PET-PANC: multicentre prospective diagnostic accuracy and health economic analysis study of the impact of combined modality 18fluorine-2-fluoro-2-deoxy-d-glucose positron emission tomography with computed tomography scanning in the diagnosis and management of pancreatic cancer
Authors: Ghaneh Paula , Hanson Robert , Titman Andrew , Lancaster Gill , Plumpton Catrin , Lloyd-Williams Huw , Yeo Seow Tien , Edwards Rhiannon Tudor , Johnson Colin , Abu Hilal Mohammed , Higginson Antony P , Armstrong Tom , Smith Andrew , Scarsbrook Andrew , McKay Colin , Carter Ross , Sutcliffe Robert P , Bramhall Simon , Kocher Hemant M , Cunningham David , Pereira Stephen P , Davidson Brian , Chang David , Khan Saboor , Zealley Ian , Sarker Debashis , Al Sarireh Bilal , Charnley Richard , Lobo Dileep , Nicolson Marianne , Halloran Christopher , Raraty Michael , Sutton Robert , Vinjamuri Sobhan , Evans Jonathan , Campbell Fiona , Deeks Jon , Sanghera Bal , Wong Wai-Lup , Neoptolemos John P 
Published: February 2018

Background
Pancreatic cancer diagnosis and staging can be difficult in 10–20% of patients. Positron emission tomography (PET)/computed tomography (CT) adds precise anatomical localisation to functional data. The use of PET/CT may add further value to the diagnosis and staging of pancreatic cancer.

Objective
To determine the incremental diagnostic accuracy and impact of PET/CT in addition to standard diagnostic work-up in patients with suspected pancreatic cancer.

Design
A multicentre prospective diagnostic accuracy and clinical value study of PET/CT in suspected pancreatic malignancy.

Participants
Patients with suspected pancreatic malignancy.

Interventions
All patients to undergo PET/CT following standard diagnostic work-up.

Main outcome measures
The primary outcome was the incremental diagnostic value of PET/CT in addition to standard diagnostic work-up with multidetector computed tomography (MDCT). Secondary outcomes were (1) changes in patients’ diagnosis, staging and management as a result of PET/CT; (2) changes in the costs and effectiveness of patient management as a result of PET/CT; (3) the incremental diagnostic value of PET/CT in chronic pancreatitis; (4) the identification of groups of patients who would benefit most from PET/CT; and (5) the incremental diagnostic value of PET/CT in other pancreatic tumours.

Results
Between 2011 and 2013, 589 patients with suspected pancreatic cancer underwent MDCT and PET/CT, with 550 patients having complete data and in-range PET/CT. Sensitivity and specificity for the diagnosis of pancreatic cancer were 88.5% and 70.6%, respectively, for MDCT and 92.7% and 75.8%, respectively, for PET/CT. The maximum standardised uptake value (SUVmax.) for a pancreatic cancer diagnosis was 7.5. PET/CT demonstrated a significant improvement in relative sensitivity (p = 0.01) and specificity (p = 0.023) compared with MDCT. Incremental likelihood ratios demonstrated that PET/CT significantly improved diagnostic accuracy in all scenarios (p < 0.0002). PET/CT correctly changed the staging of pancreatic cancer in 56 patients (p = 0.001). PET/CT influenced management in 250 (45%) patients. PET/CT stopped resection in 58 (20%) patients who were due to have surgery. The benefit of PET/CT was limited in patients with chronic pancreatitis or other pancreatic tumours. PET/CT was associated with a gain in quality-adjusted life-years of 0.0157 (95% confidence interval –0.0101 to 0.0430). In the base-case model PET/CT was seen to dominate MDCT alone and is thus highly likely to be cost-effective for the UK NHS. PET/CT was seen to be most cost-effective for the subgroup of patients with suspected pancreatic cancer who were thought to be resectable.

Conclusion
PET/CT provided a significant incremental diagnostic benefit in the diagnosis of pancreatic cancer and significantly influenced the staging and management of patients. PET/CT had limited utility in chronic pancreatitis and other pancreatic tumours. PET/CT is likely to be cost-effective at current reimbursement rates for PET/CT to the UK NHS. This was not a randomised controlled trial and therefore we do not have any information from patients who would have undergone MDCT only for comparison. In addition, there were issues in estimating costs for PET/CT. Future work should evaluate the role of PET/CT in intraductal papillary mucinous neoplasm and prognosis and response to therapy in patients with pancreatic cancer.

Study registration
Current Controlled Trials ISRCTN73852054 and UKCRN 8166.

Funding
The National Institute for Health Research Health Technology Assessment programme.