Table 1.

Patient characteristics

	All patients (N = 51)	Primary RT cohort (n = 35)	ReRT cohort (n = 16)
Characteristic	No. (%) or median (range)	No. (%) or median (range)	No. (%) or median (range)
Sex
Male	34 (66.7%)	23 (65.7%)	11 (68.75%)
Female	17 (33.3%)	12 (34.3%)	5 (31.25%)
Age (y)	61 (26-81)	62 (26-81)	55 (30-73)
Diagnosis before RT
Anaplastic astrocytoma	10 (19.6%)	8 (22.9%)	2 (12.5%)
Glioblastoma	41 (80.4%)	27 (77.1%)	14 (87.5%)
WHO grade before RT
WHO grade 3	10 (19.6%)	8 (22.9%)	2 (12.5%)
WHO grade 4	41 (80.4%)	27 (77.1%)	14 (87.5%)
WHO grade before reRT
WHO grade 3	-	NA	1 (6.25%)
WHO grade 4	-	NA	15 (93.25%)
IDH1/2 mutational status
IDH1/2 mutated	7 (13.7%)	4 (11.4%)	3 (18.75%)
IDH1/2-wildtype	44 (86.3%)	31 (88.6%)	13 (81.25%)
MGMT promotor status
MGMT methylated	25 (49%)	15 (42.9%)	10 (62.5%)
MGMT unmethylated	25 (49%)	20 (57.1%)	5 (31.25%)
Unknown	1 (2%)	0	1 (6.25%)
Neurosurgical intervention before primary RT
Resection	11 (21.6%)	3 (8.6%)	8 (50%)
Stereotactical biopsy	40 (78.4%)	32 (91.4%)	8 (50%)
Prescribed primary RT dose
61.2 Gy (1.8 Gy × 34)	1 (2%)	0	1 (6.25%)
60 Gy (2 Gy × 30)	32 (62.7%)	20 (57.1%)	12 (75%)
55 Gy (2.2 Gy × 25)	1 (2%)	0	1 (6.25%)
40.05 Gy (2.67 Gy × 15)	17 (33.3%)	15 (42.9%)	2 (12.5%)
Neurosurgical intervention before reRT
Resection	-	NA	3 (18.75%)
Stereotactical biopsy	-	NA	5 (31.25%)
None	-	NA	8 (50%)
Prescribed reRT dose
43.2 Gy (2.4 Gy × 18)	-	NA	8 (50%)
36 Gy (2 Gy × 18)	-	NA	8 (50%)

Abbreviations: IDH = isocitrate dehydrogenase; MGMT = O⁶-alkylguanine-DNA alkyltransferase; NA = not applicable; reRT = reirradiation; RT = radiation therapy; WHO = World Health Organization.

Patients were examined with GE-180 translocator protein positron emission tomography before RT or reRT.