This is a preliminary evaluation of a radiotracer's biodistribution in human subjects. It is a prospective, single-centre, open-label, single group assignment interventional study.

Prostate cancer is very common, and PSMA imaging is currently the most accurate means of localizing these tumours.

The goal is to evaluate the biodistribution and safety of [68Ga]HTK03149 PET/CT for prostate cancer imaging.

Each subject will have a PET/CT scan using [68Ga]HTK03149 . The [68Ga]HTK03149 radioactive tracer is manufactured for this study under a Clinical Trial Application filed with Health Canada.

After providing informed written consent subjects will complete a medical history questionnaire.

Monitoring of adverse events There will be short-term evaluation of adverse events by comparison of vital signs before and after administration of [68Ga]HTK03149 . Eighteen to seventy-two hours after [68Ga]HTK03149 administration the participant will return to the imaging department to perform a follow up safety assessment and routine blood draw. The study coordinator will ask the participant if they have experienced any adverse events during that time period and complete the adverse event questionnaire.

Follow-up Assessments

The following information will be collected up to 12 months following the PET/CT scans:

Initiation of a new treatment, Laboratory results and pathology reports, Results of imaging studies, Final clinical diagnosis by physician and relevant clinical notes. The study is expected to take up to 1 year for accrual.

Inclusion Criteria:

• Participants with newly diagnosed or documented prostate cancers (PCa), with at least one measurable lesion based on CT, MR or at least one visualised lesion on PET/CT imaging (either from an 18F-DCFPyL or 68Ga-PSMA-11 PET).
• ECOG performance status of 2 or less.

Exclusion Criteria:

• Medically unstable (eg. acute illness, unstable vital signs)
• Unable to lie supine for the duration of imaging
• Unable to provide written consent
• Exceeds safe weight limit of the PET/CT bed (204.5 kg) or unable to fit through the PET/CT bore (diameter 70 cm)
• Patients with widespread liver metastases occupying more than 50% of the liver volume will not be eligible to participate in this study as this would preclude assessment of normal liver activity for dosimetry purposes.
• Patients with baseline ALT or AST higher than 5× ULN or 250 U/L.
• Patients with elevated baseline levels of total bilirubin (higher than 1.2× ULN, or 1.3 mg/dL, (with exception of Gilbert's syndrome), with INR >1.2, or platelet count below the lower limit of normal (typically <150 000/μL.
• Patients with elevated alkaline phosphatase (ALP), equal to or higher than 2× ULN or 250 U/L, unless the ALP elevation is not from a hepatic origin.