The purpose of this study was to evaluate prediction effect for acute radiation-induced oral mucositis (A-ROM) of two oral mucosa contouring methods in nasopharyngeal carcinoma (NPC) patients treated with helical tomotherapy.
A total of 151 AJCC 7th stage II-IVB histologically proven NPC patients receiving radical tomotherapy (TOMO) from Zhejiang Cancer Hospital were included. All patients received 0-4 cycles of platinum-based induction chemotherapy±1-3 cycles of concurrent chemotherapy (all patients received at least one chemotherapy). Oral cavity contour (OCC) and mucosa surface contour (MSC) were applied to radiation treatment plans. A-ROM were prospectively assessed weekly according to RTOG scoring criteria. Absolute DVH data was exported from RayStation V3.0 system. T-test, X2 test, binary logistic regression and ROC curve were used to analyses.
Morbidity of ≥ 3 grade A-ROM was 30.4%. In univariate analysis: V10, V15, V45, V55, V60, V65, V70 of OCC and V15, V55, V60, V65, Dmean of MSC were significant related to ≥ 3 grade A-ROM (Vx, percentage volume of organ received more than Gy, all P0.05). In binary logistic regression analysis, gender, smoking were found significantly related to ≥ 3 grade A-ROM by using OCC (male vs. female : OR=0.070, 95%CI=0.019-0.411, P = 0.008 ; smoking vs. non-smoking: OR = 15.250, 95%CI=4.421-61.980, P = 0.001). For MSC, gender, smoking and MSC V55 were independent predictors (male vs. female : OR=0.152, 95%CI=0.037-0.642, P0.001 ; smoking vs. non-smoking: OR = 4.028, 95%CI=2.145-32.079, P = 0.032 ; MSC-V55 : OR=2.665, 95%CI=1.172-3.365, P0.004). The cutoff of MSC-V55 was 10.38%, area under curve was 0.697, with sensitivity and specificity of 0.635 and 0.704, respectively.
We recommend MSC as a more reasonable method for oral mucosa contouring in TOMO treatment plan for nasopharyngeal carcinoma patients.
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