Comparisons of late vaginal mucosal reactions between interstitial and conventional intracavitary brachytherapy in patients with gynecological cancer: speculation on the relation between pallor reaction and stenosis

To examine late vaginal mucosal reactions in patients following interstitial brachytherapy (ISBT) compared with that of intracavitary brachytherapy (ICBT).We introduced a modified Dische score to examine late reactions in vaginal mucosa of patients with gynecological cancer who underwent vaginal brachytherapy at 6, 12, 18, 24, 36, and 60 months after treatment. A comparison was made between patients who underwent ISBT (n=37) and those under conventional ICBT (n=63) with a median follow-up time of 41 months. The ICBT group included only patients with newly diagnosed cervical cancer, whereas the ISBT group included 17 patients with recurrent and 20 with newly-diagnosed cancer.Grade 1 reactions of bleeding and discharge were exhibited by12% of patients. Erythema was detected in approximately 30% (mainly grade 1) of the patients. A total of two (3%) patients developed superficial ulceration after ICBT, whereas three (8%) grade 1 ulcers were detected in patients after ISBT. Telangiectasias were detected in approximately 70% (60% grade 1 and 10% grade 2) of patients. No statistically significant difference was found between the patients after ISBT and ICBT. After ISBT, patients have a higher stenosis rate than after ICBT (p=0.003). The pallor scores showed a strong correlation with stenosis (p0.0001) and were higher in patients after ICBT than in patients after ISBT (p=0.006).After ISBT, patients exhibited milder but similar late mucosal reactions compared to those after ICBT, except the fact that the stenosis was more severe and the pallor reaction was milder in these patients. It can be, therefore, concluded that the pallor reaction is related to stenosis.