The ultimate goal of our project is to advance imaging technology to assess treatment-related erectile dysfunction and thereby improve sexual outcomes and quality of life of prostate cancer survivors. In the United States, 2.36 million men have survived prostate cancer and are currently living with cancer-affected life years. Loss of sexual potency is the most common and debilitating long-term complication in radiotherapy for prostate cancer. Over 50% of men will suffer from post-radiation erectile dysfunction, which may lead to diminished sexual activity and desire, decreased sexual satisfaction, changes in intimate relationships, and reduced quality of life post-radiotherapy.

This project has three major steps. First, we will develop a new technique for combining MRI (magnetic resonance imaging) and US (ultrasound) images in a way that can allow physicians to see the neurovascular bundles (NVBs) clearly and measure NVB function. Second, we will confirm that these new imaging findings match the patients’ outcome with respect to their erectile function. Third, we will use the new imaging techniques to reduce radiation dose to the NVB to preserve sexual function.

The proposed research will help the 50,000 men who receive radiotherapy treatment for prostate cancer each year who develop erectile dysfunction. The NVBs are very difficult to see on CT (computed tomography) or US images, which physicians often use to plan radiation treatment. Therefore, a high dose of radiation is frequently delivered to these structures in the standard prostate radiotherapy. Our multi-modality imaging technology will allow physicians to see the NVBs clearly. Therefore, radiation oncologists can use this information in treatment planning to minimize the radiation doses to the NVBs. Less radiation damage to NVB will lead to better sexual outcome after radiation treatment.

The projected time it may take to achieve a patient-related outcome is immediate (i.e., upon project completion). Currently, MRI is a standard diagnostic imaging tool for prostate cancer. Doppler US imaging is widely available and can be performed with existing clinical US scanners. We will fuse MRI with US images to allow physicians to create a personalized plan for each patient to improve sexual potency post-radiotherapy. MRI and US are both safe imaging methods, and there are no risks associated with the proposed technology. Furthermore, it should be noted that although for the proposed clinical study three MRIs are performed (one at baseline and two during the follow-up), when implemented in the clinic our methodology only requires one baseline MRI and US scan (which is routinely done prior to radiation in the clinical setting); thus, there is very minimal additional cost or time to the patient for implementation of our proposed techniques. Also, our methodology is feasible in community practice, so our techniques will have a very broad applicability and impact.

This end-product of the proposed research will be a groundbreaking imaging technique that will be safe and widely available for NVB-sparing prostate cancer radiotherapy. The primary group that will benefit will be low- and intermediate-risk prostate cancer patients who receive definitive radiotherapy and who have no direct tumor involvement of the NVB on standard imaging. In 2 to 3 years, we will gain more knowledge of radiation-induced erectile dysfunction. We will be ready to conduct a clinical trial at the end of the current project. The results of this investigation, if successful, will be able to improve the survivorship of prostate cancer patients within the next 5 years.