Inclusion Criteria:

- 18 years of age or older

- Histologically confirmed diagnosis of adenocarcinoma of the prostate within 180
days of enrollment

- Signed informed consent

- Gleason score ≤ 7

- If Gleason 7 (3+4=7 or 4+3=7) then <50% of biopsy cores must be positive for any
pathologic grade of prostate cancer

- If Gleason score <7 then there is no limit on the percentage of biopsy cores involved
by prostate cancer

- PSA (within 90 days prior to enrollment)

- ≤ 15 ng/ml prior to start of therapy if Gleason ≤ 6 and

- ≤ 10 ng/ml prior to start of therapy if Gleason 7

- No plan to use hormone therapy prior to evidence of biochemical failure(ie: No
neoadjuvant or adjuvant ADT)

- Tumor stage: T1a, T1b, T1c, T2a, T2b

- ECOG Performance Status 0-1

Exclusion Criteria:

- A history of other malignancy diagnosed within the previous 60 months except for
non-melanoma skin cancer.

- Any patients who have received other investigational therapy within the last 60 days

- Individuals that have previously been implanted with permanent Beacon transponders

- Patients that have any prosthetic implants in the pelvic region that contain metal or
conductive materials (e.g., an artificial hip)

- Patients with implanted pacemaker or defibrillators

- Patients who are felt to have body habitus not conducive to tracking with Calypso
beacons

- Positive lymph nodes or metastatic disease from prostate cancer

- Tumor stage: T2c, T3, or T4

- Previous pelvic radiation therapy

- Previous surgery or chemotherapy for prostate cancer

- Previous transuretheral resection of the prostate (TURP) or cryotherapy to the
prostate

- Prior hormone therapy or plans for concurrent or post treatment adjuvant hormonal
therapy or chemotherapy

- Hormone therapy to include LHRH agonist or oral anti-androgen

- Finasteride and Dutasteride use not excluded

- Concomitant antineoplastic therapy (including surgery, cryotherapy, conventionally
fractionated radiation therapy, and chemotherapy) while on this protocol

- History of Crohn's Disease or Ulcerative Colitis