A Study of MRI-guided High-dose Radiation Therapy in Prostate Cancer

Inclusion Criteria:

• Intermediate-risk prostate cancer patients will be eligible for this study. Riskgroups will be assigned as per NCCN guidelines. Intermediate-risk patients will bedefined as:

• PSA 10-20 ng/ml or

• Gleason score = 7 or

• Clinical stage T2b/T2c or

• Additionally, patients will be required to meet all of the following criteria:

• Age ≥ 18

• Karnofsky Performance Status (KPS) ≥ 80 (Appendix 1)

• Prostate size ≤ 80 cc

• Presence of a T2-visible prostatic lesion with maximum dimension of ≥ 0.5 cmand no more than one additional disease focus

• MRI findings: Lesion may contact the capsular edge, possible extracapsularextension (ECE) permitted

• International Prostate Symptom Score ≤ 15

• Satisfy all MRI screening criteria and be willing to fill out the standard MRIscreening form

Exclusion Criteria:

Patient will be excluded if they meet any one of the following criteria:

• Gleason score >7

• PSA >20

• Prior or concurrent androgen deprivation therapy for prostate cancer MRI findings:suspicious for/probable ECE

• MRI findings: >2 disease foci identifiable

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

• MRI ineligibility due to: the presence of a cardiac pacemaker, defibrillator, orother implanted metallic or electronic device which is considered MR unsafe; severeclaustrophobia; inability to lie flat for the duration of the study; etc.

• Metallic implant or device in the pelvis that might distort the local magnetic fieldand compromise quality of mp-MRI

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

• Contra-indications to receiving gadolinium contrast

• KPS < 80

• Pelvic or prostate MRI or CT (MRI preferred) evidence of radiographic T3, T4, or N1disease

• Prior history of transurethral resection of the prostate

• 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, including 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)