A pilot study of cardiopulmonary exercise testing and cardiac stress positron emission tomography before major non-cardiac surgery.

Cardiac events are a common cause of peri-operative morbidity. Cardiopulmonary exercise testing can objectively assess risk, but it does not quantify myocardial ischaemia. With appropriate dietary preparation to suppress basal myocardial glucose uptake, positron emission tomography with 18 F-fluorodeoxyglucose can identify post-ischaemic myocardium, providing an attractive complement to exercise testing. We aimed to investigate the feasibility of this diagnostic algorithm. Patients referred for cardiopulmonary exercise testing before major cancer surgery were prospectively recruited. Exercise testing and positron emission tomography imaging were performed after a high fat-low carbohydrate meal. Protocol feasibility (primary end-point) included compliance with pre-test diet instructions and the completion of tests. Stress myocardial perfusion imaging was performed if either exercise testing or positron emission tomography was equivocal or positive for ischaemia. We recorded cardiac complications for 30 postoperative days. We enrolled 26 participants, 20 of whom completed protocol. Twenty-one participants proceeded to surgery: myocardial injury or infarction was diagnosed in three participants, two of whom had positive or equivocal positron emission tomography but negative myocardial perfusion imaging. We have shown that pre-operative cardiac positron emission tomography after cardiopulmonary exercise testing is feasible; protocol deviations were minor and did not affect image quality. Our findings warrant further investigation to compare the diagnostic utility of cardiac positron emission tomography imaging with standard pre-operative stress tests.

18 F-FDG PET/CT influences management in patients with known or suspected pancreatic cancer.

BACKGROUND: The aims of this study were (i) to assess and validate the incremental information of positron emission tomography/computed tomography (PET/CT) over conventional staging investigations (CSI) and (ii) to assess the management impact of PET/CT in patients with known or suspected pancreatic cancer. METHODS: Between October 2007 and September 2008, 22 PET/CT scans were performed using a dedicated PET/CT scanner in 21 patients with known or suspected pancreatic cancer. Follow up was used to reconcile discordance between PET/CT and CSI. The pre-PET/CT management plan and/or intent were prospectively recorded in all scans. The post-PET/CT management plan was determined from the medical record and/or discussions with treating clinicians. The management impact of PET/CT was classified as high, medium, low or none defined using Australian and New Zealand Association of Physicians in Nuclear Medicine PET data collection project criteria. RESULTS: PET/CT and CSI were discordant in 14/22 (64%: 95% CI; 43-84%) scans. Of the 14 discordant scans, PET/CT assessment was correct in eight, conventional imaging in four and there was insufficient information in two. Overall, PET/CT management impact was classified as high (n= 6), medium (n= 3), low (n= 9) or none (n= 4). Significant changes in management (high or medium impact) were induced by PET/CT in 9/22 scans (41%: 95% CI; 20-62%) predominantly by correctly modifying the disease extent. CONCLUSION: PET/CT has an incremental benefit over CSI and has a significant impact on management in patients with known or suspected pancreatic cancer. PET/CT merits consideration as part of the non-invasive evaluation of patients with known or suspected pancreatic cancer.