title: Multimodal sentinel lymph node mapping with single-photon emission computed tomography (SPECT)/computed tomography (CT) and photoacoustic tomography.
abstract: The identification of cancer cells in the lymph nodes surrounding a tumor is important in establishing a prognosis. Optical detection techniques such as fluorescence and photoacoustic tomography (PAT) have been reported in preclinical studies for noninvasive sentinel lymph node (SLN) mapping. A method for validation of these techniques is needed for clinical trials. We report the use of a multimodal optical-radionuclear contrast agent as a validation tool for PAT in a preclinical model. Methylene blue (MB) was radiolabeled with (125)I for multimodal SLN mapping and used in conjunction with MB to assess the feasibility of multimodal SLN mapping in a rat model by PAT and single-photon emission computed tomography (SPECT). MB provided sufficient contrast for identifying SLNs noninvasively with a PAT system adapted from a clinical ultrasound imaging system. The signal location was corroborated by SPECT using (125)I labeled MB. The translation of PAT into the clinic can be facilitated by a direct comparison with established imaging methods using a clinically relevant dual SPECT and photoacoustic imaging agent. The new high-resolution PAT is a promising technology for the sensitive and accurate SLN detection in cancer patients.
authors.affiliation: Department of Radiology, Optical Radiology Laboratory, Washington University School of Medicine, 4525 Scott Avenue, Saint Louis, MO 63108, USA.
authors.forename: Walter J
authors.initials: WJ
authors.lastname: Akers
authors.forename: W Barry
authors.initials: WB
authors.lastname: Edwards
authors.forename: Chulhong
authors.initials: C
authors.lastname: Kim
authors.forename: Baogang
authors.initials: B
authors.lastname: Xu
authors.forename: Todd N
authors.initials: TN
authors.lastname: Erpelding
authors.forename: Lihong V
authors.initials: LV
authors.lastname: Wang
authors.forename: Samuel
authors.initials: S
authors.lastname: Achilefu
mesh_terms: D000818:Animals; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D008198:Lymph Nodes / Q000000981:diagnostic imaging* / Q000473:pathology; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging* / Q000473:pathology; D008751:Methylene Blue; D009367:Neoplasm Staging; D061088:Photoacoustic Techniques; D011379:Prognosis; D011859:Radiography; D051381:Rats; D017207:Rats, Sprague-Dawley; D012680:Sensitivity and Specificity; D021701:Sentinel Lymph Node Biopsy / Q000379:methods; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
chemical_list: D007457:Iodine Radioisotopes; D008751:Methylene Blue