Biomedical Imaging - Richard A. Robb

Prostate Image Fusion

The goal of this proposed research is development of a new image-guided procedure, which uses commonly available equipment, that will produce more effective radiation coverage intra-operatively than has been possible before in treatment of prostate cancer by permanent brachytherapy.

Permanent prostate brachytherapy is the most common form of minimally invasive therapy for prostate cancer. The completeness with which the prostate, and thus the prostate cancer, is covered by the radiation correlates with the measure of success of treatment. Success of the procedure can be measured by local recurrence and prostate specific antigen (PSA) relapse-free survival.

Currently, assessment of radiation coverage of the prostate following brachytherapy is determined postoperatively. Statistics show that approximately 20% of prostate brachytherapy procedures may result in poor radiation coverage and few are corrected by implantation of additional radioactive sources. To solve this important problem we propose to develop an intra-operative, image guided procedure for optimal placement of radioactive sources by pursuing four specific aims, namely:

1. Development of an accurate and efficient method to reconstruct the 3-dimensional locations of prostate brachytherapy seeds using fluoroscopy during the implant procedure;
2. Development of a robust and efficient method for intraoperative registration of prostate brachytherapy seed positions to a 3D ultrasound image of the prostate;
3. Testing and refinement of an ultrasound probe holder designed to facilitate acquisition of 3D ultrasound images with minimal prostate deformation, allowing accurate registration of prostate brachytherapy seed positions to a 3D ultrasound image; and
4. Clinical validation of the seed reconstruction, image registration and ultrasound probe holder methods, respectively.

The algorithms to be developed in Aims 1 and 2 will be truly novel, and the probe holder in Aim 3 is a unique device invented by us. Successful completion of the proposed research will yield methods, devices and algorithms that will significantly improve the current practice and outcome of permanent prostate brachytherapy, a common and effective form of therapy for localized prostate cancer. The multidisciplinary team of experienced scientists, physicians, engineers, and therapists working in close collaboration between Mayo Clinic College of Medicine and Stanford University provides high confidence that the goal of the proposed research will be achieved.