Study of Sildenafil Citrate During and After Radiotherapy/Hormone Therapy for Erectile Function Versus Radiotherapy/Hormone Therapy for Prostate Cancer

This protocol is a randomized prospective study comparing prophylactic and on demand
Sildenafil Citrate usage administered during and after radiotherapy in combination with or
without hormone therapy versus radiotherapy alone for the preservation of erectile function
in potent patients with clinically localized prostate cancer. The primary objectives of this
protocol are to determine if prophylactic and on demand usage of Sildenafil Citrate can
preserve spontaneous erectile function as well as diminish the time to restoration of
erectile function in potent men receiving radiotherapy with or without hormone therapy for
localized prostate cancer. Secondary objectives of this study are: to determine whether
prophylactic and on demand use of Sildenafil Citrate during therapy may improve the long-term
response to the drug following treatment; to determine whether prophylactic and on demand use
of Sildenafil Citrate during therapy will reduce acute and late urinary effects of
radiotherapy; to determine the impact of dosimetry and radiation exposure to both the
neurovascular bundle and bulb of the penis on erectile function preservation in the study
population undergoing brachytherapy and hormone therapy; to asses the impact on quality of
life following prophylactic and on demand Sildenafil Citrate usage in the study population;
to determine the relationship between testosterone levels, erectile function and efficacy of
prophylactic and on demand Sildenafil Citrate usage in the study population.

Inclusion Criteria:

- To receive external beam radiation therapy and/or brachytherapy for biopsy-proven
prostate cancer.

- Baseline International Index of Erectile Function (IIEF) erectile function domain
score >= 17.

- Patients receiving radiotherapy with hormone therapy undergoing a maximum of 9 months
of hormone therapy will be acceptable.

Exclusion Criteria:

- Baseline IIEF-EF (1-30) domain score of <17 pre-therapy

- Current routine use of erectogenic agents (use of agents > 4 times per month would
constitute "routine use")

- Neoadjuvant androgen deprivation therapy started more than 1 month prior to entry into
study (intake of Bicalutamide alone does not constitute exclusion from study entry)

- Have a clinically significant penile deformity in the opinion of the investigator (ie:
Peyronie's Disease)

- Non-organ confined disease

- Prior prostate surgery or cryotherapy

- Prior prostate radiotherapy started more than 2 weeks prior to entry into study

- Currently taking 0.8mg Flomax daily

- Penile implant history

- Present at baseline with chronic angina requiring nitrates, angina occurring during
sexual intercourse or unstable angina within the last 6 months.

- History of myocardial infarction, coronary artery bypass graft surgery or percutaneous
coronary intervention within 90 days of baseline visit.

- History of significant cardiac conduction defect within 90 days of baseline visit.

- Exhibit systolic blood pressure > 170 or < 90 mm Hg or diastolic blood pressure > 100
or < 50 mm Hg at baseline visit or have a history of malignant hypertension

- Have any condition that would interfere with the subject's ability to provide informed
consent or comply with study instructions, would place subject at increased risk, or
might confound the interpretation of the study results

- Currently receive treatment with nitrates, cancer chemotherapy, or antiandrogens
(except finasteride taken as Propecia or Proscar)

- Have a history of drug, alcohol, or substance abuse within the past 6 months, as
assessed by the investigator.