Laryngeal cancer is a prevalent head and neck malignancy, with poor prognosis and low survival rates for patients with advanced disease. Treatment consists of unimodal therapy through surgery or radiotherapy in early staged tumors, while advanced stage tumors are generally treated with multimodal chemoradiotherapy or (total) laryngectomy followed by radiotherapy. Still, the recurrence rate for advanced laryngeal cancer is between 25 and 50%. In order to improve surgical resection of laryngeal cancer and reduce local recurrence rates, various intraoperative optical imaging techniques have been investigated. In this systematic review, we identify these technologies, evaluating the current state and future directions of optical imaging for this indication. Narrow-band imaging (NBI) and autofluorescence (AF) are established tools for early detection of laryngeal cancer. Nonetheless, their intraoperative utility is limited by an intrinsic inability to image beyond the (sub-)mucosa. Likewise, contact endoscopy (CE) and optical coherence tomography (OCT) are technically cumbersome and only useful for mucosal margin assessment. Research on fluorescence imaging (FLI) for this application is sparse, dealing solely with nonspecific fluorescent agents. Evidently, the imaging modalities that have been investigated thus far are generally unsuitable for deep margin assessment. We discuss two optical imaging techniques that can overcome these limitations and suggest how they can be used to achieve adequate margins in laryngeal cancer at all stages.

Anastomotic leakage is a severe complication after oesophageal resection with gastric conduit reconstruction. Poor perfusion of the gastric conduit plays an important role in the development of anastomotic leakage. Quantitative near-infrared (NIR) fluorescence angiography with indocyanine green (ICG-FA) is an objective technique that can be used for perfusion assessment. This study aims to assess perfusion patterns of the gastric conduit with quantitative ICG-FA. In this exploratory study, 20 patients undergoing oesophagectomy with gastric conduit reconstruction were included. A standardized NIR ICG-FA video of the gastric conduit was recorded. Postoperatively, the videos were quantified. Primary outcomes were the time-intensity curves and nine perfusion parameters from contiguous regions of interest on the gastric conduit. A secondary outcome was the inter-observer agreement of subjective interpretation of the ICG-FA videos between six surgeons. The inter-observer agreement was tested with an intraclass correlation coefficient (ICC). In a total of 427 curves, three distinct perfusion patterns were recognized: pattern 1 (steep inflow, steep outflow); pattern 2 (steep inflow, minor outflow); and pattern 3 (slow inflow, no outflow). All perfusion parameters were significantly different between the perfusion patterns. The inter-observer agreement was poor - moderate (ICC:0.345,95%CI:0.164-0.584). This was the first study to describe perfusion patterns of the complete gastric conduit after oesophagectomy. Three distinct perfusion patterns were observed. The poor inter-observer agreement of the subjective assessment underlines the need for quantification of ICG-FA of the gastric conduit. Further studies should evaluate the predictive value of perfusion patterns and parameters on anastomotic leakage.

Near-infrared (NIR) fluorescence imaging is an emerging imaging technique in the surgical field that uses light with a longer wavelength than visible light (the NIR-I spectrum; 700 to 1000 nm) to extract information from superficial and subsurface structures. As a result of the favorable optical properties of human tissue, photons with a wavelength in the NIR spectrum can travel further through human tissue compared with photons with wavelengths in the visible spectrum.¹ NIR fluorescence imaging is used for perfusion imaging,^{2 – 4} the visualization of critical anatomic structures,^{5 – 10} and the identification of malignant tissue.^{11 – 15} In oncological surgery, fluorescent dyes are frequently conjugated to a tumor-targeting moiety, e.g., antibodies or peptides,^16,17 to enable tumor-targeted imaging during surgery. Moreover, in fluorescence-guided liver surgery, the non-targeted fluorescent dye indocyanine green (ICG) is used to indirectly mark colorectal metastases.^{18 – 20} In contrast to tumor-targeted tracers, ICG accumulates in the tumor periphery, resulting in a typical fluorescent “rim-shaped” pattern.^18,21 Although the two types of dyes accumulate in different regions, they are both valuable in identifying tumor tissue and assessing tumor margins.

Pilonidal sinus disease (PSD) is a subcutaneous infection of the sacrococcygeal region due to entrapment of hair and/or debris. International guidelines recommend minimally invasive techniques and flap techniques. A Dutch guideline for the treatment of PSD is not available and this may lead to practice variation. The aim of this study was to perform a national survey on the surgical treatment of PSD in the Netherlands. An online survey was sent by e-mail to all surgeons and surgical residents of the Dutch Association for Surgeons. Respondents were asked to reflect on their preferences in the treatment of PSD, their perceived satisfaction with this treatment, and the need for national guidelines. A total of 819 (48.6%) of 1684 invitees responded to the survey, of whom 615 (37%) met the inclusion criteria. Traditional excision techniques were most frequently performed for all types of PSD (50.7%) followed by flap techniques (22.6%) and minimally invasive techniques (22%). Only 22.6% of the participants were satisfied with the current treatment and 82% supported the development of a national guideline. Traditional excision techniques are most frequently performed for PSD in the Netherlands but the majority of surgeons and surgical residents are not satisfied with the current treatment. There is a demand for a national guideline.

Small intestinal neuroendocrine tumours (SI-NETs) are rare lesions with a prevalence of 1 per 100 000 patients per year¹. They typically grow slowly and without initial symptoms, resulting in the majority of patients presenting with advanced local disease, multiple primary tumours, and distant metastases^2–4. Staging of SI-NETs is of paramount importance, as curative surgery is indicated only for patients with resectable disease. In general, tumour resection is not commonly undertaken in asymptomatic patients with unresectable metastatic disease⁵.

Background: Optimal intraoperative tumor identification of gastrointestinal stromal tumors (GISTs) is important for the quality of surgical resections. This study aims to assess the potential of near-infrared fluorescence (NIRF) imaging with indocyanine green (ICG) to improve intraoperative tumor identification. Methods: Ten GIST patients, planned to undergo resection, were included. During surgery, 10 mg of ICG was intravenously administered, and NIRF imaging was performed at 5, 10, and 15 min after the injection. The tumor fluorescence intensity was visually assessed, and tumor-to-background ratios (TBRs) were calculated for exophytic lesions. Results: Eleven GIST lesions were imaged. The fluorescence intensity of the tumor was visually synchronous and similar to the background in five lesions. In one lesion, the tumor fluorescence was more intense than in the surrounding tissue. Almost no fluorescence was observed in both the tumor and healthy peritoneal tissue in two patients with GIST lesions adjacent to the liver. In three GISTs without exophytic growth, no fluorescence of the tumor was observed. The median TBRs at 5, 10, and 15 min were 1.0 (0.4–1.2), 1.0 (0.5–1.9), and 0.9 (0.7–1.2), respectively. Conclusion: GISTs typically show similar fluorescence intensity to the surrounding tissue in NIRF imaging after intraoperative ICG administration. Therefore, intraoperatively administered ICG is currently not applicable for adequate tumor identification, and further research should focus on the development of tumor-specific fluorescent tracers for GISTs.