[68Ga]Ga-PSMA-11 PET/CT in the Assessment of High Risk and Recurrent Prostate Cancer

68Ga-PSMA-11 Positron Emission Tomography / Computed Tomography (PET/CT) for Assessment of High Risk or Recurrent Prostate Cancer

Prostate cancer is the third most common cause of cancer death in men. Most patients with localized prostate cancer will be cured with surgery or radiation therapy, but up to 35% of patients will have their prostate cancer return. Whether it has returned locally or distantly determines which type of treatment they will receive. Current conventional imaging modalities have limitations particularly at low prostate specific antigen levels. This study proposes to use Gallium-68-PSMA-11 (68Ga-PSMA-11) Positron Emission Tomography / Computer Tomography (PET/CT) scans which targets prostate-specific membrane antigens (PSMA) to detect where in the body the prostate cancer has recurred.

This is a prospective registry study to evaluate the diagnostic utility of 68Ga-PSMA-11 PET/CT to stage patients with high risk prostate cancer, localize sites of biochemical recurrence of prostate cancer, and restage patients with advanced prostate cancer before and after onset of new therapy.

Eligible subjects will undergo a 68Ga-PSMA-11 PET/CT at the British Columbia Cancer (BCC) - Vancouver. Each subject will receive a 68Ga-PSMA-11 PET/CT scan at the BCC - Vancouver, as part of this research study. Each study subject will receive a bolus intravenous dose of 68Ga-PSMA-11. The subject will rest in a comfortable chair for 60 minutes and will then be taken to the PET/CT scanner for images. The PET/CT scan will take approximately 2.5 hours of patient time above and beyond the time needed for standard of care.

Medical History Questionnaire: Demographic and medical history data will be collected either in person before the PET scan appointment or by mail or phone, whichever is the most convenient to the subject.

Follow-up assessments: All subjects will be contacted by phone the day after the injection of 68Ga-PSMA-11. The subjects will be asked if they experienced any undesirable effects during the 12 hours after the administration of 68Ga-PSMA-11. The local site attending nuclear medicine physician will then make an assessment as to whether these effects are likely related to 68Ga-PSMA-11 administration.

All subjects will be followed for 5 years following the 68Ga-PSMA-11 PET/CT exam to assess the presence of recurrence. The evaluation will include a chart review of available imaging, laboratory tests, and treatment. The data required can be obtained from a review of the patient's paper and electronic charts, supplemented by telephone contact as needed to complete the information.

Inclusion Criteria:

• Eastern Cooperative Oncology Group performance status of 2 or less.
• Subjects with high risk prostate cancer (CAPRA score 6 or higher) being considered for curative-intent surgery or radiation therapy (including brachytherapy)
• Subjects with biopsy confirmed prostate cancer being considered for curative-intent surgery or radiation therapy (including brachytherapy), who have unconfirmed suspicious findings on conventional medical imaging staging examinations.
• Subjects with biochemical recurrence or persistence of prostate cancer following initial curative treatment by radical prostatectomy, with two consecutive PSA values >0.2 ng/ml measured more than 6 weeks after radical prostatectomy. If subjects received subsequent systemic therapy, the most recent PSA measurement prior to PET/CT imaging must be greater than 0.2 ng/mL.
• Subjects with biochemical recurrence or persistence of prostate cancer following initial curative treatment by radical prostatectomy and subsequently treated by salvage radiotherapy or pelvic node dissection, with two consecutive PSA values >0.2 ng/ml. If subjects received subsequent systemic therapy, the most recent PSA measurement prior to PET/CT imaging must be greater than 0.2 ng/mL.
• Subjects with biochemical recurrence of prostate cancer after initial curative therapy with radiation therapy (including brachytherapy), or non-standard local ablative therapy (such as high frequency ultrasound, cryoablation, focal laser ablation, etc.), with a PSA level >2 ng/mL above the nadir after radiation therapy.
• Subjects with advanced castration sensitive or castration resistant prostate cancer being considered for localized treatment (surgery, brachytherapy, radiotherapy) of recurrent or oligometastatic prostate cancer. Castration resistance is defined as a PSA level > 1.0 ng/mL, with 2 consecutive rises above the nadir, in the presence of castrate levels of testosterone (< 1.7 nmol/L).
• Subjects with metastatic or castration resistant prostate cancer being evaluated for systemic therapy administered in therapeutic clinical trials. The PSA level must be > 1.0 ng/mL, with 2 consecutive rises above the nadir, in the presence of castrate levels of testosterone (< 1.7 nmol/L).

Exclusion Criteria:

• Medically unstable (e.g. 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)

Exclusion criteria for the use of furosemide Subjects can still participate in the research study and undergo the [68Ga]Ga-PSMA-11 scan if they are unable or unwilling to receive a furosemide injection.

• Subjects with end stage renal disease.
• Subjects with documented history of severe progressive chronic kidney disease (glomerular filtration rate less than 30 mL/min/1.73 m2).
• Subjects with hypersensitivity to furosemide (Lasix).
• While cross-reactivity between sulfonamide antibiotics and non-antibiotics has been disproven, subjects who have a history of sulfonamide antibiotics or sulfonylureas may be at a higher risk of allergic reaction to furosemide due to a higher general predisposition to allergic reactions. In those instances, the administration of furosemide is left at the discretion of the local site investigator after discussion with the study subject.
• Subjects with severe hypokalemia, hyponatremia, hypovolemia, dehydration or hypotension.
• Subjects with untreated bladder outlet obstruction or lower urinary tract symptoms, who have a history of obstructive episodes that required hospitalization, emergency department visits and/or bladder catheterization for relief of symptoms.