Diagnosing pancreatic cancer at an early stage remains difficult¹, which is why it is the fourth leading cause of death by cancer in the United States² and life expectancy after diagnosis is only 4-6 months on average.³

Traditionally, doctors have used imaging such as computed tomography (CT), magnetic resonance imaging (MRI) and endoscopies to diagnose pancreatic tumors.⁴And although these techniques provide good anatomical detail⁵, not all of them provide the level of precision needed for detecting the stage of the cancer accurately, whether it be pre-cancers, small lesions and benign tumors, or late-stage cancer that has spread beyond the pancreas.^3,4Now there is an imaging modality that combines CT with positron emission tomography (PET) emerging that can provide the doctors with more information during diagnosis.⁴

The Advantages of PET/CT

CT is the most widely used method by doctors to diagnose pancreatic cancer, but there is room to improve staging diagnoses.^1,3 As a standalone imaging method, PET's advantages include visualizing cancer on a cellular level, which makes it better at diagnosing early-stage cancer than CT alone.⁵By combining PET and CT, the two diagnostic tools together can precisely identify malignant tissue and metastases in advanced pancreatic cancers.⁷

Among PET/CT imaging types, dual-phase scans, where the procedure is performed twice, are preferred to validate the accuracy of the images with pancreatic cancers, although further studies are still needed to validate their effectiveness.⁶

PET/CT and Pancreatic Cancer

According to the National Institute for Health and Care Excellence (NICE), PET/CT can help doctors make more accurate diagnoses whether the cancer is in the late or early stages.³ If caught early, pancreatic cancer can be treatable, but often it's not discovered in time.¹ In the later stages of pancreatic cancer, PET/CT can provide doctors with information to recommend the best treatment option for the patient, whether that is surgery, chemotherapy or palliative care.^5,6Research by NICE has shown that this combined imaging modality could reduce nonessential surgery by 20 percent in individuals with severe pancreatic malignancies.⁴

Cancer Care Ontario, the principal cancer advising government organization for Ontario, has approved PET/CT scans for patients with potentially surgical pancreatic cancer since 2011.⁷ A retrospective study published in 2017 in the Journal of Clinical Oncology showed that using PET/CT allowed doctors to more accurately diagnose the cancer's stage than through CT or MRI alone.⁷

A study published in 2011 by RadioGraphics, a Radiological Society of North America journal, showed how PET and CT combined can make up for the inadequacies of using either one or the other in providing an accurate diagnosis when pancreatic cancer is suspected. Not only did PET/CT help doctors provide the best diagnosis for the patient, but it also reduced mis-diagnoses in the case of another disease such as pancreatitis that mimics pancreatic cancer.⁸

In addition, research published in the Journal of Nuclear Medicine Technology in 2015 confirmed that PET/CT outperformed all imaging modalities in the detection of distant metastases, allowing for more accurate staging.⁹

“It is important that patients with pancreatic cancer have an accurate assessment of whether the cancer has spread before undergoing major surgery," said Dr. Chris Harrison, the United Kingdom National Health Service's Clinical Director for Cancer. "This [NICE] guidance shows how modern diagnostic techniques can bring about more personalized cancer care, tailoring the treatment to the needs of the patient.”³

The number of PET/CT applications is increasing because of the its accuracy and sensitivity, including use in the initial management of pancreatic malignancies. This dual-imaging advancement fills a much-needed gap in pancreatic cancer diagnoses and could ensure high-quality care for patients.⁶

References

Can Pancreatic Cancer Be Found Early?, 2018, American Cancer Society, https://www.cancer.org/cancer/pancreatic-cancer/detection-diagnosis-staging/detection.html, (accessed 31 July 2018)
Dibble, E. H. et al., 2012, ‘PET/CT of cancer patients: part 1, pancreatic neoplasms’, AJR, 199, Pp 952-967
Pancreatic cancer patients should be offered early scans to avoid unnecessary surgery, says NICE, 2018, National Institute for Health and Care Excellence (NICE), https://www.nice.org.uk/news/article/pancreatic-cancer-patients-should-be-offered-early-scans-to-avoid-unnecessary-surgery-says-nice, (accessed 9 May 2018)
Tests for Pancreatic Cancer, 2018, American Cancer Society, https://www.cancer.org/cancer/pancreatic-cancer/detection-diagnosis-staging/how-diagnosed.html, (accessed 31 July 2018)
Positron Emission Tomography (PET), 2018, Pancreatic Cancer Action Network, https://www.pancan.org/facing-pancreatic-cancer/diagnosis/positron-emission-tomography-pet/, (accessed 10 May 2018)
Early Detection, 2018, Pancreatic Cancer Action Network, https://www.pancan.org/facing-pancreatic-cancer/diagnosis/early-detection/, (accessed 9 May 2018)
Abrahao, A. B. K. et al., 2017, ‘FDG PET/CT in pancreatic cancer staging and management: A retrospective study’, Journal of Clinical Oncology, 35 (4), Pp 464-464
Sahani, D. V. et al., 2012, ‘State-of-the-Art PET/CT of the Pancreas: Current Role and Emerging Indications’, RSNA
Jha, P. et al., 2015, ‘PET/CT for Pancreatic Malignancy: Potential and Pitfalls’, JNMT, 43 (2), Pp 92-97