F18-Choline for the evaluation of prostate cancer patients. Initial experience in Chile
Francisca Redondo1, Hugo Lavados1, Hugo Lavados1, Jessica Ribbeck1, Carlos Elgueta1, Carlos Elgueta1, Rossana Pruzzo1 and Horacio Amaral1
1 Nuclear Medicine and PET/CT Centre, Fundacion Arturo Lopez Perez, Santiago, Chile[dt_divider style=”narrow”/]
Objectives: Radiolabelled choline PET/CT has emerged as a new tool for imaging prostate cancer. In our PET/CT Centre at Oncologic Clinic Fundación Arturo López Pérez, we have recently started producing F18-methilcholine (F18-Ch) and performing our first F18-Ch PET/CT studies. Our objective is to communicate our promising initial experience.
Methods: From October to December 2011 we studied 12 patients, 4 for initial staging, 8 for restaging suspected recurrence, all in a Siemens Biograph mCT after iv administration of F18-Ch (IBA-Synthera modules, ABX reagents), mean 9.3 mCi (range 7.0-13.2). All patients were submitted to an initial acquisition of pelvis 2 minutes after tracer injection, consisting of low-dose attenuation correction CT and 2 bed, 3 min/bed, metabolic imaging; and 60 minutes later to a second PET/CT study consisting in a contrast-enhanced CT and a 2 min/bed metabolic imaging, skull base to mid-thighs. Focal uptake of F18-Ch in abnormal sites, more intense than expected or that remained stable or increased in uptake between early and late images, was considered positive for neoplastic involvement (Pos). Focal uptake that disappeared or decreased in late images was considered negative (Neg).
Results: F18-Ch labeling had mean yield of 16% and radiochemical purity of 99.5%. In 8 patients with suspected recurrence, PET/CT was Neg in 4, all with history of surgery, mean PSA 1,0 (0.5-2.0). In the remaining 4, all treated with radiotherapy, PET/CT was Pos in prostate, bladder, seminal vesicles, lymph nodes and/or pulmonary nodules, mean PSA 6.3 (1.4-8). In 4 recently diagnosed patients, PET/CT showed focal uptake in all primary lesions and in 1 of them, also, in regional lymph nodes and bone metastases, mean PSA 68.6 (41-96).
Conclusions: In our initial experience, F-Ch PET/CT seems a promising tool for the study of prostate cancer patients, with a reliable and high purity radiolabeling method, high quality images and sensitivity that increases with PSA value, as described in international literature