Purpose
Lung cancer is the commonest cancer with 1.3 million cases diagnosed every single year throughout the world.1
NICE Lung Cancer guidelines in 2011strongly recommend performing a PET-CT scan in all patients being considered for radical treatment after a staging CT scan of the neck,
chest and liver has been performed.2
If mediastinal lymphadenopathy is detected by CT scan and the aetiology is determined by intervention,
then the true value of PET-CT scan can be measured in the detection of non-nodal extrathoracic metastases.
The true yield...
Methods and materials
233 consecutive patients with suspected lung cancer and no known extrathoracic metastases were referred for a staging PET-CT scan prior to being subject to radical therapy were included.
All patients underwent a standard whole body PET-CT scan and a contrast-enhanced neck,
chest and liver CT scan at the same attendance in the same scanner.
The prior staging CT scans were reviewed in all the patients with non-nodal metastases detected on PET-CT scan to determine whether the metastasis was present but not identified.
Results
Characteristics of Study Group (n = 233)
Median age at diagnosis: 73 years (±9.6; Range: 38 to 92 years)
Sex: 139 men (60%)
Median Interval between staging CT scan and PET-CT scan:
All patients: 25 days (IQR,
18-29)
Extrathoracic metastases:
22 (9%) of 233 patients had 25 extra-thoracic and extra-cerebral metastases
9 of the 25 metastases were identified on both the CT component of the PET-CT scan and on review of the prior staging CT
16 were not visible on the staging CT scan
Conclusion
The addition of pelvic CT scan in patients referred for PET-CT staging scan prior to radical therapy may allow for increased detection of extrathoracic metastases.
PET-CT scan detects extrathoracic metastases which were missed or invisible on the staging CT scan.
Lung cancer patients should be offered a contrast-enhanced staging CT scan of the neck,
chest,
abdomen and pelvis prior to the PET-CT scan.
Potentially,
an interval CT scan should be performed if a delay of greater than 30 days has occurred prior to the PET-CT...
References
Ferlay J,
Autier P,
Boniol M,
Heanue M,
Colombet M,
Boyle P.
Estimates of the cancer incidence and mortality in Europe in 2006.
Annals of Oncology.
2007;18(3):581–92.
National Institute of Clinical Excellence.
The diagnosis and staging of lung cancer (Update).
2011.
NHS Choices.
Risks of PET scans,
http://www.nhs.uk/Conditions/PET-scan/Pages/Risks.aspx,
Date accessed 29/12/13.
NHS Choices.
Radiation,
http://www.nhs.uk/conditions/Radiation/Pages/Introduction.aspx,
Date accessed 29/12/13.