Download Protocol for use of PET scanning in the management of patients with

Protocol for use of PET scanning in the management of patients with
colorectal cancer
The five-year survival for patients with metastatic colorectal cancer (mCRC) is 8%. However
there are a small group of patients whose disease is confined to either liver or lung who are
candidates for potentially curative salvage surgery. The 5-year survival for these patients
without the use of PET scanning is 40%, and with PET the reported 3-year survival is 70%.
This is due to better selection for surgery through the PET scan picking up more extensive
disease, not apparent on routine staging with CT.
Avoiding surgery spares the patient unnecessary morbidity and mortality as well as allowing
the health service to use their limited theatre resources more effectively. As a result HMO’s
in the US approved PET scanning for evaluation of recurrent CRC in 1999. The Health
Technology Board for Scotland (HTBS) called in 2002 for the further evaluation of PET
scanning in cancer management.
Local research / audit
A grant from NHS Grampian R&D endowments enabled a project to evaluate whole body
FDG PET scanning in patients with potentially operable liver metastases to take place from
1/4/03 to 31/3/04. The project not only allowed quantification of the potential requirement for
PET scan in this group of patients (about 24 per year), but also showed the PET scan changed
the original decision to operate in 20% of patients. This equate to approximately 230 – 240
scans annually across Scotland.
Of the patients in the series where a decision not to operate was taken after knowing the PET
result one did not have any uptake on PET, did not undergo an operation and is alive and
well. All the others, where more extensive but occult mCRC was found with the PET scan,
are now dead of mCRC.
Policy for assessing patients
All patients with mCRC being considered for treatments with surgery or non-surgical therapy
(chemotherapy and / or radiotherapy) are discussed and imaging reviewed at a colorectal
cancer multidisciplinary team (MDT) meeting.
Indication for the use of PET scanning
In the first instance, the focus should be on where a PET scan would/could change
management/treatment plans. A PET scan is only appropriate on an individual named patient
basis where there was some indication that it would change management and the role of the
scan will be subject to detailed audit.
Patients who are considered for whole body FDG PET scanning come from the following
categories.
(1)
Patients with apparently organ-restricted liver or lung metastases (either at primary
presentation or during follow-up) who are beinig considered for resection, either immediately
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or following initial cytoreductive chemotherapy. The identification of CT-occult metastatic
disease prior to resection or chemotherapy may render resection inappropriate.
(2)
Where the diagnosis of local or distant recurrence remains in doubt despite other
imaging such as high resolution CT, targeted USS or MRI for example in the discrimination
of soft tissue abnormalities in the pelvis after multimodal treatment of rectal cancer..
(3)
Persistently elevated CEA levels where conventional imaging/endoscopy is not
diagnostic.
Cancer Strategies
November 2006
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