title: β-Radioluminescence Imaging: A Comparative Evaluation with Cerenkov Luminescence Imaging.
abstract: Cerenkov luminescence imaging (CLI) can provide high-resolution images of (18)F-FDG-avid tumors but requires prolonged acquisition times because of low photon sensitivity. In this study, we proposed a new modality, termed β-radioluminescence imaging (β-RLI), which incorporates a scintillator with a γ-rejection strategy for imaging β particles. We performed a comparative evaluation of β-RLI with CLI in both in vitro and in vivo systems.
  
  
  METHODS
  Using in vitro phantoms, we characterized the photon sensitivity and resolution of CLI and β-RLI. We also conducted a series of in vivo experiments with xenograft mouse models using both amelanotic (A375, UMSCC1-Luc) and melanotic (B16F10-Luc) cell lines. The B16F10 and UMSCC1 cell lines were transfected with the luciferase gene (Luc). CLI was acquired over 300 s, and β-RLI was acquired using two 10-s acquisitions. We correlated (18)F -: FDG activities, as assessed by PET, with tumor radiances for both β-RLI and CLI. We also compared tumor signal-to-background ratios (SBRs) between these modalities for amelanotic and melanotic tumors.
  
  
  RESULTS
  For in vitro experiments, the photon sensitivity for β-RLI was 560-fold greater than that for CLI. However, the spatial resolution for β-RLI (4.4 mm) was inferior to that of CLI (1.0 mm). For in vivo experiments, correlations between (18)F-FDG activity and tumor radiance were 0.52 (P < 0.01) for β-RLI, 0.81 (P = 0.01) for amelanotic lesions with CLI, and -0.08 (negative contrast; P = 0.80) for melanotic lesions with CLI. Nine of 13 melanotic lesions had an SBR less than 1 for CLI, despite an SBR greater than 1 among all lesions for β-RLI.
  
  
  CONCLUSIONS
  β-RLI can produce functional images of both amelanotic and melanotic tumors in a shorter time frame than CLI. Further engineering developments are needed to realize the full clinical potential of this modality.
authors.affiliation: Department of Radiation Oncology, Stanford University, Stanford, California mtking12@gmail.com.
authors.forename: Martin T
authors.initials: MT
authors.lastname: King
authors.affiliation: Department of Radiation Oncology, Stanford University, Stanford, California.
authors.forename: Colin M
authors.initials: CM
authors.lastname: Carpenter
authors.affiliation: College of Pharmacy, Oregon State University, Portland, Oregon.
authors.forename: Conroy
authors.initials: C
authors.lastname: Sun
authors.affiliation: Department of Radiology, Stanford University, Stanford, California Department of Nuclear Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China; and.
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Ma
authors.affiliation: Department of Radiation Oncology, Stanford University, Stanford, California.
authors.forename: Quynh-Thu
authors.initials: QT
authors.lastname: Le
authors.affiliation: Department of Otolaryngology, Stanford University, Stanford, California.
authors.forename: John B
authors.initials: JB
authors.lastname: Sunwoo
authors.affiliation: Department of Radiology, Stanford University, Stanford, California.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Cheng
authors.affiliation: Department of Radiation Oncology, Stanford University, Stanford, California.
authors.forename: Guillem
authors.initials: G
authors.lastname: Pratx
authors.affiliation: Department of Radiation Oncology, Stanford University, Stanford, California.
authors.forename: Lei
authors.initials: L
authors.lastname: Xing
mesh_terms: D000818:Animals; D001610:Beta Particles; D045744:Cell Line, Tumor; D005260:Female; D008163:Luminescent Measurements / Q000379:methods*; D051379:Mice; D008819:Mice, Nude; D009374:Neoplasms, Experimental / Q000000981:diagnostic imaging*; D011877:Radionuclide Imaging / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: Cerenkov; beta; melanoma; radioluminescence; surgery