She was speaking on receiving the award for the best scientific work at the XXVI National Congress of the Spanish Society for Nuclear Medicine (SEMN), held recently in Maspalomas (the Canary Islands). The study, entitled, "Value of PET with FDG and 11C-Choline in early diagnosis of relapsed treated prostate carcinoma", has analysed for the first time in Spain the utility of 11C-Choline for the detection of relapses in these tumours. To date, conventional FDG (F18-fluorodeoxyglucose) has been used as a radiopharmaceutical, offering good specificity but poor sensitivity in the diagnosis of relapsed prostate carcinoma. The research centred on the analysis of the role of the choline and compared it with the results using FDG. The research, carried out with 38 patients at the Navarre University Hospital, found that 11C-Choline gives better results in diagnosing relapsed prostate cancer. Although both radiopharmaceuticals have a specificity and a predictive negative value of 100%, 11C-Choline shows a sensitivity of 65% in the detection of relapses with low PSA (prostate-specific antigen) level, compared to 28% of FDG. Thus, it is shown to be a radiopharmaceutical especially useful for the early detection of relapsed prostate carcinoma. What is needed now are more studies to enable comparison of its results in function of the treatment that primary tumours require - radiotherapy, surgery, etc. The awarded study forms part of the thesis of Macarena Rodríguez who is to concentrate on the value of the choline in the pre-surgical diagnosis of prostate cancer. This involves analysing the degree of capture of choline by the tumour could have a prognostic value in the illness. This work is of great importance for its immediate utility for clinical studies of carcinoma of the prostate gland. Prostate carcinoma Cancer of the prostate is one of the most frequent causes of death amongst males in the industrialised countries; in fact, it is the second most common tumour amongst this population. Moreover, it has very high rates of relapse - about 15-40% within ten years. The rise of PSA after curative treatment is the most sensitive diagnostic tool for the detection of relapse, but it does not enable pin-pointing its location - thus PET with 11C-Choline may be of great help in this situation.