Added value of histogram analysis of ADC in predicting radiation-induced temporal lobe injury of patients with nasopharyngeal carcinoma treated by intensity-modulated radiotherapy

Insights into Imaging

Table 1 Characteristics of patients in the training and validation cohorts

Characteristic	Training cohort	Validation cohort	p value
Characteristic	(n = 135)	(n = 79)	p value
Age (y)*	46.67 ± 12.81 (9–73)	44.43 ± 13.59 (11–69)	0.23
Sex
Male	88	57	0.29
Female	47	22
NLRs (mean ± SD) (range) *	3.22 ± 4.38 (0.43–48.63)	3.43 ± 2.31 (0.90–14.18)	0.70
T stage			0.34
T1	8	4
T2	8	6
T3	62	45
T4	57	24
N stage			0.53
N0	16	12
N1	47	28
N2	51	32
N3	21	7
TNM stage			0.22
I	1	1
II	6	3
III	56	44
IV	72	31
Pathology			0.98
Differentiated	43	25
Undifferentiated	92	54
Treatment			0.51
A	17	16
B	51	24
C	31	14
D	19	13
E	8	4
F	9	8
PGTV_NX (mean ± SD) (range) (Gy) *	73.51 ± 1.25 (67.72–74.20)	73.72 ± 0.87 (69.96–73.92)	0.20
LD_max (mean ± SD) (range) (Gy) *	68.41 ± 5.68 (53.72–78.16)	68.11 ± 5.94 (52.86–86.07)	0.72
RD_max (mean ± SD) (range) (Gy) *	68.78 ± 5.28 (55.16–78.57)	68.62 ± 5.67 (55.93–86.07)	0.84

^*Data are mean ± standard deviation; data in parentheses are range. Treatment: A-Radiotherapy, B-Concurrent Chemoradiotherapy, C-Concurrent Chemoradiotherapy + Targeted Therapy, D-Induction chemotherapy + Concurrent Chemoradiotherapy, E-Induction chemotherapy + Concurrent Chemoradiotherapy + Targeted therapy, F-Radiotherapy + Targeted therapy. p > 0.05 suggests no significant difference between the subjects in the two cohorts. LD_max = maximum dose of left temporal lobe, NLRs = neutrophil-to-lymphocyte ratios, PGTV_NX = planning gross tumor volume included the primary nasopharyngeal tumor or enlarged retropharyngeal nodes, RD_max = maximum dose of right temporal lobe, TNM = tumor-node-metastasis