Early changes of PSMA PET signal after initiation of androgen receptor signaling inhibitors in mCRPC: An international multicenter retrospective study.
[en] Background: Androgen receptor signaling inhibitors (ARSi) play a relevant role in the treatment of prostate cancer. A potential influence of ARSi on PSMA expression has been described. We evaluated early changes of PSMA-expression by PET in mCRPC patients. Methods: This retrospective study included 5 international sites. Patients with mCRPC undergoing 68Ga-PSMA-11 PET/CT prior to (PET1) and early after ARSi (PET2 within 29 days maximum) were included. Whole-body (WB) PSMA-positive tumor volume (PSMA-TV) was evaluated using a liver-specific semi-automatically threshold (Affinity 3.0.2, Hermes Medical Solutions). WB PSMA-TV, SUVmean and SUVmax and their respective changes (%) were analyzed. PSA changes between PET 1 and PET2 were evaluated. Median values and ranges are provided. Results: 54 patients were included in the analysis. ARSi was initiated 1 day (range 0 – 28) after PET1 while PET2 was performed 14 days (range 7 – 29) after ARSi initiation. PSA at PET1 and PET2 was 9.5 ng/ml (range 0.2 – 490.0) and 8.7 ng/ml (range 0.1 – 732.0), respectively (p = 0.035): -33.0% (range -98% – +496%). The WB PSMA-TV at PET1 and PET2 was 89.9 ml (0.0 – 3097.0) and 112.2 ml (0.0 – 3133.0) ml, respectively (p = 0.016; change of +6.0% (range -88% – +260%). WB PSMA SUVmean and SUVmax at PET1 and PET2 was 9.0 (range 5.0 – 43.7) and 9.3 (range 0.0 – 42.5) and 26.5 (range 0.0 – 125.0) and 28.5 (range 0.0 – 212.0), respectively (p = 0.194 and p = 0.353): % change of +3 % (-85% – +71%) and 0% (-55% – +232%). Four of 7 patients with PSA increases at PET2 had an increasing PSMA-TV, 6/7 showed an increasing SUVmean and 5/7 presented with an increased SUVmax. Decreasing WB-PSMA-TV in 18/54 (33%) patients was accompanied by decreasing SUVs in 10 of them (56%). Percent PSA change was unrelated to changes in PSMA-TV, SUVmean and SUVmax. Conclusions: PSMA-PET performed early after ARSI revealed slight increases in the WB-PSMA-TV, stable WB-PSMA SUVs while serum PSA decreased in most of the patients. We conclude that ARSi does not have a strong effect on PSMA expression within 30 days after treatment initiation.
Disciplines :
Oncology
Author, co-author :
Unterrainer, Lena; Ahmanson Translational Theranostics Division, Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA
Farolfi, Andrea; Division of Nuclear Medicine, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
Rosar, Florian; Department of Nuclear Medicine, Saarland University, Homburg, Germany
Denis, Chloé ; Centre Hospitalier Universitaire de Liège - CHU > > Service d'oncologie médicale
Emmett, Louise; St. Vincent's Hospital, Sydney, Australia
de Kouchkovsky, Ivan; University of California San Francisco, Helen Diller Family Comprehensive Cancer Center, San Francisco, CA
Hope, Thomas A.; Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA
Hotta, Masatoshi; Division of Nuclear Medicine, Department of Radiology, National Center for Global Health and Medicine, Shinjuku-ku, Tokyo, Japan, Tokyo, Japan
Gafita, Andrei; Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD
Djaileb, Loic; Department of Nuclear Medicine, Grenoble Alpes University Hospital, Grenoble, France
Czernin, Johannes; Ahmanson Translational Theranostics Division, University of California, Los Angeles, CA
Calais, Jeremie; Ahmanson Translational Theranostics Division, University of California, Los Angeles, CA
Language :
English
Title :
Early changes of PSMA PET signal after initiation of androgen receptor signaling inhibitors in mCRPC: An international multicenter retrospective study.
