Early assessment of the efficacy of temozolomide chemotherapy in experimental glioblastoma using [18F]FLT-PET imaging.

Abstract

UNLABELLED:

Addition of temozolomide (TMZ) to radiation therapy is the standard treatment for patients with glioblastoma (GBM). However, there is uncertainty regarding the effectiveness of TMZ. Considering the rapid evolution of the disease, methods to assess TMZ efficacy early during treatment would be of great benefit. Our aim was to monitor early effects of TMZ in a mouse model of GBM using positron emission tomography (PET) with 3'-deoxy-3'-[(18)F]fluorothymidine ([(18)F]FLT).

METHODS:

Human glioma cells sensitive to TMZ (Gli36dEGFR-1) were treated with sub-lethal doses of TMZ to obtain cells with lower sensitivity to TMZ (Gli36dEGFR-2), as measured by growth and clonogenic assays. Gli36dEGFR-1 and Gli36dEGFR-2 cells were subcutaneously (s.c.) or intracranially (i.c.) xenografted into nude mice. Mice were treated for 7 days with daily injection of 25 or 50 mg/kg TMZ. Treatment efficacy was measured using [(18)F]FLT-PET before treatment and after 2 days. Computed Tomography (CT) or Magnetic Resonance Imaging (MRI) were used to determine tumor volumes before treatment and after 7 days.

RESULTS:

A significant difference was observed between TMZ and DMSO treated tumors in terms of variations of [(18)F]FLT T/B ratio as soon as day 2 in the i.c. as well as in the s.c. mouse model. Variations of [(18)F]FLT T/B uptake ratio between days 0 and 2 correlated with variations of tumor size between days 0 and 7 (s.c. model: n(tumor) = 17 in n(mice) = 11, P<0.01; i.c. model: n(tumor/mice) = 9, P<0.01).

CONCLUSIONS:

Our results indicate that [(18)F]FLT-PET may be useful for an early evaluation of the response of GBM to TMZ chemotherapy in patients with glioma.

• Authors: Thomas Viel, Sonja Schelhaas, Stefan Wagner, Lydia Wachsmuth, Katrin Schwegmann, Michael Kuhlmann, Cornelius Faber, Klaus Kopka, Michael Schäfers, Andreas H Jacobs
• Journal: PloS one (PLoS One) Vol. 8 Issue 7 Pg. e67911 ( 2013) ISSN: 1932-6203 [Electronic] United States
• PMID: 23861829 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antineoplastic Agents, Alkylating
• Biomarkers, Pharmacological
• Fluorodeoxyglucose F18
• Dacarbazine
• Temozolomide

Topics

• Animals
• Antineoplastic Agents, Alkylating (pharmacology)
• Biomarkers, Pharmacological (analysis)
• Brain Neoplasms (diagnosis, diagnostic imaging, drug therapy)
• Dacarbazine (analogs & derivatives, pharmacology)
• Early Diagnosis
• Female
• Fluorodeoxyglucose F18 (administration & dosage)
• Glioblastoma (diagnosis, diagnostic imaging, drug therapy)
• Humans
• Injections, Intraventricular
• Injections, Subcutaneous
• Mice
• Mice, Nude
• Neoplasms, Experimental (diagnosis, diagnostic imaging, drug therapy)
• Temozolomide
• Tomography, Emission-Computed
• Treatment Outcome
• Tumor Burden (drug effects)