Motoyuki Umekawa

Dr. Motoyuki Umekawa

University of Tokyo Hospital, Tokyo, Japan
orcid

Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 August 2018 in World Neurosurgery
Verified
Journal Article
Closed access
MUMotoyuki Umekawa
Motoyuki Umekawa
Hirotaka HasegawaHirotaka Hasegawa
Hirotaka Hasegawa
MSMasahiro Shin
Masahiro Shin
MKMariko Kawashima
Mariko Kawashima
SNSeiji Nomura
Seiji Nomura
NSNobuhito Saito
Nobuhito Saito

28 June 2022 in Current Oncology
Verified
Journal Article
Open access
PDF file
YHYudai Hirano
Yudai Hirano
YSYuki Shinya
Yuki Shinya
TAToshiya Aono
Toshiya Aono
Hirotaka HasegawaHirotaka Hasegawa
Hirotaka Hasegawa
MKMariko Kawashima
Mariko Kawashima
NSNobuhito Saito
Nobuhito Saito
Stereotactic frame-based brain tumor biopsy (SFB) is a potent diagnostic tool considering its minimal invasiveness, though its diagnostic power and safety for brainstem lesions remain to be discussed. Here, we aimed to examine the usefulness of SFB for brainstem tumors. Twenty-two patients with brainstem tumors underwent 23 SFBs at our institution during 2002–2021. We retrospectively analyzed patient characteristics, tumor pathology, surgical procedures, and outcomes, including surgery-related complications and the diagnostic value. Seven (32%) tumors were located from the midbrain to the pons, eleven (50%) in the pons only, and four (18%) from the pons to the medulla oblongata. The target lesions were in the middle cerebellar peduncles in sixteen procedures (70%), the cerebellum in four (17%), the inferior cerebellar peduncles in two (9%), and the superior cerebellar peduncles in one (4%). A definitive diagnosis was made in 21 patients (95%) at the first SFB. The diagnoses were glioma in seventeen (77%) cases, primary central nervous system lymphoma in four (18%), and a metastatic brain tumor in one (5%). The postoperative complications (cranial nerve palsy in three [13%] cases, ataxia in one [4%]) were all transient. SFB for brainstem tumors yields a high diagnostic rate with a low risk of morbidity.

31 December 2019 in Neurospine
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Journal Article
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MUMotoyuki Umekawa
Motoyuki Umekawa
KTKeisuke Takai
Keisuke Takai
MTMakoto Taniguchi
Makoto Taniguchi
To analyze the relationship between age and perioperative complications of spine surgery in a Japanese cohort with the longest average life expectancy in the world. Patients with spinal stenosis who underwent standard spine surgery without instrumented fusion were divided into 4 groups: adults (20-64 years), the young-old (65-74), the middle old (75-84), and the oldest-old (≥85). Data on medical complications, surgical complications, and deaths within 30 days of index surgery were compared across the groups. Risk factors for complications were identified through multivariate analysis. A total of 584 patients underwent 673 operations: 35% were performed on adult patients, 33% on the young-old, 27% on the middle old, and 5% on the oldest-old. The rates of total or [major] medical complications significantly increased with age (8% [0.8%], 11% [0.9%], 27% [3.9%], 45% [9.1%], respectively; p<0.001 [p=0.003]), whereas those of surgical complications did not differ (11%, 8.1%, 14%, 9.1%, respectively; p=0.25). Independent risk factors for medical complications were an age of 75 years or older (75-84: odds ratio [OR], 5.1; ≥85: OR, 6.2) and American Society of Anesthesiologists (ASA) physical status classification III (OR, 5.4). Two patients older than 85 years died from medical complications. The complications of spine surgery increased in the middle and oldest-old patients because of medical complications; however, most were minor and treatable. Major complications were associated with preoperative medical comorbidities and their severities; therefore, most elderly patients with low ASA physical status classification (≤II) may benefit from spine surgery.

1 January 2019 in World Neurosurgery
Verified
Journal Article
Closed access
KTKeisuke Takai
Keisuke Takai
MNManabu Niimura
Manabu Niimura
HHHiroki Hongo
Hiroki Hongo
MUMotoyuki Umekawa
Motoyuki Umekawa
ATAkio Teranishi
Akio Teranishi
MTMakoto Taniguchi
Makoto Taniguchi

14 January 2022 in Journal of Neuro-Oncology
Verified
Journal Article
Closed access
PDF file
MUMotoyuki Umekawa
Motoyuki Umekawa
YSYuki Shinya
Yuki Shinya
HHHirotaka Hasegawa
Hirotaka Hasegawa
MSMasahiro Shin
Masahiro Shin
MKMariko Kawashima
Mariko Kawashima
NSNobuhito Saito
Nobuhito Saito

18 February 2024 in Journal of Neuro-Oncology
Verified
Journal Article
Open access
PDF file
MUMotoyuki Umekawa
Motoyuki Umekawa
YSYuki Shinya
Yuki Shinya
Hirotaka HasegawaHirotaka Hasegawa
Hirotaka Hasegawa
RMRamin A. Morshed
Ramin A. Morshed
AKAtsuto Katano
Atsuto Katano
NSNobuhito Saito
Nobuhito Saito
Purpose: This study investigated whether Ki-67 labeling index (LI) correlated with clinical outcomes after SRS for atypical meningiomas. Methods: This retrospective study examined 39 patients with atypical meningiomas who underwent SRS over a 10-year study period. Ki-67 LI was categorized into 3 groups: low (< 5%), intermediate (5%–10%), and high (> 10%). Local tumor control rates (LCRs), progression-free rates (PFRs), disease-specific survival (DSS) rates, and adverse radiation-induced events (AREs) were evaluated. Results: The median follow-up periods were 26 months. SRS was performed at a median prescription dose of 18 Gy for tumors with a median Ki-67 LI of 9.6%. The 3-year LCRs were 100%, 74%, and 25% in the low, intermediate, and high LI groups, respectively (p = 0.011). The 3-year PFRs were 100%, 40%, and 0% in the low, intermediate, and high LI groups (p = 0.003). The 5-year DSS rates were 100%, 89%, and 50% in the low, intermediate, and high LI groups (p = 0.019). Multivariable Cox proportional hazard analysis showed a significant correlation of high LI with lower LCR (hazard ratio [HR], 3.92; 95% confidence interval [CI] 1.18–13.04, p = 0.026), lower PFR (HR 3.80; 95% CI 1.46–9.88, p = 0.006), and shorter DSS (HR 6.55; 95% CI 1.19–35.95, p = 0.031) compared with intermediate LI. The ARE rates were minimal (8%) in the entire group. Conclusion: Patients with high Ki-67 LI showed significantly more tumor progression and tumor-related death. Ki-67 LI might offer valuable predictive insights for the post-SRS management of atypical meningiomas.