Table 2.
Summary of measurement characteristics
| Mean values ± SD | ADC (× 10−3mm2/s) | ΔADC (%) | SFR (ml/min) | ΔSFR (%) | XQ-sum (scores) | ||||
|---|---|---|---|---|---|---|---|---|---|
| PGs | SMGs | PGs | SMGs | Unstimulated | Stimulated | Unstimulated | Stimulated | ||
| Pre-RT | 1.08 ± 0.11 | 1.38 ± 0.14a | – | – | 0.32 ± 0.25 | 0.87 ± 0.70b | – | – | 0.46 ± 0.21 |
| 1m-post-RT | 1.61 ± 0.19 | 1.79 ± 0.25a | 48.87 ± 18.45 | 29.19 ± 13.23 | 0.13 ± 0.14 | 0.27 ± 0.25b | −55.94 ± 24.55 | −49.07 ± 34.27 | 12.97 ± 5.24 |
| 3m-post-RT | 1.63 ± 0.22 | 1.83 ± 0.26a | 50.64 ± 20.80 | 32.03 ± 16.82 | 0.10 ± 0.09 | 0.31 ± 0.27b | −56.79 ± 20.17 | −47.76 ± 27.91 | 12.65 ± 4.35 |
| 6m-post-RT | 1.53 ± 0.21 | 1.71 ± 0.25a | 41.67 ± 20.50 | 23.65 ± 14.92 | 0.14 ± 0.13 | 0.40 ± 0.34b | −46.60 ± 23.34 | −32.24 ± 28.37 | 10.65 ± 4.12 |
| 9m-post-RT | 1.41 ± 0.19 | 1.61 ± 0.27a | 31.24 ± 20.04 | 16.67 ± 16.43 | 0.16 ± 0.15 | 0.47 ± 0.40b | −30.74 ± 23.86 | −29.48 ± 29.62 | 9.52 ± 4.49 |
| 12m-post-RT | 1.31 ± 0.19 | 1.52 ± 0.26a | 21.72 ± 19.83 | 9.70 ± 16.87 | 0.23 ± 0.18 | 0.62 ± 0.44b | −11.61 ± 10.71 | −12.08 ± 12.37 | 6.45 ± 3.02 |
RT radiation therapy, pre-RT 2–3 weeks before RT, (i)m-post-RT the ith month after completion of RT, PGs parotid glands, SMGs submandibular glands, ADC apparent diffusion coefficient, ΔADC (ADCpost-HT − ADCpre-HT)/ADCpre-HT, SFR saliva flow rate, ΔSFR (SFRpost-HT − SFRpre-HT)/SFRpre-HT, XQ-sum summary scores of xerostomia questionnaire
aDenotes a significant difference between SMGs and PGs (P < 0.001)
bDenotes a significant difference between SFR under stimulated and unstimulated conditions (P ≤ 0.001)