title: Detection of melanoma metastases in resected human lymph nodes by noninvasive multispectral photoacoustic imaging.
abstract: Objective. Sentinel node biopsy in patients with cutaneous melanoma improves staging, provides prognostic information, and leads to an increased survival in node-positive patients. However, frozen section analysis of the sentinel node is not reliable and definitive histopathology evaluation requires days, preventing intraoperative decision-making and immediate therapy. Photoacoustic imaging can evaluate intact lymph nodes, but specificity can be hampered by other absorbers such as hemoglobin. Near infrared multispectral photoacoustic imaging is a new approach that has the potential to selectively detect melanin. The purpose of the present study is to examine the potential of multispectral photoacoustic imaging to identify melanoma metastasis in human lymph nodes. Methods. Three metastatic and nine benign lymph nodes from eight melanoma patients were scanned ex vivo using a Vevo LAZR(©) multispectral photoacoustic imager and were spectrally analyzed per pixel. The results were compared to histopathology as gold standard. Results. The nodal volume could be scanned within 20 minutes. An unmixing procedure was proposed to identify melanoma metastases with multispectral photoacoustic imaging. Ultrasound overlay enabled anatomical correlation. The penetration depth of the photoacoustic signal was up to 2 cm. Conclusion. Multispectral three-dimensional photoacoustic imaging allowed for selective identification of melanoma metastases in human lymph nodes.
authors.affiliation: Department of Surgery, The Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands ; Biomedical Photonic Imaging Group, MIRA Institute, University of Twente, Post Box 217, 7500 AE Enschede, The Netherlands.
authors.forename: Gerrit Cornelis
authors.initials: GC
authors.lastname: Langhout
authors.affiliation: Biomedical Photonic Imaging Group, MIRA Institute, University of Twente, Post Box 217, 7500 AE Enschede, The Netherlands.
authors.forename: Diederik Johannes
authors.initials: DJ
authors.lastname: Grootendorst
authors.affiliation: Melanoma Institute Australia, 40 Rocklands Road, North Sydney, NSW 2060, Australia.
authors.forename: Omgo Edo
authors.initials: OE
authors.lastname: Nieweg
authors.affiliation: Department of Surgery, The Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands.
authors.forename: Michel Wilhelmus Jacobus Maria
authors.initials: MW
authors.lastname: Wouters
authors.affiliation: Department of Surgery, The Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands.
authors.forename: Jos Alexander
authors.initials: JA
authors.lastname: van der Hage
authors.affiliation: Fujifilm Visualsonics Inc., Post Box 66, 3080 Yonge Street 6100, Toronto, ON, Canada.
authors.forename: Jithin
authors.identifier: 0000-0003-4007-0997
authors.initials: J
authors.lastname: Jose
authors.affiliation: Department of Pathology, The Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands.
authors.forename: Hester
authors.initials: H
authors.lastname: van Boven
authors.affiliation: Biomedical Photonic Imaging Group, MIRA Institute, University of Twente, Post Box 217, 7500 AE Enschede, The Netherlands.
authors.forename: Wiendelt
authors.initials: W
authors.lastname: Steenbergen
authors.affiliation: Biomedical Photonic Imaging Group, MIRA Institute, University of Twente, Post Box 217, 7500 AE Enschede, The Netherlands.
authors.forename: Srirang
authors.initials: S
authors.lastname: Manohar
authors.affiliation: Department of Surgery, The Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands ; Nanobiophysics Group, MIRA Institute, University of Twente, Post Box 217, 7500 AE Enschede, The Netherlands.
authors.forename: Theodoor Jacques Marie
authors.initials: TJ
authors.lastname: Ruers