Tailored resections in oral and oropharyngeal cancer using narrow band imaging

MRI and frozen section evaluation of mylohyoid muscle in determining surgical approach for T2-T3 floor of the mouth cancer

PURPOSE

The choice of surgical approach for floor of the mouth (FOM) cancer, particularly for intermediate-stage tumors (cT2-cT3), remains controversial. This study aims to evaluate a method considering mylohyoid muscle (MM) invasion as a determinant for surgical approach selection, utilizing magnetic resonance imaging (MRI) preoperatively and frozen section (FS) analysis intraoperatively.

METHODS

This observational retrospective cohort study analyzed patients undergoing surgical resection of cT2 and cT3 FOM squamous cell carcinoma (SCC) between January 2013 and June 2023. MM infiltration assessed by preoperative MRI determined the surgical approach: clear infiltration led to compartmental surgery (CS), while doubtful or absent infiltration led to transoral surgery (TOS). Conversion from TOS to CS occurred intraoperatively based on macroscopic evidence or positive FS. Data collected included demographic, clinical, surgical, and pathological variables. Survival analysis was conducted using Kaplan-Meier method.

RESULTS

Among 44 patients included, majority had cT2 tumors (59.1%). MM resection was necessary in 22.7% of cases. Overall survival (OS) and progression-free survival (PFS) did not significantly differ between TOS and CS groups. Radiological depth of invasion (rDOI) < 10 mm is correlated with MM preservation in 89% of cases, while rDOI > 10 mm is correlated with MM resection only in 23.8% of cases. Pathological depth of invasion (pDOI) discrepancies were observed in the two groups: in CS group is shown a higher pDOI (> 10 mm) confirmation (90%). Surgical complications and functional outcomes differed between TOS and CS groups.

CONCLUSION

Considering MM invasion for surgical approach selection in cT2-cT3 FOM tumors appears oncologically safe, with better functional outcomes in muscle preservation. Preoperative MRI for MM assessment combined with intraoperative FS analysis provides reliable guidance for surgical decision-making.

Feasibility of an MR-based digital specimen for tongue cancer resection specimens: a novel approach for margin evaluation

Objective

This study explores the feasibility of ex-vivo high-field magnetic resonance (MR) imaging to create digital a three-dimensional (3D) representations of tongue cancer specimens, referred to as the "MR-based digital specimen" (MR-DS). The aim was to create a method to assist surgeons in identifying and localizing inadequate resection margins during surgery, a critical factor in achieving locoregional control.

Methods

Fresh resection specimens of nine tongue cancer patients were imaged in a 7 Tesla small-bore MR, using a high-resolution multislice and 3D T2-weighted Turbo Spin Echo. Two independent radiologists (R1 and R2) outlined the tumor and mucosa on the MR-images whereafter the outlines were configured to an MR-DS. A color map was projected on the MR-DS, mapping the inadequate margins according to R1 and R2. We compared the hematoxylin-eosin-based digital specimen (HE-DS), which is a histopathological 3D representation derived from HE stained sections, with its corresponding MR-images. In line with conventional histopathological assessment, all digital specimens were divided into five anatomical regions (anterior, posterior, craniomedial, caudolateral and deep central). Over- and underestimation 95th-percentile Hausdorff-distances were calculated between the radiologist- and histopathologist-determined tumor outlines. The MR-DS' diagnostic accuracy for inadequate margin detection (i.e. sensitivity and specificity) was determined in two ways: with conventional histopathology and HE-DS as reference.

Results

Using conventional histopathology as a reference, R1 achieved 77% sensitivity and 50% specificity, while R2 achieved 65% sensitivity and 57% specificity. When referencing to the HE-DS, R1 achieved 94% sensitivity and 61% specificity, while R2 achieved 88% sensitivity and 71% specificity. Range of over- and underestimation 95HD was 0.9 mm - 11.8 mm and 0.0 mm - 5.3 mm, respectively.

Conclusion

This proof of concept for volumetric assessment of resection margins using MR-DSs, demonstrates promising potential for further development. Overall, sensitivity is higher than specificity for inadequate margin detection, because of the radiologist's tendency to overestimate tumor size.

Intraoperative Imaging Techniques to Improve Surgical Resection Margins of Oropharyngeal Squamous Cell Cancer: A Comprehensive Review of Current Literature

Inadequate resection margins in head and neck squamous cell carcinoma surgery necessitate adjuvant therapies such as re-resection and radiotherapy with or without chemotherapy and imply increasing morbidity and worse prognosis. On the other hand, taking larger margins by extending the resection also leads to avoidable increased morbidity. Oropharyngeal squamous cell carcinomas (OPSCCs) are often difficult to access; resections are limited by anatomy and functionality and thus carry an increased risk for close or positive margins. Therefore, there is a need to improve intraoperative assessment of resection margins. Several intraoperative techniques are available, but these often lead to prolonged operative time and are only suitable for a subgroup of patients. In recent years, new diagnostic tools have been the subject of investigation. This study reviews the available literature on intraoperative techniques to improve resection margins for OPSCCs. A literature search was performed in Embase, PubMed, and Cochrane. Narrow band imaging (NBI), high-resolution microendoscopic imaging, confocal laser endomicroscopy, frozen section analysis (FSA), ultrasound (US), computed tomography scan (CT), (auto) fluorescence imaging (FI), and augmented reality (AR) have all been used for OPSCC. NBI, FSA, and US are most commonly used and increase the rate of negative margins. Other techniques will become available in the future, of which fluorescence imaging has high potential for use with OPSCC.

Postoperative Examination of Laryngeal Malignant Tumor Based on Narrowband Imaging Resolution Enhancement Technology

The application of endoscopic imaging in the biopsy of malignant laryngeal lesions is one of the current research hotspots in the medical field. Based on the narrowband imaging resolution enhancement technology, a model for postoperative examination of laryngeal malignant tumor was constructed in this paper. The article calculated the biopsy detection rate of malignant lesions and the correct biopsy detection rate of the two groups and made a statistical comparison. In the NBI mode group, the mucosal morphology and superficial mucosal microvascular morphology of the same lesion under two different modes of white light and NBI were compared, which solved the problem of data processing of cases. During the case comparison process, patients who needed biopsies to be sent for pathology were selected for inclusion in the study and were randomly divided into two groups. The coincidence rate of EUS combined with NBI diagnosis was significantly higher than that of ordinary white light gastroscopy (47.92%), and the difference was statistically significant (P=0.000 < 0.05). The experimental results compared the accuracy of the normal white light mode and the NBI mode to diagnose the nature of the lesions: according to the Kudo classification criteria, 23 cases of tumor lesions were to be diagnosed in the normal white light mode, with an accuracy rate of 69.70%, and the NBI mode was to be used to diagnose tumors. There were 81 cases of sexual lesions, with an accuracy rate of 93.94%. The NBI mode was more accurate in diagnosing the nature of the lesions under the Kudo classification standard (P < 0.05). In 64 cases, the accuracy rate was 63.63%. Under the NBI mode, 29 cases of tumor lesions were proposed to be diagnosed, and the accuracy rate was 87.88% to promote the application of NBI endoscopy in the biopsy of malignant laryngeal lesions.

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.

Post-operative outcomes of different surgical approaches to oropharyngeal squamous cell cancer: a case-matched study

OBJECTIVE

To compare the post-operative outcomes of transoral laser microsurgery, lateral pharyngotomy and transmandibular surgery in oropharyngeal cancer management.

METHODS

Records of 162 patients treated with transmandibular surgery, transoral laser microsurgery or lateral pharyngotomy were reviewed. The transoral laser microsurgery cohort was matched with the lateral pharyngotomy and transmandibular surgery cohorts for tumour stage, tumour subsite and human papilloma virus status, and the intra- and post-operative outcomes were compared.

RESULTS

Duration of surgery and hospital stay were significantly longer for transmandibular surgery. Tracheostomy and nasogastric feeding tube rates were similar, but time to decannulation and to oral feeding were longer in the transmandibular surgery group. Transmandibular surgery more frequently required flap reconstruction and had a greater complication rate. Negative margins were fewer in the lateral pharyngotomy group than in the transoral laser microsurgery and transmandibular surgery groups.

CONCLUSION

In comparison with transmandibular surgery, transoral laser microsurgery and lateral pharyngotomy were associated with fewer complications and faster functional recovery. Lateral pharyngotomy had a higher rate of positive margins than transoral laser microsurgery, with a consequently greater need for adjuvant therapy. Many patients are nonetheless unsuitable for transoral surgery. All these factors should be considered when deciding on oropharyngeal cancer surgical treatment.

Narrow-Band Imaging in oncologic otorhinolaryngology: State of the art

OBJECTIVES

To describe the diagnostic performance of Narrow Band Imaging (NBI) combined with White Light Imaging (WLI) in the diagnosis of mucosal lesions at each location of the upper aerodigestive tract, for detection of primary tumor in case of carcinoma of unknown primary, for determination of intraoperative resection margins, and to describe its main diagnostic pitfalls.

MATERIAL AND METHODS

A PubMed search was carried out according to the PRISMA method.

RESULTS

Four hundred and seventy-seven articles published between 2007 and 2020 were identified, 133 of which met the study inclusion criteria and were assessed.

CONCLUSION

The current literature seems to support the use of NBI in diagnosis and/or follow-up of (pre-)malignant head & neck tumors, and in the determination of intraoperative resection margins.

NBI utility in oncologic surgery: An organ by organ review

The main aims of the oncologic surgeon should be an early tumor diagnosis, complete surgical resection, and a careful post-treatment follow-up to ensure a prompt diagnosis of recurrence. Radiologic and endoscopic methods have been traditionally used for these purposes, but their accuracy might sometimes be suboptimal. Technological improvements could help the clinician during the diagnostic and therapeutic management of tumors. Narrow band imaging (NBI) belongs to optical image techniques, and uses light characteristics to enhance tissue vascularization. Because neoangiogenesis is a fundamental step during carcinogenesis, NBI could be useful in the diagnostic and therapeutic workup of tumors. Since its introduction in 2001, NBI use has rapidly spread in different oncologic specialties with clear advantages. There is an active interest in this topic as demonstrated by the thriving literature. It is unavoidable for clinicians to gain in-depth knowledge about the application of NBI to their specific field, losing the overall view on the topic. However, by looking at other fields of application, clinicians could find ideas to improve NBI use in their own specialty. The aim of this review is to summarize the existing literature on NBI use in oncology, with the aim of providing the state of the art: we present an overview on NBI fields of application, results, and possible future improvements in the different specialties.

An alternative to skin graft for superficial surgical defect in oral cancer surgery

Introduction

After surgery for oral cavity cancer, superficial surgical defects are usually covered with a skin graft that can be harvested with different thicknesses depending on the reconstructive need. Despite its popularity and efficacy, this solution has the disadvantage of excessive harvesting times and scarring of the donor site. Other surgeons have proposed the use of bovine pericardium as a reconstructive solution. Its use in otorhinolaryngology especially after oral cavity surgery has never been reported.

Objective

The aim of this manuscript is to present our preliminary experience with the use of a collagen membrane obtained from bovine pericardium in the reconstruction of small and superficial defects after transoral resection of oral cavity tumors.

Methods

A bovine collagen membrane was used to cover surgical defects in 19 consecutive patients undergoing transoral resection of small/superficial oral cancers. Photographs were obtained in the postoperative period to follow the healing process. We analyzed the pro and cons of this tool, recorded data on postoperative chewing-, speech- and taste-related quality of life, and tested the most appropriate settings providing the best reconstructive result.

Results

The bovine collagen membrane allowed us to cover surgical defects of varying size in different oral sites. Shaping and placement proved to be simple. The membrane facilitated physiologic tissue repair: after one month it was completely absorbed and replaced by the patient’s own mucosa. No adverse features were observed in the cohort.

Conclusion

A bovine collagen membrane can represent a fast and easy solution in cases of split-thickness defect. Unlike a skin graft, it is not associated with donor site morbidity and allows the patient’s own mucosa to be restored with a more physiological result.

Impact of dysplastic surgical margins for patients with oral squamous cell carcinoma

OBJECTIVES

Dysplastic changes at the surgical margin of oral squamous cell carcinoma (OSCC) could be encountered frequently. However, the impact of a dysplastic surgical margin on patients with OSCC remains unclear.

MATERIALS AND METHODS

Retrospectively, we reviewed patients with OSCC who were diagnosed and treated at the National Taiwan University Hospital between January 2010 and December 2015. Patients were divided into four groups: clear (≥5 mm), close (<5 mm), positive, and dysplastic margins.

RESULTS

Of 1642 patients, 596 had clear margin, 169 had positive margin, 707 had close margin, and 170 had dysplastic margin. The mean age at diagnosis was 55 ± 11 years (range, 16-97 years). Dysplastic margins were frequently present in patients with primary T1/T2 OSCC (odds ratio [OR] = 1.7, p = 0.009), tumor without perineural invasion (OR = 1.48, p = 0.04), and tumor thickness ≤10 mm (OR = 1.94, p = 0.001). In patients with clear, close, positive, and dysplastic margins, the 5-year disease-free survival rates were 63.1%, 51%, 37.2%, and 54.7%, respectively; overall survival (OS) rates were 71.1%, 61.9%, 49%, and 72%, respectively. Disease-free and overall survival were not significantly different in patients with dysplastic and clear margins (p = 0.37 and p = 0.38, respectively). Adjuvant radiotherapy had no significant benefit for patients with dysplastic margins. Finally, a multivariate analysis showed that the presence of a dysplastic margin was not an independent risk factor for disease-free (p = 0.43) and overall survival (p = 0.71).

CONCLUSIONS

The survival rates of the patients with OSCC who had dysplastic margin were significantly better than those with positive margin.

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.

How we improve the transoral resection for oral and oropharyngeal cancer: the CO2 waveguide laser

PURPOSE

The main aim of this study was to evaluate the CO₂ waveguide laser (CO₂ WGL) with flexible fiber (Lumenis, Santa Clara, CA) in the treatment of oral and oropharyngeal cancers specifically focusing on the lateral thermal damage (LTD) induced by this instrument and therefore on the reliability of the analysis of frozen sections collected during margin mapping.

METHODS

A total of 48 patients with oral and oropharyngeal cancers from T1 to T4a were prospectively enrolled in the study. We collected data about LTD, pathologic tumor and node stage (pTNM), surgical intervention, kind of reconstruction (no flap, local vs free flap), need for tracheotomy and time of removal, postoperative complications (such as bleeding, mucosal dehiscence, and fistula), need for feeding tube and time of removal.

RESULTS

Mean LTD was 164.7 ± 92.4 μm. Comparing frozen section histology before and after formalin embedding we found 5 true positives, 170 true negatives, 4 false positives and 4 false negatives, with a sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 55.6%, 98%, 55.6%, 98%, and 96.1%, respectively.

CONCLUSION

CO₂ WGL is a very manageable tool, which allows a precise cut. However, its high costs, the inability to re-use the fibers and its low coagulation capability must be considered.

A novel integrated platform for the identification of surgical margins in oral squamous cell carcinoma: results from a prospective single-institution series

BACKGROUND

The optimal surgical margins assessment is capital in oral squamous cell carcinoma (OSCC) management. We evaluated the clinical benefits of integrating intraoperative macroscopic margin (MM) assessment and narrow band imaging (NBI).

METHODS

Sixteen OSCC patients eligible for surgery were prospectively enrolled. For each patient, 2 to 6 bioptic samples of MM and NBI margins were obtained and histologically analyzed for the presence of dysplasia and lymphocytes. Microvessel density was investigated by CD34 immunohistochemistry.

RESULTS

Taken together, 104 specimens were analyzed, including 15% tumors, 33% MM, 33% NBI margins, and 19% MM-NBI overlapping margins. The NBI margins were closer to the lesion in 50% cases, while the same number of MM were more conservative than NBI, irrespective of the tumor site. The rate of histologically positive margins was similar among the two methods, akin to the microvessel density.

CONCLUSIONS

MM assessment should be integrated but not replaced with the NBI technology to allow for more conservative surgery.

Intraoperative Margin Control in Transoral Approach for Oral and Oropharyngeal Cancer

OBJECTIVES

Piecemeal resection provides an innovative conceptual tool for margins surveillance because it entails the intraoperative evaluation of the whole resection margins and not just sample points, which should result in a better control of deep margins compared to en bloc resection. Although it is recognized that the intraoperative use of narrow band imaging (NBI) results in a better control of superficial margins, in this exploratory study we investigated whether NBI and piecemeal resection could be used in combination to improve margin control at both superficial and deep levels. Because piecemeal resection is based on frozen section analysis, we wanted to verify its reliability compared to definitive histological examination.

METHODS

The status of resection margins in a group of patients with oral and oropharyngeal cancers treated with NBI and laser CO2 piecemeal resection (group 1) was compared with that of an historical group of patients (group 2) treated with NBI and conventional en bloc resection. In group 1, sensitivity, specificity, and positive and negative predictive values were used to verify the rate of concordance between frozen section and definitive histology.

RESULTS

The difference between deep positive margins in the two groups was statistically significant (P = 0.042). The high sensitivity and specificity (94.6% and 94.7%, respectively) of frozen section analysis also demonstrated its reliability in the examination of larger samples corresponding to the whole margin.

CONCLUSION

Even if our findings are limited by the small number of patients, we are confident that the combined use of NBI and piecemeal resection could represent an attractive surgical strategy to improve margin control.

LEVEL OF EVIDENCE

2b Laryngoscope, 129:1810-1815, 2019.

Transoral surgery (TOS) in oropharyngeal cancer: Different tools, a single mini-invasive philosophy

Surgery with or without adjuvant therapy and radiotherapy with or without chemotherapy have traditionally represented the possible treatment options for oropharyngeal cancer. The adverse effects of non-surgical treatments and recent technical innovations have prompted a new interest in the surgical approach. However, in parallel to the possibility of achieving radical cancer clearance, we should remember the impact that traditional open surgery has on the patient's cosmesis, functionality and quality of life. As a result, transoral surgery is an attractive option for oropharyngeal tumors. The term "transoral surgery" only indicates that the tumor is accessed and resected via the oral cavity, but the surgeon can choose among different resection methods, such as transoral laser microsurgery, transoral robotic surgery, transoral videolaryngoscopic surgery, endoscopic laryngo-pharyngeal surgery, and transoral ultrasound surgery. The aim of this paper is to review the recent literature on the transoral treatment of oropharyngeal cancer, to standardize the terminology of transoral procedures, analyzing the common aspects, main differences and future perspectives of the various forms of transoral surgery.