Table 3 Univariate and multivariate analysis for factors of complete response

Age < 70 vs. ≥70

Gender Male vs. Female

ECOG Performance status 0–1 vs.2–3

BMI < 20 vs. ≥20

Primary site Oropharynx vs. others

T-classification 1–2 vs. 3–4

N-classification 0-2b vs. 2c-3

Histology SCC vs. others

Brinkman index < 500 vs. ≥500

Habitual alcoholic consumption Yes vs. No

Use of ACEi or ARB Yes vs. No

Use of PPI or H2 blocker Yes vs. No

Oral hygiene before treatment Good vs. Poor

Coexistence of other malignancies Yes vs. No

Charlson comorbidity index 0–1 vs. ≥2

Serum albumin before treatment Within normal limits vs. less than normal range

Hemoglobin before treatment Within normal limits vs. less than normal range

Use of sleeping pills before treatment Yes .vs No

Induction chemotherapy Yes vs. No

Concurrent chemotherapy regimen CDDP vs. others

Radiation technique Conventional 3D-CRT vs. IMRT

Radiation dose 70Gy vs. <70Gy

Irradiation field Local vs. whole neck

Percutaneous endoscopic gastrostomy prior to treatment Yes vs. No

Treatment Inpatient vs. Outpatient

The worst mucositis grade during treatment 1–2 vs. 3–4

The worst dysphagia score during treatment 1–2 vs. 3–4

Aspiration pneumonia during treatment Yes vs. No