Mucositis incidence, OMAS scale. P = .007. (WA = 2.5 × [(Σui : 3 ×Nu) + (Σei : 2 × Ne)], in which Σui is the sum of the ulcerous area, Nu equals the number of ulcerous areas, Σei is the sum of the erythema's intensity, and Ne is the number of areas with erythemas.