Establishment and validation of a nomogram with intratumoral heterogeneity derived from 18F-FDG PET/CT for predicting individual conditional risk of 5-year recurrence before initial treatment of nasopharyngeal carcinoma

Table 1 Patient characteristics in the training and validation cohorts

Characteristics	Training cohort (N = 101)	Validation cohort (N = 70)	P value^a
Age (years), median (min-max)	43 (16–78)	46 (17–70)	0.61
Gender, n (%)			0.18
Male	81 (80.20)	50 (71.43)
Female	20 (19.80)	20 (28.57)
EBV antibody, n (%)			0.19
Positive	46 (45.54)	39 (55.71)
Negative/Unknown	55 (54.46)	31 (44.29)
Histology, WHO Type^b, n (%)			0.24
I/II	31 (30.69)	15 (21.43)
III	70 (69.31)	55 (78.57)
BMI (Kg/m²), mean (min-max)	23.14 (17.30–32.91)	22.30 (15.40–29.05)	0.09
T stage, n (%)			0.88
T1	31 (30.69)	21 (30.00)
T2	13 (12.87)	8 (11.43)
T3	45 (44.56)	33 (47.14)
T4	12 (11.88)	8 (11.43)
N stage, n (%)			0.81
N0	5 (4.95)	3 (4.29)
N1	21 (20.79)	13 (18.57)
N2	57 (56.44)	42 (60.00)
N3	18 (17.82)	12 (17.14)
M stage, n (%)			0.75
M0	94 (93.07)	66 (94.29)
M1	7 (6.93)	4 (5.71)
TNM stage (AJCC), n (%)			0.48
III	67 (66.34)	50 (71.43)
IV a	27 (26.73)	16 (22.86)
IV b	7 (6.93)	4 (5.71)
Concomitant systemic treatment with IMRT, n (%)			0.92
None	6 (5.94)	1 (1.43)
Chemotherapy	80 (79.21)	61 (87.14)
Targeted Therapy	15 (14.85)	8 (11.43)
Treatment results
Median Follow-up, months, (min-max)	63 (4–109)	67.5 (3–113)	0.57
5-year LRC rate	89.11%	87.14%	0.29
5-year PFS rate	79.21%	68.57%	0.12

^aStatistical comparisons between the training and validation cohorts were computed using the Mann–Whitney U test for continuous variables and χ² test for categorical variables. A P-value of < 0.05 indicates a significant difference
^bWHO Type I = keratinizing, WHO Type II = non-keratinizing (differentiated), WHO Type III = non-keratinizing (undifferentiated)
Abbreviations: WHO World Health Organization, AJCC American Joint Committee on Cancer, IMRT Intensity-modulated radiation therapy, LRC Loco-regional control, PFS Progression-free survival

ISSN: 1471-2407