Dynamic optical contrast imaging as a novel modality for rapidly distinguishing head and neck squamous cell carcinoma from surrounding normal tissue

Real-Time Intraoperative Detection of Margins for Oral Cavity Squamous Cell Carcinoma

Obtaining negative surgical cancer margins is the strongest predictor for the long-term survival of oral cavity squamous cell carcinoma patients. To verify that the tumor has been completely removed, surgeons rely on pathologic evaluation of frozen sections to determine surgical margins, which can be time-consuming and subjective. Herein, we detail the real-time intraoperative use of dynamic optical contrast imaging (DOCI), a novel imaging modality that rapidly distinguishes head and neck cancer from healthy adjacent tissues based on fluorescence decay information from spectral bands in the UV-VIS range. Analysis of DOCI revealed microscopic characterization sufficient for tissue type identification consistent with histology (p < .05). DOCI delivers a clinically relevant tool that may better inform and drive precision surgery, directly impacting surgical outcomes and improving overall survival for our patients.

Immediate resection of positive margins improves local control in oral tongue cancer

OBJECTIVES

This study investigates the impact of immediate resection of positive margins on local control of oral tongue cancer.

MATERIALS AND METHODS

We analyzed 273 consecutive oral tongue cancers resected from 2013 to 2018. Additional resection was performed in cases during the initial operation based on surgeon inspection of the specimen and/or frozen margins. Positive margins were defined as invasive carcinoma/high-grade dysplasia < 1 mm from the inked edge. Patients were grouped as follows: negative margin (Group 1); positive margin with immediate additional tissue resection (Group 2); and positive margin without additional tissue resection (Group 3).

RESULTS

Overall, the rate of local recurrence was 7.7 % (21/273), and the rate of positive main specimen margin was 17.9 %. Of these patients, 38.8 % (19/49) underwent immediate additional resection of the presumed positive margin. Group 3 had higher local recurrence rates than Group 1 after adjustment for T-stage (aHR 2.8 [95 % CI 1.0-7.7], p = 0.04). Group 2 had similar rates of local recurrence (aHR 0.45 [95 % CI 0.06-3.6], p = 0.45). Three year local recurrence free survival for Groups 1, 2, and 3 were 91 %, 92 % and 73 %, respectively. Compared to the main specimen margin, sensitivity of intraoperative frozen tumor bed margins was 17.4 %, and specificity was 95 %.

CONCLUSION

In patients with positive main specimen margins, anticipation and detection in real-time with immediate additional tissue resection reduced local recurrence to rates similar to those with negative main specimen margins. These findings support the use of technology to provide real-time intraoperative margin data and guide additional resection for improved local control.

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.

Label-free, real-time detection of perineural invasion and cancer margins in a murine model of head and neck cancer surgery

Surgical management of head and neck cancer requires a careful balance between complete resection of malignancy and preservation of function. Surgeons must also determine whether to resect important cranial nerves that harbor perineural invasion (PNI), as sacrificing nerves can result in significant morbidity including facial paralysis. Our group has previously reported that Dynamic Optical Contrast Imaging (DOCI), a novel non-invasive imaging system, can determine margins between malignant and healthy tissues. Herein, we use an in vivo murine model to demonstrate that DOCI can accurately identify cancer margins and perineural invasion, concordant with companion histology. Eight C3H/HeJ male mice were injected subcutaneously into the bilateral flanks with SCCVIISF, a murine head and neck cancer cell line. DOCI imaging was performed prior to resection to determine margins. Both tumor and margins were sent for histologic sectioning. After validating that DOCI can delineate HNSCC margins, we investigated whether DOCI can identify PNI. In six C3H/HeJ male mice, the left sciatic nerve was injected with PBS and the right with SCCVIISF. After DOCI imaging, the sciatic nerves were harvested for histologic analysis. All DOCI images were acquired intraoperatively and in real-time (10 s per channel), with an operatively relevant wide field of view. DOCI values distinguishing cancer from adjacent healthy tissue types were statistically significant (P < 0.05). DOCI imaging was also able to detect perineural invasion with 100% accuracy compared to control (P < 0.05). DOCI allows for intraoperative, real-time visualization of malignant and healthy tissue margins and perineural invasion to help guide tumor resection.

Intraoperative In Vivo Imaging Modalities in Head and Neck Cancer Surgical Margin Delineation: A Systematic Review

Surgical margin status is one of the strongest prognosticators in predicting patient outcomes in head and neck cancer, yet head and neck surgeons continue to face challenges in the accurate detection of these margins with the current standard of care. Novel intraoperative imaging modalities have demonstrated great promise for potentially increasing the accuracy and efficiency in surgical margin delineation. In this current study, we collated and analyzed various intraoperative imaging modalities utilized in head and neck cancer to evaluate their use in discriminating malignant from healthy tissues. The authors conducted a systematic database search through PubMed/Medline, Web of Science, and EBSCOhost (CINAHL). Study screening and data extraction were performed and verified by the authors, and more studies were added through handsearching. Here, intraoperative imaging modalities are described, including optical coherence tomography, narrow band imaging, autofluorescence, and fluorescent-tagged probe techniques. Available sensitivities and specificities in delineating cancerous from healthy tissues ranged from 83.0% to 100.0% and 79.2% to 100.0%, respectively, across the different imaging modalities. Many of these initial studies are in small sample sizes, with methodological differences that preclude more extensive quantitative comparison. Thus, there is impetus for future larger studies examining and comparing the efficacy of these intraoperative imaging technologies.

John MA, Stafsudd O. Ex vivo hypercellular parathyroid gland differentiation using dynamic optical contrast imaging (DOCI)

Primary hyperparathyroidism, often caused by a single adenoma (80-85%) or four-gland hyperplasia (10-15%), can lead to elevated parathyroid hormone (PTH) levels and resultant hypercalcemia. Surgical excision of offending lesions is the standard of care, as the removal of pathologic adenomas reduces PTH and calcium values to baseline. The small size, variable location, and indistinct external features of parathyroid glands can make their identification quite challenging intraoperatively. Our group has developed the dynamic optical contrast imaging (DOCI) technique, a novel realization of dynamic temporally dependent measurements of tissue autofluorescence. In this study, we evaluated the efficacy of using the DOCI technique and normalized steady-state fluorescence intensity data for differentiating types of human parathyroid and thyroid tissues. We demonstrate that the DOCI technique has the capability to distinguish normal parathyroid tissue from diseased parathyroid glands as well as from adjacent healthy thyroid and adipose tissue across 8 different spectral channels between 405nm-600nm (p<0.05). Patient tissue DOCI data was further analyzed with a logistic regression classifier trained across the 8 spectral channels. After computer training, the computer-aided identification was able to accurately locate hypercellular parathyroid tissue with 100% sensitivity and 98.8% specificity within the captured DOCI image.

Assessment of the deep resection margin during oral cancer surgery: A systematic review

The main challenge for radical resection in oral cancer surgery is to obtain adequate resection margins. Especially the deep margin, which can only be estimated based on palpation during surgery, is often reported inadequate. To increase the percentage of radical resections, there is a need for a quick, easy, minimal invasive method, which assesses the deep resection margin without interrupting or prolonging surgery. This systematic review provides an overview of technologies that are currently being studied with the aim of fulfilling this demand. A literature search was conducted through the databases Medline, Embase and the Cochrane Library. A total of 62 studies were included. The results were categorized according to the type of technique: 'Frozen Section Analysis', 'Fluorescence', 'Optical Imaging', 'Conventional imaging techniques', and 'Cytological assessment'. This systematic review gives for each technique an overview of the reported performance (accuracy, sensitivity, specificity, positive predictive value, negative predictive value, or a different outcome measure), acquisition time, and sampling depth. At the moment, the most prevailing technique remains frozen section analysis. In the search for other assessment methods to evaluate the deep resection margin, some technologies are very promising for future use when effectiveness has been shown in larger trials, e.g., fluorescence (real-time, sampling depth up to 6 mm) or optical techniques such as hyperspectral imaging (real-time, sampling depth few mm) for microscopic margin assessment and ultrasound (less than 10 min, sampling depth several cm) for assessment on a macroscopic scale.

Imaging-based navigation technologies in head and neck surgery

PURPOSE OF REVIEW

Image guided navigation has had significant impact in head and neck surgery, and has been most prolific in endonasal surgeries. Although conventional image guidance involves static computed tomography (CT) images attained in the preoperative setting, the continual evolution of surgical navigation technologies is fast expanding to incorporate both real-time data and bioinformation that allows for improved precision in surgical guidance. With the rapid advances in technologies, this article allows for a timely review of the current and developing techniques in surgical navigation for head and neck surgery.

RECENT FINDINGS

Current advances for cross-sectional-based image-guided surgery include fusion of CT with other imaging modalities (e.g., magnetic resonance imaging and positron emission tomography) as well as the uptake in intraoperative real-time 'on the table' imaging (e.g., cone-beam CT). These advances, together with the integration of virtual/augmented reality, enable potential enhancements in surgical navigation. In addition to the advances in radiological imaging, the development of optical modalities such as fluorescence and spectroscopy techniques further allows the assimilation of biological data to improve navigation particularly for head and neck surgery.

SUMMARY

The steady development of radiological and optical imaging techniques shows great promise in changing the paradigm of head and neck surgery.

John MA. Detection of surgical margins in oral cavity cancer: the role of dynamic optical contrast imaging

PURPOSE OF REVIEW

The quantity of tissue removed during an oncologic surgical procedure is not standardized and there are numerous reports of local recurrence despite histologically adequate resection margins. The oral cavity is one of the sites in the head and neck with high chances of recurrence following negative margins. To address this need, this article reviews the recent applications of Dynamic Optical Contrast Imaging (DOCI) towards both oral screening and the intraoperative evaluation of tumor margins in head and neck surgery.

RECENT FINDINGS

Human ex-vivo and in-vivo trials suggest DOCI is well tolerated, low-cost, and sensitive for differentiating cancerous from normal tissues throughout the head and neck, in addition to the oral cavity. Ex-vivo imaging of OSCC specimens generated histologically verified image contrast. Furthermore, in-vivo intraoperative results demonstrate significant potential for image-guided detection and resection of oral cavity squamous cell carcinoma (OSCC).

SUMMARY

DOCI augments tissue contrast and may enable surgeons to clinically screen patients for oral cancer, make histologic evaluations in vivo with fewer unnecessary biopsies, delineate clinical margins for tumor resection, provide guidance in the choice of biopsy sites, and preserve healthy tissue to increase the postoperative functionality and quality of life of the patient.