Research: 2018 – Niagara

Project Title:
Clinical and Dosimetric Effects of Peri-rectal Spacers on Erectile Function in Men Undergoing Image Guided Prostate Radiotherapy
Investigators:
Dr. Abhi Hallock MD FRCPC LLM, Walker Family Cancer Center, Niagara Health
Dr. A. Ishkanian
Dr. D. Cuthbert
Dr. T. Tskaradis
Dr. S. Tatzel
Dr. K. Mattar
Dr. J Shoebridge
Dr. M. Dion
Dr. T. Song
Dr. I. Brown
Dr. R. Tolakanahalli
Dr. M. Levesque
Lead Investigator Bio:
Abhi Hallock received her medical training at McMaster University and postgraduate training and a fellowship in CNS at the University of Western Ontario. She has a Masters in Health Law from Osgoode School of Law. She is the Medical Head of the Department of Radiation Oncology at Walker Family Cancer Center, which is an integrated radiation therapy program with a tertiary centre affiliated with McMaster University in Hamilton, Ontario. She has worked in both the United States and other centers in Canada before settling in Niagara when the department first opened. It helped fulfill one of her professional goals of helping to enable Canadians to receive treatments close to their homes and community. Her research interests are in late effects of radiation and she has peer reviewed articles and oral presentations at major national and international conferences. She has received a Provincial Association of Residents of Ontario (PARO) award for teaching and Ed-Brecevic Award for compassionate care.
Project Abstract:
Erectile dysfunction (ED) as a result of prostate cancer radiation treatment can be a common late side effect affecting quality of life. Radiation dose to the penile bulb which lies at the apex of the prostate is thought to be directly related to the risk of erectile dysfunction. Recent prostate cancer trials have shown that spacers (hydrogel that expands and solidifies) significantly reduce dose to nearby organs. The spacer is stable during radiation treatment and subsequently absorbed by the body. In this preliminary feasability study, we evaluate the dose to penile bulb based on treatment planning scans and impact on clinical erectile function as observed by patients using the Validated International Index for Erectile Function (IIEF) in 8 patients who will undergo curative radiation treatments for prostate cancer with hydrogel spacer injected in the perirectal region.
Scientific Abstract:
Erectile dysfunction (ED) is one of the primary causes of decline in quality of life of men who undergo radiation treatments for prostate cancers. While there is minimal literature to guide dose limits to the penile bulb (PB); dose to PB is correlated to ED. The PB can be determined on CT as oval shape between paired cura, corpora spongiosum anteriorly and the levator ani posteriorly. This is a prospective single institution trial assessing ED outcomes in prostate cancer patients who undergo rectal spacer implantation prior to curative image guided radiotherapy (IGRT). 8 patients (men with T1 or T2 prostate cancer and ISUP grade 1,2, or 3) with PSA less than twenty and ECOG score 0 with no extracapsular extension, less than 50% core involvement, recent androgen deprivation therapy or prior surgery/radiation and who choose to undergo IGRT are eligible. Patients will undergo hydrogel spacer injection under an aspectic transperineal technique prior to proceeding with institutional protocol for IGRT. Spacer safety and impact on dose to PB and ED will be evaluated at 3 mnths, 6 mnths, 12 mnths and 24 mnths.
Impact on prostate cancer patients:
Erectile dysfunction as a result of prostate cancer radiation treatment can be a common late side effect. While there are many factors that can impair erectile function in this population such as age, smoking, medications, and co-morbid issues such as diabetes, hypertension; radiation is an independent risk factor. This is thought to be secondary to the dose to the surrounding vasculture of the penile bulb. Lowering dose to this area will impact the risk of development of erectile dysfunction.