Purpose: The purpose of this study was to determine by using (99m)Tc-diethylenetriaminepentaacetic acid (DTPA) lung scintigraphy whether amifostine given before irradiation protects alveolocapillary integrity in a rabbit model.
Methods and materials: Twenty white New Zealand rabbits were randomly divided into 4 groups: (1) control (CONT), (2) amifostine alone (AMF), (3) radiation (RAD), and (4) radiation plus amifostine (RAD+AMF). The AMF and RAD+AMF groups received amifostine. The RAD and RAD+AMF groups were irradiated to the right hemithorax with a single dose of 20 Gy using a (60)Co treatment unit. Amifostine (200 mg/kg) was given i.p. 30 min before irradiation. The (99m)Tc-DTPA radioaerosol study was performed 14 day after irradiation.
Results: The mean clearance rate of (99m)Tc-DTPA in control subjects was 140 +/- 21 min. The highest t((1/2)) value was noted in the RAD group (603 +/- 105 min, p = 0.001). There were no significant differences between the (99m)Tc-DTPA lung clearance rates of the CONT, RAD+AMF (238 +/- 24 min), and AMF groups (227 +/- 54 min). The mean penetration index values of CONT, RAD, AMF, and RAD+AMF are 63% +/- 1.6%, 63% +/- 2.5%, 60% +/- 2.9%, and 63% +/- 2%, respectively.
Conclusions: We concluded that amifostine treatment before the lung irradiation protects the lung alveolocapillary integrity. This study confirms the protective effect of amifostine in an acute phase of radiation lung injury.