Primary Objective:

To evaluate the safety and tolerability of PET imaging following a single intravenous infusion of [⁶⁸Ga]Ga-ELI421 injection in patients with prostate cancer.

Secondary Objectives:

To evaluate the biodistribution characteristics of [⁶⁸Ga]Ga-ELI421 injection; To evaluate the radiation dosimetry characteristics of [⁶⁸Ga]Ga-ELI421 injection; To evaluate the diagnostic efficacy of PET imaging with [⁶⁸Ga]Ga-ELI421 injection.

Inclusion Criteria:

1. Has been fully informed about the study and voluntarily provided written informed consent prior to initiation of any study-related procedures;
2. Aged ≥ 18 years;
3. In generally good condition with an Eastern Cooperative Oncology Group (ECOG) performance status score of 0-1;
4. Patients with histopathologically and/or cytologically confirmed prostate cancer;
5. Has an indication for PSMA PET imaging;
6. No clinically significant abnormal findings on physical examination, vital signs, laboratory tests, 12-lead ECG, or other examinations that may compromise subject safety or imaging results.
7. Subjects of reproductive potential agree to refrain from pregnancy, sperm donation, and voluntarily use highly effective contraceptive methods (including by their partner) for 6 months after study drug administration, such as condoms, oral or injectable contraceptives, intrauterine devices (IUDs), etc.

Exclusion Criteria:

1. Presence of comorbidities that may compromise subject safety or interfere with imaging results;
2. Concomitant medications that may compromise subject safety or interfere with imaging results;
3. Insufficient washout period following prior anti-tumor therapies (including cytotoxic chemotherapy, immunotherapy, radiotherapy, etc.), which may compromise subject safety or interfere with imaging results;
4. Known hypersensitivity to ionizing radiation or alcohol, or hypersensitivity to [⁶⁸Ga]Ga-ELI421 injection or its excipients, or other history of severe allergic reactions;
5. Inability to complete PET imaging as required;
6. Any other conditions deemed inappropriate by the investigator for participation in this study.