Relapse patterns after radiochemotherapy of glioblastoma with FET PET-guided boost irradiation and simulation to optimize radiation target volume

Table 4 Volumes of standard and simulated PTVs on the basis of FET-PET

Pat. No.	PTV-2 MRI standard (ml)	PTV FET-1 +5 mm margin (ml)	PTV FET-1 +7 mm margin (ml)	PTV FET-1 +10 mm margin (ml)
1	245	122	147	214
2	164	98	118	163
3	117	92	112	143
4	248	125	150	194
5	161	101	114	146
6	256	182	213	286
7	224	106	126	166
8	348	216	253	308
9	209	161	187	259
10	160	138	160	216
11	364	233	263	304
12	386	265	297	342
13	231	175	197	258
mean	240	155	180	230
median	231	138	160	216
SD	83	56	62	67
Range	117–386	92–265	112–297	143–342

(Volumes of conventional PTV2 and simulated PTVs based on FET uptake at baseline (FET-1) expanded by 5, 7 and 10 mm margin in ml. The PTV include an additional margin of 5 mm around the CTV which is standardly used to compensate the set-up- and immobilisation uncertainties)
PTV Planning Target Volume
FET-1: pathological FET-Volume in ml at baseline (post surgery)
MRI-1:Gd-contrast-enhancement in ml at baseline (post surgery)
SD Standard Deviation

ISSN: 1748-717X