Kuniaki Saito

DualNet: Domain-invariant network for visual question answering

Visual question answering (VQA) tasks use two types of images: abstract (illustrations) and real. Domain-specific differences exist between the two types of images with respect to “objectness,” “texture,” and “color.” Therefore, achieving similar performance by applying methods developed for real images to abstract images, and vice versa, is difficult. This is a critical problem in VQA, because image features are crucial clues for correctly answering the questions about the images. However, an effective, domain-invariant method can provide insight into the high-level reasoning required for VQA. We thus propose a method called DualNet that demonstrates performance that is invariant to the differences in real and abstract scene domains. Experimental results show that DualNet outperforms state-of-the-art methods, especially for the abstract images category.

Toxicity and Outcome of Radiotherapy with Concomitant and Adjuvant Temozolomide in Elderly Patients with Glioblastoma: A Retrospective Study.

Radiation therapy with concomitant and adjuvant temozolomide (TMZ) is the standard therapy for nonelderly patients with glioblastoma. However, TMZ-based chemoradiotherapy for elderly patients with glioblastoma is controversial. The aim of this study was to investigate the benefits and adverse effects of this combined therapy in elderly patients with glioblastoma. Of the 76 newly diagnosed glioblastoma patients who were treated with standard radiotherapy (60 Gy/30 fractions) and TMZ, treatment toxicity and therapeutic outcome were evaluated in 27 elderly patients (age 65 years or older) and compared with those of 49 nonelderly counterparts (age younger than 65 years). The incidence of common toxicity criteria Grade 4 adverse events during the concomitant course was higher in the elderly group than that in the nonelderly group (26% versus 8%; p = 0.046). Cognitive dysfunction was observed only in the elderly group (p = 0.042). The median overall survival (OS) and median progression-free survival in the elderly group were 15.2 months (95% confidence interval [CI]; 12.9–18.5) and 8.4 months (95% CI; 5.1–11.7), respectively. OS was significantly shorter in the elderly group than in the nonelderly group (p = 0.021). The recursive partitioning analysis score was a prognostic factor for OS. TMZ-based chemoradiotherapy was associated with an increased risk of Grade 4 adverse events in the elderly patients during concomitant use. Thus, elderly patients who undergo a concomitant course of TMZ must be closely monitored for adverse events. Treatment of glioblastoma in elderly patients must be optimized to reduce toxicity to acceptable levels and to maintain efficacy.

Ptosis as Partial Oculomotor Nerve Palsy Due to Compression by Infundibular Dilatation of Posterior Communicating Artery, Visualized with Three-Dimensional Computer Graphics: Case Report

Oculomotor nerve palsy (ONP) due to internal carotid-posterior communicating artery (PcomA) aneurysm generally manifests as partial nerve palsy including pupillary dysfunction. In contrast, infundibular dilatation (ID) of the PcomA has no pathogenic significance, and mechanical compression of the cranial nerve is extremely rare. We describe a 60-year-old woman who presented with progressive ptosis due to mechanical compression of the oculomotor nerve by an ID of the PcomA. Three-dimensional computer graphics (3DCG) accurately visualized the mechanical compression by the ID, and her ptosis was improved after clipping of the ID. ID of the PcomA may cause ONP by mechanical compression and is treatable surgically. 3DCG are effective for the diagnosis and preoperative simulation.

Stereotactic Radiosurgery for Intracranial Gliomas

This article presents an overview of stereotactic radiosurgery for intracranial glioma. It assists readers in reviewing up-to-date literature on this topic and determining indications of radiosurgery in the treatment of glioma. Discussion also includes its recent advances and future perspectives.

Surgery for Ruptured Aneurysms or Arteriovenous Malformations Associated with Impending Herniation Due to Intracerebral Hematoma Necessitating Emergency Surgery Without Preoperative Angiography

Preoperative angiography is basically essential for a patient of intracerebral hematoma, so as to check any underlying vascular anomaly such as a ruptured aneurysm or an arteriovenous malformation (AVM). When the hematoma causes impending herniation, however, we omit preoperative angiography to save time and perform emergency surgery even if a ruptured aneurysm or an AVM is highly suspected. We experienced 8 such cases during 2.5 years: 6 cases of ruptured aneurysm and 2 of AVM. Three of them achieved good recovery and none died. Some special considerations and tactics are required before and during surgery to ensure safety. When a ruptured aneurysm is suspected, a microscope, a self-retractor and clips should be ready prior to surgery. The superficial temporal artery should be preserved just in case. After the craniotomy, the hematoma is evacuated partially for decompression away from the suspected aneurysm. Then, in case of premature rupture, the dissection is performed directly toward the bleeding site; otherwise sylvian fissure is dissected for aneurysm exploration. When an AVM is suspected, care must be taken not to injure the draining veins. It is safer to finish the emergency surgery after evacuating the hematoma and to go on to cerebral angiography. The resection of an AVM should then be performed in the chronic period. In our experiences, we were able to perform emergency surgery safely for a ruptured aneurysm or an AVM, even when we had to omit preoperative angiography because of impending herniation.

Open Set Domain Adaptation by Backpropagation

Numerous algorithms have been proposed for transferring knowledge from a label-rich domain (source) to a label-scarce domain (target). Most of them are proposed for closed-set scenario, where the source and the target domain completely share the class of their samples. However, in practice, a target domain can contain samples of classes that are not shared by the source domain. We call such classes the “unknown class” and algorithms that work well in the open set situation are very practical. However, most existing distribution matching methods for domain adaptation do not work well in this setting because unknown target samples should not be aligned with the source. In this paper, we propose a method for an open set domain adaptation scenario, which utilizes adversarial training. This approach allows to extract features that separate unknown target from known target samples. During training, we assign two options to the feature generator: aligning target samples with source known ones or rejecting them as unknown target ones. Our method was extensively evaluated and outperformed other methods with a large margin in most settings.

Abstract 1356: Frequent H3F3A K27M mutations in thalamic gliomas from young adult patients

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CA Introduction. Mutations in the H3F3A gene, which encodes histone H3.3, were recently reported in cases of pediatric glioblastoma. H3F3A K27M mutations occur in gliomas that arise at midline locations, including the pons, thalamus, and spine; moreover, this particular mutation is found mainly in tumors in children and adolescents. In this study, we aimed to determine the association between H3F3A mutations and adult thalamic glioma. Methods. Genomic H3F3A was sequenced from 20 separate thalamic gliomas. Of the 20 tumors, 18 were high-grade thalamic gliomas, and of these 18, 11 were from patients under 50 years of age (median age, 38 years; range, 17 - 46), and seven were from patients more than 50 years of age. Additionally, for 14 of the 20 gliomas, 639 genes\_including cancer-related genes and chromatin-modifier genes\_were sequenced, and the Infinium HumanMethylation450K BeadChip was used to examine DNA methylation across the genome. Results. The H3F3A K27M mutation was present in 10 of (91%) of the 11 younger patients, and absent from all seven older patients. Additionally, H3F3A K27M was not detected in the two diffuse astrocytomas. By additional sequencing, recurrent mutations were identified in TP53, ATRX, NF1, and EGFR. In addition, a KDM6A mutation was found in one case of diffuse astrocytoma and a CREBBP mutation was identified in one case of glioblastoma with the H3F3A K27M mutation. Gliomas with H3F3A K27M from pediatric or young-adult patients had similar, characteristic DNA methylation profiles. In contrast, thalamic gliomas with wild-type H3F3A had DNA methylation profiles similar to those of hemispheric glioblastomas. Conclusion. We found that high-grade thalamic gliomas from young adults, like those from children and adolescents, frequently have the H3F3A K27M mutation. Citation Format: Akitake Mukasa, Koki Aihara, Kengo Gotoh, Kuniaki Saito, Genta Nagae, Shingo Tsuji, Kenji Tatuno, Shogo Yamamoto, Shunsaku Takayanagi, Yoshitaka Narita, Soichiro Shibui, Hiroyuki Aburatani, Nobuhito Saito. Frequent H3F3A K27M mutations in thalamic gliomas from young adult patients. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1356. doi:10.1158/1538-7445.AM2014-1356