Vessel Sparing Prostate Radiation Therapy

Study Overview
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Brief Summary
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Prostate cancer 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. Previous 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, hopefully preserving critical artery function. This study will collect 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.

Detailed Description
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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.

Official Title
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Vessel Sparing Prostate Radiation Therapy: Dose Limitation to Critical Erectile Structures (Corpus Cavernosum and Internal Pudendal Artery) by MRI Based Treatment Planning

Conditions
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Cancer of the PROSTATE

Intervention / Treatment
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* Radiation: Radiation Therapy


Participation Criteria
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Eligibility Criteria
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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).

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Intervention<br>Vessel Sparing Radiation Therapy using MRI based treatment planning to limit dose to critical erectile structures | Radiation: Radiation Therapy<br>* Radiation Therapy Using MRI Based Treatment Planning<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The Percentage of Patients Able to be Sexually Active With or Without the Use of Aids | The primary endpoint of the study was to accurately determine the preservation of erectile function post radiation therapy. Erectile preservation was defined as a score of 1 or 2 on the three-tier patient reported questionnaire equating to being able to be sexually active with or without aids. Scoring: Sexually active without aids Sexually active with aids Not sexually active with or without aids | 5 years from end of radiation treatment |