Table A1.
Results of the univariate logistic regression analysis with acute salivary dysfunction grade ≥ 2 as primary endpoint. Age was divided in five year intervals; Body Mass Index (BMI) was considered as a continuous variable and as a dichotomous one, with cutoff values set at 25.0 kg/m2 and 30.0 kg/m2 according to WHO definition of overweight and obese, respectively; histology was grouped into undifferentiated versus Squamous Cell Carcinoma (SCC); stage was dichotomised in ‘low-intermediate’ if I, II, III and ‘high’ if IVA or IVB; T stage was considered as ‘low-intermediate’ if 1, 2, 3 and ‘high’ if 4. Nodal status is 0 if N0 or N1, 1 if N2, N3a or N3b.
| Variable | Coefficient | SE | p-Value | OR | 95% CI |
|---|---|---|---|---|---|
| Gender = Male vs. Female | −0.470 | 0.426 | 0.27 | 0.63 | 0.27–1.44 |
| Age (5-year interval) | 0.064 | 0.070 | 0.36 | 1.07 | 0.93–1.22 |
| BMI (continuous variable) | 0.023 | 0.041 | 0.57 | 1.02 | 0.94–1.11 |
| BMI ≥ 25 kg/m2 = 1 | 0.066 | 0.382 | 0.86 | 1.07 | 0.51–2.26 |
| BMI ≥ 30 kg/m2 = 1 | 0.223 | 0.491 | 0.65 | 1.25 | 0.48–3.27 |
| Smoke = Yes | 0.405 | 0.514 | 0.43 | 1.50 | 0.55–4.11 |
| Comorbidities | |||||
| Hypertension = yes | 0.013 | 0.533 | 0.98 | 1.01 | 0.36–2.88 |
| Diabetes mellitus = yes | 5.483 | 6.752 | 0.42 | 240.57 | 0.0–1.3 × 108 |
| Cardiological = yes | 0.880 | 1.112 | 0.43 | 2.41 | 0.27–21.32 |
| Haematological = yes | 1.075 | 1.097 | 0.33 | 2.93 | 0.34–25.13 |
| Histology = SCC (reference) vs. undifferentiated | −0.054 | 0.632 | 0.93 | 0.95 | 0.27–3.27 |
| Stage low-intermediate (reference) vs. high | 0.065 | 0.377 | 0.86 | 1.07 | 0.51–2.23 |
| T low-intermediate (reference) vs. high | −0.606 | 0.438 | 0.17 | 0.55 | 0.23–1.29 |
| N 0 (reference) vs. 1 | 0.019 | 0.456 | 0.97 | 1.02 | 0.42–2.49 |
| GTVN Volume (cc) | 0.024 | 0.026 | 0.36 | 1.02 | 0.97–1.08 |
| Chemotherapy RT-CHT (reference) vs. iCHT + RT-CHT | 0.090 | 0.442 | 0.84 | 1.09 | 0.46–2.60 |
| RT Mode IMRT (reference) vs. VMAT | 0.243 | 0.376 | 0.52 | 1.28 | 0.61–2.67 |
| Fractionation 2.0 Gy/fraction (reference) vs 2.12 Gy/fraction |
−0.217 | 0.433 | 0.62 | 0.81 | 0.34–1.88 |
| DOSIMETRIC PARAMETERS | |||||
| cPG D98% (continuous) | 0.051 | 0.022 | 0.02 | 1.05 | 1.01–1.10 |
| Constant | −0.557 | 0.577 | |||
| OC EUD (n = 0.05, continuous) | 0.126 | 0.041 | 0.002 | 1.13 | 1.05–1.23 |
| Constant | −6.809 | 2.474 |
Abbreviations: SE = standard error; OR = odds ratio; CI = confidence interval; GTVN = nodal gross target volume, OC = oral cavity, cPG = combined parotid glands, EUD = equivalent uniform dose, RT = radiotherapy, RT-CHT = concomitant chemoradiotherapy; iCHT = induction chemotherapy; IMRT = intensity.