Trial Information

FTPC (Focal Therapy for Prostate Cancer): A Pilot Study Using Focal Low Dose Rate Brachytherapy as an Alternative to Active Surveillance and Radical Treatment for Favourable Risk Prostate Cancer.

1. Purpose

To test the efficacy, acute side effects and long term safety of Focal Therapy in
Prostate Cancer, as compared to conventional radical lose dose radiation prostate
brachytherapy (LDR-PB).

2. Hypothesis

We hypothesize that, in an appropriately selected group of early-stage, favourable risk
prostate cancer patients, focal LDR-PB will lead to fewer acute side effects, long term
complications resulting is a better quality of life than radical LDR-PB.

We also hypothesize that multi-modal, multi-parametric imaging will enable monitoring
of the results of focal therapy with an accuracy that is high enough to eventually
replace repeated (and invasive) mapping biopsies.

3. Justification

The imaging study we propose is unique in terms of its multi-modality, multi-parametric
approach. Local disease will be monitored by a very complete set of multi-parametric
MR, ultrasound and PET-CT imaging. Potential spread of the disease may be captured by
abdominal and whole-body PET-CT. Comparison with biopsies will be more accurate than in
other studies because biopsy location will be accurately provided by the trans-perineal
three-dimensional template-guided pathological mapping biopsy (TTMB), in contrast to
Post-radical prostatectomy (RP) studies that use axial whole mount slices which suffer
from a significant change in prostate physical shape and unpredictable deformation due
to fixation, making an accurate registration of pathology and imaging difficult.

The impact of our study on the field of medical imaging will also be significant.
Advances in the topics of deformable multi-modal registration, dosimetry, and the
characterization of cancer as image features in MR, ultrasound and PET-CT are expected.
These findings will be widely disseminated in papers addressing both clinical and
technical publications.

We are not aware of any study in which TTMB-guided focal brachytherapy has been
implemented and tested. A center of our size, with our record in outcomes, and with a
complete set of imaging expertise and tools to help with patient selection and
monitoring, may make a very significant impact in how focal therapy can be implemented
and evaluated. Therefore, we have the potential to provide valuable input on how to
translate focal therapy into standard care for appropriately selected patients.

4. Objectives

The specific objectives of this study are:

1. To develop provisional criteria for what constitutes focal disease and treatment
plans appropriate for focal LDR-PB.

2. To show that patients undergoing focal therapy have a better quality of life than
those undergoing radical therapy.

3. To correlate multi-modal, multi-parametric imaging results with the results of
mapping biopsies with the goal of developing image-based techniques for patient
selection and monitoring.

5. Research Method

Participants in the study will undergo multi-modal, multi-parametric imaging as
outlined in the study protocol (MRI, Ultrasound imaging, and PET/CT). Participants that
are eligible to continue in the study and receive focal therapy will undergo 3D-
Template-Guided Trans-Perineal Pathological Mapping Biopsy (TTMB). Participants will
also be asked to complete study surveys and have repeat pathological mapping done at 2
year post treatment..

6. Statistical Analysis

In our recruiting plan, we have assumed that approximately 50% of the participants who are
initially eligible will continue to focal therapy. The planned sample size for this pilot
study is 10.

Imaging hypotheses: The hypothesis that focal treatment will change the imaged treated area
tissue properties but will leave unchanged properties of tissue in the untreated area will
be tested using paired data on each participant.