Positron emission tomography (PET) scans are invaluable in oncology, offering insight into the biological activity of tumours. Among these, FDG PET scans stand out for their ability to detect and evaluate metabolically active tumours.
This article explores the definition, mechanisms, applications, and future directions of FDG PET scans, with a focus on their use in neuroendocrine tumours (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.
An FDG PET scan is an imaging technique that combines functional and anatomical insights to detect cancer activity in the body. It uses fluorodeoxyglucose (FDG), a radiotracer that mimics glucose, to highlight cells with heightened metabolic activity, such as tumour cells.
Fluorodeoxyglucose is a glucose analog tagged with a radioactive isotope. Some cancer cells, will consume glucose at higher rates than normal cells, absorb FDG in larger quantities. The radiotracer then emits signals the PET scanner detects, creating detailed images of metabolic activity.
This makes FDG PET scans very effective for identifying aggressive cancers and monitoring disease progression.
Here’s how the specific mechanism of FDG PET scans work:
By targeting metabolic activity, FDG PET scans provide a real-time picture of tumour behaviour. This capability is particularly valuable for identifying rapidly growing cancers that might not be apparent on anatomical imaging alone.
FDG PET scans are often combined with CT scans to provide both functional and anatomical imaging. The integration of these modalities allows for precise localisation of tumour activity, enhancing diagnostic accuracy and treatment planning.
FDG PET scans are extremely effective for detecting aggressive tumours, including high-grade neuroendocrine tumours (NETs). These scans can identify poorly differentiated cancers that might not express markers detected by other imaging methods.
They can also assist in a range of other diagnostic steps, including:
FDG PET scans are particularly useful for high-grade and poorly differentiated NETs, which exhibit higher metabolic activity.
As always, these scans should complement other diagnostic tools to offer insights into the aggressiveness of the tumour.
There’s no one-size-fits-all test for NETs. Every diagnostic tool and treatment should be viewed in the context of an entire care place.
While Dotatate PET scans are ideal for low-grade NETs with somatostatin receptor expression, FDG PET scans excel in identifying high-grade NETs that may not express these receptors. Together, these imaging modalities provide a comprehensive view of NET behaviour.
As such, FDG PET scans and Dotatate PET scans are often used in combination. This dual approach helps capture the full spectrum of NET activity, from low-grade, well-differentiated tumours to high-grade, poorly differentiated tumours.
To learn if FDG PET scans are right for you, or how they can fit within your care plan, be sure to talk to your healthcare team. Being informed and proactive is the best way towards successful diagnosis and treatment.
There are several advantages to undertaking FDG PET scans that far outmatch other diagnostic methods. Whether or not a patient can access these advantages largely depends on the patient’s individual circumstances.
FDG PET scans are highly sensitive for detecting metabolically active tumours, making them invaluable in oncology. Their ability to identify even small areas of active disease is a significant advantage.
The whole-body nature of FDG PET scans allows for a thorough evaluation of disease extent. This is crucial for staging cancer and planning effective treatment strategies.
FDG PET scans provide real-time information about tumour activity, enabling dynamic monitoring of disease progression and response to therapy.
As with every NET diagnostic method, FDG PET scans aren’t perfect, and have several limitations.
FDG PET scans are less effective for low-grade, well-differentiated NETs, which often have lower metabolic activity. Other imaging modalities, such as Dotatate scans, may be better suited for these cases.
Inflammatory and infectious processes can also exhibit high FDG uptake, leading to false positives. Clinicians must interpret results carefully in the context of the patient’s clinical history.
FDG PET scans can be expensive and may not be readily available in all healthcare settings. Cost and accessibility can limit their widespread use, particularly in resource-limited environments.
It is imperative that patients prepare for a FDG PET scan to ensure best results and the highest levels of comfort throughout the course of testing.
Patients are typically asked to fast for several hours before an FDG PET scan to enhance the accuracy of the test. They may also need to avoid strenuous physical activity the day before the scan to minimise glucose uptake by muscles.
During the procedure, patients receive an intravenous injection of FDG and wait for about an hour while the radiotracer is distributed throughout the body. The scan itself is painless and takes approximately 30-60 minutes. After the procedure, patients are encouraged to stay hydrated to help eliminate the radiotracer from their system.
Patients should report any adverse reactions to clinicians. Although rare, these reports can help guide and refine future treatment.
Like a number of other diagnostic tools related to NETs and other cancers, FDG PET scans continue to improve and advance as research continues. While FDG PET scans are primarily used in oncology, their applications are expanding into other fields, such as cardiology and neurology. These advancements could make PET imaging even more versatile in the future.
Research is ongoing into new radiotracers that could offer greater specificity for certain tumour types. These advancements aim to expand the utility of PET imaging beyond FDG.
Artificial intelligence (AI) is being integrated into PET imaging to improve the accuracy and efficiency of scan interpretation. AI algorithms can help identify subtle patterns and reduce the risk of human error.
FDG PET scans are a cornerstone of modern cancer imaging, offering unparalleled insights into tumour activity and disease progression. Their role in managing high-grade neuroendocrine tumours (NETs) highlights their value in personalised oncology care.
For more information about FDG PET scans and their use in cancer management, patients are encouraged to consult their healthcare provider or contact Neuroendocrine Cancer Australia.
Further information and support for people diagnosed with NETs is available by calling the NECA NET nurse line.
