Fatigue during chemoradiotherapy for nasopharyngeal cancer and its relationship to radiation dose distribution in the brain.

BACKGROUND AND PURPOSE: Fatigue during head and neck radiotherapy may be related to radiation dose to the central nervous system (CNS). The impact of patient, tumour, and dosimetric variables on acute fatigue was assessed in nasopharyngeal cancer patients undergoing chemoradiotherapy. MATERIAL AND METHODS: Radiation dose to the following retrospectively-delineated CNS structures; brainstem, cerebellum, pituitary gland, pineal gland, hypothalamus, hippocampus and basal ganglia (BG) and clinical variables were related to incidence of ⩾ grade 2 fatigue in 40 patients. RESULTS: Sixty per cent of patients reported fatigue during and following radiotherapy. Dmean and D2 to the BG and Dmean to the pituitary gland were significantly associated with fatigue during radiation (P<0.01). Dmean to the cerebellum was associated with fatigue following radiotherapy and at any time (P < 0.01). After adjusting for clinical factors, an association remained between fatigue during radiotherapy and mean dose and D2 to the pituitary gland and BG (P = 0.012, 0.036, 0.009 and 0.018) and mean dose to the cerebellum following radiation and at any time (P = 0.042 and 0.029). CONCLUSION: Disruption of connections between BG, cerebellum, and higher cortical centres or disruption of pituitary-regulated hormonal balance may be implicated in the pathophysiology of radiation-related fatigue.