BrachyView: Combining LDR seed positions with transrectal ultrasound imaging in a prostate gel phantom
RIS ID
112067
Abstract
Purpose
BrachyView is a novel in-body imaging system which aims to provide LDR brachytherapy seeds position reconstruction within the prostate in real-time. The first prototype is presented in this study: the probe consists of a gamma camera featuring three single cone pinhole collimators embedded in a tungsten tube, above three, high resolution pixelated detectors (Timepix).
Methods
The prostate was imaged with a TRUS system using a sagittal crystal with a 2.5 mm slice thickness. Eleven needles containing a total of thirty 0.508 U125I seeds were implanted under ultrasound guidance. A CT scan was used to localise the seed positions, as well as provide a reference when performing the image co-registration between the BrachyView coordinate system and the TRUS coordinate system. An in-house visualisation software interface was developed to provide a quantitative 3D reconstructed prostate based on the TRUS images and co-registered with the LDR seeds in situ. A rigid body image registration was performed between the BrachyView and TRUS systems, with the BrachyView and CT-derived source locations compared.
Results
The reconstructed seed positions determined by the BrachyView probe showed a maximum discrepancy of 1.78 mm, with 75% of the seeds reconstructed within 1 mm of their nominal location. An accurate co-registration between the BrachyView and TRUS coordinate system was established.
Conclusions
The BrachyView system has shown its ability to reconstruct all implanted LDR seeds within a tissue equivalent prostate gel phantom, providing both anatomical and seed position information in a single interface.
Grant Number
NHMRC/1113631
Publication Details
Alnaghy, S., Cutajar, D. L., Bucci, J. A., Enari, K., Safavi-Naeini, M., Favoino, M., Tartaglia, M., Carriero, F., Jakubek, J., Pospisil, S., Lerch, M., Rosenfeld, A. B. & Petasecca, M. (2017). BrachyView: Combining LDR seed positions with transrectal ultrasound imaging in a prostate gel phantom. Physica Medica: an international journal devoted to the applications of physics to medicine and biology, 34 55-64.