Prospective pilot study to explore the melatonin level in brain tumor patients undergoing radiotherapy.

PURPOSE Our aim was to assess if the radiotherapy dose decreased the melatonin levels as well as the quality of life and sleep in brain tumor patients. METHODS We performed a follow-up study on melatonin levels in saliva and its urinary metabolite sulfatoxi-melatonine (STM) samples in patients with brain tumors treated with radiotherapy close to the pineal gland's area. We analyzed the cortisol, cortisone, and excrection of STM normalized by urinary creatinine. In some cases, a polysomnography (PSG) was performed. Quality of life questionnaires, distress scale, and sleepiness inventories were also administered. RESULTS We included twelve patients (experimental arm) and eight healthy controls (control group). No differences were observed between experimental arm and control group at baseline. No differences were detected in the experimental arm before and after delivering the radiotherapy. No clinically significant differences were found according to the radiotherapy dose delivered. CONCLUSION Melatonin levels and PSG outcomes do not change after receiving radiotherapy. The findings of this study do not show a statistically significant association between the treatment and the quality of life and sleep.