The Role of Ga68-PSMA-11 PET Imaging in Prostate Cancer Patients Undergoing Androgen Deprivation Therapy
Condition: Metastatic Prostate Cancer
MeSH terms: Prostatic Neoplasms
Study type: Interventional

Summary: 
      This is an open-label single arm clinical trial, Plan to enroll approximately a total of 43
      evaluable subjects. According to the estimated missing rate 15%, the sample size in this
      study is 51.

      Inclusion criteria:

      To be eligible for inclusion, each patient must fulfill all of the following criteria:

        1. Males with 40-85 years of age and life expectancy more than 3 months

        2. Pathology-proved prostate cancer patients and classified as clinical stage III or IV
           (including lymph node or bone metastasis)

        3. Willing to sign the informed consent

      Exclusion criteria:

      Patient who has any of the following criteria will be excluded from the trial:

        1. Unable to tolerate the PET/CT scan, such as those with claustrophobia, unable to lie
           still, consciousness unclear, vital sign unstable.

        2. With renal impairment (glomerular filtration rate lower than 30 ml/min/1.73 m2), and
           allergy to medium contrast.

        3. Significant abnormal lab data (AST or ALT more than three times of normal value), and
           high risk to conduct examination after evaluations of PI.

        4. Patient had previous malignancy history

        5. Patient had known allergy history or is probably allergy to Ga68-PSMA-11
    

Detailed description: 
      It is a single-arm clinical trial. The primary endpoint is diagnostic positivity rate of
      Ga68-PSMA-11 in metastasis lesion. Sample size calculation is performed using two-sided
      one-proportion test to achieving an 82% power at the 5% level of significance. The primary
      measurement of positivity can be obtained for the one-proportion test with statistical
      hypotheses H0: P = P0 versus H1: P≠P0. We assume the alternative positivity rate is 65.9% and
      the null positivity rate is 43.9% which is the reference value from Maurer T et al (J Urol.
      2016;195:1436-1443). Thus, the sample size needed is 43. According to the estimated missing
      rate 15%, the sample size in this study is 51. The sample size calculation was performed
      using PASS software (Power Analysis and Sample Size version 11.0.8, NCSS, Kaysville, Utah,
      USA). All subjects enrolled must meet eligibility criteria based on the inclusion/exclusion
      criteria detailed in Section 5.4 and 5.5.

      For PET/CT PSMA scan, the subject will have catheter(s) placed for intravenous administration
      of [68Ga]PSMA-11. Subjects will receive a single intravenous bolus of 2-5 mCi [68Ga]PSMA-11
      and received PET/CT scan 60 minutes later. The data acquisition begin with non-contrast CT at
      120kVp, automated mAs, and a pitch of 1.5, followed by PET acquisition from the mid-thigh to
      skull-base, 3 minutes each bed. After image acquisition, the subject will be observed for
      half an hour, and will be discharged if no adverse event happens. EKG, blood and biochemistry
      test will be performed before and after scan no more than two weeks. Patient will underwent
      two times of PSMA-11 PET/CT scans before and under androgen deprivation therapy within a
      10-14 weeks interval. In the follow up period, if metastatic castration-resistance status
      happens, patient may underwent optional PSMA-11 PET/CT scan by attending's discrimination in
      order to give appropriate treatment suggestions.

      Time elapsed from the last PSA determination until PET scan was no more than 6 weeks in all
      patients. Patients will receive complementary workups. All of the images were interpreted by
      a team of two nuclear medicine physicians and one radiologist. In cases of questionable
      findings, the decision was made by consensus of at least two observers using pre-specified
      criteria. For patients with discrepancy image findings between each modality, biopsy results
      may be taken into consideration to determine the final status.
    

Intervention name(s): Ga-68 PSMA ligand
Intervention type(s): Drug
Intervention description(s): For PSMA PET/CT scan, the subject will have catheter(s) placed for intravenous administration of [68Ga]PSMA-11. Subjects will receive a single intravenous bolus of 2-5 mCi [68Ga]PSMA-11 and received PET/CT scan 60 minutes later. Patient will underwent two times of PSMA-11 PET/CT scans before and under androgen deprivation therapy within a 10-14 weeks interval.
Other intervention name(s): Ga68-PSMA-11 (Gallium-68 labeled HBED-CC PSMA)
Intervention MeSH terms: Gallium 68 PSMA-11
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Diagnostic
Keywords: Prostate cancer; Androgen deprivation therapy; Ga-68 PSMA Ligand; Treatment response