Iodine-123-vasoactive intestinal peptide receptor scanning in patients with pancreatic cancer.

UNLABELLED

Recent data demonstrated a high sensitivity (>90%) in the visualization of primary/recurrent pancreatic cancer as well as metastases by means of 123I-labeled vasoactive intestinal peptide (VIP). The aim of this study was to investigate the diagnostic value of radioiodinated VIP in patients suffering from adenocarcinoma of the exocrine pancreas.

METHODS

Sixty consecutive patients (26 women, 34 men; mean age 59 yr) with histologically verified pancreatic cancer were investigated in this study. Twenty-one patients presented with organ-confined malignancy (19 at study entry and 2 during follow-up after initial surgery developed tumor recurrence), while 25 patients had distant metastases along with the local malignancy, and 7 patients had liver metastases after resection of the primary lesion (6 on study entry and 1 during follow-up showed tumor development). In 5 of these patients, abdominal lymph node metastases were present at the time of scanning. Of 10 patients, who had undergone potentially curative surgery for their cancer, 7 remained free of disease during follow-up until death or for at least 6 mo. Iodine-123-VIP (150-200 MBq; approximately 1 microg VIP) was administered to all patients. Scintigraphic results were evaluated as compared to conventional radiologic imaging methods and surgical exploration.

RESULTS

Primary pancreatic tumors were visualized by 123I-VIP in 19/21 patients (90%) with disease confined to the pancreas and in 8/25 patients (32%) suffering both from locoregional and disease metastatic to the liver. The overall 123I-VIP scan sensitivity for primary pancreatic adenocarcinomas was 58% (27/46 scans). Liver metastases were imaged in 29/32 patients (scan sensitivity 90%) and abdominal lymph node metastases in 4/5 patients. In 5 patients, the VIP receptor scan indicated the malignant lesion before CT. In vitro results confirmed specific binding of 123I-VIP to primary pancreatic tumor cells as well as to PANC1 adenocarcinoma cells.

CONCLUSION

Iodine-123-VIP receptor scanning has the potential to offer additional information to augment diagnostic standard methods and could influence the decision-making process in the treatment of pancreatic cancer.