Niyazi M, Geisler J, Siefert A, Schwarz SB, Ganswindt U, Garny S, Schnell O, Suchorska B, Kreth FW, Tonn JC, Bartenstein P, la Fougère C, Belka C. FET-PET for malignant glioma treatment planning.
Radiother Oncol 2011;
99:44-8. [PMID:
21458093 DOI:
10.1016/j.radonc.2011.03.001]
[Citation(s) in RCA: 109] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2010] [Revised: 02/28/2011] [Accepted: 03/10/2011] [Indexed: 11/28/2022]
Abstract
BACKGROUND AND PURPOSE
The aim of this study was to compare MRI-based morphological gross tumour volumes (GTVs) to biological tumour volumes (BTVs), defined by the pathological radiotracer uptake in positron emission tomography (PET) imaging with (18)F-fluoroethyltyrosine (FET), subsequently clinical target volumes (CTVs) and finally planning target volumes (PTVs) for radiotherapy planning of glioblastoma.
PATIENTS AND METHODS
Seventeen patients with glioblastoma were included into a retrospective protocol. Treatment-planning was performed using clinical target volume (CTV=BTV+20mm or CTV=GTV+20mm+inclusion of the edema) and planning target volume (PTV=CTV+5mm). Image fusion and target volume delineation were performed with OTP-Masterplan®. Initial gross tumour volume (GTV) definition was based on MRI data only or FET-PET data only (BTV), secondarily both data sets were used to define a common CTV.
RESULTS
FET based BTVs (median 43.9 cm(3)) were larger than corresponding GTVs (median 34.1cm(3), p=0.028), in 11 of 17 cases there were major differences between GTV/BTV. To evaluate the conformity of both planning methods, the index (CTV(MRT)∩CTV(FET))/(CTV(MRT)∪CTV(FET)) was quantified which was significantly different from 1 (0.73 ± 0.03, p<0.001).
CONCLUSION
With FET-PET-CT planning, the size and geometrical location of GTVs/BTVs differed in a majority of patients. It remains open whether FET-PET-based target definition has a relevant clinical impact for treatment planning.
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