Diagnostic value of a pancreatic mass on computed tomography in patients undergoing pancreatoduodenectomy for presumed pancreatic cancer.
BACKGROUND
Previous studies have shown that 5-14% of patients undergoing pancreatoduodenectomy for suspected malignancy ultimately are diagnosed with benign disease. A "pancreatic mass" on computed tomography (CT) is considered to be the strongest predictor of malignancy, but studies describing its diagnostic value are lacking. The aim of this study was to determine the diagnostic value of a pancreatic mass on CT in patients with presumed pancreatic cancer, as well as the interobserver agreement among radiologists and the additional value of reassessment by expert-radiologists.


METHODS
Reassessment of preoperative CT scans was performed within a previously described multicenter retrospective cohort study in 344 patients undergoing pancreatoduodenectomy for suspected malignancy (2003-2010). Preoperative CT scans were reassessed by 2 experienced abdominal radiologists separately and subsequently in a consensus meeting, after defining a pancreatic mass as "a measurable space occupying soft tissue density, except for an enlarged papilla or focal steatosis".


RESULTS
CT scans of 86 patients with benign and 258 patients with (pre)malignant disease were reassessed. In 66% of patients a pancreatic mass was reported in the original CT report, versus 48% and 50% on reassessment by the 2 expert radiologists separately and 44% in consensus (P < .001 vs original report). Interobserver agreement between the original CT report and expert consensus was fair (kappa = 0.32, 95% confidence interval 0.23-0.42). Among both expert-radiologists agreement was moderate (kappa = 0.47, 95% confidence interval 0.38-0.56), with disagreement on the presence of a pancreatic mass in 29% of cases. The specificity for malignancy of pancreatic masses identified in expert consensus was twice as high compared with the original CT report (87% vs 42%, respectively). Positive predictive value increased to 98% after expert consensus, but negative predictive value was low (12%).


CONCLUSIONS
Clinicians need to be aware of potential considerable disagreement among radiologists about the presence of a pancreatic mass. The specificity for malignancy doubled by expert radiologist reassessment when a uniform definition of "pancreatic mass" was used.
Department of Surgery, University Medical Center Utrecht, Utrecht, The Netherlands; Department of Surgery, Academic Medical Center, Amsterdam, The Netherlands.
Arja
A
Gerritsen
Department of Radiology, St. Antonius Hospital, Nieuwegein, The Netherlands.
Thomas L
TL
Bollen
Department of Radiology, Academic Medical Center, Amsterdam, The Netherlands.
C Yung
CY
Nio
Department of Surgery, University Medical Center Utrecht, Utrecht, The Netherlands.
I Quintus
IQ
Molenaar
Clinical Research Unit, Academic Medical Center, Amsterdam, The Netherlands.
Marcel G W
MG
Dijkgraaf
Department of Surgery, University Medical Center Utrecht, Utrecht, The Netherlands.
Hjalmar C
HC
van Santvoort
Department of Pathology, University Medical Center Utrecht, Utrecht, The Netherlands.
G Johan
GJ
Offerhaus
Department of Pathology, University Medical Center Utrecht, Utrecht, The Netherlands; Department of Pathology, Academic Medical Center, Amsterdam, The Netherlands.
Lodewijk A
LA
Brosens
Department of Pathology, Erasmus Medical Center, Rotterdam, The Netherlands.
Katharina
K
Biermann
Department of Surgery, University Medical Center Groningen, Groningen, The Netherlands.
Egbert
E
Sieders
Department of Surgery, University Medical Center Groningen, Groningen, The Netherlands.
Koert P
KP
de Jong
Department of Surgery, Maastricht University Medical Center, Maastricht, The Netherlands.
Ronald M
RM
van Dam
Department of Surgery, Maasstad Ziekenhuis, Rotterdam, The Netherlands.
Erwin
E
van der Harst
Department of Surgery, Radboud University Medical Center, Nijmegen, The Netherlands.
Harry
H
van Goor
Department of Surgery, St. Antonius Hospital, Nieuwegein, The Netherlands.
Bert
B
van Ramshorst
Department of Surgery, Leiden University Medical Center, Leiden, The Netherlands.
Bert A
BA
Bonsing
Department of Surgery, Catharina Hospital, Eindhoven, The Netherlands.
Ignace H
IH
de Hingh
Department of Surgery, OLVG, Amsterdam, The Netherlands.
Michael F
MF
Gerhards
Department of Surgery, Erasmus Medical Center, Rotterdam, The Netherlands.
Casper H
CH
van Eijck
Department of Surgery, Academic Medical Center, Amsterdam, The Netherlands.
Dirk J
DJ
Gouma
Department of Surgery, University Medical Center Utrecht, Utrecht, The Netherlands.
Inne H M
IH
Borel Rinkes
Department of Surgery, Academic Medical Center, Amsterdam, The Netherlands.
Olivier R C
OR
Busch
Department of Surgery, Academic Medical Center, Amsterdam, The Netherlands. Electronic address: m.g.besselink@amc.nl.
Marc G H
MG
Besselink
D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010182:Pancreatic Diseases / Q000000981:diagnostic imaging / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D016577:Pancreaticoduodenectomy; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed