Search

Brachytherapy (BT) plays a key role in cancer treatment by delivering a high dose to a small volume over a short time. The use of BT is currently validated in a wide range of cancers such as cervical, prostate and breast cancers while being a favourable choice for organ preservation, such as in penile or rectal cancer, or in the setting of reirradiation. Consideration of the radiobiology of BT is integral to the choices made around dose and fractionation and combination with other techniques such as external beam radiotherapy (EBRT). Much of the radiobiology of brachytherapy is based on historic data, but fortunately there is a drive to integrate translational research including radiobiologic parameters into modern BT research. In a changing therapeutic landscape moving to a high dose rate (HDR) based on high dose per fraction, it is important to ensure that the incorporation of new radiobiology knowledge helps to drive clinical practice.This manuscript takes the ESTRO Brachytherapy pre-meeting course (May 3, 2024 - Glasgow ESTRO meeting) as a base and develops the concepts to present an overview of radiobiology in brachytherapy. Presented are 3 different considerations: the fundamentals of BT radiobiology (BT radiobiology history, biology and BT, α/β and re-irradiation), the pre-clinical radiobiology approach (pulsed dose radiotherapy (PDR) vs HDR, BT vs best EBRT techniques, high dose regions and integrated boost) and clinical radiobiology approaches (optimal number of BT fractions, radiobiology in BR for cervical, prostate, breast, skin/H&N and gastro-intestinal cancers). Presented is an analysis of radiobiology and modelling in BT aiding the integration of scientific pre-clinical and clinical data to allow a better understanding of the use of radioactive sources for cancer treatment.

PURPOSE: With the growing popularity of badminton worldwide, the incidence of badminton-related ocular injuries is expected to rise. The high velocity of shuttlecocks renders ocular traumas particularly devastating, especially with the possibility of permanent vision loss. This study investigated the mechanism behind ocular complications through simulation analyses of mechanical stresses and pressures upon shuttlecock impact. DESIGN: Computational simulation study. PARTICIPANTS: None. METHODS: A 3-dimensional human eye model was reconstructed based on the physiological and biomechanical properties of various ocular tissues. Finite element analysis simulations involved a frontal collision with a shuttlecock projectile at 128.7 km/hour (80 mph). Intraocular pressure (IOP) changes and tissue stress were mapped and quantified in the following ocular structures: the limbus, ciliary body, zonular fibers, ora serrata, retina, and optic nerve head. MAIN OUTCOME MEASURES: Intraocular pressure and tissue stress. RESULTS: Upon shuttlecock impact, compressive force was transferred to the anterior pole of the cornea, propagating posteriorly to the optic nerve head. Deflection of forces anteriorly contributed to refractory oscillations of compressive and tensile stress of ocular tissue. Initial impact led to a momentary (

Introduction: Reirradiation has gained increasing interest, as advances in systemic therapy increase the survival of patients with cancer, and modern radiation techniques allow more precise treatments. However, high-quality prospective evidence on the safety and efficacy of reirradiation to guide clinical practice remains scarce. This systematic review evaluates ongoing prospective studies on reirradiation to identify research gaps and priorities., Methods: A systematic review of ClinicalTrials.gov was conducted on July 11, 2024, using search terms related to reirradiation. Inclusion criteria were prospective studies that were "recruiting," "not yet recruiting," or "active, not recruiting." Studies with published results, retrospective, and in-silico studies were excluded. The review followed PRISMA 2020 guidelines and recommendations for systematic searches of clinical trial registries., Results: Among 1026 identified studies, 307 were screened, 99 were included. Fourty (40%) focused on central nervous system (CNS), 23 (23%) head and neck, and 17 (17%) on pelvic reirradiation. Most studies (90%) were interventional, with 32 (32%) phase II and 4 (4%) phase III trials. Sixteen trials were randomized (RCTs), including the 4 phase III trials for recurrent glioblastoma, rectal and nasopharyngeal cancer. Ten dose escalation trials focus on recurrent prostate, rectal, and non-small cell lung cancer as well as glioma. Modern high-precision radiotherapy techniques were frequently used, with 21 (21%) studies using stereotactic radiotherapy and 17 (17%) using particle therapy. Combinations with systemic therapies were investigated in 41 (41%) studies., Conclusion: Ongoing studies most frequently focus on CNS, head and neck, and pelvic reirradiation. There remains a critical need for RCTs, in particular for lung, breast, and gynecological cancers. Dose escalation trials, application of precision radiation techniques and combinations with modern systemic therapy may help define the optimal multimodality treatment schedules., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)