Radioprotective effects of melatonin against varying dose rates on radiotherapy-induced salivary gland damage scintigraphy findings

Aras S., Tanzer İ. O., Can Ü., Demir H., Sümer E., Baydili K. N., ...More

Radiation Physics and Chemistry, vol.193, 2022 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 193
  • Publication Date: 2022
  • Doi Number: 10.1016/j.radphyschem.2021.109953
  • Journal Name: Radiation Physics and Chemistry
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Chemical Abstracts Core, Chimica, Communication Abstracts, Compendex, EMBASE, INSPEC, Metadex, Pollution Abstracts, Civil Engineering Abstracts
  • Keywords: Flattening filter free, Melatonin, Radiotherapy, Salivary gland, Scintigraphy
  • Van Yüzüncü Yıl University Affiliated: No


The aim of present study was to evaluate the acute radioprotective effect of melatonin against radiotherapy-induced rat salivary gland damage by applying salivary gland scintigraphy imaging technique in varying dose rates. Forty-eight Sprague Dawley rats were randomly distributed into six group: the control group, only melatonin (MEL) group, flattening filter (FF-RT) and flattening filter free (FFF-RT) only radiotherapy groups and radiotherapy plus melatonin groups, (FF-RT)+Mel and (FFF-RT)+Mel. The head and neck region of experimental rat was irradiated with in a single fraction of a 16 Gy in FF and FFF modes. Melatonin was administered at a single dose of 10 mg/kg through intraperitoneal injection, 15 min before radiation exposure. The assessment of salivary gland function was performed using gamma scintigraphy prodecure before and after radiotherapy. Statistically significant difference in target-to-background (T/B) ratio, between the only melatonin and control groups were not observed (p = 0.981). However, when acute effects of irradiation are considered after radiotherapy, salivary gland T/B ratios was a significant difference (p < 0.001). In the only radiotherapy groups applied considering in the FF and FFF options no statistically significant difference was observed in the salivary gland T/B ratio FF-RT group compared to the FFF-RT group (p = 0.999). The T/B ratio between the radiotherapy plus melatonin groups for FF-RT and FFF-RT beam was significantly higher in the compared to the only radiotherapy (p < 0.05). In conclusion, our findings suggest that melatonin is a radioprotective agent for treatment of low and high dose rate against acute salivary gland damage during radiotherapy of head and neck cancer.