Introductory remarks

Background: The use of combined positron emission tomography/computerised tomography (PET/CT) scanners in oncology has been shown to improve the staging of tumours and the detection of relapses. However, mis-registration errors are increasingly recognised to be a common pitfall of PET/CT studies. Case Presentation: We report a patient with a germ cell tumour of the testis, who underwent a PET/CT scan to detect the site of relapse with a view to surgical removal. However, the PET/CT scan mislocalised the tumour site to be within the T2 vertebral body. A subsequent endoscopic ultrasound scan however showed the tumour to be anterior to the vertebral body, which was confirmed at surgery. Conclusion: In this report, we highlight the artefactual mislocalisation errors which may occur with PET/CT imaging, and the need to review and verify these scans. Background Positron emission tomography (PET) scanning using 218F-fluoro-deoxy-D-glucose (18FDG) uptake has been in clinical use for over a decade [1,2]. The advantage of PET scanning is that it provides functional information of lesions detected, and can help distinguish between malignant and non-malignant tissues. However, PET scanning has poor spatial resolution in terms of localising lesions. In contrast, computerised tomography (CT) scanning give good anatomical, but not functional information. Since 2000, purpose-built combined positron emission tomography/computerised tomography (PET/CT) scanners have been in use which overcome the respective shortcomings of PET and CT scans [3,4]. The use of PET/CT scans therefore holds much promise in the advancement of tumour localisation and management. Nevertheless, several pitfalls remain [5]. Of these, the biggest problem is that of accurate image alignment. This case report illustrates an example of mislocation of a tumour in a patient with germ cell tumour (GCT) by PET/CT, and the subsequent potential clinical impact which results. Case presentation A 38-year old man presented in 1988 with a left testicular mass which was removed and found to be a non-seminomatous GCT. Staging investigations revealed spread to the Published: 3 August 2007 BMC Cancer 2007, 7:147 doi:10.1186/1471-2407-7-147 Received: 1 September 2006 Accepted: 3 August 2007 This article is available from: http://www.biomedcentral.com/1471-2407/7/147 © 2007 Wang et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.