@article {Brastianos2017a, title = {Electromagnetic Reconstruction of Catheter Paths in Mult-Catheter Interstitial Brachytherapy: A Phantom Model.}, year = {In Press}, author = {Harry Brastianos and Thomas Vaughan and Andras Lasso and Mary Westerland and James Gooding and Gabor Fichtinger and Conrad Falkson} } @article {Vaughan2019a, title = {Needle Navigation and Catheter Reconstruction for Breast Brachytherapy Using Open Source Software}, journal = {Acta Polytechnica Hungarica}, volume = {16}, number = {8}, year = {2019}, month = {09/2019}, pages = {99-118}, abstract = {

Abstract: Interstitial breast brachytherapy is a method to deliver radiation therapy directly to the site of cancer. It is a challenging procedure because of issues in localizing the seroma, needles, and catheters within the soft tissue. In this paper we present two open-source technologies based on electromagnetic tracking: a navigation system to help target needles using a tracked needle guide, and software for electromagnetic reconstruction of catheter paths. These technologies were validated phantom studies. We found that the navigation system helped a radiation oncologist to target needles more accurately than under ultrasound guidance (60 needles under each condition, 3.8 vs 3.3 mm placement error, p = 0.04) and that reconstructed catheter paths were accurate within 0.6 mm to those determined on CT scans (144 catheters were compared to the 1.2 mm voxel size of CT scans, p \< 0.001). We conclude that these technologies accurately localize anatomy and instruments in our study.

}, author = {Thomas Vaughan and H Brastianos and Tamas Ungi and Andras Lasso and Conrad Falkson and Gabor Fichtinger} } @article {Brastianos2016c, title = {Demonstration of Catheter Insertion Using Electromagnetic Guidance in Breast Brachytherapy}, volume = {Radiother Oncol 123}, year = {2017}, month = {05/2017}, pages = {S91}, author = {Harry Brastianos and Thomas Vaughan and Andras Lasso and Mary Westerland and James Gooding and Tamas Ungi and Gabor Fichtinger and Conrad Falkson} } @article {Vaughan2017b, title = {Electromagnetically-generated catheter paths for breast brachytherapy}, year = {2017}, author = {Thomas Vaughan and Harry Brastianos and Andras Lasso and Tamas Ungi and Conrad Falkson and Gabor Fichtinger} } @article {Brastianos2017b, title = {Real Time Electomagnetic Reconstruction of Catheter Paths in Multi-Catheter Interstitial Brachytherapy: A Phantom Model}, volume = {Int J Radiat Oncol Biol Phys 99}, year = {2017}, month = {10/2017}, pages = {E642}, author = {Harry Brastianos and Thomas Vaughan and Andras Lasso and Mary Westerland and James Gooding and Gabor Fichtinger and Conrad Falkson} } @article {Vaughan2016a, title = {Catheter targeting under electromagnetic guidance in breast brachytherapy {\textendash} a demonstration of concept}, volume = {Int J CARS}, number = {Suppl 1}, year = {2016}, month = {05/2016}, pages = {S60-62}, keywords = {Brachytherapy, breast}, author = {Thomas Vaughan and Harry Brastianos and Andras Lasso and Mary Westerland and Tamas Ungi and Conrad Falkson and Gabor Fichtinger} } @article {Brastianos2016a, title = {Electromagnetic tracking for catheter insertion guidance for HDR breast brachytherapy: demonstration of concept in phantoms}, volume = {Radiother Oncol 120}, year = {2016}, month = {09/2016}, pages = {S73-S74}, address = {Banff, AB, Canada}, author = {H Brastianos and Thomas Vaughan and Andras Lasso and M Westerland and James Gooding and Gabor Fichtinger and Conrad Falkson} } @article {Brastianos2016b, title = {Electromagnetic tracking for catheter insertion guidance for HDR breast brachytherapy: a phantom experiment}, volume = {Int J Radiat Oncol Biol Phys 96}, year = {2016}, month = {09/2016}, pages = {E643}, address = {Boston, MA, USA}, author = {H Brastianos and Thomas Vaughan and Andras Lasso and M Westerland and James Gooding and Gabor Fichtinger and Conrad Falkson} } @article {Vaughan2016b, title = {Electromagnetically-guided catheter insertions in breast phantoms for brachytherapy}, year = {2016}, month = {Submitted}, keywords = {Brachytherapy, breast}, author = {Thomas Vaughan and Harry Brastianos and Andras Lasso and Mary Westerland and Tamas Ungi and Conrad Falkson and Gabor Fichtinger} } @conference {Schumacher2015, title = {3D-printed surface mould applicator for high-dose-rate brachytherapy}, booktitle = {SPIE Medical Imaging 2015}, volume = {9415}, year = {2015}, abstract = {

ABSTRACT

PURPOSE: In contemporary high-dose-rate brachytherapy treatment of superficial tumors, catheters are placed in a wax mould. The creation of current wax models is a difficult and time consuming proces.The irradiation plan can only be computed post-construction and requires a second CT scan. In case no satisfactory dose plan can be created, the mould is discarded and the process is repeated. The objective of this work was to develop an automated method to replace suboptimal wax moulding. METHODS: We developed a method to design and manufacture moulds that guarantee to yield satisfactory dosimetry. A 3D-printed mould with channels for the catheters designed from the patient{\textquoteright}s CT and mounted on a patient-specific thermoplastic mesh mask. The mould planner was implemented as an open-source module in the 3D Slicer platform. RESULTS: Series of test moulds were created to accommodate standard brachytherapy catheters of 1.70mm diameter. A calibration object was used to conclude that tunnels with a diameter of 2.25mm, minimum 12mm radius of curvature, and 1.0mm open channel gave the best fit for this printer/catheter combination. Moulds were created from the CT scan of thermoplastic mesh masks of actual patients. The patient-specific moulds have been visually verified to fit on the thermoplastic meshes. CONCLUSION: The masks were visually shown to fit onto the thermoplastic meshes, next the resulting dosimetry will have to be compared with treatment plans and dosimetry achieved with conventional wax moulds in order to validate our 3D printed moulds.

}, author = {Mark Schumacher and Andras Lasso and Ian Cumming and Adam Rankin and Conrad Falkson and John Schreiner and C.P. Joshi and Gabor Fichtinger} } @article {Cumming2014, title = {3D Printed Patient-Specific Surface Mould Applicators for Brachytherapy Treatment of Superficial Lesions}, volume = {41 (abstract in Medical Physics)}, number = {222}, year = {2014}, month = {06/2014}, abstract = {

Purpose:
Evaluate the feasibility of constructing 3D-printed patient-specific surface mould applicators for HDR brachytherapy treatment of superficial lesions.

Methods:
We propose using computer-aided design software to create 3D printed surface mould applicators for brachytherapy. A mould generation module was developed in the open-source 3D Slicer (www.slicer.org) medical image analysis platform. The system extracts the skin surface from CT images, and generates smooth catheter paths over the region of interest based on user-defined start and end points at a specified stand-off distance from the skin surface. The catheter paths are radially extended to create catheter channels that are sufficiently wide to ensure smooth insertion of catheters for a safe source travel. An outer mould surface is generated to encompass the channels. The mould is also equipped with fiducial markers to ensure its reproducible placement.

A surface mould applicator with eight parallel catheter channels of 4mm diameters was fabricated for the nose region of a head phantom; flexible plastic catheters of 2mm diameter were threaded through these channels maintaining 10mm catheter separations and a 5mm stand-off distance from the skin surface. The apparatus yielded 3mm thickness of mould material between channels and the skin. The mould design was exported as a stereolithography file to a Dimension SST1200es 3D printer and printed using ABS Plus plastic material.

Results:
The applicator closely matched its design and was found to be sufficiently rigid without deformation during repeated application on the head phantom. Catheters were easily threaded into channels carved along catheter paths. Further tests are required to evaluate feasibility of channel diameters smaller than 4mm.

Conclusion:
Construction of 3D-printed mould applicators show promise for use in patient specific brachytherapy of superficial lesions. Further evaluation of 3D printing techniques and materials is required for constructing sufficiently thin, rigid and durable surface moulds suitable for clinical deployment.

}, doi = {http://dx.doi.org/10.1118/1.4888333}, author = {Ian Cumming and C.P. Joshi and Andras Lasso and Adam Rankin and Conrad Falkson and John Schreiner and Gabor Fichtinger} } @article {Pompeu-Robinson2011, title = {Immobilization and Catheter Guidance for Breast Brachytherapy}, journal = {International Journal of Computer Assisted Radiology and Surgery}, volume = {Online First}, year = {2011}, month = {05/2011}, abstract = {

Purpose: Brachytherapy is an important mode of breast cancer treatment; however, improvements in both treatment planning and delivery are needed. In order to meet these specific needs, integration of pre-operative imaging, supplemented by computerized surgical planning and mathematical optimization were used to develop and test an intra-operative immobilization and catheter guidance system. Method: A custom template specific to each patient with optimally placed guide holes for catheter insertion was designed and fabricated. Creation of the template is based on a virtual reality reconstruction of the patient{\textquoteright}s anatomy from computed tomography imaging. The template fits on the patient{\textquoteright}s breast, immobilizing the soft tissue, and provides pre-planned catheter insertion holes for guidance to the tumor site. Agar-based phantom and target models were used for quantitative validation of the template by ascertaining the precision and accuracy of the templates. Results: Tests were performed on agar-based tissue models using computed tomography imaging for template planning and validation. Planned catheter tracks were compared to post-insertion image data and distance measurements from target location were used to create an error measure. Initial results yielded an average error of 4.5 mm. Once the workflow and template design were improved, an average error of 2.6 mm was observed, bringing the error close to a clinically acceptable range. Conclusion: Use of a patient-specific template for breast brachytherapy is feasible and may improve the procedure accuracy and outcome.

}, keywords = {Brachytherapy, Breast cancer, Guidance, Immobilization, Radiotherapy}, doi = {DOI 10.1007/s11548-011-0600-6}, author = {Alexandra M. Pompeu-Robinson and M. Kunz and Conrad Falkson and John Schreiner and C.P. Joshi and Gabor Fichtinger} }