Image guided surgery in the management of head and neck cancer

Peptide-mediated targeting of Quantum Dots in a 3D model of head and neck cancer

BACKGROUND

Oral squamous cell carcinoma (OSCC) treatment mainly relies on surgery. The status of surgical margin is a major prognostic factor for patients as positive margins are associated with lower survival. However, the anatomical particularities of this area complicate margin establishment. Fluorescence guided surgery (FGS) could be employed as an intraoperative technique to improve tumor resection and margin investigation. Quantum dots (QDs) serve as ideal contrast agents in this technique due to their brightness and stability. Since αVβ6 integrin is overexpressed in OSCC, coupling QDs with A20FMDV2 peptide (QDs-A20) targeting the αVβ6 integrin constitute a real opportunity. This study investigates the accumulation of QDs-A20 in 2D and 3D tongue cancer models, as well as QDs coupled to a scrambled version of this peptide (QDs-Scr) or without peptide (QDs-SPP), for imaging purposes.

METHODS

CdSeCdS/ZnS quantum dots were coated with sulfobetaine polymers (QDs-SPP) and conjugated to A20FMDV2 peptide (QDs-A20) or its scrambled version (QDs-Scr). Two-dimensional (2D) and three-dimensional (3D) tongue cancer cells HSC-3 were employed to test the effectiveness of intracellular accumulation of all types of QDs. Targeting ability of each QDs was assessed by flow cytometry, while the depth of penetration into cancerous spheroids was assessed by fluorescence microscopy.

RESULTS

QDs coating with sulfobetaines polymers (QDs-SPP) completely prevented their internalization by HSC-3 cells in 2D and 3D models, making QDs stealthy and preventing their non-specific accumulation. Conversely, peptides conjugated QDs (QDs-A20 & QDs-Scr) labeled HSC-3 monolayers and managed to label spheroid periphery up to 23 µm deep. However, no difference in accumulation was found between these two QDs whereas only A20 peptide could potentially target αVβ6 integrin. It appears that peptide conjugation increased QDs zeta potential, promoting their adsorption and subsequent endocytosis by cells, independently from αVβ6 integrin.

CONCLUSIONS

The present study highlighted the impact of peptide conjugation on QDs internalization in 2D and 3D tongue cancer cell models. QDs-SPP were stealthy and did not accumulate in cells. Peptides conjugated QDs could be used as contrast agents, but in a passive targeting approach. Modifications to surface chemistry are required to target αVβ6 integrin through active targeting. This study also highlights the need for controls such as scrambled peptides, the absence of which can lead to misinterpretation of results.

Trends and Future Directions in Margin Analysis for Head and Neck Cancers

Margin status in head and neck cancer has important prognostic implications. Currently, resection is based on manual palpation and gross visualization followed by intraoperative specimen or tumor bed-based margin analysis using frozen sections. While generally effective, this protocol has several limitations including margin sampling and close and positive margin re-localization. There is a lack of evidence on the association of use of frozen section analysis with improved survival in head and neck cancer. This article reviews novel technologies in head and neck margin analysis such as 3-dimensional scanning, augmented reality, molecular margins, optical imaging, spectroscopy, and artificial intelligence.

Novel color fluorescence imaging for sentinel lymph node detection in oral and oropharyngeal cancer

AIM

Fluorescence imaging (FI) using indocyanine green (ICG) is a noteworthy alternative technique for sentinel lymph node (SLN) detection without radiation exposure in oral cavity and oropharynx cancer. However, conventional FI is monochrome, so the visibility is limited. This study assessed whether color FI using the HyperEye Medical System (HEMS) is feasible as an alternative for SLN detection.

METHODS

Patients with previously untreated cT1-2N0 oral or oropharyngeal cancer who were to undergo primary tumor resection and elective neck dissection (END) in our hospital were enrolled from November 2012 to March 2016. The patients underwent SLN detection for biopsy via the HEMS following the injection of ICG solution around the primary lesion before neck dissection. The visibility and the diagnostic accuracy of the imaging were evaluated.

RESULTS

SLNs were visualized in all eight cases; however, transcutaneous fluorescence detection was not observed in all cases. Utilizing color mode imaging simplified harvest by clearly discriminating SLNs from surrounding structures, while the monochrome mode proved to be more sensitive for detection. Two cases showed occult metastases on both sentinel and regional nodes. The identification and false negative rates were 100% and 0%, respectively. There were no complications incurred due to this method.

CONCLUSION

Our results suggest that color FI with the HEMS allows for the accurate and safe harvest of SLNs with a preparatory skin incision. Although there is room for improvement of sensitivity, this easy-to-handle procedure might provide the potential to expand the role of the ICG method for SLN detection in head and neck cancer.

Autofluorescence Image-Guided Endoscopy in the Management of Upper Aerodigestive Tract Tumors

At this juncture, autofluorescence and narrow-band imaging have resurfaced in the medicine arena in parallel with current technology advancement. The emergence of newly developed optical instrumentation in addition to the discovery of new fluorescence biomolecules have contributed to a refined management of diseases and tumors, especially in the management of upper aerodigestive tract tumors. The advancement in multispectral imaging and micro-endoscopy has also escalated the trends further in the setting of the management of this tumor, in order to gain not only the best treatment outcomes but also facilitate early tumor diagnosis. This includes the usage of autofluorescence endoscopy for screening, diagnosis and treatment of this tumor. This is crucial, as microtumoral deposit at the periphery of the gross tumor can be only assessed via an enhanced endoscopy and even more precisely with autofluorescence endoscopic techniques. Overall, with this new technique, optimum management can be achieved for these patients. Hence, the treatment outcomes can be improved and patients are able to attain better prognosis and survival.

Free three-dimensional image software in local extension assessment of oral squamous cell carcinoma: a pilot study

OBJECTIVE

Oral Squamous Cell Carcinoma (OSCC) is conventionally treated by surgical resection, and positive surgical margins strongly increase local recurrence and decrease survival. This study aimed to evaluate whether a Three-Dimensional Segmentation (3DS) image of OSCC confers advantage over Multiplanar Reconstruction (MPR) of OSCC using images of computed tomography scan in surgical planning of tumor resection.

METHODS

Twenty-six patients with locally advanced OSCC had tumor morphology and dimensions evaluated by MPR images, 3DS images, and Surgical Pathology Specimen (SPS) analyses (gold standard). OSCC resection was performed with curative intent using only MPR images.

RESULTS

OSCC morphology was more accurately assessed by 3DS than by MPR images. Similar OSCC volumes and dimensions were obtained when MPR images, 3DS images and SPS measurements were considered. Nevertheless, there was a strong correlation between the OSCC longest axis measured by 3DS and SPS analyses (ICC = 0.82; 95% CI 0.59‒0.92), whereas only a moderate correlation was observed between the longest axis of OSCC measured by MPR images and SPS analyses (ICC = 0.51; 95% CI 0.09‒0.78). Taking only SPS with positive margins into account, MPR images and 3DS images underestimated the tumor's longest axis in eight out of 11 (72.7%) and 5 out of the 11 (45.5%) cases, respectively.

CONCLUSION

Our data present preliminary evidence that 3DS model represents a useful tool for surgical planning of OSCC resection, but confirmation in a larger cohort of patients is required.

LEVEL OF EVIDENCE

Laboratory study.

Spatial analysis of photoplethysmography in cutaneous squamous cell carcinoma

The primary treatment of the common malignancy squamous cell carcinoma is surgical removal. In this process, sufficient tissue removal is balanced against unnecessary mutilation. We recently presented a remote photoplethysmography algorithm, which revealed significant differences between processed video recordings of cancer biopsy areas and surrounding tissue. The aim of this study was to investigate whether spatial analyses of photoplethysmography data correlate with post-excision pathological analyses and thus have potential to assist in tumour delineation. Based on high speed video recordings of 11 patients with squamous cell carcinoma, we examined different parameters derived from temporal remote photoplethysmography variations. Signal characteristics values in sites matching histological sections were compared with pathological measures. Values were ranked and statistically tested with a Kendall correlation analysis. A moderate, negative correlation was found between signal oscillations and the width and transversal area of squamous cell carcinoma in the frequencies below 1 Hz and specifically from 0.02 to 0.15 Hz. We have presented a correlation between frequency content and prevalence of cancer based on regular video recordings of squamous cell carcinoma. We believe this is supported by published findings on malignant melanoma. Our findings indicate that photoplethysmography can be used to distinguish SCC from healthy skin.

Photoplethysmography for demarcation of cutaneous squamous cell carcinoma

A video processing algorithm designed to identify cancer suspicious skin areas is presented here. It is based on video recordings of squamous cell carcinoma in the skin. Squamous cell carcinoma is a common malignancy, normally treated by surgical removal. The surgeon should always balance sufficient tissue removal against unnecessary mutilation, and therefore methods for distinction of cancer boundaries are wanted. Squamous cell carcinoma has angiogenesis and increased blood supply. Remote photoplethysmography is an evolving technique for analysis of signal variations in video recordings in order to extract vital signs such as pulsation. We hypothesize that the remote photoplethysmography signal inside the area of a squamous cell carcinoma is significantly different from the surrounding healthy skin. Based on high speed video recordings of 13 patients with squamous cell carcinoma, we have examined temporal signal differences in cancer areas versus healthy skin areas. A significant difference in temporal signal changes between cancer areas and healthy areas was found. Our video processing algorithm showed promising results encouraging further investigation to clarify how detailed distinctions can be made.

Quenched cetuximab conjugate for fast fluorescence imaging of EGFR-positive lung cancers

Cetuximab-dye conjugates have shown great potential for image-guided surgery of epidermal growth factor receptor (EGFR)-positive cancers in clinical trials. However, their long circulation half-life and prolonged generation of high background signals require the injection of antibody conjugates several days prior to imaging, which limits the clinical applications. Herein, we developed a cetuximab-ATTO655 conjugate (i.e., Q-Cetuximab) for fast and real-time fluorescence imaging of EGFR-positive lung cancers. The fluorescence intensity of Q-Cetuximab was quenched to just 6.9% of that of the unconjugated dye when only 2.14 ATTO655 dyes were conjugated to cetuximab. In vitro real-time cell imaging showed that EGFR-positive A549 cells emitted strong fluorescence at 10 min after Q-Cetuximab treatment in the absence of the washing step, implying target-specific activation of quenched Q-Cetuximab fluorescence upon binding with EGFR-positive cancer cells. When mice with orthotropic A549 tumors received intravenous injection of Q-Cetuximab, scattered microsized tumors in the lungs could be clearly identified from near-infrared fluorescence imaging with a tumor-to-background ratio of 4.28 at 8 h post-injection. For comparison, the cetuximab-Alexa647 conjugate (i.e., ON-Cetuximab), which does not show fluorescence quenching, was synthesized as an always-on type of probe. The ON-Cetuximab-treated mice expressed strong fluorescence throughout their body at 8 h post-injection; therefore, lung tumor sites could not be discriminated using fluorescence imaging. These results confirm the benefits of Q-Cetuximab for image-guided precision surgery of EGFR-positive lung cancers.

Molecular margins in head and neck cancer: Current techniques and future directions

Complete tumor extirpation with clear surgical margins remains a central tenet of oncologic head and neck surgery. Rates of locoregional recurrence and survival are both significantly worse when clear margins are unable to be obtained. Current clinical practice relies on the use of frozen sections intra-operatively, followed by traditional histopathologic analysis post-operatively to assess the surgical margin. However, with improved understanding of tumor biology and advances in technology, new techniques have emerged to analyze margins at a molecular level. Such molecular margin analysis interrogates tissue for genetic, epigenetic, or proteomic changes that may belie tumor presence or aggressive features not captured by standard histopathologic techniques. Intra-operatively, this information may be used to guide resection, while post-operatively, it may help to stratify patients for adjuvant treatment. In this review, we summarize the current state of molecular margin analysis and describe directions for future research.

Current role of primary surgical treatment in patients with head and neck squamous cell carcinoma

PURPOSE OF REVIEW

The objective of this review article is to discuss the current role of surgery as the primary treatment modality in patients with head and neck squamous cell carcinoma (HNSCC).

RECENT FINDINGS

HNSCC represents one of the cancer locations where the primary treatment modality is the most under discussion. Indeed, the respective roles of primary surgical resection followed, as necessary, by adjuvant radiotherapy or definitive chemoradiotherapy remain controversial. The results of organ preservation trials and the drastic rise in the incidence of human papillomavirus-induced oropharyngeal tumors, which are known to be highly radiosensitive, have led to an increasing use of chemoradiation-based therapies in HNSCC patients. However, no chemoradiation-based protocol has shown better oncologic outcomes than radical primary surgery. Moreover, development of minimally invasive surgical techniques, such as transoral robotic surgery, and advances in head and neck microvascular reconstruction have considerably improved the clinical outcomes of the patients and have led to a reconsideration of the role of primary surgery in HNSCC patients.

SUMMARY

Surgery should be the primary treatment modality for most resectable oral cavity cancers and for T4a laryngeal/hypopharyngeal cancers. Primary surgery could also be the preferred modality of treatment for most early (T1-T2, N0) laryngeal and hypo/oropharyngeal carcinomas when this strategy offers an opportunity to reserve radiotherapy for a potential recurrence or second primary tumor. Primary surgery should also be considered in patients with locally advanced human papillomavirus-negative oropharyngeal carcinoma.

Value of Full-Field Optical Coherence Tomography Imaging for the Histological Assessment of Head and Neck Cancer

BACKGROUND AND OBJECTIVES

In head and neck surgery, intraoperative and postoperative evaluation of tumor margins is achieved by histopathological assessment, which is a multistep process. Intraoperative analysis of tumor margins to obtain a preliminary diagnosis is usually carried out on frozen sections. Analysis of frozen sections is challenging due to technical difficulties in processing. Full-field optical coherence tomography (FFOCT) provides ex vivo images of fresh tissue samples at a microscopic scale without tissue processing. The objectives of our study were to define the diagnostic criteria required to interpret head and neck FFOCT images and to evaluate the reliability of a histological diagnosis made on an "optical biopsy" produced by head and neck FFOCT imaging compared with conventional histology.

STUDY DESIGN/MATERIALS AND METHODS

First, we established an atlas of comparative images (FFOCT/standard histology) and defined the diagnostic criteria based on FFOCT images. Two pathologists subsequently performed a blinded review on 57 FFOCT images (32 patients). Specificity and sensitivity were measured by comparison with the standard histological diagnosis. The primary endpoint was major concordance, defined as two classifications leading to the same therapeutic decision (treatment/no treatment).

RESULTS

Pathologists identified four main criteria for tissue diagnosis on FFOCT images: heterogeneous cell distribution, stromal reaction, coiling, and keratinization abnormalities. The correlation study showed good results, with sensitivity from 88% to 90% and specificity from 81% to 87%, regardless of whether the FFOCT image review was performed by a pathologist with or without previous experience in optical imaging.

CONCLUSIONS

Our results demonstrate that FFOCT images can be used by pathologists for differential diagnosis, and that high-resolution FFOCT imaging can provide an assessment of microscopic architecture in head and neck tissues without tissue processing requirements. Lasers Surg. Med. © 2020 Wiley Periodicals, Inc.

A Self-Assembled "Albumin-Conjugate" Nanoprobe for Near Infrared Optical Imaging of Subcutaneous and Metastatic Tumors

The need for in situ accurate identification of tumor assisted real-time image-guided surgical resection calls for new near-infrared fluorescence agents with high tumor-sensitivity and excellent biocompatibility. Here, an albumin-conjugate nanoparticle system HSA-Er-RI-Cl was designed, synthesized, and applied in cancer imaging, which simultaneously achieved the EPR effect, hypoxia-targeting, and EGFR-targeting property. Our novel nanoprobe is composed of human serum albumin (HSA) and double-targeting small molecule conjugate (Er-RI-Cl): a hypoxia-targeting heptamethine carbocyanine dye (RI-Cl) conjugated with a clinic anti-EGFR antagonist (Erlotinib) by covalent bonding. This conjugate could bind to albumin proteins, forming albumin-conjugate complexes, and those complexes self-assemble into particles with diameters of approximately 100 nm in the aqueous solution. The tumor hypoxia and EGFR targeting specificity of HSA-Er-RI-Cl was, respectively, evaluated in vitro and in vivo. Using murine xenograft subcutaneous and brain metastatic tumor models, we demonstrated that HSA-Er-RI-Cl is a highly potent tumor-targeting NIR agent for noninvasive imaging with remarkable tumor localization and excellent pharmacokinetic properties.

Margin Analysis in Head and Neck Cancer: State of the Art and Future Directions

BACKGROUND

The status of surgical margins is the most important prognosticator for patients undergoing surgical resection of head and neck squamous cell carcinoma (HNSCC). Despite this, analysis of surgical margins is fraught with inconsistencies, including the ways in which margins are sampled and interpreted. Fundamentally, even the definition what constitutes a "clear" (or negative) margin may vary between institutions, surgeons, and pathologists.

METHODS

The PubMed database was queried for articles relevant to the topic, and experts in the field were consulted regarding key articles for inclusion. Abstracts were reviewed and the full text was accessed for articles of particular interest.

RESULTS

Data regarding various approaches to traditional margin analysis have been published without consensus. Several next-generation technologies have emerged in recent years that hold promise.

CONCLUSION

An overview and appraisal of traditional margin analysis techniques are provided. Additionally, we explore novel technologies that may assist in more accurate margin assessment, guide the extent of surgical resections intraoperatively, and inform decisions regarding adjuvant treatment postoperatively.

Acoustic Nanomotors for Detection of Human Papillomavirus-Associated Head and Neck Cancer

OBJECTIVE

Human papillomavirus (HPV)-associated oropharyngeal cancer (OPC) is a lethal disease with increasing incidence; however, technologies for early detection are limited. Nanomotors are synthetic nanostructures that can be powered by different mechanisms and functionalized for specific applications, such as biosensing. The objective of this investigation was to demonstrate an in vitro proof of concept for a novel nanomotor-based cancer detection approach toward in vivo detection of HPV-OPC.

STUDY DESIGN

In vitro cell line incubated with ultrasound-propelled nanomotors.

SETTING

Basic science and engineering laboratories.

SUBJECTS AND METHODS

Ultrasound-powered gold nanowire nanomotors were functionalized with graphene oxide and dye-labeled single-stranded DNA for the specific intracellular detection of HPV16 E6 mRNA transcripts. Nanomotors were incubated with HPV-positive or HPV-negative human OPC cells under static conditions or with an applied ultrasound field for 15 minutes. The resulting intracellular fluorescence was assessed with fluorescence microscopy and analysis software.

RESULTS

Nanomotors incubated with RNA extracted from HPV-positive OPC cells resulted in 60.7% of maximal fluorescence recovery, while incubation with RNA extracted from HPV-negative cells produced negligible fluorescence. Nanomotor incubation with intact HPV-negative cells produced minimal fluorescence (0.01 au), while incubation with HPV-positive cells produced a detectable signal (0.43 au) under static conditions and had 2.3-times greater intensity when powered with ultrasound.

CONCLUSION

Acoustically powered nanomotors can successfully identify HPV16 E6 mRNA transcripts extracellularly and within intact cells. This work represents the first step toward a novel, practical approach to address the challenge of visually detecting HPV-OPC in real time.

Surgical margins in oral squamous cell cancer: intraoperative evaluation and prognostic impact

PURPOSE OF REVIEW

To summarize recent findings regarding surgical management of oral squamous cell cancer (OSCC) through analysis of different intraoperative techniques for assessment of margins, evaluate the pros and cons of each, and ensuing prognostic impact.

RECENT FINDINGS

'En bloc' OSCC resection and histopathologic evaluation of margins on the formalin-fixed specimen remain the 'gold standard' for oral oncologic surgery, whereas assessment of intraoperative surgical margins and its overall clinical value are still questioned and debated in the literature. The commonly applied evaluation of frozen sections still raises concerns regarding its efficacy and reproducibility; therefore, several ancillary diagnostic methods have entered the field of head and neck oncology in the last decades, aiming to support the surgeon in achieving tumor-free margins during ablative procedures.

SUMMARY

Poor prognosis of OSCC is strongly associated with residual tumor after surgery. Negative surgical margins are one of the strongest prognosticators for disease-free survival and locoregional control, but their intraoperative determination seems still to be suboptimal and needs better refinement. The most studied techniques to assess intraoperative margins include fluorescence, Raman spectroscopy, narrow band imaging, optical coherence tomography, and cytological bone margins analysis; each has its unique characteristics that are described in detail herein.

Blood vessel detection, localization and estimation using a smart laparoscopic grasper: a Monte Carlo study

For centuries, surgeons have relied on their sense of touch to identify vital structures such as blood vessels in traditional open surgery. Over the past two decades, surgeons have shifted to minimally invasive surgical (MIS) approaches, including laparoscopic surgery, which include benefits such as less scarring, less risk for infection, and quicker recovery times. In fact, some surgeries such as cholecystectomies have seen more than an 80% adoption of this technique because of those benefits. However, due to the fundamental challenges associated with using laparoscopic surgery, there has been a lower adoption in more complex specialties, such as colorectal and thoracic surgery, where the field of surgery has bleeding, fat, scar tissue, and adhesions. These problems are exacerbated by complicating factors such as inflammation, cancer, chronic disease, obesity, and re-operations. Importantly, surgeons will often convert from laparoscopy to open surgery if they can no longer proceed using the minimally invasive approach because of issues described with these complicating factors, thereby negating the benefits that the patient would have seen. When the surgeon does attempt these procedures with those issues, the surgery takes on average 30 min - 1 hour longer. A new method by which surgeons can visualize structures like blood vessels could reduce the conversion rates and operating time, thereby driving a greater adoption of laparoscopic surgery in these complex procedures. Here, we show that by adding near infrared (NIR) LEDs and a linear image sensor onto the opposing jaws of the laparoscopic graspers, blood vessels that are embedded within tissues can be detected and localized efficiently, even those not visible using current imaging techniques. We show the results of Monte Carlo simulations to support our claim, including that blood vessels ranging from 2 to 6 mm and buried under up to 1 cm of tissue can be detected. We also report developing a smart grasper handheld prototype to run ex vivo experiments. The results of these experiments matched with those of the Monte Carlo simulations and the estimated blood vessel size showed a strong correlation with the actual size. This technology will be incorporated into already existing laparoscopic tools to assist surgeons during MIS procedures.

Trends in Surgical Research in Head and Neck Cancer

OPINION STATEMENT

The task of surgical research is to improve the efficacy of available surgical therapeutic modalities, develop new ones, and balance this well with favorable functional outcome. Therefore, surgical research is composed of a translational and a clinical component. In translational surgical research, animal models are used to better understand the biology of head and neck cancers, but even more importantly, the biology of changes to the disease and the microenvironment created by surgical interventions. Animal models additionally allow for the development of image-guided surgery systems, novel strategies of intraoperative adjuvant treatment, and patient "avatars" to test innovative anticancer drug combinations. In clinical surgical research, surgical techniques are validated in clinical trials for effectiveness of tumor control and improvement of functional recovery of the patient. In conclusion, surgical research for head and neck cancer is an active field spanning across the entire breadth of basic and clinical science devoted to a better understanding of what surgery does to the disease and to the patient.

Detection of Head and Neck Cancer in Surgical Specimens Using Quantitative Hyperspectral Imaging

Purpose: This study intends to investigate the feasibility of using hyperspectral imaging (HSI) to detect and delineate cancers in fresh, surgical specimens of patients with head and neck cancers.Experimental Design: A clinical study was conducted in order to collect and image fresh, surgical specimens from patients (N = 36) with head and neck cancers undergoing surgical resection. A set of machine-learning tools were developed to quantify hyperspectral images of the resected tissue in order to detect and delineate cancerous regions which were validated by histopathologic diagnosis. More than two million reflectance spectral signatures were obtained by HSI and analyzed using machine-learning methods. The detection results of HSI were compared with autofluorescence imaging and fluorescence imaging of two vital-dyes of the same specimens.Results: Quantitative HSI differentiated cancerous tissue from normal tissue in ex vivo surgical specimens with a sensitivity and specificity of 91% and 91%, respectively, and which was more accurate than autofluorescence imaging (P < 0.05) or fluorescence imaging of 2-NBDG (P < 0.05) and proflavine (P < 0.05). The proposed quantification tools also generated cancer probability maps with the tumor border demarcated and which could provide real-time guidance for surgeons regarding optimal tumor resection.Conclusions: This study highlights the feasibility of using quantitative HSI as a diagnostic tool to delineate the cancer boundaries in surgical specimens, and which could be translated into the clinic application with the hope of improving clinical outcomes in the future. Clin Cancer Res; 23(18); 5426-36. ©2017 AACR.