RESUMO
OBJECTIVE: To assess the role of quantitative salivary gland scintigraphy (SGS) in the detection of functional impairment of salivary glands in patients with head and neck cancer treated with radiotherapy (RT). MATERIAL AND METHODS: We studied 19 patients (17 men), mean age 62.4 years (44-75). Three studies were performed to each patient: baseline, 3 and 18 months after RT. SGS was acquired for 25 minutes following injection of 3.7 MBq/kg of (99m)Tc-pertechnetate with lemon juice at the end of minute 15. Excretion fraction (EF), counts per minute/pixel/MBq (CMPM) and uptake percentage were obtained from time-activity curves from ROIs placed over parotid (PG) and submandibular glands (SMG) and related to the doses received by the PG. RESULTS: EF showed a significant reduction from the baseline to the 3 months study (p<0.001) for the PG and SMG and from the baseline to the 18 months study for the SMG (p<0.001). A significant improvement of EF was seen from the 3 months to the 18 months study for the PG (p<0.05). CMPM did not change significantly from the baseline to the 3 months and 18 months studies for the PG and showed a significant reduction (p<0.01) for the SMG from the baseline to 18 months study. The uptake percentage did not change significantly between studies. A moderate association was observed between the doses to PG and the 3m study parameters. CONCLUSIONS: EF was more sensitive than uptake in assessing post-RT impairment of salivary function. In addition, it reflected functional recovery of parotid glands over time.