Secondary radiation damage as the main cause for unexpected volume effects: a histopathologic study of the parotid gland.

Purpose: To elucidate with a histopathological study the mechanism of region-dependent volume effects in the partly irradiated parotid gland of the rat.

Methods And Materials: Wistar rats were locally X-irradiated with collimators with conformal radiation portals for 100% volume and 50% cranial/caudal partial volumes. Single doses up to 40 Gy were applied.

Volume effects and region-dependent radiosensitivity of the parotid gland.

Purpose: To detect volume effects and possible regional differences in radiosensitivity of the rat parotid gland.

Methods And Materials: Parotid glands of male albino Wistar rats were locally X-irradiated, with collimators with conformal radiation portals used to supply 100% volume and 50% cranial/caudal partial volumes. High-resolution magnetic resonance imaging was used to provide the outlines of the parotid glands.