This is a pilot, non-randomized, two-cohort interventional study in patients who meet the inclusion criteria, using an FDA- approved androgen deprivation agent for a 3 or 6-week course of treatment prior to standard-of-care RALP with PLND. The intent of the study is to determine the effect of ADT on PSMA expression as measured by PSMA-PET scan. A second PSMA-PET scan will be performed after ADT for either 3 or 6 weeks, depending on cohort, prior to RALP and PLND.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
DIAGNOSTIC
Masking
NONE
Enrollment
10
PSMA-PET scan with Posluma agent (x2)
Administration of oral ADT for 3 and 6 weeks
Serum PSA and testosterone at study initiation and again at 3 and 6 weeks after initiation of ADT
Urology Clinics of North Texas
Dallas, Texas, United States
1. Mean change in maximum standardized uptake value (SUVmax) per lesion as measured by PSMA-PET (POSLUMA®) from baseline to post-ADT
Time Frame: Baseline and 3-6 weeks after initiation of ADT Description: SUVmax will be measured on PSMA-PET for each lesion identified prior to ADT and again after 3 or 6 weeks of ADT (depending on cohort). The primary metric will be the mean change in SUVmax per lesion, per participant. Data will be summarized as mean ± SD, and analyzed using paired statistical testing to determine significance of change.
Time frame: 3-6 weeks
New lesions not identified pre-treatment are detectable after ADT
Time Frame: Baseline and 3-6 weeks post-ADT initiation Description: PSMA-PET scans performed at 3 or 6 weeks after ADT will be compared to baseline scans to identify newly visible lesions. The outcome will be reported as the number and proportion of participants with new lesions. Descriptive statistics will be used to summarize findings.
Time frame: 3-6 weeks
Establish the optimal duration of ADT necessary to achieve castrate level of testosteroneTime to castration-level testosterone (≤50 ng/dL) following initiation of oral ADT (relugolix 120 mg daily)
Time Frame: 0 to 6 weeks after initiation of ADT Description: Serum testosterone will be measured at baseline, 3 weeks, and 6 weeks. The time point at which testosterone ≤50 ng/dL is first achieved will be recorded for each participant. Data will be summarized by frequency, proportion, and median time to castration levels.
Time frame: 3-6 weeks
Proportion of lesions visible on baseline PSMA-PET that remain detectable on post-ADT PSMA-PET
Time Frame: Baseline and 3-6 weeks after initiation of ADT Description: Lesions identified at baseline will be matched to post-ADT PSMA-PET scans. The number and proportion of lesions that remain visible after ADT will be recorded. This will help assess whether ADT obscures PSMA-positive disease on imaging.
Time frame: 3-6 weeks
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
Correlation between PSMA-PET findings and surgical pathology
Time Frame: Surgery performed 6-10 weeks after enrollment Description: Lesions identified by PSMA-PET will be compared to histopathologic findings from prostatectomy and pelvic lymph node dissection specimens. Correlation statistics (e.g., sensitivity, specificity, positive predictive value) will be calculated.
Time frame: 3-6 weeks
Concordance between study PSMA-PET and conventional imaging or alternative PSMA-PET agents (if available)
Time Frame: 3-6 weeks after ADT, when comparator imaging is available Description: In participants who undergo additional imaging (e.g., bone scan, CT, or alternative PSMA-PET tracers), lesions will be compared to those seen on study PSMA-PET. Concordance will be reported as number and proportion of lesions detected by both modalities.
Time frame: 3-6 weeks