(11)C-Choline PET/CT in castration-resistant prostate cancer patients treated with docetaxel.
OBJECTIVE
To investigate the role of (11)C-choline PET/CT for evaluating the response to treatment in patients with metastatic castration-resistant prostate cancer (mCRPC) treated with docetaxel in comparison with PSA response.


METHODS
Inclusion criteria were (a) proven mCRPC, (b) docetaxel as first line of chemotherapy (docetaxel 75 mg/m(2) + prednisone 5 mg), and (c) (11)C-choline PET/CT and PSA values assessed before and after docetaxel administration. A total of 61 patients were retrospectively enrolled (mean age 68.9 years, range 57 - 84 years). (11)C-Choline PET/CT was performed at baseline before docetaxel treatment (PET1) and after the end of treatment (PET2). PSA values were measured before treatment (PSA1) and after treatment (PSA2). PET2 was reported as complete response (CR), partial response (PR) or stable disease (SD). Progressive disease (PD) was considered if a new lesion was seen. PSA trend was calculated from the change in absolute values between PSA1 and PSA2. A decrease of ≥50 % between PSA1 and PSA2 was considered a PSA response. Clinical, radiological and laboratory follow-up ranged from 6 to 53 months (mean 13.5 months).


RESULTS
Of the 61 patients, 40 (65.5 %) showed PD on PET2, 13 (21.3 %) showed SD, 2 (3.4 %) showed PR, and 6 (9.8 %) showed CR. An increasing PSA trend was seen in 29 patients (47.5 %) and a decreasing PSA trend in 32 patients (52.5 %). A PSA response of ≥50 % was seen in 25 patients (41 %). Radiological PD was seen in 23 of the 29 patients (79.3 %) with an increasing PSA trend, in 16 of the 32 patients (50 %) with a decreasing PSA trend, and in 11 of the 25 patients (44 %) with a PSA response of ≥50 %. In the multivariate statistical analysis, the presence of more than ten bone lesions detected on PET1 was significantly associated with an increased probability of PD on PET2. No association was observed between PSA level and PD on PET2.


CONCLUSIONS
Our results suggest that an increasing PSA trend measured after docetaxel treatment could be considered predictive of PD. In patients with decreasing PSA values (decreasing PSA trend and a PSA response of ≥50 %), (11)C-choline PET/CT may be useful to identify those with radiological progression despite a PSA response. Finally, the tumour burden, expressed as number of bone lesions on PET1, is significantly associated with an increased probability of PD on PET2.
Service of Nuclear Medicine, S.Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy. francesco.ceci83@gmail.com.|UO Medicina Nucleare PAD. 30, Azienda Ospedaliero-Universitaria di Bologna, Policlinico S.Orsola-Malpighi, Via Massarenti, 9, 40138, Bologna, Italy. francesco.ceci83@gmail.com.
Francesco
http://orcid.org/0000-0001-9785-5248
F
Ceci
Service of Nuclear Medicine, S.Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy.
Paolo
P
Castellucci
Service of Nuclear Medicine, S.Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy.
Tiziano
T
Graziani
Department of Urology, S.Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy.
Riccardo
R
Schiavina
Service of Nuclear Medicine, S.Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy.
Riccardo
R
Renzi
Department of Urology, S.Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy.
Marco
M
Borghesi
Department of Oncology, S.Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy.
Piergiorgio
P
Di Tullio
Department of Urology, S.Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy.
Eugenio
E
Brunocilla
Department of Oncology, S.Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy.
Andrea
A
Ardizzoni
Service of Nuclear Medicine, S.Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy.
Stefano
S
Fanti
D000368:Aged; D000369:Aged, 80 and over; D002250:Carbon Radioisotopes; D002794:Choline; D000077143:Docetaxel; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D017430:Prostate-Specific Antigen / Q000378:metabolism; D064129:Prostatic Neoplasms, Castration-Resistant / Q000175:diagnosis* / Q000188:drug therapy* / Q000378:metabolism; D043823:Taxoids / Q000627:therapeutic use*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
D002250:Carbon Radioisotopes; D043823:Taxoids; D000077143:Docetaxel; D017430:Prostate-Specific Antigen; D002794:Choline
Biochemical relapse; CRPC; Chemotherapy prostate cancer; Docetaxel; Therapy response