Is there a future role for immunoscintigraphy in the diagnosis of colorectal carcinoma?

Immunoscintigraphy combines the advances in immunology and nuclear medicine to target tumor sites. Visualization of colorectal carcinomas is based on different monoclonal antibodies and their fragments against tumor-associated antigens labeled with gamma emitting radionuclides which accumulate in the tumor tissue due to their interaction with corresponding antigens. Available data on the role of immunoscintigraphy in detection of recurrence and metastases of colorectal carcinomas are reviewed. Despite a variety of investigations related to the application of immunoscintigraphy in diagnostics of colorectal cancer, using different radiolabeled immunoreactive agents and imaging methods there has not been a consensus among the investigators regarding the best modality of the method, including the specific radiopharmaceutical for this purpose. Some general conclusions concerning potentials of immunoscintigraphy in such diagnostics, including expectancy of the newly developed SPECT/CT systems, are suggested. The possibilities of PET imaging of colorectal carcinomas using monoclonal antibodies labeled with positron emitting radionuclides, as well as of the radioimmunoguided surgery and radioimmunotherapy are also discussed. Key words: Immunoscintigraphy, colorectal cancer, recurrences, metastases, radioimmunoguided surgery, SPECT/CT.

Estimation of the enterogastric reflux by modified scintigraphic method.

BACKGROUND/AIMS: The aim of the study was to introduce the chosen and modified model of the nuclear medicine method for the detection and quantification of enterogastric reflux, as well as evaluation of its clinical validity. METHODOLOGY: The study was performed in 172 patients: with gastric and duodenal ulcer, after Billroth I and Billroth II gastrectomy, with gastroesophageal reflux, after cholecystectomy, with chronic cholecystitis and chronic duodenal disease. Acquisition was performed with a gamma camera, during 90 min after intravenous application of 185MBq 99mTc-Dietil IDA. Test meal was given in the 30th minute, while the gastric region was marked at the end of the study. On the basis of the radioactivity changes in the regions of the stomach and hepatobiliary system, the presence of enterogastric reflux was determined and its index calculated. RESULTS: In all the groups of patients, values were significantly higher than in the controls (P < 0.05). The most frequent occurrence and the largest quantity of reflux was present in patients after Billroth II gastrectomy with significantly different values from other groups of patients (P < 0.05). CONCLUSIONS: The obtained results approve clinical value of the chosen and modified scintigraphy of enterogastric reflux, as a non-invasive and physiological method, which provides exact data about its presence and quantity.

Relationship between enterogastric reflux estimated by scintigraphy and the presence of Helicobacter pylori.

The aim of the study is assessment of the relationship between enterogastric reflux and the presence of Helicobacter pylori infection as factors that cause gastritis, peptic ulcer and adenocarcinoma ventriculi. The study was performed in 52 patients with different digestive disorders, using gamma camera, during 90 min (1 frame/min) after intravenous injection of 185 MBq 99mTc-dietil IDA in the cubital vein. According to time/activity curves from the region of hepatobiliary system and stomach, index of enterogastric reflux (EGR) was assessed. There was no correlation between the presence of Helicobacter pylori and EGR (r = 0.181, df = 52, p > 0.05). However, Helicobacter pylori was present more frequently in the patients with positive EGR (p < 0.01), but there were no significant differences (p > 0.05) in reflux value in patients with either positive or negative findings of Helicobacter pylori.