Ga-68-PSMA lyophilized ready to use kit for diagnosis of prostate cancer by PET/CT

Objectives Imaging of the prostate-specific membrane antigen (PSMA) for the detection of prostate cancer lesions is more and more subject of intense research. With a view for the production of radiopharmaceuticals existing GMP requirements radiolabeling using automated cassette systems are standard. Cold kit procedures, which shorten the synthesis time, reduce the error rate the and avoid the need of expensive hardware are objects of intense investigations and would be a reliable alternative. Herein we present our initial treatment experience of a 77 yrs old patient with prostate cancer using [68Ga]HBED-CC-PSMA produced with a room temperature cold kit methodology.

Methods [68Ga]HBED-CC-PSMA was prepared using a lyophilized Cold Kit (ANMI S.A., Belgium). A commercially produced 68Ge/68Ga generator (IGG 100, 50 mCi, Eckert&Ziegler, Germany) was eluted with 10 ml 0.1 mol/L HCl and transferred into the destined lyophilized Cold Kit vial, mixed well and kept for 10 min at room temperature. After assessing chemical and radiochemical purity with HPLC and TLC and the LAL endotoxin test performed using the Endosafe PTS. Then, PET scan was performed 30 minutes after injection of 150 MBq of [68Ga]HBED-CC-PSMA with a dynamic acquisition of 50 minutes.

Results The labeling at room temperature resulted in radiochemical yields of > 99 % and radiochemical purities of > 98 %. The diastereomeric ratio was 1:1. Endotoxins were negatives ( < 5.00 EU / mL). [68Ga]HBED-CC-PSMA lyophilized kit confirmed its ability to clearly detect the increase tracer uptake at prostate ( SUV = 12.44) and lymph node in the area of the right pelvis (SUV= 2.92) with a Gleason score of 7(3+4) and a PSA level of 46.54 ng/ml.

Conclusions The novel [68Ga]HBED-CC-PSMA Cold Kit allowed the labeling at room temperature with high efficiency (> 99%), purity of (> 98 %) and time saving of more than 75%. Furthermore, the first result showed high uptake at prostate and lymph nodes. The Cold kit methodology appears to be a reliable alternative to synthetizer based method for the diagnosis of prostate cancer by PET/CT.