform safer and more reliable surgery. Further safe surgery is expected to be possible
with the introduction of robotics in the future.

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4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

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A-0121ANALYZING THE EXTENT OF TUMOR RESECTION IN INTRAOPERATIVEULTRASOUND GUIDED SURGERIES FOR PEDIATRIC POSTERIOR FOSSATUMORS : A SINGLE CENTRE EXPERIENCE
Nadiah FUAD1, Mei Sin LIM1, Fadzlishah JOHANABAS1, Azmi Bin ALIAS1
1

Department Of Neurosurgery, Hospital Kuala Lumpur, Kuala Lumpur, Malaysia

Introduction : Malignant central nervous system (CNS) tumors are the second most common
pediatric malignancy, following hematological malignancies. The extent of tumor resection plays acrucial role in the management of CNS tumors. Intraoperative ultrasound (IOUS) has emerged as avaluable neuroimaging tool for real-time surgical guidance, offering accessibility, minimal risk, minimal
additional operative time, and lower economic investment. The objective of this study was to analyze
the extent of tumor resection in intraoperative ultrasound-guided surgeries with early post operative
MRI.
Material & Methods : We conducted a prospective observational study at Hospital Tunku Azizah,
Kuala Lumpur, including patients under 12 years of age who were admitted between December
1, 2019, and November 30, 2021, with a preoperative MRI diagnosis of posterior fossa tumors.
Intraoperative ultrasound (IOUS) was performed during the surgical procedure, and postoperative
MRI scans were conducted within 24-72 hours after surgery.
Results : A total of 13 pediatric patients who met the inclusion criteria were analyzed. Concordance
analysis between IOUS evaluation and MRI scans demonstrated good agreement. Multivariate
logistic regression analysis was performed to identify significant factors of discordance, but none ofthe variables were found to be significant.
Conclusions : Intraoperative ultrasound-guided surgeries can aid in analyzing the extent of tumor
resection for pediatric posterior fossa tumors. The findings of this study highlight the potential of IOUS
as a real-time navigation tool to improve surgical outcomes in the management of pediatric CNS
tumors.

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4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

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A-0151
Neuroendoscopic surgery for deep brain tumors using a small-diameter
ultrasonic aspirator
Naoyuki OHE1, Toru IWAMA1
1

Neurosurgery, Gifu University, Gifu, Japan

Introduction : As with cancers of other organs, minimally invasive surgery for brain tumors isincreasingly being performed using endoscopy. In particular, endoscopic surgery for brain tumors
requires careful use of tools because the surgical field is narrow. The small-diameter ultrasonicaspirator we currently use is useful, and we will introduce neuroendoscopic surgery for deep brain
tumors using the small-diameter ultrasonic aspirator.
Material & Methods : Methods : A port is inserted from the brain surface to the tumor using
navigation through a linear incision and small craniotomy. The route to reach this time is determinedby considering safe and maximum extraction from the non-eloquent area. ViewSite 21x15mm ports
are often used to secure the endoscope and perform two-handed surgery. Small tumors may beremoved with tumor forceps, but larger tumors are suctioned out using a thin ultrasonic aspirator.
This small-diameter ultrasonic aspirator can also be used for transnasal surgery. Bleeding is stopped
using a small diameter bipolar device. Patients : Infantile huge bilateral intraventrivular AT/RT case,pediatric right thalamic GBM case, skull base highly calcified chondromyxoid fibroma case.
Results : In all of the cases presented, we were able to perform subtotal resection or higher.
Conclusions : The small-diameter ultrasonic aspirator has a TissueSelet function that selectively
disrupts tissue while leaving blood vessels intact, making it possible to perform ultrasonic aspirationof tumors while preserving deep normal blood vessels. Even in highly calcified tumors, it is possible
to crush calcified lesions by maximizing the output. Tumor aspiration using a small-diameter
ultrasonic aspirator is considered to be a useful surgical technique.

54th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

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A-0197
Two-staged endoscopic surgery for craniopharyngioma with obstructivehydrocephalus
Yuichi NAGATA1, Kazuhito TAKEUCHI1, Eiji ITO1, Hideyuki HARADA1, Tatsuma KONDO1,
Ryuta SAITO1
1

Neurosurgery, Nagoya University Hospital, Nagoya, Japan

Introduction : Pediatric craniopharyngiomas are difficult to treat because radical tumor resection
can lead to high postoperative complication rate, whereas incomplete resection can lead to hightumor recurrence rate. We present herein a girl who underwent two-staged endoscopic surgery for
craniopharyngioma with acute obstructive hydrocephalus.
Material & Methods : A 9-year-old girl presented gradually worsening headache, polyuria, memory
disturbance and visual disturbance, and visited to nearby hospital. Head computed tomography
showed a suprasellar tumor with calcification and severe obstructive hydrocephalus. She wasreferred to our hospital for treatment with preoperative diagnosis of craniopharyngioma. Magnetic
resonance imaging showed a cystic suprasellar lesion, filling the third ventricle.
Results : Emergency cyst fenestration was performed via right lateral ventricle with a flexible
endoscope, and cystic components of the tumor were radically fenestrated. Her preoperative
symptoms were released just after the surgery. One month after the surgery, tumor resection was
performed via endoscopic extended trans-sphenoidal approach. The tumor was completely removed
with preservation of the pituitary stalk. The postoperative course was uneventful. Anterior pituitary
functions were partially deteriorated, therefore hormonal replacement therapy has been continued.
No tumor recurrence was observed at the last follow-up.
Conclusions : Endoscopic cyst fenestration is essential for craniopharyngioma with acute obstructivehydrocephalus not only to release the life-threatening comorbidity, but also to induce intermediateterm tumor shrinkage by natural intracranial pressure. Two-staged endoscopic surgery can be one of
the most effective treatment options for craniopharyngioma with obstructive hydrocephalus.

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A-0196
Usefullness of 4K3D-exoscopic removal for pediatric fourth ventricular tumors
Naoki KAGAWA1, Ryuichi HIRAYAMA1, Noriyuki KIJIMA1, Yoshiko OKITA1, Haruhiko KISHIMA1
1

Department Of Neurosurgery, Osaka University Graduate School OF Medicine, Osaka, Japan

Introduction : Pediatric brain tumors often occur in the fourth ventricle, and the standard approach ofsurgical removal is considered to be the cerebellomedullary fissure approach, but this approach andconcorde landing position is tough to both patients and the operators. We discuss the safeness andeffectiveness of 4K3D-exoscopic surgery for removal of fourth ventricular tumors in comparison withmicrosurgery, based on experience in our institution.
Material & Methods : The cerebellomedullary fissure approach for pediatric fourth ventricular tumors
was performed in 16 cases at our hospital between August 2015 and January 2022. Cases withlesions including invasion into the cerebellopontine angle were excluded. 9 medulloblastoma cases,
6 ependymoma cases, and a case of AT/RT were enrolled. Eight cases (group A) were removed by
4K3D-exoscope, and others (group B) were removed using a microscope. There were no apparent
statistical differences between the two groups in terms of age, maximum tumor diameter, tumor
volume, hydrocephalus, and lateral extension.
Results : Surgery using microscopy or 4K3D-exoscopy was successfully completed in all cases.
No significant differences were observed between the two groups in terms of blood loss (group A
average: 305 ml, group B average: 258 ml), surgical time (group A average: 587 minutes, group B
average: 535 minutes) and the extent of removal. The usefulness of 4K3D-exoscopic surgery was
more exellent in terms of the size of the working space, the brightness of intraoperative fluorescencediagnosis, and the burden on the surgeon during surgery.
Conclusions : 4K3D endoscopic removal for the fourth ventricular tumors can be safe and useful.

84th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

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A-0182Preoperative radiological diagnosis of pediatric posterior fossa tumors
Masae KUROHA1, Yuta FUJIWARA1, Mami YAMASHITA1, Maya KONO1, Satoshi IHARA1
1

Neurosurgery, Tokyo Metropolitan Children’s Medical Center, Fuchu-shi, Japan

Introduction : In pediatric primary posterior fossa tumors such as medulloblastoma, ependymoma,
and pilocytic astrocytoma, accurate preoperative diagnosis through radiological imaging is importantfor determining treatment strategies. The aim of this study is to compare the diagnostic accuracy
between our preoperative diagnosis and the retrospective diagnostic algorithm, and to make a better
algorithm.
Material & Methods : We conducted a retrospective analysis of <18-year-old patients with primaryposterior fossa tumors who underwent surgery and received pathological diagnoses at our institution
between April 2013 and August 2023. Cases with brain stem tumors and insufficient MRI data
were excluded. We investigated the preoperative imaging diagnosis made by neurosurgeons
and radiologists, the retrospective diagnosis by reported algorithm based on apparent diffusion
coefficient, contrast enhancement, and tumor localization, and the pathological diagnosis.
Results : A total of 37 cases were included, with mean age was 8.1±4.5 years, and 11 patients werefemale. The concordance rate between our preoperative diagnosis and retrospective diagnostic
algorithm was 81.1%. Based on the pathological results, the accuracy of our preoperative diagnosis
and retrospective diagnostic algorithm were 86.5% and 81.1%, respectively. In addition to thealgorithm’s criteria, we used cerebral blood volume to distinguished pilocytic astrocytoma fromhemangioblastoma, and age to distinguished medulloblastoma from AT/RT. With the inclusion ofthese, diagnostic accuracy improved to 89.2%.
Conclusions : Improving the accuracy of preoperative imaging diagnosis aid in decision-making
during surgery and treatment planning. The diagnostic algorithm also serves as a communication
tool when receiving referred patients from other facilities. Further development of the radiologicaldiagnosis including molecular characteristics is desired.

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4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

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A-0184Is surgical resection the first line for left hippocampal tumor in pediatric case? :a case report and literature review
Mana WAKABAYASHI1, Daisuke YAMAZAKI1, Kohei KANAYA1, Tetsuyoshi HORIUCHI1
1

Neurosurgery, Shinshu University School Of Medicine, Matsumoto, Japan

Introduction : Surgical treatment for mesial temporal lobe epilepsy is standard treatment and has
been established in its efficacy and safety. However, the hippocampal tumor is a quite rare entity
and there are controversies about treatment options. Herein, we present a pediatric case of a left
hippocampal tumor treated with surgical resection.
Material & Methods : A right-handed 8-year-old healthy boy was transferred to a hospital withbilateral tonic-clonic seizure. CT scan showed a calcified mass at the left hippocampus, and thelesion showed high T2 and FLAIR signals with less enhancement on MRI. The tumor was located in
the left hippocampus and parahippocampal gyrus, and 24 x 50 mm in size. Physical and neurologicalexamination were normal except for focal epilepsy which has been well controlled using antiseizure
medication.
Results : ”Selective” tumor resection through the transsylvian approach was planned because there
was no lesion at the lateral temporal lobe. The tumor was grayish and elastic hard. Lower-grade
glioma was suspected in intraoperative rapid diagnosis. Near total removal was achieved except
for the posterior side of the hippocampal tail. Currently, a histopathological diagnosis has not been
finished yet. Postoperatively, there were no neurological deficits including memory disturbance andobvious visual field defects.
Conclusions : We present a pediatric case with a hippocampal tumor successfully treated withsurgical treatment. Surgical treatment is invasive and challenging with a potential risk of memory
disturbance, however, we believe the maximum tumor resection can improve progression-free andoverall survival in pediatric patients with hippocampal lower-grade glioma.

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4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

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A-0101
MICROSURGICAL RESECTION FOR PEDIATRIC PINEAL REGION TUMORS:EXPERIENCES FROM VIETNAMCAN DANG DO THANH1
1

Department Of Neurosurgery, Children’s Hospital 2, Ho Chi Minh City, Vietnam,
Department Of Neurosurgery, University Of Medicine And Pharmacy At HCMC, Ho Chi Minh City, Vietnam

2Introduction : The purpose of this study is to evaluate the role of microsurgery for pineal region
tumors at Children’s Hospital 2, Southern Vietnam
M a t e r i a l & M e t h o d s : T h i s re t ro s p e c t i v e c a s e - s e r i e s o f 4 5 c o n s e c u t i v e p a t i e n t s
were diagnosed with pineal region tumors admitted at Children’s hospital 2 from April 2010 to April
2023
Results : All three surgical approaches included transcallosal, occipito-transtentorial andinfratentorial-supracerebellar routes were used for the pineal region lesions. Total and nearly total
resection wereachieved in 85%. The transcallosal and occipito-transtentorial approaches were usedmostly in 89%. The ratio of motality in 5.5% and morbidity in 16% of all patients. One patient had
temporary vision loss and two others had minor subdural CSF effusion after resection of tumours
without requiring any further procedures.
Conclusions : The multimodalities of treatments for pineal region tumors are recommended
commonly. The microsurgical resection of tumours is too complex and risky but only neccessary in 2/3
of all cases. Numerous surgical approaches are noticed worldwide. The neurosurgeons can use oneof them according to some specific categories and belonging to their own experiences.

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4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

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A-0123The diagnostic accuracy of intracranial germinomas: tumor markers versus
tumor biopsy
Sheng Che CHOU1, Shih-Hung YANG2, Meng-Fai KUO2
1

Traumatology, National Taiwan University Hospital, National Taiwan University College Of Medicine, Taipei
City, Taiwan, 2Neurosurgery, National Taiwan University Hospital, National Taiwan University College Of
Medicine, Taipei City, Taiwan

Introduction : Germinoma treatment does not typically rely on surgical resection, emphasizing theimportance of accurate diagnosis before chemotherapy and radiotherapy. This study compares thediagnostic accuracy between tumor markers and tumor biopsy.
Material & Methods : The medical record of 117 patients with intracranial germ cell tumor between
1987 and 2022 were reviewed. Patients diagnosed as germinoma by pathological examination
were included. The pathology reports and serum/cerebrospinal fluid tumor markers, including alphafetoprotein (AFP) and beta human chorionic gonadotropin (beta-HCG), and outcome were collectedin these patients for analysis.
Results : Seventy-one cases, aged 3 to 64 years were enrolled. Twenty-four cases had elevated betaHCG, with 17 between 5 to 50 IU/L, 2 between 50 to 100 IU/L, and 5 over 100 IU/L. Histologically,
syncytiotrophoblastic cells were found in five of the 71 cases. One of the 5 cases with initial betaHCG level of 38.3 IU/L had recurrence as embryonal carcinoma and yolk sac tumor 10 months later.
Two of the 5 cases with beta-HCG level of 2856 and 26110 IU/L, respectively, also had concomitantelevation of AFP, had early recurrence and poor outcomes. Metastases and beta-HCG over 100 IU/L
with elevated AFP at diagnosis were associated with poor outcomes.
Conclusions : Tumor markers may provide a more accurate diagnosis than histological examination,even when obtained through craniotomy. Sampling errors during tumor biopsy underscores theneed to consider tumor markers in treatment planning to enhance clinical outcomes of patients withintracranial germinoma.

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4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

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A-0113Long-term outcome of central nervous system germ cell tumors: Reduceddose radiotherapy and intensified chemotherapy improves clinical outcome andquality of life of long-term survivors
Naoki KAGAWA1, Ryuichi HIRAYAMA1
1

Department Of Neurosurgery, Osaka University Graduate School OF Medicine, Osaka, Japan

Introduction : Chemoradiotherapy is required for treatment against central nervous system germ
cell tumors (CNSGCT), but optimal treatment intensity should be selected from the viewpoint of both
improvement of clinical outcome and avoidance of late complications. We introduced a protocol
with reduced-dose radiotherapy and intensified chemotherapy for CNSGCT. We retrospectively
analysed the prognosis and long-term outcome of late complications, enrollment and employment, as
indicators of quality of life (QOL).
Material & Methods : 38 children and young adults with CNSGCTs treated in our institution from1997 to 2013 were enrolled in this study. They consisted of 26 germinomas including HCG-producing
cases and 12 non-germinomatous GCTs (NGGCT). Local irradiation was selected for all patients,
and the dose of irradiation was 23.4-54 Gy. The whole-brain irradiation was made in patients who
had intracranial dissemination. For NGGCT, high-dose chemotherapy and peripheral blood stem
cell transplantation (PBSCT) were introduced. Second-look surgeries were performed for cases withresidual tumors after induction chemotherapies.
Results : In germinoma group and NGGCT group, 10-year progression-free survival was 86%
and 84%, 10-year overall survival was 93% and 91%, respectively. About late complications,endocrinological replacement (39%), cerebrovascular disease such as cavernous hemangioma andarterial stenosis (18%), secondary neoplasm (2.6%) were observed. Enrollment and return to schoolrate was 92% and employment rate was 89%, which were influenced by hemipararesis associatedwith basal ganglia lesion, intractable epilepsy and whole-brain irradiation.
Conclusions : Reduced-dose radiotherapy and intensified chemotherapy for CNSGCT, especially
NGGCT, improved the clinical outcome and QOL of long-term survivors, suppressing latecomplications. Further comprehensive follow-up and analysis are needed.

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4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

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A-0028Survival and malignant transformation of pineal parenchymal tumors: A 30-year
retrospective analysis in a single-institution
Eun Jung KOH1, Tae-Hwan PARK1, Seung-Ki KIM1
1

Neurosurgery, Seoul National University Hospital, Seoul, Korea, Republic of

Introduction : This study aims to elucidate clinical features, therapeutic strategies, and prognosis of
pineal parenchymal tumors (PPT) by analyzing a 30-year dataset of a single institution.
Material & Methods : We reviewed data from 43 patients of all ages who were diagnosed with PPT
at Seoul National University Hospital between 1990 and 2020. We performed survival analyses andassessed prognostic factors.
Results : The cohort included 10 patients with pineocytoma (PC), 13 with pineal parenchymal tumor
of intermediate differentiation (PPTID), and 20 with pineoblastoma (PB). Most patients presented
with hydrocephalus at diagnosis. Most patients underwent an endoscopic third ventriculostomy andbiopsy, with some undergoing additional resection after diagnosis confirmation. Radiotherapy wasadministered with a high prevalence of gamma knife radiosurgery for PC and PPTID, and craniospinal
irradiation for PB. Chemotherapy was essential in the treatment of grade 3 PPTID and PB. The
5-year progression-free survival rates for PC, grade 2 PPTID, grade 3 PPTID, and PB were 100%,
83.3%, 0%, and 40%, respectively, and the 5-year overall survival rates were 100%, 100%, 40%, and55%, respectively. High-grade tumor histology was associated with lower survival rates. Significant
prognostic factors varied among tumor types, with WHO grade and leptomeningeal seeding (LMS)
for PPTID, and the extent of resection and LMS for PB. Three patients experienced malignant
transformations.
Conclusions : This study underscores the prognostic significance of WHO grades in PPT. It isnecessary to provide specific treatment according to tumor grade. Grade 3 PPTID showed a poor
prognosis. Potential LMS and malignant transformations necessitate aggressive multimodal treatment
and close-interval screening.

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4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

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A-0039A case series and literature review on 98 pediatric patients of germ cell tumor
developing growing teratoma syndrome
Hsin-Hung CHEN1
1

Division Of Pediatric Neurosurgery, The Neurological Institute, Taipei Veterans General Hospital, Taipei,
TaiwanIntroduction : Malignant germ cell tumors (MGCTs) can develop either extrac- ranially or
intracranially. Growing teratoma syndrome (GTS) may develop in these patients following
chemotherapy. Reports on the clinical characteristics and outcomes of GTS in children with MGCTs
are limited.
Material & Methods : We retrospectively collected the data, including the clinical character- istics
and outcomes of five patients in our series and 93 pediatric patients selected through a literature
review of MGCTs. This study aimed to analyze survival out- comes and risk factors for subsequent
events in pediatric patients with MGCTs developing GTS.
Results : The sex ratio was 1.09 (male/female). In total, 52 patients (53.1%) had intracranial
MGCTs. Compared with patients with extracranial GCTs, those with intracranial GCTs were younger,
predominantly boys, had shorter intervals be- tween MGCT and GTS, and had GTS mostly occurring
over the initial site (all p<0.001). Ninety-five patients (96.9%) were alive. However, GTS recurrence(n=14), GTS progression (n=9), and MGCT recurrence (n=19) caused a sub- stantial decrease in
event-free survival (EFS). Multivariate analyses showed that the only significant risk factors for these
events were incomplete GTS resection and different locations of GCT and GTS. Patients without any
risk had a 5-year EFS of 78.8% ± 7.8%, whereas those with either risk had 41.7% ± 10.2% (p < 0.001).
Conclusions : For patients with high-risk features, every effort should be made to closely monitor,
completely remove, and pathologically prove any newly de- veloped mass to guide relevant
treatment. Further studies incorporating the risk factors into treatment strategies may be required to
optimize adjuvant therapy.

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4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

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A-0128Treatment standard and controversies on the pediatric intracranial NGGCTGong JIAN1, Li XIANG1, Zihan YAN1, Xu HAN1, Cuiling HU1, Kaiyu FAN1
1

Department Of Pediatric Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China

Introduction : Widespread controversy surrounds the standardized treatment of pediatric intracranial
NGGCT (non-germinomatous germ cell tumors), with significant limitations observed in the existingcohort studies. Additionally, there is a lack of corresponding research in the high-incidence Asian
region. To address this gap, we conducted a single-center retrospective study to explore viable
treatment approaches.
Material & Methods : We conducted a retrospective analysis of 49 cases of pediatric intracranial
NGGCT over the past 3 years. We employed Kaplan-Meier survival analysis to assess the three-year
overall survival rate (OS) and progression-free survival rate (PFS), which were then compared withpublicly available data.
Results : Fifty-one percent of patients underwent direct surgery followed by adjuvant radiotherapy
and chemotherapy. Forty-nine percent of patients initially received chemotherapy, followed bysurgical intervention after a two-cycle assessment (wherein 10% experienced tumor reduction, and
90% showed no tumor reduction). Subsequent to surgery, routine postoperative radiotherapy andchemotherapy were administered. The complete response rate after surgery in our cohort was 100%,
whereas achieving a complete response rate solely through chemotherapy was 0%. The three-year
OS rate was 86.3%, and the PFS rate was 82.1%.
Conclusions : Surgical intervention is nearly always necessary for NGGCT patients, with the timingof surgery being crucial. For NGGCT cases characterized by smaller tumor size, greater surgicalfeasibility, and the presence of teratoma components, we recommend direct surgical excision
followed by adjuvant radiotherapy and chemotherapy. This approach can significantly enhancetreatment outcomes and efficiency.

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4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

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A-0185
A retrospective analysis of clinical course of pediatric ependymoma cases in asingle institute
Junya YAMAGUCHI1, Fumiharu OHKA1, Kazuya MOTOMURA1, Ryuta SAITO1
1

Neurosurgery, Nagoya Universiy Graduate School Of Medicine, Nagoya, Japan

Introduction : Maximum tumor removal is the most useful treatment for ependymoma, however,standard strategy of adjuvant therapy has not been established yet, because the number of cases islimited. Therefore, it is quite useful to share clinical course of experienced cases.
Material & Methods : We reviewed the clinical course of 12 consecutive cases of pediatric
ependymoma treated at our institute, retrospectively.
Results : The median age was 2.5 (0-15) years. 10 cases had posterior fossa ependymoma and2 had supratentorial ependymoma. Gross total resection (GTR) was achieved in 9 cases (75%). 5
cases were diagnosed with ependymoma, Grade II, and 7 with anaplastic ependymoma, Grade III(WHO classification in 2007 and 2016). Post-operative adjuvant therapy was performed in 8 cases.
Among 6 relapsed cases, 4 revealed local recurrence and 2 did dissemination. 2- and 5-year
progression-free survival (PFS) rates were both 60%, and 2- and 5-year overall survival rates were100% and 66.6%, respectively. For PFS, there was a better trend for GTR (HR = 0.18, 95% CI: 0.025- 1.28) and supratentorial lesion (HR = 0.18, 95% CI: 0.030 - 1.11), but no difference for WHO grade(HR = 1.022, 95% CI: 0.20 - 5.24).
Conclusions : As previous studies revealed, WHO grade did not reflect prognosis. The latest WHO
classification described that Posterior Fossa group A (PFA) ependymoma reveals unfavorable
prognosis compared with PFB and supratentorial ependymomas. In near future, determination oftreatment strategy may be needed for each subgroup. We also compare the clinical course between
PFA, PFB and supratentorial tumors in our analyzed cases.

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4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

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A-0195Multidisciplinary treatment in ependymoma
Daiuske HIROKAWA1, Dai KEINO2, Tomoko YOKOSUKA2
1

Neurosurgery, Kanagawa Children’s Medical Center, Yokohama, Japan,
Hematology/Oncology Medicine, Kanagawa Children’s Medical Center, Yokohama, Japan

2

Introduction : In intracranial ependymoma, the effectiveness of chemotherapy and radiation therapy
is unclear, and the degree of tumor removal contributes to the improvement of life prognosis.
Material & Methods : We examined ependymoma cases treated in our institution from July 1998 to
March 2017.
Results : There were 18 boys and 7 girls. The average age at the time of surgery is 5.3±3.6 years.
The pathological diagnosis was Grade II for 8 cases and Grade III for 17 cases. Genetic analysis
was performed in 16/25 cases (64%). Of the infratentorial cases, 10/11 cases (90.1%) were PFA andPFB were one case. Of the supratentorial cases, 3/5 cases (60%) were positive for RELA fusion. As
chemotherapy, 19 patients were VCR + VP-16 + CDDP + CPA. Irradiation was performed in all cases,
local irradiation (50.4-55.8Gy) in 22 cases (88%), and craniospinal irradiation in 2 cases (8%). The
7-year OS was 74.6±9% and the 7-year PFS was 59.7±10.5%. Grade III showed a short OS (p =0.053). GTR and NTR were obtained in the first excision in 14 cases (56%), and OS and PFS were
not significantly different from those in the STR group (p = 0.219, p = 0.248). GTR and NTR including
2nd-look surgery were obtained in 18 cases (72%), and significant improvement of OS was observed
compared with STR group (p = 0.02).
Conclusions : Even if it is not GTR or NTR at the first operation, improvement of OS is expected bytotal excision after chemotherapy.

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4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

Oral presentation 2: TUMOR 2

A-0112
Direct evidence of the development of a myxopapillary ependymoma of thefilum terminale into a cauda equina tumor and its clinical implication
Tzu-Hua CHEN1, Chun-Yu CHEN1, Hsin-Yi HUANG2, Sheng Che CHOU1, Shih-Hung YANG1,
Meng-Fai KUO1
1Surgery, National Taiwan University Hospital, Taipei, Taiwan,
Pathology, National Taiwan University Hospital, Taipei, Taiwan

2

Introduction : Myxopapillary ependymoma (MPE) is a variant of ependymomas with predominantlocation at filum terminale (FT), conus medullaris, and cauda equina. MPEs are assumed to arise fromependymocytes normally present in conus medullaris or ectopically in FT. Our single case aims topresent direct evidence of development of a MPE of FT into a huge cauda equina ependymoma.
Material & Methods : A 17-year-old girl presented with back pain for 3 months. Magnetic resonanceimaging of lumbosacral spine showed a cauda equina tumor from middle L1 to L4 levels with aseeding at L5 region. There’s no other neuraxis lesions. The surgical and pathological findings of thecase and our proposition will be presented.
Results : Upon durotomy, nerves of cauda equina were all encased by the encapsulated tumor,
which compressed conus medullaris without involvement of it. After peeling off the tumor from eachnerve, an enlarged FT was noted, which was en bloc removed. The pathology showed a MPE. The
central canal of FT was filled with tumor cells though both ends were free. Some tumors penetrated
the filum and connected with the main tumor in cauda equina space. The tumor at L5 level was
discrete from the main tumor. The CSF cytology was negative for tumor cells. After total excision,
there was no recurrence under 2-year follow-up.
Conclusions : This case explained the pathogenesis of ependymomas of cauda equina, where there
is no ependymocyte. The only “seeding” at the caudal portion of thecal sac further supports thetumor came from cells splitted from the FT ependymoma.

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4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

Oral presentation 3: TUMOR 3

A-0148
Utility of cerebrospinal fluid cell free DNA analysis for the diagnosis of H3K27altered diffuse midline gliomas
Manabu NATSUMEDA1, Jotaro ON1, Satoshi SHIBUMA1, Haruhiko TAKAHASHI1,
Jun WATANABE1, Yoshihiro TSUKAMOTO1, Masayasu OKADA1, Makoto OISHI1
1

Neurosurgery, Niigata University Brain Research Institute, Niigata, Japan

Introduction : Detection of Histone H3K27M mutations is critical for the diagnosis of diffuse midline
gliomas H3K27-altered. However, especially when the tumor is located in the brain stem, it is notalways easy to perform a biopsy. Therefore, we assessed the feasibility and utility of H3K27M
mutation detection from cerebrospinal fluid (CSF) cell free DNA (cfDNA).
Material & Methods : CSF was obtained from 18 clinically or histologically diagnosed diffuse midline
glioma patients between , 2019 and January, 2023 at Niigata University Hospital. CSF cfDNA wasextracted and H3F3A K27M mutations were detected by droplet digital PCR.
Results : Median patient age was 19 (range 5-75) and 7 (39%) patients were female. CSF was
obtained by lumbar puncture in 10 patients, intraventricular route during or after surgery in 7 patientsand from a cyst in 1 patient. H3K27M-mutant droplets were detected from 11 (61%) patients,
including more than 3 droplets in 3 (33%) patients. Median variant allele frequency was 7.5% (range
0-87.5%).
Conclusions : Detection of H3K27M mutant droplets from CSF cfDNA is feasible in diffuse midline
gliomas. Further efforts to improve diagnostic accuracy is necessary.

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4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

Oral presentation 3: TUMOR 3

A-0189Rapid gene analyses in pediatric central nervous system tumor using
quantitative PCR device
Fumiharu OHKA1, Sachi MAEDA1, Hiroki SHIMIZU1, Kazuya MOTOMURA1, Junya YAMAGUCHI1,
Eiji ITO1, Kazuhito TAKEUCHI1, Yuichi NAGATA1, Tomohide NISHIKAWA1, Yuji KIBE1,
Yuhei TAKIDO1, Ryuta SAITO1
1

Neurosurgery, Nagoya University Graduate School Of Medicine, Nagoya, Japan

Introduction : Recent comprehensive molecular analyses of central nervous system (CNS) tumors
identified several diagnostic or prognostic molecular markers. In pediatric CNS tumors, BRAF p.V600E
mutation in pediatric-type diffuse low-grade glioma or circumscribed astrocytic glioma and histone
H3 gene mutations in pediatric-type diffuse high-grade gliomas are quite important diagnostic
markers. CDKN2A homozygous deletion (HD) is also an important marker in high-grade astrocytoma
with piloid features (HGAP). Rapid identification of these molecular alterations could be effective fordecision-making of tumor removal strategy.
Material & Methods : In this study, we established rapid gene analysis method using rapid
quantitative PCR device, GeneSoC, by which we could obtain genotype of these important genes for
20 minutes.
Results : Using GeneSoC, we could perform 50 cycles of quantitative PCR for approximately
12 minutes. We established rapid gene analyses for mutations of H3 K27M, BRAF p.V600E andhomozygous deletion of CDKN2A for pediatric CNS tumors. For elution of DNA, we incubated atleast 1mg of tumor tissue at 95°for 5 minutes. Combined this boiling method with GeneSoC, we
could obtain those genetic alterations for 20 minutes after collection of tumor tissue. For diffuse
midline glioma, H3 K27-altered, pilocytic astrocytoma and HGAP cases, we could obtain accurate
genetic alterations (H3 K27M, BRAF p.V600E or CDKN2A HD), using this method within 20 minutes,
respectively.
Conclusions : In this study, we could obtain the genotype of important molecular markers rapidly,
using GeneSoC device. This rapid genetic analysis might be effective not only for intra-operative
molecular diagnosis, but also for immediate introduction of post-operative adjuvant therapy.

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4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

Oral presentation 3: TUMOR 3

A-0030Since the Introduction of mTOR Inhibitors, Surgical Resection of SEGA Has
Decreased, But Surgical Skills Remain an Essential Technique
Ryuya HOTTA1, Shingo NUMOTO1, Ayataka FUJIMOTO1
1

Comprehensive Epilepsy Center, Seirei Hamamatsu General Hospital, Hamamatsu, Japan

Introduction : Tuberous sclerosis complex (TSC) is a rare genetic disorder that can lead to thegrowth of benign tumors, including Subependymal Giant Cell Astrocytoma (SEGA). The introductionof mammalian target of rapamycin inhibitors (mTORi) has offered a pharmacological approach to
manage SEGA in TSC patients.
Material & Methods : This study retrospectively reviewed patient charts from August 1979 to July
2020. Patients were divided into a pre-mTORi era group (Pre-group), treated before November
2012, and a post-mTORi era group (Post-group), treated from November 2012 onward when mTORi
became available for SEGA in Japan. Treatment modalities, SEGA size, acute hydrocephalus rate,
recurrence, malignant transformation, and mTORi adverse effects were compared between groups.
Results : Of 120 TSC patients, 24 had SEGA. Surgical resection was significantly more frequentin the Pre-group (6 of 7 patients, 86%) than in the Post-group (2 of 17 patients, 12%; p = 0.001).
No malignant transformation of SEGA was observed. Patients treated with mTORi had significantly
smaller SEGA sizes compared to those under a wait-and-see policy (p = 0.012). Adverse effects wereidentified in 7 of 11 patients on mTORi (64%).
Conclusions : Since the introduction of mTORi, the frequency of surgical resection for SEGA in
TSC patients at our facility has significantly decreased. However, despite the effectiveness ofmTORi, surgical skills remain an essential technique, especially for cases not responding to mTORior experiencing significant adverse effects. The recent application of neuroendoscopic resection
has emerged as a promising, minimally invasive surgical option for selected patients with SEGA
associated with TSC.

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4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

Oral presentation 3: TUMOR 3

A-0055
Pediatric lower grade glioma surgery in the era of genomic medicine
Akira GOMI1
1

Pediatric Neurosurgery, Jichi Children’s Medical Center Tochigi, Jichi Medical University, Tochigi, Japan

Introduction : In the WHO Brain Tumor Classification 2021, pediatric-type gliomas are classified
separately from adult-type tumors. Additionally, with the advancement of cancer genomics, treatment
options have expanded. Here we would like to consider surgery for pediatric low-grade gliomas.
Material & Methods : We retrospectively analyzed 41 cases of low-grade gliomas or glioneuronaltumors in pediatric patients who underwent surgery at our institute from 2002 to 2023. We discussed
surgical strategies based on molecular classification.
Results : Among the cases, there were 34 gliomas and 7 glioneuronal tumors. According to the new
WHO classification, they corresponded to 1) Adult-type diffuse gliomas, 2) Pediatric-type diffuse lowgrade gliomas, 3) Circumscribed astrocytic tumors, or 4) Glioneuronal and neuronal tumors. Cases
without molecular diagnosis were also considered in light of the new WHO classification. Among
molecularly diagnosed astrocytomas involving the cerebral hemisphere, brain stem, spinal cord,
there were no cases of 1), and 2) 3) were the main cases. It is important in surgical selection tonote that these cases generally have a more favorable prognosis compared to the adult type andhave usefulness in diagnosing MAPK pathway abnormalities leading to the selection of molecularly
targeted drugs. 3) includes pilocytic astrocytoma, subependymal giant cell astrocytoma, andpleomorphic xanthoastrocytoma. Among these, in the treatment of pilocytic astrocytoma of the visualtract and hypothalamus, biopsy is essential for molecular diagnosis and therapeutic agent selection. 4)
is mainly an epilepsy-related tumor, and epilepsy control by resection is expected.
Conclusions : Based on the new WHO classification, a reevaluation of treatment strategies forpediatric brain tumors is necessary.

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4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

Oral presentation 3: TUMOR 3

A-0058
Clinical characteristics of three patients with deficient DNA mismatch repair
glioblastoma
Kohei UEMASU1, Ichiyo SHIBAHARA1, Mariko TOYODA1, Madoka INUKAI1, Takuichiro HIDE1,
Jiichiro SASAKI2, Toshihiro KUMABE1
1
Neurosurgery, Kitasato University School Of Medicine, Kanagawa, Japan, 2Research And Development
Center For New Medical Frontiers, Kitasato University School Of Medicine, Kanagawa, Japan

Introduction : Primary brain tumors associated with deficient mismatch repair (dMMR) are rare,accounting for less than 2% of primary brain tumors. dMMR is associated with microsatellite instability(MSI) and tumor mutational burden (TMB), subsequently leading to tumorigenesis. However,the findings in glioblastoma are still limited. We experienced three cases of dMMR-associatedglioblastoma.
Material & Methods : All three patients were young adult males with left temporal IDH-wildtype
glioblastoma having common distinctive feature of giant multinucleated cells. At the molecular level,
Case1 had TMB-high and MSH6 mutation, Case 2 had TMB-high, MSI-high, and MLH1 mutation, andCase3 had TMB-high.
Results : Case 1 presented distant recurrence 14 months postoperatively. Case 2 was treatedwith Pembrolizumab, an immune-checkpoint inhibitor, but presented distant recurrence 15 months
postoperatively. Case 3 presented good tumor control after Stupp regimen but presented a distantrecurrence 48 months after the initial surgery.
Conclusions : Giant multinucleated cells in young patients with glioblastoma can suggest a dMMRassociated tumor. Therefore, genetic testing is highly recommended if we encounter such clinicalfeatures. All three cases presented distant recurrences, indicating that follow-up MRI needs to be
extra cautious not to overlook distant lesions including the spinal cord. Effectiveness of an immunecheckpoint inhibitor for a dMMR-associated glioblastoma should be investigated in a prospective
study.

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4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

Oral presentation 3: TUMOR 3

A-0078Genetic diagnosis of pediatric brain tumors by liquid biopsy
Kenichi USAMI1, Takanori MIZUNO2, Ryota SHIRAI2, Takako YOSHIOKA3, Keita TERASHIMA4,
Chikako KIYOTANI4, Hideki OGIWARA1, Motohiro KATO2
1

Division Of Neurosurgery, National Center For Child Health And Development, Tokyo, Japan, 2Department
Of Pediatric Hematology And Oncology Research, National Center For Child Health And Development,
Tokyo, Japan, 3Department Of Pathology, National Center For Child Health And Development, Tokyo, Japan,
4
Division Of Neuro-Oncology, Children’s Cancer Center, National Center For Child Health And Development,
Tokyo, Japan

Introduction : For genetic diagnosis of brain tumors, it is necessary to directly harvest tumor cells bysurgery. In this study, we performed genetic diagnosis by liquid biopsy (LB) using cell free DNA (cfDNA) extracted from plasma and cerebrospinal fluid (CSF) in children with brain tumors.
Material & Methods : The study included children who underwent surgical resection or biopsy forbrain tumors between January 2019 and December 2020. Tumor-specific mutations were identified
using whole exome sequencing on genomic DNA extracted from both tumor samples obtained
through biopsy or resection procedures and blood cells. CSF (1-2 ml) collected intraoperatively andplasma (500-700 µl) obtained during surgery were used to analyze tumor-specific mutations throughdroplet digital PCR.
Results : Tumor-specific mutations were detected in 6 of 13 (46.2%) CSF samples. Two of the 6
samples had Class II or lower CSF cytology, and genetic mutations were also detected in one case of
low-grade pilocytic astrocytoma. The median variant allele frequency in CSF was 16.0% (0.6-86.1%).
On the other hand, no genetic mutations were detected in plasma in all patients.
Conclusions : In certain pediatric brain tumors, genetic diagnosis using cfDNA extracted from CSF,
which can be repeatedly obtained with minimal invasiveness, is feasible. This approach has thepotential to diagnose cases even with negative cytology or low-grade tumors.

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4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

Oral presentation 3: TUMOR 3

A-0094
Molecular pathological analysis of radiation-induced glioblastoma after
pediatric cerebellar medulloblastoma treatment
Naoyuki OHE1, Takafumi OKUBO2, Kenji SHODA1, Natsuko SUZUI2, Noriyuki NAKAYAMA1,
Tatsuhiko MIYAZAKI2
1

Neurosurgery, Gifu University, Gifu, Japan, 2Pathology, Gifu University, Gifu, Japan

Introduction : The number of long-term survivors of pediatric medulloblastoma has been increasing
due to improved treatment options. However, secondary cancer can be an issue for long-term
survivors. We report the molecular pathological evaluation of two cases of radiation-induced
glioblastoma.
Material & Methods : Of the 27 patients with cerebellar medulloblastoma treated at our institution,
two developed cerebellar glioblastomas after the initial treatment at five years and 11 months and 22
years and eight months, respectively. These two cerebellar glioblastomas were clinically diagnosed
as radiation-induced secondary cancer.
Results : Both of the two cases we clinically diagnosed as radiation-induced glioblastoma had
negative IDH-1, EGFR expression and positive p53 expression in immunohistochemistry.
Conclusions : It has been reported that EGFR expression is negative as a molecular feature ofradiation-induced glioblastoma, and the two cases we experienced were consistent with radiationinduced secondary cancers. In general, primary glioblastoma is positive for EGFR expression in the
supratentorial region and negative in the infratentorial region. Therefore, in the case of supratentorial
glioblastoma, it is useful to evaluate EGFR expression to distinguish primary glioblastoma fromsecondary glioblastoma.

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4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

Oral presentation 3: TUMOR 3

A-0186
Efficacy and safety of bevacizumab, irinotecan, and temozolomide combination
for relapsed or refractory pediatric central nervous system embryonal tumor
Yoshiki SHIBA1, KAZUYA MOTOMURA1, Fumiharu OHKA1, Michihiro KURIMOTO3,
Rieko TANIGUCHI2, Kosuke AOKI1, Eiji ITO1, Junya YAMAGUCHI1, Sachi MAEDA1,
Takuma NAKASHIMA4, Hiromichi SUZUKI4, Hideki MURAMATSU2, Yoshiyuki TAKAHASHI2,
Ryuta SAITO1
1

Neurosurgery, Nagoya University, Nagoya, Japan, 2Pediatrics, Nagoya University, Nagoya, Japan,
Neurosurgery, Aichi Children’s Health And Medical Center, Nagoya, Japan,
4Brain Tumor Translational Research, National Cancer Center Research Institute, Tokyo, Japan
3

Introduction : Multidisciplinary treatment, which combines surgical treatment, various types ofchemotherapy, and radiation therapy, is becoming standard in the treatment of pediatric brain tumors.
However, there is a lack of evidence regarding treatments for treatment-resistant, recurrent, anddisseminated cases. The purpose of this study was to evaluate the efficacy and safety of combination
therapy of bevacizumab (Bev), irinotecan (CPT-11), and temozolomide (TMZ) in patients withrelapsed/refractory central nervous system embryonal tumors.
Material & Methods : We retrospectively examined 13 pediatric patients with relapsed or
refractory CNS embryonal tumors who received combination therapy. Specifically, 9 patients had
medulloblastoma, 3 had atypical teratoid/rhabdoid tumor (AT/RT), and 1 had CNS embryonal tumor
with rhabdoid features. Of the 9 medulloblastoma cases, 2 were categorized in the Sonic hedgehog
subgroup and 6 in molecular subgroup 3 for medulloblastoma.
Results : The complete and partial objective response rates were 66.6% in patients withmedulloblastoma and 75.0% in patients with AT/RT or CNS embryonal tumors with rhabdoid features.
Furthermore, the 12- and 24-month progression-free survival rates were 69.2% and 51.9% for
all patients. In contrast, the 12- and 24-month overall survival rates were 67.1% and 58.7% for all
patients. We observed grade 3 neutropenia, thrombocytopenia, proteinuria, hypertension, diarrhea,
and constipation in 23.1%, 7.7%, 23.1%, 7.7%, 7.7%, and 7.7% of patients, respectively. Furthermore,
grade 4 neutropenia was observed in 7.1% of patients. Nonhematological adverse effects were mild
and controlled with standard antiemetics.
Conclusions : Our findings suggest favorable survival outcomes and safety of combination therapyof TMZ, Bev, and CPT-11 in patients with relapsed/refractory embryonal tumors.

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4th Congress of Asian-Australasian Society for Pediatric Neurosurgery (AASPN2023)

Oral presentation 3: TUMOR 3

A-0085
Pediatric brain stem gliomas: the past, present and future
Kentaro CHIBA1, Yasuo AIHARA1, Kim KILSOO1, Yuichi ODA1, Takakazu KAWAMATA1
1

Neurosurgery, Tokyo Women’s Medical University, Tokyo, Japan

Introduction : Tumors arising in the brainstem can be broadly classified as; pattern of progression(exophytic or intrinsic), location (midbrain, pons, medulla oblongata, or upper cervical cord) and typeof extension (diffuse or focal). we retrospectively reviewed the imaging, histopathology, and course oftreatment in patients with and without surgical treatment.
Material & Methods : Twenty-one cases of brain stem tumors under the age of 20 years old between
2006 to 2023 were eligible for this retrospective review. Location; Four cases at midbrain, 15 cases atpons (including diffuse intrinsic pontine glioma), and one case at medulla oblongata.
Results : Headache, diplopia, and facial nerve palsy were the most common initial symptoms.
Histological diagnosis was performed in 14/21 (67%); 9 cases of pediatric type high grade glioma;
5 cases of p-low grade glioma (p-LGG). Histological diagnosis: stereotactic biopsy in 1 case; open
biopsy/extraction in 13 cases. Prognosis: morality rate 18/21 (86%); mean survival 13.8 months (8-27
months).
Conclusions : The prognosis of brain stem tumors is still devastating and surgical intervention canrarely be candidates for treatment. With the development of surgical instruments and the increasing
availability of gene panel tests in recent years, histological diagnosis of brainstem lesions, especiallyfor DIPG, has become increasingly important not only for diagnosis but also treatment. Besides, theevaluation of cranial nerve is necessary for assess the clinical course of brain stem tumors.

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