Validation of an established prognostic score after re-irradiation of recurrent glioma

Figures & data

Table 1. Patients’ characteristics.

	Patients, n (%)
Gender
Female	87 (43.7)
Male	112 (56.3)
Karnofsky Performance Score (KPS)
≥80	110 (55.3)
<80	89 (44.7)
Neurological symptoms before Re-RT
Yes	116 (58.3)
No	83 (41.7)
Primary histology
Glioblastoma, WHO IV	128 (64.3)
Gliosarcoma, WHO IV	5 (2.5)
Anaplastic astrocytoma, WHO III	21 (10.6)
Anaplastic oligoastrocytoma, WHO III	11 (5.5)
Anaplastic oligodendroglioma, WHO III	5 (2.5)
Astrocytoma, WHO II	15 (7.5)
Oligoastrocytoma, WHO II	5 (2.5)
Oligodendroglioma, WHO II	7 (3.5)
Astrocytoma, WHO I	2 (1.0)
Histology at recurrence
Glioblastoma, WHO IV	145 (72.9)
Gliosarcoma, WHO IV	6 (3.0)
Anaplastic astrocytoma, WHO III	24 (12.1)
Anaplastic oligoastrocytoma, WHO III	13 (6.5)
Anaplastic oligodendroglioma, WHO III	9 (4.5)
Astrocytoma, WHO II	1 (0.5)
Oligoastrocytoma, WHO II	1 (0.5)
Time from primary RT to Re-RT, (median, range) [months]
WHO I/II glioma	34.0 (1.0–228.1)
WHO III glioma	19.1 (5.8–175.7)
WHO IV glioma	14.4 (1.9–77.7)
RT treatment median dose in EQD2 (a/ß=10Gy) [Gy]
≤36 (mainly 36 à 2 Gy), Group A	23 (11.6)
>36 ≤ 38 (only 30 à 5 Gy), Group B	90 (45.2)
>38 ≤ 40 (only 36 à 3 Gy), Group C	36 (18.1)
>40 (mainly 46 à 2 Gy), Group D	29 (14.6)
Radiosurgery and early treatment termination	21 (10.6)

Re-RT: re-irradiation; RT: radiotherapy; WHO: World Health Organization.

Table 2. Scoring scheme to calculate the prognostic score according to the previously published work by Combs et al. [8].

Prognostic factor	Prognostic value
Primary histology
Glioblastoma WHO IV	2
Anaplastic glioma WHO III	1
Low-grade glioma WHO II/I	0
Age
≥50 years	1
<50 years	0
Time between primary radiotherapy and Re-irradiation
≤12 months	1
>12 months	0

Table 3. p Values for univariate and multivariate analysis on overall survival (using log-rank test).

	Univariate analyses			Multivariate analyses
	HR	95% CI	p Value	HR	95% CI	p Value
Primary histology
WHO I/II**			<0.001*			0.003*
WHO III	0.43	0.27–0.69		0.25	0.10–0.60
WHO IV	0.60	0.40–0.90		0.49	0.27–0.91
Age (≥50 years vs. <50 years)	1.68	1.21–2.35	0.002*	1.69	1.00–2.85	0.049*
Time between primary RT and Re-RT (>12 months vs. ≤12 months)	1.90	1.37–2.65	<0.001*	1.61	1.00–2.59	0.05*
KPS (≥80% vs. <80%)	1.98	1.44–2.71	<0.001*	2.52	1.51–4.23	<0.001*
Neurological symptoms (yes vs. no)	1.19	0.87–1.64	0.3	0.90	0.55–1.45	0.6
Gender (male vs. female)	1.05	0.77–1.43	0.8	0.94	0.61–1.45	0.8
PTV volume (≥47 ml vs. <47 ml)	0.74	0.50–1.08	0.1	1.07	0.67–1.71	0.8
Dose group
A**			0.038*			0.018*
B	1.91	0.90–4.04		1.68	0.68–4.15
C	1.45	0.77–2.73		1.06	0.49–2.27
D	2.35	1.19–4.65		2.45	1.11–5.38

HR: hazard ratio; KPS: Karnofsky Performance Score; PTV: planning target volume; Re-RT: re-irradiation; RT: radiotherapy; WHO: World Health Organization. * Significant p value; ** reference group of categorical variable.

Figure 1. Overall survival after Re-irradiation according to the Combs Prognostic Score (p < 0.001*).

Table 4. Combs Prognostic Score: median overall survival and life table.

			Proportion surviving after
Score	Number of patients	Median OS	6 months	12 months	24 months	36 months
0	14 (7.0%)	21.3	84%	84%	44%	16%
1	30 (15.1%)	11.6	73%	50%	20%	15%
2	41 (20.6%)	9.6	85%	30%	7%	4%
3	66 (33.2%)	8.1	62%	20%	5%	5%
4	48 (24.1%)	6.3	53%	19%	0%	0%

OS: Overall survival.

Combs SE, Edler L, Rausch R, et al. Generation and validation of a prognostic score to predict outcome after re-irradiation of recurrent glioma. Acta Oncol. 2012;52:147–152.

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