A comparative experimental study on the impact of radiotherapy dose rate and melatonin pretreatment in tongue and esophageal tissues
International Journal of Radiation Biology, cilt.102, sa.9, ss.1149-1158, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 102 Sayı: 9
- Basım Tarihi: 2026
- Doi Numarası: 10.1080/09553002.2026.2669157
- Dergi Adı: International Journal of Radiation Biology
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, Chemical Abstracts Core, EMBASE, MEDLINE, Academic Search Ultimate (EBSCO), Biomedical Reference Collection: Corporate Edition (EBSCO)
- Sayfa Sayıları: ss.1149-1158
- Anahtar Kelimeler: Radiotherapy, flattening filter, flattening filter free, melatonin, radioprotection
- Sağlık Bilimleri Üniversitesi Adresli: Evet
Özet
Aim: This study aimed to investigate the differential biological responses in tongue and esophageal tissues induced by flattening filter (FF) and flattening filter-free (FFF) beams at varying dose rates, and to assess the radioprotective role of melatonin (MEL) pretreatment. Materials and methods: Forty female Wistar albino rats (6–8 weeks) were divided into five groups: control (G1), FF (16 Gy at 600 MU/min, G2), FF + MEL (G3), FFF (16 Gy at 2400 MU/min, G4), and FFF + MEL (G5). Radiotherapy (RT) was delivered to the head and neck region. MEL (50 mg/kg, intraperitoneal) was administered 15 minutes prior to irradiation. Serum levels of IFN-γ, IL-1β, IL-6, IL-10, caspase-3, and LDH were measured using enzyme-linked immunosorbent assay (ELISA). Histopathological evaluations of tongue and esophageal tissues were performed with hematoxylin and eosin staining, and BCL-2 expression was assessed by immunofluorescence. Results: Serum IFN-γ, IL-1β, IL-6, caspase-3, and LDH levels were significantly increased in the RT groups (G2 and G4) (p < .05); MEL pretreatment (G3 and G5) showed a tendency to reduce these increases but did not reach statistical significance (p > .05). Histopathological evaluation showed increased tissue damage in the esophageal and tongue tissues in groups G2 and G4; histopathological scores were significantly lower in the groups pretreated with MEL (G3 and G5) (p < .05). BCL-2 expression showed an increased trend after irradiation, and this trend was more pronounced in the MEL-treated groups, although the differences between the groups were not statistically significant (p > .05). No significant differences were found between FF and FFF beams in terms of biochemical, histopathological, and immunofluorescence results (p > .05). Conclusions: Melatonin pretreatment significantly reduced histopathological tissue damage following irradiation. However, reductions in serum inflammatory and apoptotic markers did not reach statistical significance. No significant differences were observed between FF and FFF beam modalities.