Are We Scanning Enough Positron Emission Tomography (PET) Patients in Radiation Therapy Planning (RTP) Position?*
Objectives: To show if the use of the RTP flat pallet during PET/CT correlates with the number of patients having RT, and whether it is disease specific or dependant on the purpose of the PET scan, for example staging of the disease.
To investigate the number of repeated PET scans to gain RTP positional information and to decide if it would be beneficial to scan more PET patients in RTP position initially.
Method: During a two month period the request forms of scanned PET/CT patients were collected. Data was recorded showing the purpose for the PET scan and the type of disease being investigated. Every Queensland RT department was then contacted to determine which patients had RT within 8 weeks of having their PET scan.
Results:
386 PET scans were performed, 35 (9%) scans were in RTP position.
115 (30%) of the total patients scanned had RT.
The most common diseases requiring RT were non small cell lung cancer (NSCLC) (27.2%) and head and neck carcinomas (28.9%).
The most common reasons for a PET scan prior to RT was to stage the disease (83%)
14 patients had repeated PET scans, but not for the purpose of RTP.
Conclusion: A significant number of PET patients are having RT post scan regardless of whether it has been indicated on their PET referral.
It would be beneficial to scan more patients in RTP position in order to better correlate PET/CT images with RTP CT images, thus providing a more accurate RT target volume.