Comparison of predicted and clinical response to radiotherapy: A radiobiology modelling study

Figures & data

Table I.  Individual patient data.

Pt	Vol cc^3	Radiotherapy	Brachy-therapy	Tpot (h)	SF2	Chemo- therapy/ response	Surgery	Q	LR
2	11.5	1.7bid/64.6Gy/35d	–	26	0.30	CR	–	0	–
4	14.2	1.7bid/64.6Gy/31d	+IRT	40	0.43	CR	–	0	–
5	6.3	1.7bid/64.6Gy/32d	+IRT	43	0.66	–	–	0	Yes
7	T3	1.7bid/64.6Gy/31d	+IRT	103	0.28	CR	–	1	–
8	14.1	1.7bid/64.6Gy/31d	+IRT	47	0.28	PR	–	1	–
9	> > 4.2	1.7bid/64.6Gy/31d	+IRT	49	0.53	MR	–	0	–
11	47.7	1.7bid/51Gy/18d	–	101	0.94	MR	yes	0	Yes
13	0.4	1.7bid/68Gy/31d	–	102	0.29	CR	–	1	–
15	58.6	1.7bid/64.6Gy/31d	+IRT	87	0.44	PR	–	0	–
17	>14.1	1.7bid/64.6Gy/29d	+IRT	195	0.40	CR	–	0.97	–
18	3.1	1.7bid/64.6Gy/31d	–	112	0.49	–	yes	0	–
19	9.8	1.7bid/64.6Gy/36d	+IRT	250	0.42	–	–	0.92	Yes
20	> > 4.2	1.7bid/68Gy/32d	–	143	0.17	PR	–	1	–
21	17.7	1.7bid/40.8Gy/15d	+IRT	446	0.28	–	yes	0.80	–
24	T3	1.7bid/68Gy/37d	–	33	0.32	NE	–	0.06	–
25	8.2	1.7bid/64.6Gy/35d	–	56	0.46	PR	yes	0	Yes
26	4.2	1.7bid/61.2Gy/32d	+IRT	36	0.5	NE	–	0	–
28	22.45	1.7bid/64.6Gy/32d	+IRT	38	0.55	PR	–	0	–
29	23.6	1.7bid/64.6Gy/36d	–	660	0.66	–	–	0	–
30	14.1	1.7bid/51Gy/25d	+IRT	26	0.73	PR	–	0	–
31	0.8	1.7bid/40.8Gy/32d	+IRT	127	0.28	PR	–	0.78	–
32	33.5	1.7bid/64.6Gy/31d	+IRT	265	0.16	PR	–	1	–
33	11.8	1.7bid/51Gy/27d	–	324	0.66	PR	yes	0	–
34	19.2	1.7bid/64.6Gy/32d	+IRT	141	0.38	PR	–	0.98	–
35	51.1	1.7bid/64.6Gy/31d	–	58	0.22	–	–	1	–
36	39.3	1.7bid/64.6Gy/31d	+IRT	427	0.25	MR	–	1	–
37	T4	1.7bid/64.6Gy/31d	+IRT	135	0.32	PR	–	1	Yes
38	14.1	1.7bid/64.6Gy/38d	+IRT	125	0.34	PR	yes	1	–
39	47.7	1.7bid/64.6Gy/37d	–	24	1.00	CR	–	0	Yes
40	3.3	1.7bid/64.6Gy/31d	+IRT	68	0.40	PR	–	0.63	–
41	0.6	1.7bid/61.2Gy/36d	+IRT	111	0.70	–	–	0	–
42	T2	1.7bid/64.6Gy/31d	–	11	0.33	PR	–	0	Yes
43	T4	1.7bid/64.6Gy/35d	+IRT	179	0.59	–	–	0	–
44	5.9	1.7bid/64.6Gy/36d	+IRT	411	0.82	PR	–	0	–
45	19.2	1.7bid/64.6Gy/35d	+IRT	185	0.28	PR	–	1	–
46	13.6	1.7bid/64.6Gy/31d	+IRT	118	0.40	CR	–	0.88	–
47	33.5	1.7bid/51Gy/21d	–	186	0.41	MR	yes	0	Yes
48	3.1	1.7bid/64.6Gy/31d	+IRT	236	0.40	MR	–	1	–
49	33.5	1.7bid/64.6Gy/31d	+IRT	87	0.34	MR	–	1	–
50	119.1	2/60Gy/50d	–	141	0.41	PR	–	0	Yes
52	7.9	1.7bid/54.4Gy/49d	+IRT	166	0.36	MR	–	0.41	–
53	7.9	1.7bid/64.6Gy/31d	+IRT	273	0.29	MR	–	1	–
54	8.2	1.7bid/64.6Gy/37d	–	299	0.47	MR	–	0.15	Yes
55	0.07	1.7bid/68Gy/35d	–	186	0.52	MR	–	0.74	Yes
56	113.1	1.7bid/51Gy/32d	–	140	0.31	MR	yes	0.57	–
57	T3	1.7bid/64.6Gy/31d	–	81	0.20	MR	–	1	–

Vol = tumour volume; Chem res = response to chemotherapy; LR = local recurrence; CR = complete response; PR = partial response; MR = minor response; NE = non evaluable; Bid = two fractionations daily. Q = probability of cure (1 equals 100%). IRT = Brachytherapy; >.> > = larger or much larger than. T3/T4= volume according to T stage (see methods and material).

Table II.  Predicted vs. actual local control in the 18 patients who only received ERT (brachtherapy not included). No clinical local control equals residual disease. In the fourth column average data are presented using the same SF2 and Tpot in all patients.

	Local control
Patient	Predicted (Q)	Actual	Other treatment	Predicted local control (Q) based on average data SF2 0.4 and Tpot 120h
2	0	Yes	Cr chemo	0.79
11	0	No	Op. less than pr chemo	0
13	0.99	Yes	Cr chemo	0.99
18	0	Yes	Op. no chemo	0.97
20	1	Yes	Pr chemo	0.99
24	0.06	Yes	Chemo non evaluable	0.96
25	0	No	Op. chemo pr	0.88
29	0	Yes	Died <5 mth*	0.67
33	0	Yes	Op. chemo pr	0
35	0.99	Yes	No chemo	0.64
39	0	No	Cr chemo	0.39
42	0	No	Pr chemo	0.96
47	0	No	Op. less than pr chemo	0
50	0	No	Pr chemo	0
54	0.15	No	Less than pr chemo	0.85
55	0.74	No	Less than pr chemo	0.99
56	0.57	Yes	Op. less than pr chemo	0
57	1	Yes	Less than pr chemo	0.92

Cr = Complete response. Pr = Partial response. Q = Probability where 1 equals 100%

* No evidence of disease at death.

Table III.  Local control in relation to probability of cure.

	Number of patients
Local control	Q > 95%	Q = 95–50%	Q = 50–5%	Q < 5%
No	0/18	1/18	1/18	6/18
Yes	4/18	1/18	1/18	4/18

Q = probability of cure

Table IV.  Individual compared to average data at the level 0.95 < Q<0.05.

	Sensitivity	Specificity	PPV	NPV
Individual data	75%	40%	60%	100%
Average data	38%	40%	60%	67%

PPV = positive predictive value; NPV = negative predictive value.