Artificial intelligence (AI) has been increasingly investigated as a means of supporting various radiotherapy processes. Radiotherapy is considered a suitable field for the application of AI-based technologies, owing to its complex and time-consuming clinical workflow. This review provides an overview of recent developments in AI applications across the radiotherapy workflow, including contouring, treatment planning, quality assurance, outcome prediction, and adaptive radiotherapy. This study summarizes common research directions and patterns reported in the literature, rather than focusing on the details of individual algorithms. AI-based approaches have shown the potential to improve workflow efficiency and consistency; however, their roles and levels of clinical implementation vary across radiotherapy processes. AI systems in radiotherapy may directly influence irradiation parameters, which places greater demands on safety, explainability, and quality assurance. Therefore, this review discusses not only technical progress but also clinical and operational considerations for implementation, validation, and accountability. By outlining current trends and remaining challenges, this article aims to provide an overview of AI in radiotherapy and support a broader understanding of its opportunities and limitations in clinical practice.

Therapeutic options for dementia have been extremely limited, relying on a small number of symptomatic treatments. These medications are indicated for patients with dementia and are not approved for patients with mild cognitive impairment (MCI). Since 2023, however, two anti-Aβ monoclonal antibodies for Alzheimer's disease (AD) have been available. The most widely accepted etiology for Alzheimer's disease pathogenesis is the amyloid hypothesis, which proposes that disease procession begins with amyloid-β accumulation, followed by phosphorylated tau deposition, finally leading to neuronal loss. Anti-Aβ antibody therapies are the first disease-modifying treatments designed to target this initial pathological cascade. Results from clinical trials to date indicate that therapeutic efficacy is limited to individuals with early stage dementia or those in MCI phase. These results emphasize the importance of early diagnosis and intervention, driving a substantial paradigm shift in dementia care. To enable timely diagnosis and treatment, it is essential to improve diagnostic accuracy among dementia specialists, promote collaboration between hospitals and community clinics to facilitate earlier patient referrals, and encourage government participation. These steps have proven effective in fostering early detection in other areas, including cancer screening and lifestyle-related disease checkups.

Remarkable progress has been achieved in the treatment of neurological diseases in recent years. In particular, the advent of molecular-targeted therapies, mainly monoclonal antibodies, has enabled the effective prevention of relapse and the stabilization of symptoms, leading to major advances in clinical practice. Neuroimmunological disorders include multiple sclerosis, neuromyelitis optica spectrum disorders, myasthenia gravis, and chronic inflammatory demyelinating polyneuropathy. This expanding range of therapeutic options is expected to improve the functional outcomes and quality of life of the affected patients. This review provides an overview of the neuroimmunological diseases and summarizes the latest therapeutic strategies.

Atrial fibrillation (AF) is an arrhythmia that increases with age and is a major cause of stroke and heart failure. Cardioembolic stroke associated with AF accounts for approximately 20-30% of ischemic strokes, most of which originate from thrombus formation in the left atrial appendage (LAA). Traditionally, stroke prevention has relied on anticoagulation therapy, which carries an inherent bleeding risk.

The left atrial appendage occlusion (LAAO) procedure, exemplified by the WATCHMAN device, offers a structural approach by mechanically preventing thrombus formation within the LAA, thus enabling discontinuation or reduction of anticoagulation therapy. This approach is particularly beneficial for patients with contraindications to long-term anticoagulation and has shown both stroke reduction and bleeding benefits in major clinical trials.

Although LAAO is still under development in Japan, it is well established in Western countries and represents a promising new preventive strategy for stroke in the aging population. LAAO represents an important adjunctive strategy for stroke prevention in patients with AF, complementing pharmacological and rhythm-control therapies.

Cerebrovascular diseases remain a major cause of mortality in Japan, and subarachnoid hemorrhage (SAH) is one of the most devastating types due to its high fatality and morbidity rates. The widespread use of brain screening and advances in imaging technology have increased the detection of unruptured intracranial aneurysms (UIAs). The prevalence of UIAs is approximately 3% among adults, with significant risk factors including family history, hypertension, smoking, female sex, and aging. Magnetic resonance angiography (MRA) and three-dimensional computed tomography angiography (3D-CTA) are the main diagnostic modalities, and recent developments such as 3T-MRI, vessel wall imaging (VWI), and optical coherence tomography (OCT) have improved detection and rupture risk assessment. According to the Unruptured Cerebral Aneurysm Study of Japan (UCAS Japan), the annual rupture rate of UIAs is 0.95%, and the PHASES score is widely used for risk stratification. Endovascular therapy has become increasingly prevalent, replacing surgical clipping as the primary treatment for many cases. Coil embolization remains the standard approach, supplemented by dual-catheter-, balloon-, and stent-assisted techniques. Recently, novel devices such as flow diverters and flow disruptors have expanded treatment options for wide-neck and large aneurysms. With ongoing advances in device technology and artficial intelligence (AI)-assisted treatment planning, endovascular therapy is evolving toward safer and more personalized management of unruptured intracranial aneurysms.