Vessel Sparing Prostate Radiation Therapy

The vast majority of patients diagnosed with prostate cancer in the modern era of PSA
screening have localized and potentially curable disease. Patients have a number of excellent
treatment options to consider, and quality of life following treatment is often a
consideration in treatment choice. One critical quality of life concern for patients
diagnosed with prostate cancer is sexual function. Studies of sexual function post-radiation
therapy fall into three categories: incidence studies; correlative (dose and toxicity)
studies; mechanism(functional) studies. All these studies point to a vascular mechanism of
impotence post-radiation therapy, as opposed to a nerve-based mechanism following surgery. In
this study, the critical vascular structures (internal pudendal artery and corpus cavernosum)
are defined by MRI-based imaging and included in treatment planning for radiation treatments.
Investigators propose that this technique will improve quality of life, sexual function, and
relapse-free survival.

This study's primary aim is to determine erectile function preservation rates at 5-years
post-vessel-sparing radiotherapy with or without aids using the patient reported using the
simplified three-question erectile function scale.

Inclusion Criteria:

- Histologically confirmed diagnosis of prostate cancer

- Patients must have measurable erectile function. Patients with erectile function on
Viagra and drugs of the same class are eligible. Patients who require 6 months of
hormonal therapy or less are eligible, provided baseline erectile function is measured
prior to or within 14 days of the start of hormonal therapy.

- Baseline PSA (Prostate Specific Antigen), TNM stage (a classification of malignant
tumors in cancer), and Gleason Score (A system of grading prostate cancer tissue based
on how it looks under a microscope): Patients with low (PSA less than 10, T2a or less,
Gleason 6 or less), intermediate, or high (Gleason 8-10, T3a, PSA over 20) risk
disease are eligible for this protocol. Patients on finasteride or drugs of the same
class are eligible.

- Patients must be 18 years or older. No upper age restriction.

- Patients treated with external beam radiotherapy alone or external beam therapy plus
implant therapy are eligible.

- Patients must have an ECOG (Eastern Cooperative Oncology Group system of grading
patient status that attempts to quantify cancer patients' general well-being and
activities of daily life) performance status <2.

- The patient must sign study specific informed consent approved by the IRB of U of M
indicating they are aware of the investigational nature of the treatment.

Exclusion Criteria:

- Patients who are impotent or have an IIEF (International Index of Erectile Function)
<16.

- Patients who are medically ineligible for radiation therapy due to other medical
conditions.

- Patients given hormonal therapy before baseline questionnaires filled out.

- Patients who receive implant only therapy.

- Patients unable to undergo MRI (Magnetic Resonance Imaging).