Abstract The purpose of this study was to evaluate a novel device for non-surgical implantation of tumor cells using ultrasonic (US) image guidance. There are a variety of mouse model cancer types (e.g. sub-cu, orthotopic, genetically engineered). Orthotopic tumors are increasingly prevalent but usually require surgery, which reduces throughput and injures the surrounding anatomy. Injections are an alternative to surgery, but usually require image guidance or extensive training. US guided injection systems exist, but are suboptimal because they require significant training, as the US beam is not necessarily coplanar with needle location or trajectory, reducing accuracy and throughput. We tested a new approach to image guided injection which ensures that the US beam is coplanar with the needle. To test the efficacy of the image guided injection device across a variety of common orthotopic tumors, we delivered luc-tagged cells to the prostate (2.5e5 cells in 40 µL, PC3, N=8), liver (2e6 cells in 100 µL, Hep G2, N=5), and brain (1.75e5 cells in 100 µL, U87-MG, N=3). The brain tumor model was introduced via intracardiac injection to simulate metastases. Between 3 and 8 mice were injected for each tumor model. For injection, animals were anesthetized and positioned on motion stage. A 1 mL syringe was mounted to the adjustable injection gantry with the needle co-planar with the US beam, and the target organ was visualized with US. Cells were delivered to the targets using the US live stream as a guide. Between 1 to 3 weeks after the injections, tumors were confirmed via BLI with an IVIS (Revvity, Waltham, MA, USA). For each of the three tumor cell lines, animal preparation and injections could be performed in 10 mins by recently-trained novice users. All three cell lines could be effectively delivered to the orthotopic host tissues, and this was confirmed by using BLI of the cells. This study represents the first time a co-planar US beam and needle delivery mechanism was used for the purpose of non-surgical implantation of orthotopic tumors. Future developments of this platform could include improvements to automation of needle placement and trajectory to ensure successful payload delivery by novice users. Citation Format: Thomas M. Kierski, Juan D. Rojas, Nathan Beaumont, Theresa Charity, Robert D. Marek, Kenneth H. Young, Gregory M. Palmer, Ryan C. Gessner, Tomek J. Czernuszewicz. Feasibility of a novel image guided injection tool for non-surgical implantation of orthotopic tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4137.