Limited value of positron emission tomography in treatment of pancreatic cancer: Surgeon’s view

Abstract

We aimed to assess, from a surgical point of view, the value of positron emission tomography (PET) in the routine preoperative diagnostic evaluation of a pancreatic mass. In particular, we were interested in PET's ability to distinguish a malignancy from a nonmalignant process and its impact on surgical decision making. We documented prospectively the results of preoperative ultrasonography, computed tomography (CT), endoscopic retrograde cholangiopancreatography (ERCP), and PET in terms of a correct diagnosis of malignancy in 103 patients. All patients underwent surgery at our department and had a complete histologic workup. We then related the preoperative findings to the intraoperative and histologic findings and analyzed the advantages and limitations of PET in comparison with conventional diagnostic techniques. Both CT and PET showed high sensitivities (82% and 84%, respectively) but rather low specificities (61%). ERCP showed good specificity at 83% but weak sensitivity at 46%. The positive predictive value was higher than 80% for all methods, whereas the negative predictive value was around 60% at best. Both the CT and the PET diagnoses were wrong in 15% of the cases. In all cases with a false CT diagnosis, the results of the other conventional examinations provided sufficient evidence to indicate the need for surgical intervention. In all cases where PET gave misleading results, CT findings indicated the need for surgery. PET overlooked pT1 cancers in three of the patients. PET does not reliably prove or exclude malignancy in situations where conventional diagnostic procedures leave doubt as to the nature of a pancreatic mass. PET does introduce a new procedure-related spectrum of misinterpretations to the diagnostic process.

Mass-forming pancreatitis with positive fluoro-2-deoxy-d-glucose positron emission tomography and positive diffusion-weighted imaging-magnetic resonance imaging: Report of a case

“…13 According to previous studies, the diagnostic sensitivity and specifi city for pancreatic cancer by FDG-PET are 80%-100% and 60%-90%, respectively (Table 1). 1,4,[13][14][15][16][17][18][19][20][21] Bearing in mind the false-negative cases of diabetes mellitus, which are frequently associated with pancreatic head cancer, its high sensitivity can be deemed as suffi cient. However, its specifi city around 80%, mainly due to misdiagnosis of mass-forming chronic pancreatitis, is considered to be below an acceptable level.…”

Positron Emission Tomography Does Not Add to Computed Tomography for the Diagnosis and Staging of Pancreatic Cancer

“…Subsequently Kasperk et al [29] from the same institution in Aachen reported on a slightly expanded data set of 130 patients and concluded that FDG PET did not reliably prove or exclude malignancy when CT was equivocal. Buell and Zimny [32] have conceded that false-negative findings can occur if FDG PET is used in patients with increased blood glucose levels and that false positives may arise in the presence acute inflammatory benign disease.…”

“…Although FDG PET has been shown to have considerable clinical utility for colorectal and oesophageal cancers [54], this and other studies have cast doubt on its value in pancreatic cancer [28, 29, 31, 41, 42, 48]. Tracer uptake measured FDG PET however may have prognostic significance in patients with either resected or advanced pancreatic cancer [55, 56], may predict the response to chemotherapy [55] and may be valuable in detecting localised or distant neoplastic recurrence [26].…”

“…More recent studies have however failed to demonstrate any advantage for FDG PET compared to CT [28, 29, 31, 41, 42]. The experience of using FDG PET for the diagnosis and staging of pancreatic cancer is reported from a tertiary pancreatic centre in which the distinction of pancreatic cancer from chronic pancreatitis is particularly problematic.…”

“…There are limitations however in the diagnosis of small tumours, detection of lymph node metastases and other intra-abdominal metastatic lesions, as well as in the ability of CT to distinguish between pancreatic malignancy and chronic pancreatitis [15,16,17,18,19]. During the last decade, 18 F-fluoro-2-deoxy- D -glucose (FDG) positron emission tomography (PET) that uses neoplastic metabolism as the basis for differential tracer uptake has been evaluated as a diagnostic and staging tool in pancreatic cancer [20,21,22,23,24,25,26,27,28,29,30,31,32]. FDG is a positron-emitting radio-tracer that is transported intracellularly via glucose transporters which are highly expressed in pancreatic cancer, then FDG is phosphorylated by hexokinase to FDG-6-PO 4 [33, 34].…”