Purpose: Preclinical studies indicate a normal tissue sparing effect when ultra-high dose rate (FLASH) radiation is used, while tumor response is maintained. This differential response has promising perspectives for improved clinical outcome. This study investigates tumor control and normal tissue toxicity of pencil beam scanning (PBS) proton FLASH in a mouse model.
Methods And Materials: Tumor bearing hind limbs of non-anaesthetized CDF1 mice were irradiated in a single fraction with a PBS proton beam using either conventional (CONV) dose rate (0.33-0.63 Gy/s field dose rate, 244 MeV) or FLASH (71-89 Gy/s field dose rate, 250 MeV). 162 mice with a C3H mouse mammary carcinoma subcutaneously implanted in the foot were irradiated with physical doses of 40-60 Gy (8-14 mice per dose point). The endpoints were tumor control (TC) assessed as no recurrent tumor at 90 days after treatment, the level of acute moist desquamation (MD) to the skin of the foot within 25 days post irradiation, and radiation induced fibrosis (RIF) within 24 weeks post irradiation.
Results: TCD (dose for 50% tumor control) was similar for CONV and FLASH with values (and 95% confidence intervals) of 49.1 (47.0-51.4) Gy for CONV and 51.3 (48.6-54.2) Gy for FLASH. RIF analysis was restricted to mice with tumor control. Both endpoints showed distinct normal tissue sparing effect of proton FLASH with MDD (dose for 50% of mice displaying moist desquamation) of <40.1 Gy for CONV and 52.3 (50.0-54.6) Gy for FLASH, (dose modifying factor at least 1.3) and FD (dose for 50% of mice displaying fibrosis) of 48.6 (43.2-50.8) Gy for CONV and 55.6 (52.5-60.1) Gy for FLASH (dose modifying factor of 1.14).
Conclusions: FLASH had the same tumor control as CONV, but reduced normal tissue damage assessed as acute skin damage and radiation induced fibrosis.
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http://dx.doi.org/10.1016/j.radonc.2022.05.014 | DOI Listing |
Int J Radiat Biol
January 2025
Department of Biomedical Imaging and Radiological Sciences, National Yang Ming Chiao Tung University, Taipei City, Taiwan.
Purpose: Breast cancer ranks as the most prevalent cancer in women, characterized by heightened fatty acid synthesis and glycolytic activity. Fatty acid synthase (FASN) is prominently expressed in breast cancer cells, regulating fatty acid synthesis, thereby enhancing tumor growth and migration, and leading to radioresistance. This study aims to investigate how FASN inhibition affects cell proliferation, migration, and radioresistance in breast cancer, as well as the mechanisms involved.
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February 2025
Edwin L. Steele Laboratories, Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts.
Background Introduction: Vestibular schwannoma (VS) tumors typically present with sensorineural hearing loss (SNHL). Losartan has recently demonstrated prevention of tumor-associated SNHL in a mouse model of VS through suppression of inflammatory and pro-fibrotic factors, and the current study investigates this association in humans.
Methods: This is a retrospective study of patients with unilateral VS and hypertension followed with sequential audiometry at a tertiary referral hospital from January 1994 to June 2023.
Mol Oncol
January 2025
Department of Oral Pathology, College of Dentistry, Gangneung-Wonju National University, Korea.
The dynamics of focal adhesions (FAs) are essential physiological processes involved in cell spreading, metastasis, and regulation of the actin cytoskeleton. FAs are complex structures comprising proteins, such as paxillin and zyxin, which interact with extracellular membranes and influence cell motility and morphology. Although related studies have been reported in various cancers, the function and molecular mechanisms of oral squamous cell carcinoma (OSCC) remain unknown.
View Article and Find Full Text PDFMedicine (Baltimore)
January 2025
The Department of Clinical Laboratory, Zhejiang Hospital, Hangzhou, China.
Rationale: Gitelman syndrome (GS) is a rare hereditary electrolyte disorder caused by mutations in the SLC12A3 gene. There is limited literature on the role of hydrochlorothiazide (HCT) testing and the SLC12A3 single heterozygous mutation in the diagnosis and management of patients with GS. In addition, cases of GS with concomitant kidney stones are rare.
View Article and Find Full Text PDFSci Adv
January 2025
Texas Children's Cancer Center, Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA.
Chimeric antigen receptor T cells (CART) targeting CD19 through CD28.ζ signaling induce rapid lysis of leukemic blasts, contrasting with persistent tumor control exhibited by 4-1BB.ζ-CART.
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