Prostate-specific membrane antigen (PSMA) agents have shown promise in detecting and treating prostate cancer. Gallium-68-labeled PSMA-11 (68Ga-PSMA-11) is a radioactive agent that binds to prostate cancer cells and can be imaged using positron emission tomography (PET) scanners that detect radioactivity in the body. This early phase I study will use PET to determine if delivering 68Ga-PSMA-11 directly into the prostatic artery (intra-arterial (IA) administration) results in greater uptake in the prostate than delivering 68Ga-PSMA-11 into a vein in the arm (intravenous (IV) administration).
PRIMARY OBJECTIVE: I. To compare the maximum standardized uptake value (SUVmax) in tumoral regions-of-interest during prostatic arterial and intravenous 68Ga-PSMA-11 infusions. SECONDARY OBJECTIVES: I. To compare the tumoral time-activity curves for selective prostatic arterial and intravenous 68Ga-PSMA-11 infusions. II. To study PSMA receptor saturation kinetics during selective prostatic arterial infusion of 68Ga-PSMA-11 (obtained only from arterial time activity curves \[TACs\] ipsilateral to the side of infusion). OUTLINE: Patients receive 68Ga-PSMA-11 IV over 30 minutes and undergo dynamic PET imaging over infusion period and for 15 minutes after on day 1. 1-14 days later, patients undergo pelvic angiogram and prostatic arterial catheterization. Patients then receive 68Ga-PSMA-11 IA over 30 minutes and undergo dynamic PET imaging over infusion period and for 15 minutes after. After completion of study, patients are followed up with 24 hours after the IA infusion and PET scan.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
5
Undergo angiogram
Undergo prostatic arterial catheterization
Given IV and IA
Undergo PET scan
University of California San Francisco
San Francisco, California, United States
Maximum standardized uptake value (SUVmax)
A two-sided paired t-test will determine whether the ipsilateral SUVmax values obtained during selective arterial 68Ga-PSMA-11 infusions are greater than those obtained during venous infusions. A similar paired analysis will be made during arterial infusions to compare tumoral regions of interest (ROIs) ipsilateral and contralateral to the side of the infusion. Means/medians, ranges/standard deviations will be calculated for each endpoint.
Time frame: Day 1 and from Day 2 up to Day 15 (2 days total)
Comparison of Mean SUV (SUVmean)
Paired t-tests will determine whether SUVmean is different for intra-arterial (IA) time activity curves (TACs) when compared to intravenous (IV) TACs. Means/medians, ranges/standard deviations will be calculated for each endpoint.
Time frame: Day 1 and from Day 2 up to Day 15 (2 days total)
Comparison of Time to SUVmax (TSUV)
Paired t-tests will determine whether TSUV is different for IA TACs when compared to IV TACs. Means/medians, ranges/standard deviations will be calculated for each endpoint.
Time frame: Day 1 and from Day 2 up to Day 15 (2 days total)
Comparison of Area under the curve (AUC)
Paired t-tests will determine whether AUCs are different for IA TACs when compared to IV TACs. Means/medians, ranges/standard deviations will be calculated for each endpoint.
Time frame: Day 1 and from Day 2 up to Day 15 (2 days total)
Comparison of Rate of 68Ga-PSMA-11 uptake
To assess whether the rate of uptake is significantly different with selective arterial infusion, a two-sided paired t-test will compare the slopes for Selective arterial infusion, tumor ipsilateral to the side of radiotracer injection (IAIpsi) curves and Intravenous infusion, tumor ipsilateral to the side of corresponding arterial injection (IVIpsi) curves during each of the nine time intervals. Selective arterial infusion, tumor contralateral to the side of radiotracer injection (IACont) slopes will be similarly compared to those acquired from corresponding Intravenous infusion, tumor contralateral to the side of corresponding arterial injection (IVCont) data. Means/medians, ranges/standard deviations will be calculated for each endpoint.
Time frame: Day 1 and from Day 2 up to Day 15 (2 days total)
Comparison of Time to early saturation effects
Specific to the IAIpsi TACs, the time to early saturation effects (Tese) will represent the time at which the second derivative of the curve becomes negative (i.e. when concavity in the curve is first noted). For the purposes of Tese, the aforementioned curve partitioning method will not be used. Descriptive statistics of Tese will be established, along with statistics for the corresponding mass dose administered (MDese) at Tese. Means/medians, ranges/standard deviations will be calculated for each endpoint.
Time frame: 1 day
Comparison of Mass dose at saturation
Descriptive statistics of Tese will be established, along with statistics for the corresponding mass dose administered (MDese) at Tese. Means/medians, ranges/standard deviations will be calculated for each endpoint.
Time frame: Day 1 and from Day 2 up to Day 15 (2 days total)
Comparison of Mean SUV during 15-minute washout (SUVwashout)
The mean SUVwashout and its standard deviation will be calculated for the 15-minute post-injection periods.
Time frame: 1 day
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