Are CAT-scans necessary for preoperative localization of insulinomas?
OBJECTIVES: Do CAT-scans provide useful information in terms of preoperative localization of insulinomas after a biochemical diagnosis is established or may CAT-scan imaging be safely abandoned? PATIENTS AND METHODS: CAT-scan results from 30 consecutive patients between 1980-1990 with established insulinomas were retrospectively evaluated with regard to actual tumour size (volume) and identification and localization as verified during surgery. RESULTS: In all patients, the tumours were easily detected by manual palpation during surgery, although the size of 67% of the tumours (n = 20) was less than 2.5 cm3. In only 7 patients (23%) the tumour had been correctly localized by computer tomography. Detected tumours were significantly larger than undetected tumours (median size 5.3 vs 1.3 cm3; p < 0.005). CONCLUSION: Despite the low sensitivity of computer tomography as documented in this study, all patients with an insulinoma were definitely cured after surgical intervention. Thus, CAT-scans are neither necessary nor helpful for preoperative localization of insulinomas.