18F-DCFPyL Imaging as a Method to Assess Treatment Response to Stereotactic Body Radiation Therapy

Background:

Radiotherapy is a highly effective treatment for localized prostate cancer; however, recurrence is more common in patients with unfavorable intermediate and high-risk prostate cancer, and is usually diagnosed by rising prostate specific antigen (PSA - biochemical failure).

Early identification of disease persistence or recurrence before meeting criteria of biochemical failure may allow effective potentially curative salvage treatment, but identification of local recurrence or persistence at early stages is challenging. CT imaging is relatively insensitive at localizing recurrence, while MRI is more sensitive for local recurrence but is non-specific.

Prostate specific membrane antigen (PSMA) targeted PET imaging was recently FDA approved for imaging men with suspected prostate cancer metastases who are potentially curable by radiation or surgery. PSMA based imaging has been used in prospective trials to define extent of disease and to alter radiation treatment volumes.

18F-DCFPyL, a second generation PSMA PET agent that binds with high affinity to PSMA yet clears rapidly from the blood pool, has recently been approved by the FDA as a method to stage high risk cancer and detect recurrent disease.

Primary Objective:

To define 18F-DCFPyL PET/CT imaging response in participants with localized prostate cancer after treatment with stereotactic body radiation therapy (SBRT) with or without androgen deprivation therapy (ADT).

Eligibility:

Biopsy proven localized prostate cancer in whom prostate SBRT with or without ADT is appropriate therapy

Must have at least 1 MRI detected, biopsy proven site of prostate cancer.

ECOG 0-2

Design:

This is a single center, prospective study aimed at recruiting the following cohorts:

Up to 40 evaluable participants with presumed localized prostate cancer (intermediate or high risk) scheduled to undergo radiotherapy with systemic androgen deprivation therapy.

Up to 40 evaluable participants with presumed localized prostate cancer (intermediate or high risk) scheduled to undergo SBRT without androgen deprivation therapy.

Up to 20 evaluable participants with presumed localized prostate cancer (intermediate or high risk) scheduled to undergo radiotherapy with localized androgen deprivation therapy.

Participants receiving neoadjuvant androgen deprivation therapy will undergo a second 18F-DCFPyL PET/CT and multiparametric MRI (mpMRI) at 8 weeks after initiation of ADT but before SBRT.

All participants will undergo 18F-DCFPyL PET/CT and mpMRI 6 months following completion of SBRT and at recurrence, if applicable.

Participants will be followed for up to 2 years after completion of SBRT to evaluate longitudinal quality of life and biochemical control.

• INCLUSION CRITERIA:
• Biopsy proven localized prostate cancer in whom stereotactic body radiation treatment (SBRT) with or without neoadjuvant androgen deprivation therapy (ADT) is planned for definitive management (NIH laboratory of pathology confirmation is not required).
• Must have at least 1 MRI detected, biopsy proven localized prostate cancer.
• Age >= 18 years
• ECOG performance status <= 2
• For individuals with evidence of human immunodeficiency virus (HIV) infection, individuals must be on effective anti-retroviral therapy with undetectable viral load within the prior 6 months are eligible.
• For individuals with evidence of chronic hepatitis B virus (HBV) infection, the HBV viral load must be undetectable on suppressive therapy, if indicated.
• For individuals with a history of hepatitis C virus (HCV), the infection must have been treated and cured. For individuals with HCV infection who are currently on treatment, they are eligible if they have an undetectable HCV viral load.
• Ability of subject to understand and the willingness to sign a written informed consent document.
• Men must agree to use adequate contraception with their partner (hormonal or barrier method of birth control; abstinence) for the duration of study participation and 2 months after the last 18F-DCFPyL scan.

Exclusion criteria

• Receiving prior androgen deprivation therapy, radiotherapy, or surgery for prostate cancer.
• Any condition that is likely to interfere with study procedures or results.
• Individuals in whom pelvic nodal irradiation is planned.
• Serum creatinine > 2 times the upper limit of normal.
• Weighing > 350 lbs (weight limit for scanner table), or unable to fit in imaging gantry.
• Evidence of tumor spread beyond the prostate/seminal vesicles (lymph nodes, metastases).
• Contraindications to radiation or SBRT.