18F-FDG PET/CT as predictor of tumour biology and prognosis in epithelial ovarian carcinoma. / PET/TC con 18F-FDG como predictor de la biología tumoral y del pronóstico en el cáncer epitelial ovárico.

ABSTRACT

OBJECTIVE: To investigate the relationship between maximum standardised uptake value (SUVmax) of ovarian lesions and histopathology subtypes, and their involvement in the response and prognosis of patients with epithelial ovarian carcinoma (EOC). MATERIAL AND METHODS: A retrospective analysis of 31 patients with EOC and 18F-FDG-PET/CT before treatment, including an assessment of the SUVmax of ovarian lesion. Histopathological diagnosis and follow-up was performed. A study was made on the relationship between the SUVmax and histological type (type I and II) and tumour stage, as well as the role of various parameters (SUVmax, histology, stage) on the patient outcomes (complete response [CR], overall survival [OS], disease-free survival [DFS], and disease-free [DF] status, at 12 and 24 months). RESULTS: The medium SUVmax in type I lesions was lower than in type II (6.3 and 9.3, respectively; P=.03). A 7.1 cut-off was set for SUVmax in order to identify type II EOC (sensitivity 77.8%, specificity 69.2%; AUC=0.748; P=.02). No significant relationship was found between tumour stage and SUVmax. CR was more common in early stages; relative risk (RR) of 1.64; P=.003, as well as in type I tumours and a lower SUVmax. Tumour stage was decisive in DFS (P=.04), LE24m (0.07) and OS (P=.08). Longer DFS and a higher percentage of DF 24m were observed in type I tumours (RR 1.32; P=.26). CONCLUSIONS: SUVmax was related to EOC histology, so could predict the response and prognosis of these patients. No association was found between glycolytic activity of the primary tumor with the response and prognosis.