Diagnostic Value of 99mTc Scintigraphy in Major Salivary Glands Hypofunction

Technetium pertechnetate (99mTc) scintigraphy is widely used to investigate salivary gland disorders, with results well correlated with secretion rates in salivary dystrophic conditions, such as Sjögren's syndrome, irradiation therapy and gland aplasia. Its diagnostic value in assessing salivary glands hypofunction is uncertain. Objectives: To evaluate the correlation between hypofunction of the major salivary glands and scintigraphy in patient's complaining of xerostomia who were diagnosed with idiopathic or drug-induced salivary glands hypofunction. Methods: For the study, 20 xerostomic patients (3 men, 17 women) diagnosed with drug-induced (14 patients) or idiopathic (6 patients) salivary glands hypofunction during 2004 and 2005 were clinically evaluated. Age ranged from 25 to 82 years (mean 59.7 y). As part of the routine diagnostic workup, unstimulated and stimulated parotid and submandibular/ sublingual (SM/SL) sialometry and Technetium pertechnetate (99mTc) scintigraphy were carried out. Results: Parotid gland and SM/SL salivary flow rate was lower than normal values in 15 (75%) and 17 (85%) of the patients, respectively. Low 99mTc uptake was observed in only 3 patients (one of them demonstrated normal parotid and SM/SL flow rate). Delayed 99mTc clearance was observed in only 3 patients (one of them demonstrated normal parotid and low SM/SL flow rate). Both 99mTc uptake and clearance were normal in 14 patients. A low parotid flow rate in 11 of these patients (79%), and a low SM/SL flow rate in 12 (86%) were recorded. Conclusions: No correlation between 99mTc scintigraphy and sialometry was observed in patients complaining of xerostomia who had idiopathic or drug-induced salivary glands hypofunction. Further studies are needed.