Project Summary/Abstract Glioblastoma (GBM) is one of the most prevalent and challenging cancers to cure. Each year, nearly 12,000 new cases of GBM are diagnosed in the US, with the overall median survival being only 12 to 18 months. GBM rarely metastasizes to other organs; however, there is no effective treatment for GBM tumors. Standard therapies with surgery combined with adjuvant radiation and FDA-approved drugs can add a few months to median survival but cannot prevent the recurrence of GBM. For recurrent GBM (rGBM), prognosis is even more dismal. Repeated surgery is often not recommended since patients have already gone through it during the treatment of initial GBM, and the efficacy of other treatment options is very limited. Laser interstitial thermotherapy (LITT) is an emerging technique for minimally invasive treatment of rGBM. By introducing a slender laser probe into a brain tumor, LITT can ablate the tumor tissue percutaneously using laser radiation. However, existing LITT devices which often set the tip of a laser probe at the core of the tumor are inadequate to achieve conformal ablation (i.e., ablation with the maximum tumor coverage and minimum collateral damage), especially when tumors are large, irregularly shaped, or multifocal. Hence, to achieve conformal ablation and improve the efficacy of LITT, we propose a novel robot to deliver thermal radiation at multiple locations inside a brain tumor. We will develop a novel steerable laser interstitial thermotherapy (SLIT) robot with a slender footprint and a custom- designed flexible laser ablation probe. We will introduce SLIT to the peripheral of a brain tumor through a small burr hole, manipulate SLIT around critical structures, and perform ablation at targets that are planned by clinicians under the guidance of magnetic resonance imaging (MRI). All aspects of new procedure will be remotely monitored and controlled by clinicians using intra-operative MRI and thermometry (MRT) to ensure precision and safety. In this project, we will 1) Design and develop an MR-compatible steerable robot with a flexible ablation probe, 2) Develop software that enables planning and control of multi-site tumor ablation, and 3) Evaluate the safety and functionality of SLIT using clinically relevant models. We have formed a multidisciplinary team with expertise in minimally invasive surgical robots, biomedical fiber lasers, neurosurgery, neurosurgical devices, neuropathology, advanced MR imaging, animal models, and neuroradiology to successfully conduct the proposed studies. LITT for rGBM therapy will serve as a model for technology development, while the outcome will generate a transformative platform with applications to many neurosurgical procedures that require dexterous minimally invasive access to brain lesions.

Project Narrative Laser interstitial thermotherapy (LITT) is an emerging minimally invasive technique for treatment of glioblastoma (rGBM), which is a common primary brain tumor associated with an extremely dismal prognosis. However, existing LITT devices can only ablate tissue around the tip of a fixed laser probe and are thus inadequate for large, irregularly shaped, and multifocal tumors. To achieve conformal tumor ablation, this project proposes a steerable laser interstitial thermotherapy (SLIT) robot that can navigate a brain tumor along multiple trajectories and ablate tumor tissue at multiple locations under intra-operative MR guidance.