439P - Comparison of CT and 18F-FLT PET/CT imaging for target volume delineating in patients with glioma

Date 28 September 2014
Event ESMO 2014
Session Poster Display session
Topics Central Nervous System Malignancies
Imaging, Diagnosis and Staging
Presenter Xudong Hu
Citation Annals of Oncology (2014) 25 (suppl_4): iv137-iv145. 10.1093/annonc/mdu330
Authors X. Hu, S. Wang, L. Ma, S. Yuan, J. Yu
  • Radiation Oncology, Shandong Cancer Hospital & Institute, 250117 - JINAN/CN

Abstract

Aim

The aim of this pilot study was to compare computed tomography (CT) and 3′-deoxy-3′-[18F] fluorothymidine (18F-FLT) positron emission tomography/ computed tomography (PET/CT) imaging for gross tumor volume (GTV) and clinical target volume (CTV) delineation, and to analyze the impact of proliferative tumor volume delineated by 18F-FLT PET/CT.

Methods

12 patients with glioma were enrolled into this study. The relation of 18F-FLT uptake and pathology, Ki-67 index were studied in 9 patients. All of the 12 patients underwent 18F-FLT PET/CT imaging before radiotherapy. The enhanced CT images and 18F-FLT PET/CT images were all transferred to planning system and the target volumes from each image were delineated and compared.

Results

18F-FLT PET/CT SUVmax increased significantly with glioma grade (p = 0.007). SUVmax of 18F-FLT PET/CT (p= 0.03), T/N ratio (p < 0.0013) and Ki-67 proliferation index were positively correlated. The average of GTVCT was 226.82 ± 78.55, and the average of GTVPET/CT was 151.47 ± 76.64 (p = 0.001). CTVPET/CT volume are smaller than CTVCT volume (367.71 ± 32.35 vs. 245.23 ± 32.74, p= 0.039). CT target volume was big than PET target volume, there are two situations: first, 58.3% (7/12) of the CT include PET target; second, 41.7% (5/12) target CT and PET target cross.

Conclusions

The uptakes of 18F-FLT were positively correlated with grade of glioma and tumor cell proliferation index. To delineate target volume by 18F-FLT PET/CT imaging, the GTV and CTV are smaller than CT. It maybe improves the accuracy of GTV and CTV in patients with glioma and, meanwhile, provides potential benefits to normal brain tissue.

Disclosure

All authors have declared no conflicts of interest.