Parotid Gland Stem Cell Preservation during Intensity-Modulated Radiotherapy for Nasopharyngeal Carcinoma: Dosimetric Analysis and Feasibility

Table 5

Comparison of mean irradiation doses of other organs at risk in IMRT plans of the two groups.

Organs at risk	Regular group (n = 35)	Restricted group (n = 45)	t
Spinal cord	21.95 ± 3.54	21.74 ± 4.37	0.2313	0.8177
Brainstem	29.25 ± 2.19	30.31 ± 2.10	2.1981	0.0309
Left temporal lobe	18.79 ± 3.12	18.55 ± 3.41	0.3240	0.7468
Right temporal lobe	19.06 ± 2.39	19.58 ± 3.39	0.7703	0.4435
Left temporomandibular joint	38.54 ± 3.40	39.05 ± 3.65	0.6386	0.5249
Right temporomandibular joint	39.61 ± 3.28	39.47 ± 3.32	0.2136	0.8314
Left lens	5.28 ± 1.26	5.31 ± 1.24	0.3531	0.7249
Right lens	5.47 ± 1.68	5.53 ± 1.71	0.1348	0.8931
Left optic nerve	33.07 ± 2.77	32.85 ± 2.45	0.3763	0.7077
Right optic nerve	34.55 ± 3.05	34.71 ± 3.34	0.2207	0.8259
Left eyeball	11.17 ± 1.67	11.26 ± 2.08	0.2088	0.8351
Right eyeball	10.83 ± 1.70	10.92 ± 1.35	0.3520	0.7258
Left submandibular gland	38.24 ± 4.26	38.64 ± 4.38	0.7219	0.4725
Right submandibular gland	38.11 ± 3.97	38.18 ± 3.94	0.0553	0.9560
Left middle ear	44.87 ± 6.41	44.62 ± 7.05	0.1441	0.8857
Right middle ear	45.68 ± 5.47	45.41 ± 5.53	0.2095	0.8346
Left mandible	34.08 ± 2.32	35.22 ± 2.09	2.3063	0.0237
Right mandible	34.91 ± 1.96	36.06 ± 2.66	2.1437	0.0352
Throat	32.30 ± 2.79	32.49 ± 3.39	0.2683	0.7892
Oral cavity	31.36 ± 2.96	33.63 ± 3.64	2.9972	0.0036

The bold text means statistically significant.