20 May 2019 Positron emission tomography with computed tomography (PET-CT) is a nuclear medicine diagnostic technique that produces functional images with anatomical references. It differs from other nuclear medicine diagnosis methods because of use of positron-emitting radiopharmaceuticals , which mark molecules in physiological processes. It shows their distribution in the body and gives a precise anatomical reference. Fluorine-18-labeled choline is a radiopharmaceutical indicated for urology PET-CT scans, especially in prostate cancer . This radiopharmaceutical with 511KeV photon emission is very well suited for staging and restaging patients with prostate cancer. It largely replaces other tests, such as fluorodeoxyglucose (FDG) PET-CT, which has very low sensitivity to these tumours. Prostate tumour is one of the most prevalent in men. Indications of 18F-Coline PET-CT for prostate tumours include: Initial staging in cases of prostate cancer; Detection of recurrences and relapses; Monitoring and evaluation of response to therapy. In prostate cancer, PET-CT using 18F-FDG can be used in cases of prostate-specific antigen (PSA) levels greater than 5 ng / ml and of suspected relapse. Fluorine-18-labeled choline may be used in patients with PSA levels below 5 ng / ml at baseline (even with PSA below 1 ng / ml). There is no known contraindication for the use of 18F-choline in PET-CT examinations and the precautions are those documented for positron emitters, Fluor-18. The 70 kg adult dose is 280 MBq. As there is no cyclotron in Portugal, patients in need of evaluation of early-stage prostate cancer go to European or American centres for a carbon-11 labelled choline test. The possibility of labelling choline with fluor-18, which has a half-life of two hours, means that this radiopharmaceutical can be obtained from a cyclotron in Madrid. It is therefore possible to study these patients in Portugal. This article was written with the support of physicians and other clinical professionals from the Hospital da Luz network. . The content published in the Health Guide is intended for the general public and is provided for informational and educational purposes only. It does not replace individual medical assessment, diagnosis, or personalized clinical advice from a qualified healthcare professional. The content is produced or reviewed by physicians and other healthcare professionals at Hospital da Luz and is based on the knowledge available at the time of publication or the most recent update, as indicated at the beginning of each item.
