Positron emission tomography/computed tomography with F-18-fluorocholine for restaging of prostate cancer patients: meaningful at PSA < 5 ng/ml?

• Published in: Molecular imaging and biology 2006-01, Vol.8 (1), p.43-48
• Main Authors: Heinisch, Martin, Dirisamer, Albert, Loidl, Wolfgang, Stoiber, Franz, Gruy, Bernhard, Haim, Silke, Langsteger, Werner
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Choline; Fluorine Radioisotopes - pharmacokinetics; Follow-Up Studies; Humans; Male; Medical research; Middle Aged; Neoplasm Staging; Positron-Emission Tomography; Prostate cancer; Prostate-Specific Antigen - blood; Prostatectomy; Prostatic Neoplasms - blood; Prostatic Neoplasms - diagnostic imaging; Prostatic Neoplasms - pathology; Prostatic Neoplasms - radiotherapy; Prostatic Neoplasms - surgery; Radiation therapy; Radiopharmaceuticals - pharmacokinetics; Retrospective Studies; Tomography, X-Ray Computed
• ISSN: 1536-1632; 1860-2002
• DOI: 10.1007/s11307-005-0023-2

According to reports, re-staging of patients suffering from prostate cancer by positron emission tomography (PET) using C-11-choline has failed to produce positive findings at a PSA level of < 5 ng/ml. Hence, the purpose of our study has been to determine whether this is true also for PET/CT using F-18-fluorocholine (FCH PET/CT) or whether it is possible to obtain true positive results by FCH PET/CT even at lower PSA levels. In 34 patients with prostate cancer who had undergone initial therapy (radical prostatectomy n = 31, radiotherapy n = 3), a PET/CT scan was performed using F-18-fluorocholine (FCH) during follow-up in case of demonstrable or rising PSA levels. Current PSA levels were determined in all patients at the time of examination. Median PSA in FCH positive patients was 6.1 ng/ml (mean PSA 17.1 ng/ml), median PSA in FCH negative patients was 2.3 ng/ml (mean PSA 3.4 ng/ml), respectively (p < 0.05). In eight of 17 examinations (47%) with PSA < 5 ng/ml, at least one FCH-positive focus was detected. So far the findings could be confirmed by correlating imaging methods (CT and/or MR), biopsy/histology and the course of the disease, respectively, in seven of the eight FCH-positive cases with PSA < 5 ng/ml, so that a true positive FCH PET/CT finding was obtained all in all in seven of 17 (41%) examinations with PSA < 5 ng/ml. In four of these seven FCH PET-positive patients with PSA < 5 ng/ml, adjuvant hormonal therapy was administered at the time of the examination or prior to the examination. In re-staging patients with prostate cancer, FCH PET/CT is able to yield true positive findings even at PSA < 5 ng/ml. Therefore, FCH PET/CT should not be restricted to patients with PSA > 5 ng/ml.