Gallium-68 Dotatate Scan for Neuroendocrine Tumours
Neuroendocrine tumours (NETs) are complex cancers that often require advanced imaging techniques for accurate diagnosis and effective management. One of the most reliable and precise methods used is the Gallium-68 Scan.
In the following article, we will:
- Outline what a Dotatate scan entails
- Investigate its advantages over other imaging methods
- Learn how it contributes to the care of patients with NETs
Neuroendocrine Cancer Australia (NECA), is dedicated to supporting individuals diagnosed with NETs, and their families. NECA offers a wealth of resources, educational programs, and advocacy efforts aimed at deepening the understanding of NETs, improving patient care, and encouraging research advancements. Patients diagnosed with NETs can engage with NECA’s comprehensive support and information by calling the NET nurse line.
What is a Dotatate scan?
A Dotatate scan, also known as a Ga68-DOTATATE PET/CT scan, is a cutting-edge imaging tool specifically designed for detecting and monitoring neuroendocrine tumours.
The scan creates detailed images of the body by combining:
- Positron emission tomography (PET)
- Computed tomography (CT)
It is particularly effective for identifying NETs that express somatostatin receptors, which are present on the surface of many neuroendocrine cancer cells. By using functional imaging, the Dotatate scan can highlight areas of active disease that might not be visible with other imaging techniques.
The primary purposes of a Dotatate scan is to:
- Locate neuroendocrine tumours
- Assess the extent of the disease
- Evaluate how far the cancer has spread
This information is crucial for staging the disease, planning treatment, and monitoring the effectiveness of therapy.
How does it differ from other imaging techniques?
Unlike traditional imaging methods such as MRI and CT scans, which primarily focus on anatomical details, the Dotatate scan provides functional information. It reveals the biological activity of tumour cells, showing where cancer cells are growing and how they behave. This combination of anatomical and functional data allows for a more comprehensive understanding of the patient’s condition, facilitating more tailored treatment plans.
Mechanism of Dotatate scan – how it works
The Dotatate scan relies on the radiotracer Ga68-DOTATATE, which is a compound that combines gallium-68, a radioactive isotope, with DOTATATE, a molecule that binds specifically to somatostatin receptors.
These receptors are commonly found on NET cells. Once injected into the body, Ga68-DOTATATE travels through the bloodstream, attaches to these receptors, and emits signals that are captured by the PET/CT scanner.
Somatostatin receptors are a hallmark of many neuroendocrine tumours. By targeting these receptors, the radiotracer ensures that the imaging is highly sensitive and specific to NETs.
This precision is what sets the Dotatate scan apart from other imaging modalities, making it an essential tool for NET diagnosis and management.
Imaging procedure and process
The Dotatate scan is a multi-step procedure. Here’s how it works in a nutshell:
- First, the patient receives an intravenous injection of Ga68-DOTATATE.
- The radiotracer then circulates throughout the body and binds to somatostatin receptors on tumour cells.
- After a waiting period of approximately 60 minutes, the patient undergoes the PET/CT scan.
- The scanning process itself takes around 30 to 60 minutes, during which patients must remain as still as possible to ensure accurate imaging.
The entire appointment generally lasts two to three hours.
Advantages of Dotatate scans in NET diagnosis
Dotatate scans can provide a number of benefits and advantages over traditional scanning and diagnostic methods.
High sensitivity and specificity
One of the most significant advantages of the Dotatate scan is its high sensitivity and specificity for neuroendocrine tumours. This accuracy reduces the likelihood of false positives and false negatives, and provides clinicians with the confidence they need to make informed decisions about patient care.
Ability to detect small and early-stage tumours
Early detection is crucial in the diagnosis and treatment of all cancer. Dotatate scan excels at identifying small and early-stage NETs that might be missed by other imaging techniques. This capability allows for early intervention, which can improve outcomes and expand the range of treatment options available.
Superior imaging of metastases
The Dotatate scan is also highly effective at detecting metastases, even in hard-to-image areas like the liver or bones. This superior imaging capability is essential for staging the disease and understanding its spread, which in turn influences treatment strategies and overall prognosis.
Indications for Dotatate scans in NET patients
Dotatate scans are frequently used to diagnose primary neuroendocrine tumours and to identify metastases. Dotatate scans in NET patients can provide several indications, including:
- Guidance for biopsies and other diagnostic procedures
- The ability to monitor the disease over time
- Detection of any signs of progression or recurrence early
- The allowance for prompt intervention and adjustments
- Suitability for specific treatments, such as peptide receptor radionuclide therapy (PRRT)
Comparison with other imaging modalities
A true investigation of Dotatate cannot be complete without comparing it to other kinds of imaging and diagnostic tools.
PET/CT and Octreoscan
The Dotatate scan is a more advanced version of the older Octreoscan. While both methods use radiotracers to target somatostatin receptors, Ga68-DOTATATE provides higher resolution images and greater accuracy. The shorter imaging time and better image quality make the Dotatate scan a preferred choice for many specialists.
MRI and CT scans
MRI and CT scans remain important tools in the imaging of neuroendocrine tumours, especially for assessing anatomical details. However, they lack the functional imaging capabilities of the Dotatate scan. The Dotatate scan complements these traditional imaging methods, providing a more holistic view of the disease.
Preparation and procedure for patients – what to expect before, during, and after the scan
Patients preparing for a Dotatate scan should check with their imaging centre in preparation as instructions can change from person to person. During the scan, you may receive an injection of the radiotracer, which may cause a brief sensation of warmth.
The scan itself is painless, but patients must remain still to ensure high-quality images. After the scan, patients can usually resume normal activities, although they may be advised to drink plenty of fluids to help flush the radiotracer from their system.
Potential risks
The level of radiation exposure from a Dotatate scan is considered low and generally safe. The benefits of accurate tumour detection often outweigh the potential risks, but patients who are pregnant or breastfeeding should inform their healthcare provider. Doctors weigh the risks and benefits carefully to ensure the safety of each patient.
You are also advised to minimise contact with pregnant women and children (younger than 12 years old.) for 2 hours after your appointment.
Interpreting Dotatate scan results
Dotatate scan results provide critical information about
- Size
- Location
- Spread
- Stage
- Response to treatment
Although highly accurate, Dotatate scans are not infallible, particularly in cases where tumours do not express somatostatin receptors, the scan will not be able to detect the NET . Additional tests and clinical evaluations are often required to confirm the diagnosis and ensure that the treatment plan is appropriate.
Dotatate’s role in treatment planning and prognosis
Dotatate scans play a crucial role in planning surgeries and other therapeutic interventions. By providing a detailed map of tumour locations, these scans help surgeons operate with greater precision. They also aid in deciding whether non-surgical treatments, such as PRRT or hormone therapy, are viable options.
For patients receiving PRRT or other targeted treatments, Dotatate scans are used to monitor progress. The scans can reveal how well the tumour is responding to therapy, helping doctors decide whether to continue, adjust, or change the treatment plan.
Research and advances in Dotatate imaging
Research in somatostatin receptor imaging is continuously evolving. New radiotracers and imaging technologies are being developed to improve the accuracy and efficiency of Dotatate scans. These advancements promise even more precise detection and monitoring of neuroendocrine tumours in the future.
The future of NET imaging holds exciting possibilities, including hybrid imaging technologies that combine the strengths of different modalities. Researchers are also exploring ways to make radiotracers more effective and safer, paving the way for more personalised and effective treatment strategies for NET patients.
For more information on Dotatate scans and other imaging techniques for neuroendocrine tumours, patients are encouraged to contact Neuroendocrine Cancer Australia. NECA offers a wealth of resources, including a NET nurse line, to support patients and their families throughout their cancer journey.
Further information and support for people diagnosed with NETs is available by calling the NECAÂ NET nurse line.
