FDG-PET for detection of recurrences from malignant primary bone tumors: comparison with conventional imaging.
BACKGROUND: The aim of this study was to assess the diagnostic ability of positron emission tomography using 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG-PET) in the detection of recurrences from malignant primary bone tumors compared with conventional imaging. PATIENTS AND METHODS: In 27 patients (6 osteosarcomas, 21 Ewing's sarcomas), 41 FDG-PET examinations performed for diagnosis or exclusion of recurrent disease were evaluated. Conventional imaging techniques consisted of magnetic resonance imaging of the primary tumor site, thoracic computed tomography, and Tc-99m methylene diphosphonate bone scintigraphy. The reference methods were the histopathological analysis and/or the clinical and imaging follow-up. RESULTS: In 25 examinations reference methods revealed 52 sites of recurrent disease (local n = 7; distant: osseous n = 22, pulmonary n = 13, soft tissue n = 10). On an examination-based analysis FDG-PET had a sensitivity of 0.96, a specificity of 0.81 and an accuracy of 0.90. Corresponding values for conventional imaging were 1.0, 0.56 and 0.82. CONCLUSIONS: The sensitivity, specificity and accuracy of FDG-PET in the detection of recurrences from osseous sarcomas are high. On an examination-based analysis, FDG-PET had a not significantly lower sensitivity in comparison with conventional imaging. However, FDG-PET showed a small advantage in the detection of osseous and soft-tissue recurrences compared with conventional imaging. (+info
Osteosarcoma (osteogenic sarcoma).
Osteosarcoma is a primary malignant tumour of the skeleton characterised by the direct formation of immature bone or osteoid tissue by the tumour cells. The classic osteosarcoma is a rare (0.2% of all malignant tumours) highly malignant tumour, with an estimated incidence of 3 cases/million population/year. Osteosarcoma arises predominantly in the long bones and rarely in the soft tissues. The age at presentation ranges from 10 to 25 years of age. Plain radiographs, computed tomography, magnetic resonance imaging, angiography and dynamic bone scintigraphy are used for diagnosis, evaluation the extent of tumour involvement and decision of the type of operation and, if necessary, the type of reconstruction. Years ago, all patients with osteosarcoma were treated by amputation but the cure rate was under 10% and almost all patients died within a year from diagnosis. Today, for localised osteosarcoma at onset (80% of cases) treated in specialized bone tumour centres with pre- and postoperative chemotherapy associated with surgery, the percentage of patients cured varies between 60% and 70%. Surgery is conservative (limb salvage) in more than 90% of patients. Prognosis is more severe (cure rate about 30%) for tumours located in the axial skeleton and in patients with metastasis at onset. (+info
Primary bone tumours and tumour-like lesions in children in Zaria, Nigeria.
Ossifying fibromyxoid tumour: a rare soft tissue tumour of intermediate malignancy.
Magnetic resonance chemical shift imaging in bone and soft tissue tumours.
A study was carried out in 14 patients to assess the location and differential diagnosis of bone and soft tissue tumours with a 0.5 Tesla scanner, using water and fat images obtained by the three-point Dixon technique. We compared the magnetic resonance imaging findings obtained with this technique with conventional MRI, T1-T2-weighted images, and gadalinium-diethylenetriamine penta-acetic acid enhanced T1-weighted images. Localisation was better with the three-point Dixon technique than with conventional magnetic resonance imaging. Differentiation between the fat and water component around the tumour was possible. The gadalinium-diethylenetriamine penta-acetic acid enhanced water images were very sensitive to enhancement of the tissue. The three-point Dixon technique is useful when the tumour area is difficult to detect by conventional magnetic resonance imaging and information about its components is needed; these images can be made at the low magnet field. (+info