Abstract
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Objectives: Dynamic PET studies with 68Ga-BZH3 and FDG were performed in pts. with suspected recurrent LGG for the diagnosis of tumor recurrence.
Methods: The ongoing study comprises 10 pts. with suspected recurrent LGG. Dynamic PET scans using 68Ga-BZH3 and FDG were obtained on two different days within one week. Compartment modeling was used for the PET evaluation. Gene chip analysis (U133A, Affymetrix Co.) was performed in 4 pts.
Results: Seven pts. demonstrated an increased Ga-68-BZH3 uptake and a low FDG uptake. In all these cases, tumor recurrence was histologically confirmed. Surgery was performed in 5 pts. and 2 pts. had a stereotactic biopsy. Histology revealed a glioblastoma multiforme WHO°IV in 1 pt., in 5 pts. an astrocytoma WHO°II and in 1 pt. an astrocytoma WHO°III. Three pts. revealed a low 68Ga-BZH3 and FDG uptake. The diagnosis of recurrency was made by the oncologists based on clinical data. One pt. received stereotactic interstitial seeds implantation, one pt. external radiation therapy and another pt. chemotherapy. The median values for 68Ga-BZH3 in the recurrencies were: SUV 1.3, VB: 0.118, K1: 0.179, k3: 0.046. Gene chip analysis revealed an enhanced neuromedin B expression in the evaluated tissue samples, which was correlated with an enhanced 68Ga-BZH3 uptake.
Conclusions: 68Ga-BZH3 may be helpful in patients with LGG for the differentiation between tumor recurrence and scar. The enhanced 68Ga-BZH3 seems to correlate to an overexpression of Neuromedin B.
- Society of Nuclear Medicine, Inc.