摘要
Aim To evaluate the effect of single or dual field irra- diation （IR） with the same dose on damage to miniature pig parotid glands. Methodology Sixteen miniature pigs were divided into two IR groups （n=6） and a control group （n=4）. The irradi- ation groups were subjected to 20 Gy X-radiation to one parotid gland using single-field or dual-field modality by linear accelerator. The dose-volume distributions between two IR groups were compared. Saliva from parotid glands and blood were collected at 0, 4, 8 and 16 weeks after irradiation. Parotid glands were removed at 16 weeks to evaluate tissue morphology.Results The irradiation dose volume distributions were significantly different between single and dual field irradi- ation groups （t----4.177, P=0.002）, although dose volume histogramin （DVH） indicated the equal maximal dose in parotid glands. Saliva flow rates from IR side decreased dramatically at all time points in IR groups, especially in dual field irradiation group. The radiation caused changes of white blood cell count in blood, lactate dehydrogenase and amylase in serum, calcium, potassium and amylase in saliva. Morphologically, more severe radiation damage was found in irradiated parotid glands from dual field irradi- ation group than that from single field irradiation group. Conclusion Data from this large animal model demons- trated that the radiation damage from the dual field irradiation was more severe than that of the single field irradiation at the same dose, suggesting that dose-volume distribution is an important factor in evaluation of the radiobiology of parotid glands.
Aim To evaluate the effect of single or dual field irra- diation （IR） with the same dose on damage to miniature pig parotid glands. Methodology Sixteen miniature pigs were divided into two IR groups （n=6） and a control group （n=4）. The irradi- ation groups were subjected to 20 Gy X-radiation to one parotid gland using single-field or dual-field modality by linear accelerator. The dose-volume distributions between two IR groups were compared. Saliva from parotid glands and blood were collected at 0, 4, 8 and 16 weeks after irradiation. Parotid glands were removed at 16 weeks to evaluate tissue morphology.Results The irradiation dose volume distributions were significantly different between single and dual field irradi- ation groups （t----4.177, P=0.002）, although dose volume histogramin （DVH） indicated the equal maximal dose in parotid glands. Saliva flow rates from IR side decreased dramatically at all time points in IR groups, especially in dual field irradiation group. The radiation caused changes of white blood cell count in blood, lactate dehydrogenase and amylase in serum, calcium, potassium and amylase in saliva. Morphologically, more severe radiation damage was found in irradiated parotid glands from dual field irradi- ation group than that from single field irradiation group. Conclusion Data from this large animal model demons- trated that the radiation damage from the dual field irradiation was more severe than that of the single field irradiation at the same dose, suggesting that dose-volume distribution is an important factor in evaluation of the radiobiology of parotid glands.
基金
supported by the National Natural Science Foundation of China(Grant 30430690)
Beijing Major Scientific Program Grants(D09 06007000091
