title: Formalin fixation could interfere with the clinical assessment of the tumor-free margin in tumor surgery: magnetic resonance imaging-based study.
abstract: OBJECTIVE
  The tumor-free margin in bone and soft-tissue cancer is a key factor for subsequent treatment. While flattening and shrinkage of specimens after formalin fixation have been described in breast cancer, there are no data for bone and soft tissue sarcoma. Fixation could interfere with the accuracy of the assessment of the tumor-free margin.
  
  
  METHODS
  The influence of formalin fixation was assessed on forelimb specimens in a preclinical porcine model. The specimens were subjected to magnetic resonance imaging before and after formalin fixation. Weight, width and height of the specimen were measured and different consecutive volumes (total, muscles, bones and fatty tissue) were obtained by segmentation.
  
  
  RESULTS
  After formalin fixation, the weight increased, total volume and muscle volume slightly increased while bone did not change and fatty tissue decreased. The width of the specimens increased while their height decreased.
  
  
  CONCLUSIONS
  Formalin fixation caused slight muscle expansion, fatty tissue shrinkage and flattening of the specimen. These changes could interfere with the assessment of the tumor-free margin in clinical practice.
authors.affiliation: Department of Orthopedic Surgery, Saint-Luc University Hospital, Brussels, Belgium. Pierre-Louis.Docquier@uclouvain.be
authors.forename: Pierre-Louis
authors.initials: PL
authors.lastname: Docquier
authors.forename: Laurent
authors.initials: L
authors.lastname: Paul
authors.forename: Olivier
authors.initials: O
authors.lastname: Cartiaux
authors.forename: Frédéric
authors.initials: F
authors.lastname: Lecouvet
authors.forename: Denis
authors.initials: D
authors.lastname: Dufrane
authors.forename: Christian
authors.initials: C
authors.lastname: Delloye
authors.forename: Christine
authors.initials: C
authors.lastname: Galant
mesh_terms: D000818:Animals; D001331:Automation; D001859:Bone Neoplasms / Q000473:pathology / Q000601:surgery*; D005404:Fixatives / Q000009:adverse effects*; D005557:Formaldehyde / Q000009:adverse effects*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D023421:Models, Animal; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000473:pathology; D012509:Sarcoma / Q000473:pathology / Q000601:surgery*; D013552:Swine; D016707:Tissue Fixation / Q000379:methods
chemical_list: D005404:Fixatives; D005557:Formaldehyde