Objectives : Intraoperative beta surface imaging using a navigated beta-probe in conjunction with positron-emitting radiotracers like FDG may enable control of tumor resection borders. The major challenge in this novel approach is modeling detection physics by considering beta-ranges in tissue, technical probe parameters, and the statistical nature of radiation. Previously, we validated this modality with phantoms. Here we use an in vitro tumor/background (T/B) setup with cells to validate its biological feasibility in terms of localizing tumor within tissue mass. Methods : Bladder cancer cells (EJ28luc) and human foreskin fibroblasts (HFF) were seeded and grown on Petri dishes in 2 spatial configurations, emulating residual tumor spots on top of/next to healthy tissue. On the day of the experiment, each dish was supplied with 3ml reduced-glucose medium (1mg/ml). Bioluminescence was then induced in EJ28luc cells with luciferine (0.1ml/dish) for imaging with a photographic camera (ground truth for tumor localization). Cells were incubated 30min in 3ml FDG-solution (83uCi/ml). The dish surface was scanned with a beta-probe (Node Seeker-800, IntraMedical Imaging LLC) combined with a navigation system (Polaris Vicra, Northern Digital Inc.). Cells were dyed and imaged with the mentioned camera (atlas for cell classification in T/B ratio assessment). Results : The beta-probe images were able to visually identify tumor spots in all dishes and yielded 71.86%±5.85% normalized cross-correlation to bioluminescence images. The mean T/B ratio was 3.54±0.80:1. Conclusions : Both qualitative and quantitative results validate the biological feasibility of residual tumor localization with the described beta surface imaging. As such, this novel molecular imaging modality in an intraoperative setting may be a breakthrough for minimally-invasive cancer surgery.     «

Objectives : Intraoperative beta surface imaging using a navigated beta-probe in conjunction with positron-emitting radiotracers like FDG may enable control of tumor resection borders. The major challenge in this novel approach is modeling detection physics by considering beta-ranges in tissue, technical probe parameters, and the statistical nature of radiation. Previously, we validated this modality with phantoms. Here we use an in vitro tumor/background (T/B) setup with cells to validate its b...     »