MRI-Guided Radiation Therapy in Treating Patients With Prostate Cancer

OBJECTIVES:

Primary

- Determine the maximum tolerated dose of MRI-guided intensity-modulated external beam
radiotherapy in patients with prostate cancer.

Secondary

- Correlate the radiation response to and/or toxicity of this regimen with genomic and
proteomic analyses in these patients.

- Determine the long-term effects and toxicity of this regimen after selective
intra-prostatic dose escalation in these patients.

OUTLINE: This is a dose-escalation study.

Patients undergo MRI-guided intensity-modulated external beam radiotherapy over 10 minutes
once daily 5 days a week for 8.5 weeks.

Cohorts of 3-6 patients receive escalating doses of external beam radiotherapy (to areas of
histologically confirmed prostate cancer*) until the maximum tolerated dose (MTD) is
determined. The MTD is defined as the dose preceding that at which 2 of 3 or 2 of 6 patients
experience dose-limiting toxicity.

NOTE: *Areas of the prostate with signal abnormality on MRI that cannot be biopsied or
without definite histologic evidence of prostate cancer receive intermediate doses; all
other areas of the prostate receive standard doses.

After completion of study treatment, patients are followed at 2, 4, 8, and 12 weeks, 6, 9,
12, and 18 months, and then every 6 months for up to 5 years.

PROJECTED ACCRUAL: A total of 18-36 patients will be accrued for this study within 2 years.