Association of 11C-methionine PET uptake with site of failure after concurrent temozolomide and radiation for primary glioblastoma multiforme.
OBJECTIVE
To determine whether increased uptake on 11C-methionine-PET (MET-PET) imaging obtained before radiation therapy and temozolomide is associated with the site of subsequent failure in newly diagnosed glioblastoma multiforme (GBM).


METHODS
Patients with primary GBM were treated on a prospective trial with dose- escalated radiation and concurrent temozolomide. As part of the study, MET-PET was obtained before treatment but was not used for target volume definition. Using automated image registration, we assessed whether the area of increased MET-PET activity (PET gross target volume [GTV]) was fully encompassed within the high-dose region and compared the patterns of failure for those with and without adequate high-dose coverage of the PET-GTV.


RESULTS
Twenty-six patients were evaluated with a median follow-up of 15 months. Nineteen of 26 had appreciable (>1 cm(3)) volumes of increased MET-PET activity before treatment. Five of 19 patients had PET-GTV that was not fully encompassed within the high-dose region, and all five patients had noncentral failures. Among the 14 patients with adequately covered PET-GTV, only two had noncentral treatment failures. Three of 14 patients had no evidence of recurrence more than 1 year after radiation therapy. Inadequate PET-GTV coverage was associated with increased risk of noncentral failures. (p < 0.01).


CONCLUSIONS
Pretreatment MET-PET appears to identify areas at highest risk for recurrence for patients with GBM. It would be reasonable to test a strategy of incorporating MET-PET into radiation treatment planning, particularly for identifying areas for conformal boost.
Department of Radiation Oncology, University of Michigan, Ann Arbor, MI, USA.
Irwin H
IH
Lee
Morand
M
Piert
Diana
D
Gomez-Hassan
Larry
L
Junck
Lisa
L
Rogers
James
J
Hayman
Randall K
RK
Ten Haken
Theodore S
TS
Lawrence
Yue
Y
Cao
Christina
C
Tsien
D000328:Adult; D000368:Aged; D000465:Algorithms; D018906:Antineoplastic Agents, Alkylating / Q000627:therapeutic use; D001706:Biopsy / Q000379:methods; D001921:Brain / Q000000981:diagnostic imaging; D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000378:metabolism / Q000532:radiotherapy; D003131:Combined Modality Therapy / Q000379:methods; D003606:Dacarbazine / Q000031:analogs & derivatives / Q000627:therapeutic use; D018450:Disease Progression; D005909:Glioblastoma / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000378:metabolism / Q000532:radiotherapy; D006801:Humans; D008279:Magnetic Resonance Imaging; D008715:Methionine / Q000493:pharmacokinetics; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D019233:Retreatment; D012984:Software; D000077204:Temozolomide; D017211:Treatment Failure; D055815:Young Adult
D018906:Antineoplastic Agents, Alkylating; D019275:Radiopharmaceuticals; C086242:carbon-11 methionine; D003606:Dacarbazine; D008715:Methionine; D000077204:Temozolomide