[Diagnostic usefulness of PET/CT for pancreatic malignancy].
OBJECTIVE
The purpose of this study was to evaluate the diagnostic usefulness of PET/CT for pancreatic malignancy.


METHODS
We retrospectively analyzed medical records of 115 patients with pathologically diagnosed pancreatic cancer between January 2003 to August 2008 who underwent abdominal CT and PET/CT examination before histological confirmation. CT and PET/CT images were reviewed in single-blinded status and diagnostic ability on primary pancreatic lesion, regional lymph node metastasis, and distant metastasis was evaluated.


RESULTS
99 patients (86%) had malignant diseases including 91 cases of adenocarcinoma, and 16 patients (14%) benign diseases. Only CA 19-9 value and SUV were significantly different between PET/CT positive and negative groups (p=0.001, p<0.001). Sensitivity, specificity and positive predictive values (PPV) of both modality for pancreatic lesion were same (94%, 62%, and 95%, respectively), and negative predictive values (NPV) were 67% on CT and 57% on PET/CT. PET/CT correctly diagnosed 8 cases (6.9%) of falsely diagnosed pancreatic lesion on CT. Nine cases (15.7%) of misdiagnosed lymph node metastasis on CT were correctly diagnosed on PET/CT. But, there was no significant difference in the diagnosis of regional lymph node metastasis. 3 out of 29 cases of distant metastasis, except 2 cases of supraclavicular lymph node metastasis, were additionally diagnosed by PET/CT. But, overall sensitivity of distant metastasis was significantly higher in CT (83% vs 69%, p=0.045).


CONCLUSIONS
Although PET/CT provided additional correct diagnoses in many cases, it showed fair diagnostic power for primary pancreatic lesion and lymph node metastasis, and lower sensitivity for distant metastasis. Therefore, PET/CT should be used as an supplementary modality of CT in diagnosing pancreatic malignancy.
Department of Medicine, Sungkyunkwan University School of Medicine, Seoul, Korea.
Sin Sil
SS
Park
Kyu Taek
KT
Lee
Kwang Hyuck
KH
Lee
Jong Kyun
JK
Lee
Seong Hyun
SH
Kim
Jun Young
JY
Choi
Jong Chul
JC
Rhee
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018395:CA-19-9 Antigen / Q000032:analysis; D003951:Diagnostic Errors; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000473:pathology; D049268:Positron-Emission Tomography; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
D018395:CA-19-9 Antigen