TOF-18F-FDG-PET/CT in Patients With Suspected Pancreatic Cancer

Evaluation of the Diagnostic Value of TOF-18F-FDG-PET/CT in Patients With Suspected Pancreatic Cancer

Aim of the prospective study is a better differentiation of benign and malignant lesions in the pancreas in patients with suspected pancreatic cancer using images 30 and 90 min p.i. (post injectionen) and a diagnostic CT (computed tomography) scan of the abdomen within the Time of Flight (TOF)-18F-FDG-PET/CT and thus an improvement of the quality of PET/CT findings.

In the course of this the procedure follows the necessary steps of routine treatment:

1. Assignment of the patient with a suspect of pancreatic cancer.
2. Performing time of flight (TOF)-18F-FDG-PET/CT with images 30 min and 90 min p.i.
3. Performing a diagnostic CT of the abdomen with parenteral contrast medium and pancreatic protocol (in case of normal creatinine, GFR, and TSH levels) as well as oral contrast medium (in accordance with the ESUR-guidelines) as part of the PET/CT examination.
4. Routine performance of the operation /fine needle puncture/biopsy
5. Routine histopathological evaluation of the surgical specimen/biopsy

For this study, a diagnostic CT of the abdomen with contrast medium (intravenous as well as oral) and with pancreatic protocol and without parenteral contrast medium in case of elevated creatinine or decreased TSH (thyroid-stimulating hormone) or GFR (glomerular filtration rate) levels is performed additionally within the routinely performed PET/CT for better differentiation of the target organ from adjacent structures. Furthermore, early (30 min p.i.) and delayed (90 min p.i.) images and a TOF-reconstruction following the PET/CT examination (without patient contact) should be performed for better differentiation between inflammatory and malignant lesions of the pancreas. The regional tracer-uptake should now be measured quantitatively by SUV (Standard Uptake Value) in the TOF-PET/CT images over the FDG-accumulating lesions in the pancreas at those two times. In case of an increased FDG-uptake in the early images, the lesion will be assessed as benign/inflammatory and with an increase of the FDG-uptake in the delayed images as malignant. No FDG-uptake in the early as well as in the delayed images will be classified as benign. As a reference standard, the histopathological diagnosis is used. Subsequently, a cut-off value of the SUV should be determined by ROC-analysis.

According to current scientific evidence regarding the characterization of pancreatic masses by means of "Time of Flight"(TOF)-technique, there are no studies in the literature.

Inclusion Criteria:

• patients with suspected pancreatic cancer

Exclusion Criteria:

• persons under 18 years of age
• patients with blood glucose level ≥160 mg/dl at the time of the PET/CT examination
• patients who will not be operated or biopsied and in which thus there are no histopathological findings of the pancreas
• pregnant women