5-ALA-mediated fluorescence of musculoskeletal tumors in a chick chorio-allantoic membrane model: preclinical in vivo qualification analysis as a fluorescence-guided surgery agent in Orthopedic Oncology.

Background: Fluorescence-guided surgery (FGS) with 5-aminolevulinic acid (5-ALA) and other contrast agents has shown its efficacy in improving resection margins, local recurrence and survival rates in several medical disciplines. It is the objective of this study to analyze the engraftment rate of musculoskeletal tumor specimens on the chick chorio-allantoic membrane (CAM), the rate of tumor fluorescence (PDD), and the effects of photodynamic therapy (PDT) after exposure of tumors to 5-ALA in an in vivo environment.

Methods: A total of 486 CAMs were inoculated with macroscopic tumor grafts (n = 26; n = 478 eggs) and primary cell culture suspensions (n = 2; n = 8 eggs) from 26 patients on day 10 of egg development.