11C-Choline PET/CT in the primary diagnosis of prostate cancer: impact on treatment planning.
OBJECTIVE
Aim of the present study was to evaluate the usefulness of 11C-choline PET/CT for detecting lymphatic or haematogenous spread and for planning radiotherapy in patients with medium-to-high risk prostate cancer.


METHODS
We have included 61 consecutive patients recently diagnosed with cancer prostate by biopsy. All patients were classified as medium-to-high risk: Gleason: 7-9; PSA: 6.3-30.4 ng/mL; stage T2c (N.=20) or stage T3 (N.=41). Image acquisition began 5 min after intravenous injection of 11C-choline (656+119 MBq), starting at the pelvis and continuing craniocaudally. Images were interpreted visually to evaluate uptake by the prostate gland. Lymph nodes with 11C-choline uptake were considered invaded, regardless of their size. Bone lesions were considered positive when they showed greater focal uptake than the surrounding bone. In patients with evidence of lymph-node invasion or bone metastases (15 patients), disease was classified as locoregional, oligometastatic, or multimetastatic.


RESULTS
All patients had prostate gland uptake (20 focal, 8 bifocal, and 33 multifocal). Extraprostatic disease was present in 15 patients (24.6%), as follows: 9 (60%) in a single location: in an infradiaphragmatic lymph node (N.=6), in a supradiaphragmatic lymph node (N.=1), and in bone (M1) (N.=2). Six (40%) as multifocal invasion: with both infra- and supradiaphragmatic lymph node involvement (N.=2); with infradiaphragmatic lymph node involvement and M1 bone metastases (N.=3); and infra- and supradiaphragmatic lymph node involvement plus M1 bone metastases (N.=1). Disease was classified as locoregional (N.=6), oligometastatic (N.=5), and multimetastatic (N.=4). The 11 (73.3%) patients with locoregional and oligometastatic disease were selected to undergo intensity-modulated radiation therapy with dose escalation based on the PET findings.


CONCLUSIONS
Our results suggest that 11C-choline PET/CT is a useful one-stop diagnostic procedure for evaluating patients with medium/high risk prostate cancer scheduled for radical treatment. 11C-choline PET/CT can reliably rule out lymph node involvement and remote metastases, allowing to select candidates for radiotherapy and to plan their treatment.
CETIR Unidad PET, Esplugues de Llobregat, Spain - jrgarcia@cetir.es.
J R
JR
Garcia
S
S
Jorcano
M
M
Soler
D
D
Linero
M
M
Moragas
E
E
Riera
R
R
Miralbell
F
F
Lomeña
D000368:Aged; D001706:Biopsy; D001859:Bone Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary; D002250:Carbon Radioisotopes / Q000737:chemistry; D002794:Choline / Q000737:chemistry; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D049268:Positron-Emission Tomography; D011446:Prospective Studies; D011467:Prostate / Q000000981:diagnostic imaging*; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging*; D019275:Radiopharmaceuticals / Q000737:chemistry*; D011880:Radiotherapy Planning, Computer-Assisted; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed
D002250:Carbon Radioisotopes; D019275:Radiopharmaceuticals; D017430:Prostate-Specific Antigen; D002794:Choline