[Histomorphologic and salivary gland scintigraphic findings in radiation-induced sialadenitis due to fractionated irradiation of the head and neck region of rats. A model for evaluating potentially radioprotective substances].

INTRODUCTION: The aim of this study was to correlate structural, histomorphological damage of the salivary gland with scintigraphic findings during fractioned radiotherapy.

METHODS: The head and neck area of 27 WAG/RijH rats was irradiated with (60)Co-gamma-rays (60 Gy/30f/6 weeks). A port-system was implanted and (99m)Tc-pertechnetat applied at different stages of irradiation (0, 16, 30, 46, 60 Gy and 6 months post irradiation).

RESULTS: After the application of 16 Gy an intra- and extra-cellular oedema developed in the salivary glands. The progressive vacuolisation (30 Gy) passed over into lipomatosis (46 Gy) and necrosis (60 Gy) in the parotid and mandibular glands. Six months after irradiation treatment, the chronic histomorphological damage corresponded to stage II according to Seifert. The corresponding loss in gland function was 13% (16 Gy); 26% (30 Gy); 57% (46 Gy); 75% (60 Gy) and 66.5% (6 months post irradiation).

CONCLUSION: This animal model demonstrates the correlation between histomorphological and scintigraphic findings.