FLASH radiotherapy (FLASH-RT) is an innovative approach that delivers ultra-high dose rates exceeding 40 Gy in less than a second, aiming to widen the therapeutic window by minimizing damage to normal tissue while maintaining tumor control. This review explores the advancements, mechanisms, and clinical applications of FLASH-RT across various radiation sources. Electrons have been predominantly used due to technical feasibility, but their limited penetration depth restricts clinical application. Protons, offering deeper tissue penetration, are considered promising for treating deep-seated tumors despite challenges in beam delivery. Preclinical studies demonstrate that FLASH-RT reduces normal tissue toxicity in the lung, brain, skin, intestine, and heart without compromising antitumor efficacy. The mechanisms underlying the FLASH effect may involve oxygen depletion leading to transient hypoxia, reduced DNA damage in normal tissues, and modulation of immune and inflammatory responses. However, these mechanisms are incompletely understood, and inconsistent results across studies highlight the need for further research. Initial clinical studies, including treatment of cutaneous lymphoma and bone metastases, indicate the feasibility and potential benefits of FLASH-RT in patients. Challenges for clinical implementation include technical issues in dosimetry accuracy at ultra-high dose rates, adaptations in treatment planning systems, beam delivery methods, and economic considerations due to specialized equipment requirements. Future directions will involve comprehensive preclinical studies to optimize irradiation parameters, large-scale clinical trials to establish standardized protocols, and technological advancements to overcome limitations. FLASH-RT holds the potential to revolutionize radiotherapy by reducing normal tissue toxicity and improving therapeutic outcomes, but significant research is required for real-world clinical applications.
Citations
, Bong Suk Shim Recently, antibiotic resistant organisms have increasing tendency. So, we studied causative organisms in urinary tract infection and investigated the resistance to each antibiotics.
From January 2004 to March 2004, uropathogens and antibiotic sensitivity tests in urine culture of patients with urinary tract infection were analyzed retrospectively. One hundredeleven women and 51 men in 168 adults were included.
Incidence of positive urine culture was 66.1% in women, and 33.9% in men. Mean age was 62.6 years old in men, and 61.7 years old in women. The most common uropathogen was
, Bong Suk Shim Chemical constituent of urinary stone is important for the management and the prevention of recurrence. We performed chemical analysis of the urinary stone and investigatedits chemical constituent.
From January 2003 to December 2005, stone fragments were collected after extracorporeal shock wave lithotripsy (ESWL,
80 stone fragments were collected from male (55.6%), 64 stones from female (44.4%), and male to female ratio was 1.25 : 1. The mean age between males (mean age ; 47.2 years old)and females (mean age ,47.9 years old) was not different. The most frequently found location of urinary stones was ureter(91.0%) Of 144 patients in urine analysis,54 had pyuria (37.5%). The most frequently found constituent in stone fragments was that of calcium(
Calcium is the most common chemical constituent in urinary stone. Urinary infection was complication in 100% of patients with MAP stones.
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