Stereotactic Body Radiation for Prostate Oligometastases
Condition: Prostate Cancer; Oligometastases
MeSH terms: Prostatic Neoplasms
Study type: Interventional
Phase: Phase 2

Summary: 
      Men with oligometastatic prostate cancer lesions will be randomized (1:2) to observation
      versus SBRT. The study will NOT be blinded. Within three weeks of the initial treatment
      planning, SBRT (1-5 fractions) will be administered.
    

Detailed description: 
      This research is being done to determine if we can improve the outcome of prostate cancer
      patients who have failed primary treatment - surgery or local radiation to the prostate - and
      have 3 or fewer bone metastases. Patients with metastatic prostate cancer disease will
      usually be placed on hormonal therapy which can work well for a period of time, but hormonal
      therapy can have side effects that greatly trouble men. Any effort to delay the start of
      hormonal therapy would be an advantage to the patient. Radiation treatment usually takes many
      weeks to deliver and is not given in a high enough doses to metastases to prevent them from
      coming back locally. Stereotactic body radiation therapy (SBRT) is highly focused radiation,
      given in a very dose intensive fashion and delivered in usually less than one week.
      Stereotactic body radiation has been shown to be very effective on bone metastases.
      Therefore, we are studying the effects of stereotactic body radiation treatment on patients
      with five or fewer prostate cancer bone metastases to determine if we can stall the use of
      hormonal therapy and/or prevent other bone metastases from developing elsewhere in the body.

      Additionally, fundamental analysis of the oligometastatic state with be achieved through
      correlation with investigational DCFPyL-positron emission tomography (PET) imaging, which can
      help us find cancer that has spread (metastatic disease) from its original site in people who
      have cancer in their prostate to other parts of their body.

      Specifically, 54 men with biochemically recurrent, oligometastatic prostate adenocarcinoma
      will be accrued across 3 centers in the United States. Patients were stratified by primary
      intervention (surgery vs radiotherapy), prior hormonal therapy, and PSA doubling time, then
      randomized 2:1 to SBRT or observation. The primary clinical endpoint is progression at 6
      months from randomization with the hypothesis that SBRT to all metastases will forestall
      progression by disrupting the metastatic process. Secondary clinical endpoints include local
      control at 6 months post-SBRT, SBRT-associated toxicity and quality of life, and ADT-free
      survival (ADT-FS).

      Alterations in the biology of the oligometastatic state induced by stereotactic ablative
      radiotherapy (SABR) will be investigated using leading-edge correlatives, including: analysis
      of circulating tumor cells (CTCs; Epic Sciences, San Diego, CA), deep sequencing of
      circulating tumor DNA (ctDNA) using Cancer Personalized Profiling by deep sequencing
      (CAPP-Seq) to non-invasively assess tumor burden, and ImmunoSEQ profiling of T-cell
      repertoires to elucidate the immunological response to SABR (Adaptive Technologies, Seattle,
      WA). Lastly, the use of the Color Genomics platform (Burlingame, CA), a hereditary cancer
      assay assessing pathogenic mutations in 30 cancer predisposition genes that account for >90%
      of the germline mutations known to occur in men with castrate resistant metastatic prostate
      cancer (mCRPC), will help inform and allow for efforts to advance a more personalized
      medicine approach to tailor screening and therapies in these men.
    

Intervention name(s): SBRT
Intervention type(s): Radiation
Intervention description(s): SBRT (1-5 fractions) will be administered.
Other intervention name(s): Stereotactic Body Radiation; Stereotactic Ablative Radiotherapy
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Prostate Cancer; Stereotactic Body Radiation Therapy; Stereotactic Ablative Radiotherapy; Oligometastasis