Stereotactic Body Radiotherapy (SBRT) With Concurrent Boost for Low- and Intermediate-Risk Prostate Cancer (Prostate SBRT)

• Biochemical disease-free survival [ Time Frame: 5-8 years ] [ Designated as safety issue: No ]
  Biochemical Disease-Free Survival (bDFS), the time from completion of protocol treatment to the documented PSA rise of 2 ng/mL above the PSA nadir reached after treatment.
  
  

• Grade 2 or higher acute gastrointestinal, genitourinary, and erectile toxicities [ Time Frame: 30 days from completion of protocol radiotherapy ] [ Designated as safety issue: Yes ]
  Grade 2 or higher acute gastrointestinal, genitourinary, and erectile toxicities, graded per CTCAE 3.0. Acute adverse events will be recorded as the first occurrence of worst severity of the adverse event ≤ 30 days from completion of protocol radiotherapy.
  
  
• Grade 3 or higher late gastrointestinal, genitourinary, and erectile toxicities [ Time Frame: >30 days to 5 years from completion of protocol radiotherapy ] [ Designated as safety issue: Yes ]
  Grade 3 or higher late gastrointestinal, genitourinary, and erectile toxicities, graded per CTCAE 3.0. Late adverse events are defined as the first occurrence of a late grade 3+ adverse event > 30 days from completion of protocol radiotherapy.
  
  
• Freedom from failure [ Time Frame: 5-8 years ] [ Designated as safety issue: No ]
  Freedom from failure, defined as the time from the first date of radiation to first event of biochemical failure (nadir + 2 ng/mL), local recurrence, regional recurrence, or distant disease as defined below.
  
  
• Local recurrence-free survival [ Time Frame: 5-8 years ] [ Designated as safety issue: No ]
  Local recurrence-free survival, defined as the time from the first date of radiation to first pathologic confirmation of in-prostate tumor recurrence. The local recurrence will be dated when the palpable progression was first identified. In the event of biochemical failure followed by negative metastatic workup and positive biopsy for in-prostate recurrence, the local recurrence will be dated the date of the documented biochemical failure.
  
  
• Distant disease-free survival [ Time Frame: 5-8 years ] [ Designated as safety issue: No ]
  Distant disease-free survival, defined as the time from the first date of radiation to first documentation of metastatic disease by any method, regardless of the occurrence of any intervening local or regional failure or non-prostate second primary cancer. If metastatic diagnosis was prompted by biochemical failure, distant recurrence will be dated the date of biochemical failure.
  
  
• Cause-specific survival [ Time Frame: 5-8 years ] [ Designated as safety issue: No ]
  A death will be deemed a prostate cancer specific death if death is due to prostate cancer or a complication from treatment.
  
  
• Overall survival [ Time Frame: 8-10 years ] [ Designated as safety issue: No ]
  Overall survival, defined as the time from the first date of radiation to death due to any cause.
  
  
• Health-related quality of life [ Time Frame: 2-3 years ] [ Designated as safety issue: No ]
  Health-related quality of life (HRQOL), measured with the Extended Prostate Cancer Index Composite questionnaire - short form (EPIC-26).
  
  

Standard external beam radiation therapy (EBRT) for low- to intermediate-risk prostate cancer involves several weeks of daily treatment sessions. Stereotactic body radiation therapy (SBRT) is a newer form of EBRT that gives fewer treatments but higher doses of radiation per treatment. In many patients there are certain areas within the prostate with more prominent cancerous growth (intraprostatic lesions), which may require higher doses of radiation (boost) to treat effectively. This study will treat the prostate with simultaneous boost(s) to intraprostatic lesion(s) in 5 treatments over 10-14 days.