Histopathological changes in parotid and submandibular glands of patients treated with preoperative chemoradiation therapy for oral cancer

We retrospectively evaluated the relationship between computed tomography (ct)- and histopathological findings of parotid and submandibular glands in six patients treated for advanced oral cancer. eligibility criteria were a pathologic diagnosis of oral squamous cell carcinoma,preoperative chemoradiation therapy (crt) with a total dose of 30 gy and oral s-1 (80 mg/m2/day),the availability of morphological assessments by ct and of functional assessments with the saxon test before- and 2 weeks after crt,and the availability of histopathological slides of irradiated parotid and submandibular glands. in the histopathological interpretation,gland structures were divided into acinar-,duct-,and adipose cells and other tissues. the mann-whitney test and the spearman rank correlation test were used to determine histopathological changes. after 30-gy irradiation,saliva production and parotid and submandibular volumes were significantly decreased (p < 0.05 each). histopathological analysis demonstrated that 30-gy irradiation resulted in a loss of acinar cells although acinar cells in the submandibular gland were relatively retained; the median acinar rate in the parotid and submandibular glands was 1.1% and 19.0%,respectively. the ct values after crt were inversely correlated with adipose ratios (r = -0.98,p < 0.01) and there was a strong correlation between ct values before and after crt (r = 0.97,p < 0.01). our results suggested that acinar cell loss is a main contributor to changes in the volume and function of irradiated human parotid and submandibular glands. the ct value may reflect the adipose ratio rather than salivary function.