NeedleFinder is an open-source extension available for 3D Slicer that provides fast and accurate segmentation of needles from Magnetic Resonance Imaging (MRI) data.
The worldwide gynecological cancer mortality rate including cervical, ovarian, vaginal and vulvar cancers is more than 20,000 per year in the US alone. In many countries, including the US, external beam radiotherapy followed by high dose rate brachytherapy is the standard of care, and the superior ability of MR to visualize soft tissue has led to an increase in its usage in brachytherapy treatment planning and delivery. One of the technical challenges associated with the use of MRI for brachytherapy, in contrast to that of CT imaging, is the visualization of catheters that are used to place radiation sources into cancerous tissue.
We developped a precise, accurate method for achieving catheter segmentation and visualization. The algorithm, with the assistance of manually provided tip locations, performs segmentation using image-features, and is guided by a catheter-specific, estimated mechanical model. A final quality-control step removes outliers or conflicting catheter trajectories.
Patients treated in AMIGO often have very large tumors that may have spread to surrounding structures. Image-guided interstitial catheter placement increases the likelihood that the catheters will be properly placed in the center of the tumor, thereby improving radiation dosimetry. The physician is able to see the tumor with much greater accuracy using MRI in AMIGO than is possible with other imaging modalities and it allows direct placement of an interstitial catheter into the tumor and away from the normal tissue, minimizing future toxicity to the patient. In the case of larger tumors that often require insertion of multiple catheters, each area of the tumor can be treated with the appropriate dose. AMIGO, with its unique integration of surgery, PET/CT, MRI, and brachytherapy, offers many possibilities for translational research with the potential for improving patient care for patients with gynecologic tumors. In terms of MRI, AMIGO facilitates assessment of potentially biologically active residual regions of tumors. In the laboratory, biopsied tissue obtained during AMIGO imaging allows correlation between imaging and pathology. The ultimate goal is to use these novel approaches to increase disease-free intervals and minimize long-term toxicities frequently associated with radiation treatment.