IODINE-123-VASOACTIVE INTESTINAL PEPTIDE RECEPTOR SCANNING IN PATIENTS WITH PANCREATIC-CANCER

Recent data demonstrated a high sensitivity (>90%) in the visualizatio n of primary/recurrent pancreatic cancer as well as metastases by mean s of I-123-labeled vasoactive intestinal peptide (VIP). The aim of thi s study was to investigate the diagnostic value of radioiodinated VIP in patients suffering from adenocarcinoma of the exocrine pancreas. Me thods: Sixty consecutive patients (26 women, 34 men; mean age 59 yr) w ith histologically verified pancreatic cancer were investigated in thi s study. Twenty-one patients presented with organ-confined malignancy (19 at study entry and 2 during follow-up after initial surgery develo ped tumor recurrence), while 25 patients had distant metastases along with the local malignancy, and 7 patients had liver metastases after r esection of the primary lesion (6 on study entry and 1 during follow-u p showed tumor development). In 5 of these patients, abdominal lymph n ode metastases were present at the time of scanning. Of 10 patients, w ho had undergone potentially curative surgery for their cancer, 7 rema ined free of disease during follow-up until death or for at least 6 mo . Iodine-123-VIP (150-200 MBq; similar to 1 mu g VIP) was administered to all patients. Scintigraphic results were evaluated as compared to conventional radiologic imaging methods and surgical exploration. Resu lts: Primary pancreatic tumors were visualized by I-123-VIP in 19/21 p atients (90%) with disease confined to the pancreas and in 8/25 patien ts (32%) suffering both from locoregional and disease metastatic to th e liver. The overall I-123-VIP scan sensitivity for primary pancreatic adenocarcinomas was 58% (27/46 scans). Liver metastases were imaged i n 29/32 patients (scan sensitivity 90%) and abdominal lymph node metas tases in 4/5 patients. In 5 patients, the VIP receptor scan indicated the malignant lesion before CT. In vitro results confirmed specific bi nding of I-123-VIP to primary pancreatic tumor cells as well as to PAN C1 adenocarcinoma cells. Conclusion: Iodine-123-VIP receptor scanning has the potential to offer additional information to augment diagnosti c standard methods and could influence the decision-making process in the treatment of pancreatic cancer.