Andrew - Week 1

I had a great first week. I immediately met with my mentor, Dr. Pannullo in neuro-oncology, following orientation and we discussed my research project for the summer. My project involves a new medical object for brachytherapy, which is in situ placement of radioisotopes for radiological treatment of cancer. The current technique is to place either free "seeds" of radioactive material, in this case cesium-131, into the cavity that results from the resection of a tumor, or to place strings of these seeds into the cavity. A problem with this is that it is very difficult to place the seeds in a ordered pattern to create a homogeneous radioactive cloud to kill cancer cells that were left behing. My project is to develop a king of balloon out of a bioabsorbable polymer, and to incorporate radioactive seeds onto the surface of this balloon. The idea is to inflate this device into the cavity and then leave it behind. This would be well suited for metastases to the brain because these are often spherical in shape. I have done extensive research in the literature and identified a promising polymer, poly-4-hydroxybutyrate, with which to construct the device. I will be moving forward with the device design using a CAD software. A crucial feature of this device will be that it must have an apparatus to inflate it in the resection cavity, and then it must be able to be sealed and left behind, removing the tube or whatever that was used to inflate it with saline. I am thinking about building in a simple one-way valve, or a secondary balloon that goes inside the primary balloon that can be deflated and withdrawn, as with stents. The advisor for this project is actually going to be Dr. Wernicke in radiologic oncology. I observed the placement of these seeds into a resection cavity in the OR to get a better idea of how my device would be utilized.

I have followed Dr. Pannullo in to the clinic to see several patients. All so far have been post-op, and are there to discuss next steps based on the most recent MRI scans of their brains. Possible next steps are often chemotherapy, radiation treatment, or both. I am enjoying learning about the attributes of each treatment type, and why one is chosen over the other. I have also observed a stereoradio surgery case, in which a brain tumor is ablated with ionizing radiation. It was extremely interesting to see the engineering approach to specifically targeting this radiation so that it will converge at the tumor and have minimal effect on surrounding, healthy tissue. This is accomplished by taking a CT scan of the head while it is in a cage (screwed onto the skull) to provide spacial reference points. This image in then input to a computer and overlayed with the MRI which shows the tumor, and a physicist programs where to shoot the radiation.