Somatostatin receptor scintigraphy with In-111 octreotide in the detection of gastroenteropancreatic carcinoids and their metastases
Background: Carcinoid tumours are a very rare malignancy
most frequently arising in the gastrointestinal tract. The
method of choice for detection of these tumours is
somatostatin receptors scintigraphy (SRS). The aim of the
present study was to evaluate the diagnostic sensitivity and
accuracy of this technique in the detection of gastroenteropancreatic
carcinoid tumours and their metastases in
comparison with conventional imaging methods.
Methods: In 24 patients with confirmed carcinoids and 7
under investigation SRS was performed. The results were
compared with those of conventional imaging methods
(chest X-ray, upper abdominal US, chest CT, upper and
lower abdominal CT) and other combinations.
Results: SRS visualized primary or metastatic sites in 71.0%
of cases vs 61.3% of conventional imaging. The diagnostic
sensitivity of the method was higher in patients with
suspected lesions (85.7% vs 57.1%). SRS was less sensitive
in the detection of metastatic sites (78.9% vs 84.2%). The
metastatic sites undetectable by SRS were all in the liver.
Between several imaging combinations, the combinations
chest X-ray/upper abdominal CT/SRS and chest CT/upper abdominal CT/SRS showed the highest sensitivity (88.75%)
in terms of the number of detected lesions. The combinations
chest X-ray/upper abdominal US/SRS and chest CT/upper
abdominal US/SRS yielded a similar sensitivity (82%).
Conclusions: SRS imaging is a very sensitive method for
the detection of gastroenteropancreatic carcinoids but is
less sensitive than US and CT in the detection of liver
metastases. Between several imaging combinations, the
combination chest x-ray/upper abdominal CT/SRS showed
the highest sensitivity.
Key words: Somatostatin receptors scintigraphy, gastroenteropancreatic
carcinoids, cost effectiveness