Near-infrared (NIR) fluorescence imaging using exogenous fluorescent agents provides whole-field images in real-time to assist the surgeon in the excision of a tumor. Although the method has high sensitivity, the specificity can sometimes be lower than expected. Raman spectroscopy can detect tumors with high specificity. Therefore, a combination of both techniques can be advantageous. A complication that must be addressed is that the NIR spectral region is favored by both techniques for (in vivo) tissue analysis. When fluorescence and Raman emissions spectrally overlap, it becomes challenging or impossible to detect the Raman signal. In this paper, by avoiding this overlap, we describe a Raman spectroscopy setup capable of recording high-quality Raman spectra from tissue containing NIR exogenous fluorescent agents. We identify an optimal wavelength interval (900-915 nm) for Raman excitation, which avoids both excitation of fluorescent dyes and Raman signal self-absorption by the tissue. In this way, Raman spectroscopy can be combined with the currently most-used NIR fluorescent dyes. This combined novel setup could pave the way for clinical trials benefiting from both fluorescence imaging and Raman spectroscopy to avoid positive margins in cancer surgery.

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Intraoperative near-infrared (NIR) fluorescence imaging using tumor-specific exogenous fluorescent agents provides whole-field images in real-time to assist the surgeon in the complete resection of tumor tissue. Although the method has high sensitivity, the specificity can sometimes be lower than expected. Raman spectroscopy can differentiate between tumor and healthy tissue with high specificity based on their molecular composition. Therefore, a combination of these modalities can be advantageous. A complication that must be addressed is that the NIR spectral region is favored by both techniques for intraoperative tissue analysis. When fluorescence and Raman emissions spectrally overlap, it becomes challenging or impossible to detect the Raman signal. Therefore, these techniques were traditionally considered mutually exclusive for clinical implementation. Here, a Raman spectroscopy setup capable of recording high-quality Raman spectra from tissue containing NIR exogenous fluorescent agents is described. In this setup, an optimal wavelength interval for Raman excitation is identified, which avoids both excitation of fluorescent agent and Raman signal self-absorption by the tissue. This combined novel setup could pave the way for clinical trials benefiting from the complementary value of intraoperative NIR fluorescence imaging and Raman spectroscopy to avoid positive margins in cancer surgery.@en

A clear margin is an important prognostic factor for most solid tumours treated by surgery. Intraoperative fluorescence imaging using exogenous tumour-specific fluorescent agents has shown particular benefit in improving complete resection of tumour tissue. However, signal processing for fluorescence imaging is complex, and fluorescence signal intensity does not always perfectly correlate with tumour location. Raman spectroscopy has the capacity to accurately differentiate between malignant and healthy tissue based on their molecular composition. In Raman spectroscopy, specificity is uniquely high, but signal intensity is weak and Raman measurements are mainly performed in a point-wise manner on microscopic tissue volumes, making whole-field assessment temporally unfeasible. In this review, we describe the state-of-the-art of both optical techniques, paying special attention to the combined intraoperative application of fluorescence imaging and Raman spectroscopy in current clinical research. We demonstrate how these techniques are complementary and address the technical challenges that have traditionally led them to be considered mutually exclusive for clinical implementation. Finally, we present a novel strategy that exploits the optimal characteristics of both modalities to facilitate resection with clear surgical margins.

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To study the relation between the microstructure of white matter in the brain and hearing function in older adults we carried out a population-based, cross-sectional study. In 2562 participants of the Rotterdam Study, we conducted diffusion tensor imaging to determine the microstructure of the white-matter tracts. We performed pure-tone audiogram and digit-in-noise tests to quantify hearing acuity. Poorer white-matter microstructure, especially in the association tracts, was related to poorer hearing acuity. After differentiating the separate white-matter tracts in the left and right hemisphere, poorer white-matter microstructure in the right superior longitudinal fasciculus and the right uncinate fasciculus remained significantly associated with worse hearing. These associations did not significantly differ between middle-aged (51–69 years old) and older (70–100 years old) participants. Progressing age was thus not found to be an effect modifier. In a voxel-based analysis no voxels in the white matter were significantly associated with hearing impairment.

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For patients with recurrent and/or metastatic squamous cell carcinoma of the head and neck (R/M SCCHN), chemotherapy can prolong life and alleviate symptoms. However, expected gains may be small, not necessarily outweighing considerable toxicity and high costs. Treatment choice is to a large extent dependent on preferences of doctors and patients and data on these choices are scarce. The purpose of this study is to obtain real-world information on palliative systemic treatment and costs of R/M SCCHN in the Netherlands. In six Dutch head and neck treatment centers, data were collected on patient and tumor characteristics, treatment patterns, disease progression, survival, adverse events, and resource use for R/M SCCHN, between 2006 and 2013. 125 (14 %) out of 893 R/M SCCHN patients received palliative, non-trial first-line systemic treatment, mainly platinum + 5FU + cetuximab (32 %), other platinum-based combination therapy (13 %), methotrexate monotherapy (27 %) and capecitabine monotherapy (14 %). Median progression-free survival and overall survival were 3.4 and 6.0 months, respectively. 34 (27 %) patients experienced severe adverse events. Mean total hospital costs ranged from €10,075 (±€9,891) (methotrexate monotherapy) to €39,459 (±€21,149) (platinum + 5FU + cetuximab). Primary cost drivers were hospital stays and anticancer drug treatments. Major health care utilization and costs are involved in systemically treating R/M SCCHN patients with a limited survival.@en