title: In vivo tumor detection in small animals by hematoporphyrin-mediated fluorescence imaging.
abstract: OBJECTIVE
  Noninvasive in vivo imaging of human tumors implanted in mice provides a reliable and economic tool for the investigation of tumor progression and metastasis and of the effectiveness of the antiblastic drugs on them. The purpose of this study is to report on the performance achievable by the well-known and extensively investigated HP-FRI (HematoPorphyrin (HP)-mediated Fluorescence Reflectance Imaging) when a high-quality image-acquisition device is used.
  
  
  BACKGROUND
  Previous articles of ours showed that HP-FRI still represents a useful, simple and reliable optical imaging technique to detect surface tumors. Therefore, it is particularly suitable to be used in combination with other imaging modalities in a multimodal imaging system endowed with diagnostic capabilities much better than each separate modality.
  
  
  METHODS
  Six-week-old Crl:CD-1 nude mice were subcutaneously inoculated with tumor cells. Tumor-bearing mice were irradiated in vivo by a frequency-doubled pulsed Nd:YAG laser (lambda = 532 nm). A cooled CCD digital camera recorded fluorescence light emitted by HP injected in mice through a cut-on long-wavelength pass filter.
  
  
  RESULTS
  The system we developed allows in vivo imaging of surface tumors on small animals with a large field of view, high photometric sensitivity, adequate space resolution, and short measurement time. The estimated spatial resolution is 730 microm for a fluorescence source placed about 0.5 mm under the mouse skin. The first exploration of the capabilities of this HP-FRI setup on few mice shows that it allows the detection of (a) both types of investigated tumors, (b) early stage and late stage but visually unrecognizable tumors, (c) the gross structure of tumors, and (d) the discrimination of necrotic and nonnecrotic tumor regions.
authors.affiliation: Dipartimento di Scienze Fisiche, Università di Napoli Federico II, Napoli, Italy.
authors.forename: Maddalena
authors.initials: M
authors.lastname: Autiero
authors.forename: Rosanna
authors.initials: R
authors.lastname: Cozzolino
authors.forename: Paolo
authors.initials: P
authors.lastname: Laccetti
authors.forename: Marcello
authors.initials: M
authors.lastname: Marotta
authors.forename: Maria
authors.initials: M
authors.lastname: Quarto
authors.forename: Patrizia
authors.initials: P
authors.lastname: Riccio
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Roberti
mesh_terms: D000818:Animals; D055088:Early Detection of Cancer / Q000379:methods*; D006415:Hematoporphyrins; D007091:Image Processing, Computer-Assisted; D053844:Lasers, Solid-State; D051379:Mice; D008819:Mice, Nude; D009336:Necrosis; D009374:Neoplasms, Experimental / Q000175:diagnosis* / Q000473:pathology; D017319:Photosensitizing Agents; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence
chemical_list: D006415:Hematoporphyrins; D017319:Photosensitizing Agents