Radiotherapy to the Prostate and Dominant Intra-Prostatic Lesion (DIL)

Inclusion Criteria:

- Intermediate risk prostate cancer patients will be eligible for this study. Risk
groups will be assigned as per NCCN guidelines. Intermediate risk patients will be
defined as:

- PSA 10-20 ng/ml or

- Gleason score = 7 or

- Clinical stage T2b/T2c

- Additionally, patients will be required to meet the following criteria:

- Age ≥ 18

- KPS ≥ 80

- Prostate size ≤ 60cc

- Presence of a prostatic lesion with maximum dimension of >/= 0.5cm and no more
than two additional disease foci, each with a maximum dimension less than that of
the dominant lesion.

- International Prostrate Symptom Score ≤ 15

- Subjects must fill out the standard MRI screening form and satisfy all MRI
screening criteria

Exclusion Criteria:

- Prior androgen deprivation therapy for prostate cancer

- Evidence of metastatic disease on bone scan or MRI/CT

- MRI ineligibility due to the presence of a cardiac pacemaker, defibrillator or other
implanted metallic or electronic device which is considered MR unsafe, severe
claustrophobia or inability to lie flat for the duration of the study, etc.

- Metallic hip implant, metallic implant or device in the pelvis that might distort the
local magnetic field and compromise quality of MP-MRI.

- Lateral pelvic separation greater than 50 cm and/or anterior-posterior separation
greater than 35 cm which are incompatible with MRCAT reconstruction

- Contra-indications to receiving gadolinium contrast

- KPS < 80

- Pelvic MRI or CT (MRI preferred) evidence of radiographic T3, T4 or N1 disease.

- Prior history of transurethral resection of the prostate

- Prior history of chronic prostatitis

- Prior history of urethral stricture

- Prior history of pelvic irradiation

- History of inflammatory bowel disease

- Unable to give informed consent

- Unable to complete quality of life questionnaires

- Abnormal complete blood count. Any of the following

- Platelet count less than 75,000/ml

- Hb level less than 10 gm/dl

- WBC less than 3.5/ml

- Abnormal renal function tests (creatinine > 1.5)