Objective: To evaluate the use of a fixation device in whole-body postiron emission tomography/computed tomography (PET/CT).
Methods: Two hundred and thirty patients were prospectively included over a period of 3 months. Different single-phase and multiphase contrast-enhanced PET/CT protocols were used for whole-body examination. An unforced expiration state was applied as breathing protocol for CT examination. Patients were placed on a deflating device (1.0 m x 1.5 m) with arms elevated but supported in order to prevent full extension in shoulders and elbows providing comfortable positioning. Image quality was assessed by means of alignment of the liver quantitatively on co-registered PET/CT images. After the examination, patients were asked to complete a survey on subjective sensations such as pain in different body regions (yes/no). They were asked to give a final evaluation for the whole-body PET/CT examination (comfortable/not comfortable). Additionally, a control group (n=30) was assessed without the aid of additional devices.
Results: Examination protocols using the device showed minor misalignment of 5 mm. Different protocols did not reveal significant differences in misalignment. When comparing the control group misalignment was significantly higher with approx. 7 mm. The majority (75%) evaluated the positioning as comfortable despite 46% of the patients in this group feeling more or less severe pain in at least one body region. For controls, misalignment was slightly higher whereas only 39% found the positioning comfortable (chi(2)=13.03; P<0.0005) and 61% reported pain (NS).
Conclusion: Both the technical aspects and patient evaluations favour the use of the vacuum device in whole-body PET/CT examinations. In particular, in time consuming protocols using multiphase CT examination the fixation device leads to excellent co-registration quality and patient compliance.