Dose-volume analysis of predictors for acute anal toxicity after radiotherapy in prostate cancer patients

Radiation Oncology

Table 4 Predictive value analysis of hemorrhoids and/or anal canal V20

Groups	Models	AAT (cases)	NAAT (cases)	Sensitivity (%)	Specificity(%)	+PV (%)	-PV (%)	AUC
Training group (N = 248 cases)	Model 1: Anal canal V20
	High(V20 > 74.93%)	53	45	54.01	70.00	54.08	70.00	0.620
	Low(V20 ≤ 74.93%)	45	105	54.01	70.00	54.08	70.00	0.620
	Model 2: Hemorrhoid
	Yes	84	55	85.71	63.33	60.43	87.16	0.745
	No	14	95	85.71	63.33	60.43	87.16	0.745
	Model 3:
	High V20 with hemorrhoid	46	13	46.94	91.33	77.97	72.49	0.691
	Others	52	137	46.94	91.33	77.97	72.49	0.691
	Model 4:
	High V20 without hemorrhoid	7	32	7.14	78.67	17.95	56.46	0.429
	Others	91	118	7.14	78.67	17.95	56.46	0.429
	Model 5:
	Low V20 with hemorrhoid	38	42	38.78	72.00	47.50	68.35	0.554
	Others	50	108	38.78	72.00	47.50	68.35	0.554
	Model 6:
	Low V20 without hemorrhoid	7	63	7.14	58.00	10.00	48.88	0.326
	Others	91	87	7.14	58.00	10.00	48.88	0.326
Validation group (N = 99 cases)	Model 1: Anal canal V20
	High(V20 > 74.93%)	18	13	58.06	80.88	58.06	80.88	0.665
	Low(V20 ≤ 74.93%)	13	55	58.06	80.88	58.06	80.88	0.665
	Model 2: Hemorrhoid
	Yes	23	29	74.19	57.35	44.23	82.98	0.658
	No	8	39	74.19	57.35	44.23	82.98	0.658
	Model 3:
	High V20 with hemorrhoid	11	4	35.48	94.12	75.00	76.19	0.631
	Others	20	64	35.48	94.12	75.00	76.19	0.631
	Model 4:
	High V20 without hemorrhoid	7	9	22.58	86.76	43.75	71.08	0.534
	Others	24	59	22.58	86.76	43.75	71.08	0.534
	Model 5:
	Low V20 with hemorrhoid	14	23	45.16	66.18	37.84	72.58	0.529
	Others	17	45	45.16	66.18	37.84	72.58	0.529
	Model 6:
	Low V20 without hemorrhoid	2	29	6.45	57.35	6.45	57.35	0.306
	Others	29	39	6.45	57.35	6.45	57.35	0.306

Abbreviations: V20 percentage of anal canal volume receiving more than 20 Gy; AAT acute anal toxicity; NAAT no-acute anal toxicity; +PV positive predictive value; −PV negative predictive value; AUC area under the curve

ISSN: 1748-717X