Valor clínico de la tomografía de emisión de positrones con F-18-FDG en el seguimiento de pacientes con cáncer de ovario

Abstract

Background. Positron emission tomography with fluor- 18-deoxyglucose (PET-FDG) is an efficient technique for the detection of tumoural tissue. The aim of the paper is to evaluate the PET-FDG in the diagnosis of residual disease or relapse in patients with cancer of the ovary. Methods. A total of 24 patients, diagnosed and treated for cancer of the ovary with surgery and subsequent chemotherapy, were included. With 12 patients the study was carried out prior to second-look surgery, and with the other 12 after objectivising an increase of the tumoural marker in the follow up. Abdominal-pelvic CAT, determination of the seric levels of CA-125 and PET-FDG of thorax, abdomen and pelvis were carried out on all patients. The PET-FDG was evaluated in a qualitative way through the visual study of the images, and quantitatively through the SUV or standard uptake value. The definitive diagnosis was confirmed through an anatomopathological study in 13 cases and through clinical follow up in the rest with an average of 11.2±5.4 months (range 6-24). Results. A CA-125 value higher than 35 UI/ml was considered positive, obtaining a sensitivity of 77% and a specificity of 100%. The sensitivity of the CAT was 23% and the specificity 91%. With the FDG-PET sensitivity was 92% and the specificity 90%. A SUV value ≥ 3 was considered pathological, obtaining the same results as with the visual evaluation. The FDG-PET was positive in 5 patients with non-conclusive CAT, 4 with negative CAT and 2 with negative CA-125. Conclusion. These preliminary results suggest that the FDG-PET could be useful in the follow up of patients treated for cancer of the ovary. The FDG-PET could be efficient in the differentiation between residual disease or recurrence, as opposed to sequels to the treatment, when the CAT is not conclusive due to anatomical distortion. The FDG-PET could be more sensitive than an increased marker value, and facing an increase of the latter it permits a non-invasive localisation of the disease.