[18F] Dihydro-testosterone Pet and MR Imaging In Patients With Localized Prostate Cancer

Inclusion criteria

• Male aged 21 years or older and below 80 years of age.
• Signed written informed consent and willingness to comply with protocol requirements.
• Histologically confirmed diagnosis of prostate cancer.
• Staging imaging workup including a baseline MRI of the prostate and pelvis performed at MSKCC.
• Baseline imaging to rule out distant metastatic disease (99mTc bone scan, NaF PET, total body MRI, or CT chest/abdomen/pelvis)
• Karnofsky performance status ≥ 70
• Clinical criteria required to be eligible:

a. One of the following i.Pre-treatment PSA ≥10 ng/dL, OR ii. Clinical T-stage assessed by digital rectal exam of ≥T2a, OR ii . Radiographic ≥T3a on MRI, OR iv. Gleason score of ≥3+4=7 c. Visible intraprostatic tumor foci ≥1 cm in largest dimension on T2-weighted images based on initial pre-treatment MRI

• Physician recommendation of ADT.

Exclusion criteria

• Metastatic disease on standard staging imaging (beyond regional lymph node involvement).

o Absence of metastatic disease (beyond regional lymph node involvement) as defined by a negative bone scan, NaF PET, CT chest/abdomen/pelvis, or total body MRI.

• Prior treatment of the prostate gland for malignant conditions (surgery, cryotherapy, radiotherapy, or photodynamic therapy).
• Physician prescription of androgen receptor antagonist therapy (examples: bicalutamide, flutamide, or enzalutamide) during time of protocol scans.

o Note: ADT consists of chemical castration (i.e. degarelix) to remove endogenous DHT. Androgen receptor antagonists will bind to the androgen receptor and inhibit FDHT from binding.

• Patients receiving testosterone supplementation .
• Any contraindication to baseline MRI based on departmental MR questionnaire, or inability to cooperate for an MRI scan.
• History of allergic reactions attributed to compounds of similar chemical or biologic composition to FDHT.
• Hepatic laboratory values:

• Bilirubin >1.5 x ULN (institutional upper limits of normal)
• AST/ALT >2.5 x ULN
• Albumin <2 g/dL
• Creatinine >2.5 mg/dL
• Calcium >11 mg/dL
• Other serious illness(es) which might preclude completion of this study or interfere with determination of causality of any adverse effects experienced in this study.