Comparing Pertechnetate SPECT/CT and Intragastric Pressure During Nutrient Drink for Gastric Accommodation

Functional dyspepsia (FD) is a common gastrointestinal disorder which can present with early satiety, postprandial fullness, epigastric pain and burning sensation in the absence of underlying disease. The most troubling symptom is weight loss, prevalent in up to 40% of FD patients and is often associated with impaired gastric accommodation.

Gastric accommodation by definition is a reflex, mediated vagally which causes reduction in gastric tone, increased in compliance and increment in gastric volume post meal ingestion. It allows large volumes of liquid or solid ingestion without causing postprandial symptoms. Impairment of gastric accommodation has been linked to gastrointestinal symptoms which includes nausea, bloating, early satiety, weight loss and epigastric pain.

There are several studies aimed to assess efficacy in the treatment of functional dyspeptic patients. A myriad of tests can measure gastric accommodation such as gastric barostat and single photon emission computed tomography (SPECT). An alternative study known as the nutrient drink test has also been proposed and can be combined with high-resolution manometry.

So far, none of the nuclear medicine centers in Malaysia are providing clinical service for radionuclide gastric accommodation study. The gold standard for gastric accommodation assessment is the gastric barostat method. However, the technique is invasive and caused discomfort to patients. Radionuclide gastric accommodation study using 99mTc-pertechnetate with SPECT/CT is a non-invasive method that can be used to assess patient with FD and enables quantitative evaluation of treatment response to medications. Hence, the role of non-invasive gastric volume assessment with 99mTc-pertechenate SPECT/CT in the evaluation of healthy individuals was studied first, and then compared with intragastric pressure measurements from high-resolution manometry and nutrient drink test.