The work was to study protective effect of simultaneous modulated accelerated radiation therapy (SMART) on salivary function of nasopharyngeal cancer patients. Forty-six patients were treated by SMART with 2.5Gy/fraction at gross tumor volume to a total does of 70 Gy

and 2.0 Gy/fraction at the clinical treatment volume to a total does of 56 Gy. The SMART was practiced in step-and-shoot mode

one time a day

and five times each week. Fourteen patients were treated by conventional radiation therapy. All the patients received salivary gland function imaging for their uptake index

excretive index and excretive speed

so as to evaluate their degree of salivary function injury. Meanwhile

the dry discomfort in mouth of the patients was recorded and classified. The results showed that the functional indexes of the SMART group were significantly higher than those of the conventional radiation therapy group (P<0.05). The 14 patients treated by conventional radiation therapy showed xerostomia and mucositis

with only one patient in Grade 1

three in Grade 2 and 10 in Grade 3. The patients in SMART group felt much better

with14 of no xerostomia

18 in Grade 1

9 in Grade 2

and just 5 in Grade 3. The difference between the two groups is obvious (χ2 =23.52

P<0.005). Therefore

SMART can play a key role in protecting salivary gland function of naso- pharyngeal cancer patients.