Publikationsrepositorium - Helmholtz-Zentrum Dresden-Rossendorf

Ziel/Aim:

Therapy response varies considerably in advanced cervical carcinoma(ACC). Glucose metabolism and microvascular characteristics of the tumor have been evaluated as biomarkers for identification of patients with poor response before or early during treatment. The combination of both biomarkers for detection of tumor regions with a ‘malignant mismatch’(MM), i.e. strongly increased glycolysis at low blood flow levels, might indicate resistance to therapy. The aim of the present study was to test whether ACC show MM that can be detected by the combination of FDG- and O-15-water-PET.

Methodik/Methods:

Twelve women (27-69y) with locally ACC (FIGO IIB-IIIB; grade G2 n=7, G3 n=5) were included prior to chemo-radiation. Regional blood flow was computed voxel-by-voxel from the O-15-water PET using a weighted integral approach and an image-derived arterial input function. FDG uptake was characterized by SUV. The primary tumor was segmented manually in the CT. A tumor voxel was considered to present MM if the perfusion was lower than the median perfusion in the tumor and the SUV was higher than the median SUV. The absolute total MM volume (aMMV) was obtained by multiplying the number of MM voxels with the voxel volume. The relative MM volume (rMMV) was obtained by dividing the aMMV by the tumor volume.

Ergebnisse/Results:

The volumes of the primary tumors ranged from 54 to 225ml. The tumors were quite heterogeneous with respect to both FDG uptake and perfusion. The aMMV ranged from 7.7 to 35.5ml, the rMMV from 7.9 to 26.6%. There was no correlation between rMMV and tumor volume (p=0.517). T-testing revealed a tendency (p=0.083) for an association between aMMV and histological grading, aMMV being higher in the G3 than in the G2 tumors. There was no association between grading and rMMV (p=0.888).

Schlussfolgerungen/Conclusions:

ACC show a metabolism/perfusion MM to a strongly variable extent. The mismatch volume seems to be associated with the tumor grade. Evaluation of the prognostic value requires follow-up data in a larger cohort.