Nuklearmedizin 2019; 58(02): 193-194
DOI: 10.1055/s-0039-1683739
Poster
Theranostik
Georg Thieme Verlag KG Stuttgart · New York

Evaluation of [68Ga]Ga-PSMA-PET/CT in therapy response assessment of PSMA-targeted radionuclide therapy in patients with castration resistant prostate cancer

J Kurth
1   Universitätsmedizin Rostock, Klinik und Poliklinik für Nuklearmedizin, Rostock
,
J Kretzschmar
1   Universitätsmedizin Rostock, Klinik und Poliklinik für Nuklearmedizin, Rostock
,
M Heuschkel
1   Universitätsmedizin Rostock, Klinik und Poliklinik für Nuklearmedizin, Rostock
,
G Kundt
2   Universitätsmedizin Rostock, Institut für Biostatistik, Informatik in der Medizin und Altersforschung, Rostock
,
OW Hakenberg
3   Universitätsmedizin Rostock, Klinik und Poliklinik für Urologie, Rostock
,
BJ Krause
1   Universitätsmedizin Rostock, Klinik und Poliklinik für Nuklearmedizin, Rostock
,
SM Schwarzenböck
1   Universitätsmedizin Rostock, Klinik und Poliklinik für Nuklearmedizin, Rostock
› Author Affiliations
Further Information

Publication History

Publication Date:
27 March 2019 (online)

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    Ziel/Aim:

    The aim of this study was to retrospectively evaluate the value of [68Ga]Ga-PSMA-PET/CT in monitoring early and late response to PSMA-targeted radionuclide therapy (Lu-177/Y-90) in castration resistant prostate cancer patients.

    Methodik/Methods:

    38 patients were referred for [68Ga]Ga-PSMA-PET/CT before the first cycle (PET 1), after one/two cycles (PET 2) and after a mean of 3 cycles (range 3 to 5 cycles) (PET 3) of PSMA radioligand therapy (Lu-177/Y-90) for patient-based therapy response assessment. PET-based therapy response was assessed according to EORTC and PERCIST criteria, for PET 2 vs. 1 (early response assessment, ERA) as well as for PET 3 vs. 1 (late response assessment, LRA). PET-classified response was compared to the results of ERA and LRA based on clinical criteria and percentual change in PSA. Additionally, relationship between change of SUVmax/SUVmean and PSA (early and late, respectively) was evaluated. Prognostic value of initial SUVmax and SUVmean was assessed.

    Ergebnisse/Results:

    About 76% of the patients were classified as SD or PR (SD: 65.2%; PR: 10.9%) by clinical criteria and 77% by change in PSA as response criterion (SD: 46.7%; PR: 31.1%). However, by PET-based response assessment approx. 95% were classified as SD or PR (PERCIST: SD 23.9%; PR: 71.7%; EORTC: SD 23.9%; PR: 69.6%). Cohens kappa analysis showed no statistically significant concordance between EORTC/PERCIST based and clinical criteria/PSA-based ERA and LRA; kappa < 0.2. No statistically significant correlation was found between change in SUV and PSA in ERA and LRA; r < 0.1, for both ERA and LRA. No statistically significant prognostic value of initial SUVmax and SUVmean could be shown.

    Schlussfolgerungen/Conclusions:

    Pretherapeutic [68Ga]Ga-PSMA-PET/CT is an essential prerequisite to detect sufficient expression of the molecular target. However, a significant correlation between [68Ga]Ga-PSMA-PET/CT based and clinical criteria/PSA-based therapy response assessment during the early and late course of PSMA targeted therapy could not be shown. The role of [68Ga]Ga-PSMA-PET/CT in this setting has to be evaluated in further studies.


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