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

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: Assignment of the patient with a suspect of pancreatic cancer. Performing time of flight (TOF)-18F-FDG-PET/CT with images 30 min and 90 min p.i. 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. Routine performance of the operation /fine needle puncture/biopsy 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.

Prospective study with one single group with two kinds of PET/CT imaging (with TOF-reconstruction and without TOF-reconstruction) for each patient.

All parties involved in the clinical trial have knowledge of the interventions assigned to the individual participants.

Diagnostic CT of the abdomen or upper abdomen (in case of already performed diagnostic CT of the abdomen < 2 weeks ago) with 2 phases, 1 - 4 mSv, ca. 20 sec., 1 x Contrast medium (Iodixanol 550 mg/ml) 1 x 1.4 ml/kg body weight i.v. for 40 sec, 1 x if creatinine, GFR, and TSH levels are within the normal range 1 x 500 ml water oral, 1 x Biopsy or FNA (fine-needle aspiration) or operation of the pancreas

Diagnostic CT of the abdomen or upper abdomen with parenteral contrast medium (Visipaque=Iodixanol) if creatinine, GFR, and TSH levels are within the normal range and oral (water) contrast medium within TOF-18F-FDG PET/CT. In the case of elevated creatine or decreased GFR or TSH levels a diagnostic CT of the abdomen or upper abdomen without contrast medium is performed. Biopsy or FNA or operation of the pancreas.

Quantitative measurement of regional tracer uptake by SUVmax in the TOF-PET/CT and standard PET/CT images over the FDG-accumulating lesions in the pancreas 30 and 90min p.i. The histopathological findings (malignant or benign) were assigned to the corresponding SUVmax values of the pancreatic lesions for the calculation of AUC values in ROC analysis. Then AUC values with and without TOF were compared with the DeLong-test to analyze if there is a significant difference in characterization of pancreatic lesions with TOF.

The number of participants with increased tracer uptake over the pancreatic lesion, i.e. the number of pancreatic lesions with increased tracer uptake with and without TOF. One pancreatic lesion per patient was measured.

Lesion or tumor size in cm in the pancreas measured in the diagnostic CT of the abdomen or upper abdomen.

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

De-identified individual participant data (IPD) will be available apart from the principle investigator only to the statistician who carries out the statistical evaluation of the study.

Santhosh S, Mittal BR, Bhasin D, Srinivasan R, Rana S, Das A, Nada R, Bhattacharya A, Gupta R, Kapoor R. Role of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography in the characterization of pancreatic masses: experience from tropics. J Gastroenterol Hepatol. 2013 Feb;28(2):255-61. doi: 10.1111/jgh.12068.

Nagamachi S, Nishii R, Wakamatsu H, Mizutani Y, Kiyohara S, Fujita S, Futami S, Sakae T, Furukoji E, Tamura S, Arita H, Chijiiwa K, Kawai K. The usefulness of (18)F-FDG PET/MRI fusion image in diagnosing pancreatic tumor: comparison with (18)F-FDG PET/CT. Ann Nucl Med. 2013 Jul;27(6):554-63. doi: 10.1007/s12149-013-0719-3. Epub 2013 Apr 12.

Stacul F, van der Molen AJ, Reimer P, Webb JA, Thomsen HS, Morcos SK, Almen T, Aspelin P, Bellin MF, Clement O, Heinz-Peer G; Contrast Media Safety Committee of European Society of Urogenital Radiology (ESUR). Contrast induced nephropathy: updated ESUR Contrast Media Safety Committee guidelines. Eur Radiol. 2011 Dec;21(12):2527-41. doi: 10.1007/s00330-011-2225-0. Epub 2011 Aug 25.