Pancreas: New procedure detects tumours more efficiently

The arrow points to the accumulation of the low-level radioactive substance in the insulinoma. In this case, the insulinoma was localized in the head of the pancreas. As the substance is released through the kidneys, the kidneys are visible as well. Credit: Nuklearmedizin, Universitätsklinikum Freiburg i. Br.

Swiss researchers have developed a method that is able to reliably localise certain tumours in the pancreas known as insulinomas. The new method was presented online in the renowned medical journal Lancet on 25 July. The print publication is due to follow in September. The study has been supported by the Swiss National Science Foundation, the Swiss Cancer League and the United Kingdom's Department of Health.

Dangerously low blood sugar levels

Insulinomas are rare tumours that produce hormones, especially insulin. They are normally found in the pancreas and are mostly benign and small (approx. 1 to 1.5 cm in diameter). As they release insulin uncontrollably, however, they repeatedly cause dangerously levels (hypoglycaemia), which can lead to disorientation, and in rare cases to seizures or coma. They often take a long time to be diagnosed. For the patients, this means a prolonged and intensive period of suffering.

Operate – but where?

The only cure is to remove the insulinoma by a surgical intervention. However, the surgeon needs to know the exact location of the insulinoma. Using conventional imaging such as CT (computed tomography) and MRI (), only sixty to seventy per cent of these tumours can be located, which means thirty to forty per cent cannot be identified. So far, invasive investigations are proposed in case of a negative outcome of conventional imaging: these include insulin concentration measurements in the vessels surrounding the pancreas. For this purpose, a catheter has to be inserted into the pancreatic vessels and the liver vein. Alternatively, a including an of the pancreas is performed in order to detect smaller tumours.

Tumour made visible radioactively

In order to localize the insulinomas, the researchers injected an artificial substance combined with low-level radioactive indium into thirty patients with a strong suspicion of insulinomas. The substance accumulates in the tumour and, thanks to its low-level radioactive radiation, renders the mini-tumour visible in a special camera. As a result, ninety-five per cent of the insulinomas could be localised. With CT or MRI, the detection rate would only have been forty-seven per cent. "It is likely that this method will replace the existing invasive methods for locating insulinomas in the future," says Professor Emanuel Christ from the Inselspital Berne, the endocrinologist (metabolism specialist) responsible for this research project.

Success thanks to international network

What might sound simple was only possible thanks to years of pioneering work and a national and international research network: at the Inselspital and the University Hospital Basel, Christ, nuclear medicine researcher Professor Damian Wild and private lecturer Flavio Forrer defined the aim of the study, the study method and the criteria for patient selection. Together with colleagues in St. Gallen, Lucerne, Freiburg im Breisgau (Germany) and London, they then selected patients for the study. In a proof-of-concept study, the researchers successfully investigated six Swiss patients in 2009. The aim of this subsequent prospective large-scale study was to confirm the results.

Tumour outsmarted with keyhole technique

Dr Martin Béhé (now at the Paul Scherrer Institute) and colleagues developed the low-level radioactive substance to outwit the invisible tumour by exploiting a familiar phenomenon: nearly all insulinomas have a large number of so-called GLP-1 receptors on their surface – a kind of keyhole that can only be opened with a single key, the chemical substance GLP-1. The researchers used a similar substance they had co-developed, exendin-4, which fits the same "keyhole". Using exendin-4, the low-level radioactive indium could thus be smuggled into the tumour and its veil of camouflage lifted.

More information: Christ, E. et al. Glucagon-like peptide-1 receptor imaging for the localisation of insulinomas: a prospective multicentre imaging study, The Lancet Diabetes & Endocrinology, Early Online Publication, 25 July 2013.

Related Stories

New marker substance for cancer cells

date Jul 04, 2013

Scientists from ETH Zurich have developed a new substance that enables certain tumour types to be rendered visible in high resolution using positron emission tomography. The so-called tracer has successfully ...

Sugar makes cancer light-up in MRI scanners

date Jul 07, 2013

A new technique for detecting cancer by imaging the consumption of sugar with magnetic resonance imaging (MRI) has been unveiled by UCL scientists. The breakthrough could provide a safer and simpler alternative ...

Lymphatic fluid takes detour

date May 20, 2013

When tumours metastasise, they can block lymphatic vessels, as researchers from ETH Zurich have discovered using a new method. The lymphatic fluid subsequently has to find a new path through the tissue. Such ...

Brain tumour cells killed by anti-nausea drug

date Mar 18, 2013

(Medical Xpress)—New research from the University of Adelaide has shown for the first time that the growth of brain tumours can be halted by a drug currently being used to help patients recover from the side effects of ...

Recommended for you

Faster heart rate linked to diabetes risk

date 8 hours ago

An association between resting heart rate and diabetes suggests that heart rate measures could identify individuals with a higher future risk of diabetes, according to an international team of researchers.

EBV co-infection may boost malaria mortality in childhood

date 23 hours ago

Many people who live in sub-Saharan Africa develop a natural immunity to malaria, through repeated exposure to Plasmodium parasites. Even so, the disease kills close to half a million children per year, according ...

Three important things you didn't know about diabetes

date May 21, 2015

When we think of diabetes, we tend to think of rich people with poor lifestyles. A chronic disease linked with obesity, heart disease and worse outcomes for some infectious diseases, diabetes tends to be ...

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.