Hybrid techniques for intraoperative sentinel lymph node imaging: early experiences and future prospects. (April 2013)

• Record Type: Journal Article
• Authors: Rietbergen, Daphne DD; van den Berg, Nynke S; van Leeuwen, Fijs WB; Valdés Olmos, Renato A
• Is Part Of: Imaging in medicine. Volume 5:Number 2(2013)
• Page Start: 147
• Page End: 159
• Publication Date: 2013-04
• Subjects: breast cancer -- fluorescence imaging -- head and neck cancer -- image-guided surgery -- indocyanine green -- melanoma -- prostate carcinoma -- radioguided surgery -- sentinel lymph node biopsy; Diagnostic imaging -- Periodicals; 616.075405
• DOI: 10.2217/iim.13.16
• Languages: English
• ISSNs: 1755-5205

Abstract

Sentinel lymph node biopsy (SLNB) has become widely accepted as a standard of care in the surgical staging of the axilla in breast cancer patients, and it has been increasingly used as a staging procedure for various other malignancies such as melanoma, head and neck cancer, and gynecological and urogenital malignancies. SLNB accurately predicts regional nodal status, determines prognosis and is helpful in devising therapeutic strategies. In spite of these achievements, there is a need to advance the intraoperative identification beyond the current state-of-the-art. This will help facilitate surgeons to find sentinel lymph nodes (SLNs) more accurately. Accurate visualization appears to be essential during surgeries in complex areas, as frequently observed in malignancies with deep lymphatic drainage or with drainage to multiple basins. By placing the SLNs within their anatomical context, the introduction of SPECT/CT, in addition to lymphoscintigraphy, has significantly improved the generation of preoperative 2D and 3D surgical roadmaps. In addition, dedicated intraoperative tools, such as portable γ-cameras, help provide real-time imaging to surgeons regarding the location of the radioactive SLN. In recent years, fluorescent dyes were introduced to enable (superficial) fluorescence guidance towards the SLNs. However, in order to combine the two approaches, hybrid tracers are required to enable simultaneous radioactive and fluorescence detection. The initial experiences using these novel hybrid tracers, which preserve preoperative mapping with lymphoscintigraphy and SPECT/CT, for SLNB in patients with breast cancer, prostate cancer, melanoma and head and neck cancer, are discussed in this review. The hybrid approach for SLNB is confronted with both the conventional modalities and the use of single fluorescent tracers. Following the initial clinical experience, further validation of hybrid tracers must follow on larger series of patients on the basis of a protocol combining preoperative mapping (lymphoscintigraphy and SPECT/CT) with intraoperative hybrid signal detection using separate imaging devices for the detection of radioactive and fluorescent signals. It is expected that the use of hybrid tracers will lead to improved SLN detection; principally in complex anatomical areas or when SLNs are localized close to primary lesions.