A clinical assessment of external beam focal therapy for localized prostate cancer measured by Gafchromic film

Background: Traditionally, EBRT prostate treatments have been administered using three different techniques: three-dimensional conformal radiation therapy (3D-CRT), intensity modulated radiation therapy (IMRT), and volumetric modulated arc therapy (VMAT). These radiation therapy treatment techniques are often combined with additional options focusing on treating systemic disease and the entire volume of the prostate. A novel approach to EBRT is currently in development, a localized treatment administered to only the primary disease within the prostate volume termed ‘Focal Therapy’. Methods: /Design: The proposed research study is aimed to simulate 10 random EBRT prostate focal therapy treatments replicated within two treatment planning software; Monaco treatment planning system and Eclipse treatment planning system. All ten plans will be contoured simulations of focal therapy imaging sets replicated from authentic mpMRI anatomical images of focal therapy eligible prostate cancer patients. Following the completion of the 10 clinical plans, QA plans will be generated and administered via each products current commercial linacs; the TrueBeam and the Versa. All QA plans will have their radiation doses measured with Gafchromic EBT3 radiochromic film and analyzed using the gamma analysis index (γ). Discussion: To examine the uncertainties and limitations of an EBRT focal therapy prostate cancer treatment, it’s imperative that a large study replicating many clinical cases under varying conditions should be conducted. This allows the ability for the clinician to investigate errors and uncertainties at each stage of the treatment process prior to committing to a clinical study. The experimental results can also be used as a reference for the creation of a standard guideline for the administration of focal therapy as a curative treatment for prostate cancer.