Prospective evaluation of [11C]Choline PET/CT in therapy response assessment of standardized docetaxel first-line chemotherapy in patients with advanced castration refractory prostate cancer.
OBJECTIVE
The aim of this study was to prospectively evaluate the value of [11C] Choline PET/CT in monitoring early and late response to a standardized first-line docetaxel chemotherapy in castration refractory prostate cancer (mCRPC) patients.


METHODS
Thirty-two patients were referred for [11C] Choline PET/CT before the start of docetaxel chemotherapy, after one and ten chemotherapy cycles (or - in case of discontinuation - after the last administered cycle) for therapy response assessment. [11C] Choline uptake (SUVmax, SUVmean), CT derived Houndsfield units (HUmax, HUmean), and volume of bone, lung, and nodal metastases and local recurrence were measured semi-automatically at these timepoints. Change in SUVmax, SUVmean, HUmax, HUmean,and volume was assessed between PET 2 and 1 (early response assessment, ERA) and PET 3 and 1 (late response assessment, LRA) on a patient and lesion basis. Results of PET/CT were compared to clinically used RECIST 1.1 and clinical criteria based therapy response assessment including PSA for defining progressive disease (PD) and non-progressive disease (nPD), respectively. Relationships between changes of SUVmaxand SUVmean(early and late) and changes of PSAearlyand PSAlatewere evaluated. Prognostic value of initial SUVmaxand SUVmeanwas assessed. Statistical analyses were performed using SPSS.


RESULTS
In the patient-based ERA and LRA there were no statistically significant differences in change of choline uptake, HU, and volume between PD and nPD applying RECIST or clinical response criteria. In the lesion-based ERA, decrease in choline uptake of bone metastases was even higher in PD (applying RECIST criteria), whereas in LRA the decrease was higher in nPD (applying clinical criteria). There were only significant correlations between change in choline uptake and PSA in ERA in PD, in LRA no significant correlations were discovered. Initial SUVmaxand SUVmeanwere statistically significantly higher in nPD (applying clinical criteria).


CONCLUSIONS
There is no significant correlation between change in choline uptake in [11C] Choline PET/CT and clinically routinely used objective response assessment during the early and late course of docetaxel chemotherapy. Therefore, [11C] Choline PET/CT seems to be of limited use in therapy response assessment in standardized first-line chemotherapy in mCRPC patients.
Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich, Germany. sarah.schwarzenboeck@med.uni-rostock.de.|Department of Nuclear Medicine, Rostock University Medical Centre, Gertrudenplatz 1, 18057, Rostock, Germany. sarah.schwarzenboeck@med.uni-rostock.de.
Sarah M
SM
Schwarzenböck
Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich, Germany.
Matthias
M
Eiber
Department of Biostatistics and Informatics, Rostock University Medical Centre, Ernst-Heydemann-Str. 8, 18057, Rostock, Germany.
Günther
G
Kundt
Department of Urology, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich, Germany.
Margitta
M
Retz
Department of Nuclear Medicine, Rostock University Medical Centre, Gertrudenplatz 1, 18057, Rostock, Germany.
Monique
M
Sakretz
Department of Nuclear Medicine, Rostock University Medical Centre, Gertrudenplatz 1, 18057, Rostock, Germany.
Jens
J
Kurth
Department of Urology, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich, Germany.
Uwe
U
Treiber
Department of Urology, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich, Germany.
Roman
R
Nawroth
Institute of Radiology, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich, Germany.
Ernst J
EJ
Rummeny
Department of Urology, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich, Germany.
Jürgen E
JE
Gschwend
Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich, Germany.
Markus
M
Schwaiger
Department of Urology, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich, Germany.
Mark
M
Thalgott
Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich, Germany.|Department of Nuclear Medicine, Rostock University Medical Centre, Gertrudenplatz 1, 18057, Rostock, Germany.
Bernd J
BJ
Krause
D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use; D002250:Carbon Radioisotopes; D002794:Choline; D000077143:Docetaxel; D004334:Drug Administration Schedule; D016903:Drug Monitoring / Q000379:methods; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care / Q000379:methods; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D011446:Prospective Studies; D064129:Prostatic Neoplasms, Castration-Resistant / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D019275:Radiopharmaceuticals; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D043823:Taxoids / Q000008:administration & dosage* / Q000592:standards; D016896:Treatment Outcome
D000970:Antineoplastic Agents; D002250:Carbon Radioisotopes; D019275:Radiopharmaceuticals; D043823:Taxoids; D000077143:Docetaxel; D002794:Choline
Advanced prostate cancer; Choline; Docetaxel therapy; PET/CT; Therapy response assessment