Patients presenting with refractory upper abdominal pain may undergo CT or ultrasound imaging that demonstrates a pancreatic ‘mass’ (or more commonly a ‘fullness’). The significance of this finding rests in the ominous prognosis of patients with pancreatic carcinoma. There is an obligation to investigate this radiological finding fully so that the therapy of a potentially curable neoplasm is not delayed and to ensure that a normal variant is not surgically treated. The former goal requires imaging tests with high sensitivity, whereas the latter necessitates high specificity.
The sensitivity and specificity of various imaging procedures for detecting or excluding pancreatic neoplasms have been studied extensively. Most importantly, recent studies have evaluated the performance of EUS, helical CT, state of the art magnetic resonance imaging (MRI) and positron emission tomography (PET). Despite advances in other techniques, EUS is the most sensitive and specific technique (Table 1). The sensitivity of EUS ranges from 93% to 100%, and the specificity from 33% to 100%. The low specificity of 33% for EUS was reported by Legmann et al, whose study included only three patients without tumours. In a larger series, Muller et al demonstrated a higher specificity of EUS (16 of 16, 100%) than of CT (nine of 14, 64%). In this same series, for tumours smaller than 2 cm, the sensitivity was 90% (nine of 10 tumours) with EUS, 40% (four of 10 tumours) with CT and 33% (three of nine tumours) with MRI. Learn how to save money – buy antibiotics online to enjoy your shopping and your treatment.
Sensitivity and specificity of imaging techniques in detecting pancreatic tumours
|EUS (%)||CT (%)||MR (%)||PET(%)|
|Muller et al (1)||49||94||100||69||64||83||100||–||–|
|Legmann et al (2)*||33||100||33||92||100||–||–||–||–|
|Gress et al (3)||81||100||–||74||–||–||–||–||–|
|Mertz et al (4)||35||93||75||53||25||–||–||87||50|
|Midwinter et al (5)*||48||97||–||76||–||–||–||–||–|
*Dual-phase helical computed tomography (CT). EUS Endoscopic ultrasound; MR Magnetic resonance; PET Positron emission tomography. Reproduced with permission from reference 38
In patients with suspected small pancreatic lesions on CT, Bender et al reported that EUS was helpful in distinguishing normal subjects from patients with neoplasms. For small lesions, the specificity of EUS (88%) was twice that of dynamic CT (41%), which supports the role of EUS in confirming the presence of a tumour. Further studies are needed to determine whether dual-phase helical CT has a superior specificity.
Category: Pancreatic carcinoma
Tags: Biopsy, Computed tomography, Endosonography, Pancreas adenocarcinoma, Pancreas neoplasm