Insulinoma Support Network

Scanning for insulinomas

Scanning for insulinomas


Endoscopic ultrasound This is usually carried out under sedation and involves looking at the gastrointestinal tract with a flexible camera. The test can help pick up small tumors that might not be clearly visible on a scan.

Octreotide scan This is a useful diagnostic test that can help reveal the site of tumours. Some NETs have special receptors on their surfaces called somatostatin receptors. Octreotide is a somatostatin analogue, a substance that copies or mimics the action of somatostatin. When Octreotide is combined with a mildly radioactive agent and then injected via a vein in the arm, it sticks to somatostatin receptors on the tumour surface and the tumors light up on the screen as radioactive 'hot spots'.

CT scan A computerised tomography (CT) scan provides a three dimensional picture of the inside of the body. It can be used to determine the position and size of the insulinoma and regular scans are useful to find out the rate of tumour growth. 

MRI scan This 'whole body' magnetic resonance imaging (MRI) scan can help reveal where the tumours are positioned. It uses magnetism rather than X-rays to take pictures of the inside of the body. For some parts of the body and for some tpes of tumour, it can produce clearer results than a CT scan. For other situations, the CT scan is better. MRI is better than CT at showing how deeply the tumour has grown into body tissues. Your own doctor will know which is the best type of scan for you. 

PET scan These are different types of Positron emission tomography (PET) scan that may be used for NET patients. PET scanners are used in many cancer types. The scan looks for the activity of the cell tissue and the growing speed of the cells.

Like the Octreotide scan a special tracer (most commonly called FDG [18F] fluorodexyglucose is injected intravenously and the PET camera then produces a 3-dimensional image, highlighting any abnormal activity.

More recently a PET scan is used in combination with a CT camera which is a more advanced diagnostic tool.

A PET scan is not required for everyone but more likely to be used in more aggressive disease.

Another type of PET scan is the GA-DOTA-Octreotate PET scan, which has been shown to have a higher sensitivity (can see more) for NETs compared to the octreotide scan. Not only is this a more sensitive scan but it is also much quicker than the Octreotide scan and results are available in a shorter time. This is new technology and an advancement in NET scanning but at present there are only a few available in the UK. Having the scan, find out more

Bone scan You will be given a small injection of radioactive tracer which over time will be absorbed into your skeleton. It takes about three hours for this to occur. Pictures of your skeleton are taken in order to help your doctor determine whether there are any problems associated with it. This procedure takes about ten minutes, and you will be asked to return for the second set of pictures you will again be asked to lie or sit in front of the gamma camera. The scan will take approximately 30-45 minutes.

Ultrasound scan Ultrasound imaging also called ultrasound scanning or sonography, involves exposing part of the body to high-frequency sound waves to produce pictures of the inside of the body. Ultrasound exams do not use ionizing radiation (as used in X-rays). Because ultrasound images are captured in real-time, they can show the structure and movement of the body's internal organs, as well as blood flowing through blood vessels.