Patterns of recurrence in HNSCC patients treated definitively with upfront surgery, chemoradiation.

PURPOSE: Locally-advanced oropharynx (LA-OPSCC) and hypopharynx/larynx (LA-HPLSCC) cancers may be treated with surgical or non-surgical modalities. While survival outcomes are comparable, patterns of disease recurrence are not well established. METHODS: Retrospective review of 98 consecutive patients with LA-OPSCC or LA-HPLSCC treated by either surgery plus adjuvant therapy (S-POAT, n = 48) or chemoradiation (CRT, n = 50). RESULTS: CRT-treated patients had higher recurrence risk (42% vs 14.6%, p = 0.003). This was significant only among LA-OPSCC (p = 0.002) but not LA-HPLSCC patients (p = 0.159). Median time to recurrence in LA-OPSCC was 16.8 vs 11.6 months, and 16.6 vs 15.1 months in LA-HPLSCC, comparing surgically treated and CRT cohorts. Surgically-treated p16-negative LA-OPSCC experienced improved locoregional control than CRT-treated patients (100% vs 12.5%, p = 0.045) and 3-year RFS (83.0% vs 33.3%, p < 0.001). CONCLUSION: Locoregional control and RFS benefit was observed in surgically treated p16 negative LA-OPSCC patients. Locoregional recurrence is the main reason of treatment failure in LA-HNSCC, occurring commonly within the first 2 years post-treatment, regardless of treatment option.

Cell-free DNA and circulating tumor cell kinetics in a pre-clinical head and neck Cancer model undergoing radiation therapy.

BACKGROUND: Monitoring circulating tumor DNA (ctDNA) and circulating tumor cells (CTCs), known as liquid biopsies, continue to be developed as diagnostic and prognostic markers for a wide variety of cancer indications, mainly due to their minimally invasive nature and ability to offer a wide range of phenotypic and genetic information. While liquid biopsies maintain significant promising benefits, there is still limited information regarding the kinetics of ctDNA and CTCs following radiation therapy which remains a vital treatment modality in head and neck cancers. This study aims to describe the kinetics of ctDNA and CTCs following radiation exposure in a preclinical rabbit model with VX2 induced buccal carcinoma. METHODS: Seven rabbits were inoculated with VX2 cells in the buccal mucosa and subjected to radiation. At selected time points, blood sampling was performed to monitor differing levels of ctDNA and CTC. Plasma ctDNA was measured with quantitative PCR for papillomavirus E6 while CTCs were quantified using an immunomagnetic nanoparticles within a microfluidic device. Comparisons of CTC detection with EpCAM compared to multiple surface markers (EGFR, HER2 and PSMA) was evaluated and correlated with the tumor size. RESULTS: Plasma ctDNA reflects the overall tumor burden within the animal model. Analysis of correlations between ctDNA with tumor and lymph node volumes showed a positive correlation (R = 0.452 and R = 0.433 [p < 0.05]), respectively. Over the course of treatment, ctDNA levels declined and quickly becomes undetectable following tumor eradication. While during the course of treatment, ctDNA levels were noted to rise particularly upon initiation of radiation following scheduled treatment breaks. Levels of CTCs were observed to increase 1 week following inoculation of tumor to the primary site. For CTC detection, the use of multiple surface markers showed a greater sensitivity when compared to detection using only EpCAM. Plasma CTC levels remained elevated following radiation therapy which may account for an increased shedding of CTCs following radiation. CONCLUSION: This study demonstrates the utility of ctDNA and CTCs detection in response to radiation treatment in a preclinical head and neck model, allowing for better understanding of liquid biopsy applications in both clinical practice and research development.

Assessment of a liposomal CT/optical contrast agent for image-guided head and neck surgery.

This study evaluates a long-acting liposomal fluorescence / CT dual-modality contrast agent (CF800) in head and neck cancer to enhance intraoperative tumor demarcation with fluorescence imaging and cone-beam computed tomography (CBCT). CF800 was administered to 12 buccal cancer-bearing rabbits. Imaging was acquired at regular time points to quantify time-dependent contrast enhancement. Surgery was performed 5-7 days after, with intraoperative near-infrared fluorescence endoscopy and CBCT, followed by histological and ex-vivo fluorescence assessment. Tumor enhancement on CT was significant at 24, 96 and 120 hours. Volumetric analysis of tumor segmentation showed high correlation between CBCT and micro-CT. Fluorescence signal was apparent in both ex-vivo and in-vivo imaging. Histological correlation showed [100%] specificity for primary tumor. Sensitivity and specificity of CF800 in detecting nodal involvement require further investigation.CF800 is long acting and has dual function for CT and fluorescence contrast, making it an excellent candidate for image-guided surgery.

Histopathologic prognostic indices in tongue squamous cell carcinoma.

PURPOSE: Consistent prognosticators are needed to guide adjuvant treatment in tongue squamous cell carcinoma (SCC). We validate the prognostic significance of histopathologic parameters in surgically treated tongue SCC. METHODS: Archival specimens of 88 consecutive patients who were treated surgically for tongue SCC from 2003 to 2016 were re-analyzed by one pathologist. Patient records were retrospectively reviewed. Prognosticators of recurrence-free survival (RFS), overall survival (OS), and disease-specific survival (DSS) were identified using multivariate analysis. RESULTS: Tumor depth of invasion (DOI) > 6 mm (OR 4.76; 95%CI 1.22-18.5; p = 0.024) and lymphovascular invasion (OR 5.61; 95%CI 1.00-31.5; p = 0.05) were independent predictors of nodal metastases. The overall 5-year RFS, OS and DSS were 70%, 82% and 84% respectively. Positive margins predicted poor RFS (HR 3.91; 95%CI 1.58-9.65; p = 0.003) and local recurrence-free survival (HR 4.96; 95%CI 1.36-18; p = 0.015). Presence of nodal metastases (HR 5.03; 95%CI 1.73-14.6; p = 0.003), tumor DOI > 6 mm (HR 9.91; 95%CI 1.26-78.0; p = 0.029) and positive margins (HR 8.26; 95%CI 2.75-24.8; p < 0.001) were independent predictors of poor OS. Presence of nodal metastases (HR 3.87; 95%CI 1.17-12.8; p = 0.027) and positive margins (HR 12.3; 95%CI 3.54-42.9; p < 0.001) also independently predicted poor DSS. CONCLUSION: Margins' status was the only independent predictor of local recurrence. Tumor DOI, nodal and margin status were key prognosticators of survival and may determine the necessity for adjuvant therapy.

Sentinel lymph node mapping using ICG fluorescence and cone beam CT - a feasibility study in a rabbit model of oral cancer.

BACKGROUND: Current sentinel lymph node biopsy (SLNB) techniques, including use of radioisotopes, have disadvantages including the use of a radioactive tracer. Indocyanine green (ICG) based near-infrared (NIR) fluorescence imaging and cone beam CT (CBCT) have advantages for intraoperative use. However, limited literature exists regarding their use in head and neck cancer SLNB. METHODS: This was a prospective, non-randomized study using a rabbit oral cavity VX2 squamous cell carcinoma model (n = 10) which develops lymph node metastasis. Pre-operatively, images were acquired by MicroCT. During surgery, CBCT and NIR fluorescence imaging of ICG was used to map and guide the SLNB resection. RESULTS: Intraoperative use of ICG to guide fluorescence resection resulted in identification of all lymph nodes identified by pre-operative CT. CBCT was useful for near real time intraoperative imaging and 3D reconstruction. CONCLUSIONS: This pre-clinical study further demonstrates the technical feasibility, limitations and advantages of intraoperative NIR-guided ICG imaging for SLN identification as a complementary method during head and neck surgery.

Efficacy of Sialendoscopy in the Management of Noncalculi-Related Sialadenitis.

PURPOSE: Sialendoscopy has effectively changed the paradigm for the treatment of sialolithiasis. Its effect on noncalculi-related recurrent sialadenitis is, however, unclear, especially regarding the long-term outcomes. The objectives of the present study were to evaluate the long-term efficacy of sialendoscopy for noncalculi-related recurrent sialadenitis and determine the clinical and intraoperative features that might be prognosticate outcomes. PATIENTS AND METHODS: We performed a prospective cohort study of 33 consecutive patients who had undergone sialendoscopy for recurrent noncalculi-related sialadenitis by a single surgeon in a tertiary institution from January 2010 to December 2016. The patient-reported outcome measures were used as the primary determinant of treatment efficacy. The clinical features and endoscopic findings were evaluated as variables that might predict the treatment outcomes. The Fischer exact test was used to analyze the descriptive data, and a P value of < .05 was considered to indicate statistical significance. RESULTS: Of the 33 patients with recurrent noncalculi-related sialadenitis, 1 was lost to follow-up and thus excluded from the analysis. The mean and median follow-up period for the 32 patients was 27 and 21.5 months, respectively. Of the 33 patients, 28 (87.5%) reported symptom improvement, and 19 patients (59.4%) were symptom free after a single sialendoscopic treatment. The chronicity of symptoms, younger patient age, and concurrent autoimmune disease were predictive of recurrent symptoms despite sialendoscopy. CONCLUSIONS: The use of sialendoscopy achieved sustained long-term improvements or resolution of symptoms for most patients with recurrent noncalculi-related sialadenitis. The data from our study support the benefits of sialendoscopy for patients with recurrent noncalculi-related sialadenitis.

Evaluation of a 3D Printed Silicone Oral Cavity Cancer Model for Surgical Simulations.

Adequate surgical margins are essential in oral cancer treatment, this is, however, difficult to appreciate during training. With advances in training aids, we propose a silicone-based surgical simulator to improve training proficiency for the ablation of oral cavity cancers. A silicone-based tongue cancer model constructed via a 3D mold was compared to a porcine tongue model used as a training model. Participants of varying surgical experience were then asked to resect the tumors with clear margins, and thereafter asked to fill out a questionnaire to evaluate the face and content validity of the models as a training tool. Eleven participants from the Otolaryngology-Head and Neck Surgery unit were included in this pilot study. In comparison to the porcine model, the silicone model attained a higher face (4 vs. 3.6) and content validity (4.4 vs. 4.1). Tumor consistency was far superior in the silicone model compared to the porcine model (4.1 vs. 2.8, p = 0.0042). Fellows and staff demonstrated a better margin clearance compared to residents (median 3.5 mm vs. 1.0 mm), and unlike the resident group, there was no incidence of positive margins. The surgical simulation was overall useful for trainees to appreciate the nature of margin clearance in oral cavity cancer ablation.

Outcomes of SWI/SNF complex-deficient sinonasal carcinomas in a Southeast Asian cohort.

BACKGROUND: SWI/SNF complex-deficient sinonasal carcinomas are rare, genetically distinct, and aggressive entities. METHODS: SMARCB1 and SMARCA4 immunohistochemistry was retrospectively performed on a cohort of undifferentiated, poorly differentiated, and poorly defined sinonasal carcinomas. Survival outcomes were compared between SMARCB1/SMARCA4 (SWI/SNF complex)-deficient and -retained groups. RESULTS: Eight SWI/SNF complex-deficient (six SMARCB1-deficient, two SMARCA4-deficient) cases were identified among 47 patients over 12 years. Triple-modality treatment was more frequently utilized in SWI/SNF complex-deficient carcinomas than in SWI/SNF complex-retained carcinomas (71.4% vs. 11.8%, p = 0.001). After a median follow-up of 21.3 (IQR 9.9-56.0) months, SWI/SNF complex-deficient sinonasal carcinomas showed comparable recurrence rates (57.1% vs. 52.9%, p = 0.839), time-to-recurrence (7.3 [IQR 6.6-8.3] vs. 9.1 [IQR 3.9-17.4] months, p = 0.531), and overall survival (17.7 [IQR 11.8-67.0] vs. 21.6 [IQR 8.9-56.0] months, p = 0.835) compared to SWI/SNF complex-retained sinonasal carcinomas. CONCLUSION: Triple-modality treatment may improve survival in SWI/SNF complex-deficient sinonasal carcinomas.

Clinical performance of a prefabricated immunofluorescence assay for nasopharyngeal cancer screening.

BACKGROUND: Epstein-Barr virus (EBV) IgA serology for viral capsid antigen (VCA) and early antigen (EA) aids early detection of nasopharyngeal cancer (NPC), resulting in improved survival. We evaluated the diagnostic performance of a prefabricated immunofluorescent assay (IFA) for NPC screening in high-risk individuals. METHODS: Sera from 96 biopsy-proven patients with NPC diagnosed at the outpatient clinic and 96 healthy family members were tested for EBV-VCA IgA and EBV-EA IgA using the prefabricated IFA from EUROIMMUN (EI) and the traditional immunofluorescence method. RESULTS: The AUC of EI EBV-VCA IgA and EBV-EA IgA was 0.907 (95% confidence interval [CI]: 0.894-0.965) and 0.898 (95% CI: 0.848-0.947), respectively. Combined testing with the prefabricated assay at a threshold of VCA ≥1:320 or EA ≥1:10 showed 92.7% sensitivity and 81.2% specificity. Overall, the traditional EBV-EA IgA assay demonstrated the best accuracy (sensitivity 91.7% and specificity 96.9%) at a threshold of ≥1:5. CONCLUSION: While the traditional IFA method was more accurate, the prefabricated IFA test kit can be a useful tool for NPC screening in high-risk populations.

Nanoparticle-mediated Photodynamic Therapy as a Method to Ablate Oral Cavity Squamous Cell Carcinoma in Preclinical Models.

Photodynamic therapy (PDT) is a tissue ablation technique able to selectively target tumor cells by activating the cytotoxicity of photosensitizer dyes with light. PDT is nonsurgical and tissue sparing, two advantages for treatments in anatomically complex disease sites such as the oral cavity. We have previously developed PORPHYSOME (PS) nanoparticles assembled from chlorin photosensitizer-containing building blocks (∼94,000 photosensitizers per particle) and capable of potent PDT. In this study, we demonstrate the selective uptake and curative tumor ablation of PS-enabled PDT in three preclinical models of oral cavity squamous cell carcinoma (OCSCC): biologically relevant subcutaneous Cal-33 (cell line) and MOC22 (syngeneic) mouse models, and an anatomically relevant orthotopic VX-2 rabbit model. Tumors selectively uptake PS (10 mg/kg, i.v.) with 6-to 40-fold greater concentration versus muscle 24 hours post-injection. Single PS nanoparticle-mediated PDT (PS-PDT) treatment (100 J/cm2, 100 mW/cm2) of Cal-33 tumors yielded significant apoptosis in 65.7% of tumor cells. Survival studies following PS-PDT treatments demonstrated 90% (36/40) overall response rate across all three tumor models. Complete tumor response was achieved in 65% of Cal-33 and 91% of MOC22 tumor mouse models 14 days after PS-PDT, and partial responses obtained in 25% and 9% of Cal-33 and MOC22 tumors, respectively. In buccal VX-2 rabbit tumors, combined surface and interstitial PS-PDT (200 J total) yielded complete responses in only 60% of rabbits 6 weeks after a single treatment whereas three repeated weekly treatments with PS-PDT (200 J/week) achieved complete ablation in 100% of tumors. PS-PDT treatments were well tolerated by animals with no treatment-associated toxicities and excellent cosmetic outcomes. SIGNIFICANCE: PS-PDT is a safe and repeatable treatment modality for OCSCC ablation. PS demonstrated tumor selective uptake and PS-PDT treatments achieved reproducible efficacy and effectiveness in multiple tumor models superior to other clinically tested photosensitizer drugs. Cosmetic and functional outcomes were excellent, and no clinically significant treatment-associated toxicities were detected. These results are enabling of window of opportunity trials for fluorescence-guided PS-PDT in patients with early-stage OCSCC scheduled for surgery.

Hydrogel-chitosan and polylactic acid-polycaprolactone bioengineered scaffolds for reconstruction of mandibular defects: a preclinical in vivo study with assessment of translationally relevant aspects.

Background: Reconstruction of mandibular bone defects is a surgical challenge, and microvascular reconstruction is the current gold standard. The field of tissue bioengineering has been providing an increasing number of alternative strategies for bone reconstruction. Methods: In this preclinical study, the performance of two bioengineered scaffolds, a hydrogel made of polyethylene glycol-chitosan (HyCh) and a hybrid core-shell combination of poly (L-lactic acid)/poly ( ε -caprolactone) and HyCh (PLA-PCL-HyCh), seeded with different concentrations of human mesenchymal stromal cells (hMSCs), has been explored in non-critical size mandibular defects in a rabbit model. The bone regenerative properties of the bioengineered scaffolds were analyzed by in vivo radiological examinations and ex vivo radiological, histomorphological, and immunohistochemical analyses. Results: The relative density increase (RDI) was significantly more pronounced in defects where a scaffold was placed, particularly if seeded with hMSCs. The immunohistochemical profile showed significantly higher expression of both VEGF-A and osteopontin in defects reconstructed with scaffolds. Native microarchitectural characteristics were not demonstrated in any experimental group. Conclusion: Herein, we demonstrate that bone regeneration can be boosted by scaffold- and seeded scaffold-reconstruction, achieving, respectively, 50% and 70% restoration of presurgical bone density in 120 days, compared to 40% restoration seen in spontaneous regeneration. Although optimization of the regenerative performance is needed, these results will help to establish a baseline reference for future experiments.

Efficacy of computed tomographic scans in the evaluation of patients with esophageal foreign bodies.

OBJECTIVES: This study aimed to determine whether computed tomographic (CT) scans on which foreign body impaction cannot be detected can be relied upon to decide whether a patient requires further investigation by esophagoscopy. This information might minimize unnecessary esophagoscopy without incurring the risk of a missed impacted foreign body. METHODS: In a retrospective chart review of all patients admitted to National University Hospital, Singapore, over the period 2004 to 2011 for an ingested foreign body, case files of patients who underwent preoperative CT scanning followed by esophagoscopy were identified and reviewed. The results of the CT scan and the findings of esophagoscopy in these patients were analyzed. RESULTS: A total of 376 patients underwent rigid esophagoscopy for an ingested foreign body during this period. Of these, 119 patients had CT scans performed before the endoscopy. Based on our analysis, the sensitivity of CT scanning was 100%, and the specificity was 70.6%. The positive predictive value was 89.5%, and the negative predictive value was 100%. None of the patients who had CT scans with no detectable foreign body had complications on follow-up. CONCLUSIONS: CT scanning appeared to be sensitive and specific in investigation of patients with an ingested foreign body. It also has a high negative predictive value, which may allow it to be the only preliminary investigation in these patients. Based on these data, a prospective study with close monitoring of patients who have CT scans with no detectable foreign body can be designed to accrue more patients to answer this query.

Projected cutting guides using an augmented reality system to improve surgical margins in maxillectomies: A preclinical study.

BACKGROUND: Positive margins have been reported up to 80% in advanced maxillary cancers. Intraoperative navigation (IN) aims to improve margins, but provides a two-dimensional view of a registered instrument without anticipating any cutting directions, and the information is displayed in monitors outside surgical field. Augmented Reality (AR) can delineate margins while addressing the gaze-toggling drawback of IN. In a preclinical setting, we implemented preoperative-planned osteotomies needed for maxillectomies and projected this information on the surgical field using AR. We aimed to improve negative margin rates while retaining the benefits of AR. METHODS: Five maxillary tumor models were built. Five fellowship-trained surgeons completed virtual unguided and AR-guided maxillectomies. Comparisons in terms of intratumoral cuts, close, adequate, and excessive distances from the tumor were performed. Differences between "ideal" cutting-plan and the AR-guided virtual osteotomies was obtained. Workload questionnaires to evaluate the technology were completed. RESULTS: 115 virtual osteotomies were analyzed. Intra-tumoral and "close" margins were lower for the AR-assisted osteotomies (0.0% vs 1.9% p < 0.0001 and 0.8% vs 7.9% p < 0.0001). Proportion of "adequate" margins were higher in the AR simulations (25.3% vs 18.6%, p = 0.018). The AR osteotomies had high similarity with the pre-planned with interclass correlation index close to 1 in "adequate" margins 0.893 (95% CI: 0.804-0.949). Workload scores were better for AR-guided simulations for the domains of mental demand, performance, effort and frustration. CONCLUSION: The projector-based AR method improved margin delineation, and preoperative planning was accurately translated to the simulations. Clinical translation will aim to consolidate our preclinical findings to improve outcomes.

The MUSES∗: a prognostic study on 1360 patients with sinonasal cancer undergoing endoscopic surgery-based treatment: ∗MUlti-institutional collaborative Study on Endoscopically treated Sinonasal cancers.

BACKGROUND: Over the last 2 decades, transnasal endoscopic surgery (TES) has become the most frequently employed surgical technique to treat sinonasal malignancies. The rarity and heterogeneity of sinonasal cancers have hampered large non-population-based analyses. METHODOLOGY: All patients receiving TES-including treatment between 1995 and 2021 in 5 referral hospitals were included. A prognostic study was performed, and multivariable models were transformed into nomograms. Training and validation sets were based on results from 3 European and 2 non-European centres, respectively. RESULTS: The training and validation set included 940 and 420 patients, respectively. The mean age at surgery, primary-versus-recurrent presentation, histology distribution, type of surgery, T category and type of adjuvant treatment were differently distributed in the training and validation set. In the training set, 5-year overall survival and recurrence-free survival with a 95%-confidence interval were 72.7% (69.5-76.0%) and 66.4% (63.1-69.8%), respectively, significantly varying with histology. At multivariable analyses, age, gender, previous treatment, the extent of resection on the cranial, lateral and posterolateral axes, grade/subtype, T category, nodal status, margin status and adjuvant treatment were all associated with different prognostic outcomes, displaying a heterogeneous significance and effect size according to histology. The internal and external validation of nomograms was satisfactory (optimism-corrected C-index >0.7 and cumulative area under curve >0.7) for all histologies but mucosal melanoma. CONCLUSIONS: Outcomes of TES-based treatment of sinonasal cancers vary substantially with histology. This large, non-population-based study provides benchmark data on the prognosis of sinonasal cancers that are deemed suitable for treatment including TES.

An ex vivo platform to guide drug combination treatment in relapsed/refractory lymphoma.

Although combination therapy is the standard of care for relapsed/refractory non-Hodgkin's lymphoma (RR-NHL), combination treatment chosen for an individual patient is empirical, and response rates remain poor in individuals with chemotherapy-resistant disease. Here, we evaluate an experimental-analytic method, quadratic phenotypic optimization platform (QPOP), for prediction of patient-specific drug combination efficacy from a limited quantity of biopsied tumor samples. In this prospective study, we enrolled 71 patients with RR-NHL (39 B cell NHL and 32 NK/T cell NHL) with a median of two prior lines of treatment, at two academic hospitals in Singapore from November 2017 to August 2021. Fresh biopsies underwent ex vivo testing using a panel of 12 drugs with known efficacy against NHL to identify effective single and combination treatments. Individualized QPOP reports were generated for 67 of 75 patient samples, with a median turnaround time of 6 days from sample collection to report generation. Doublet drug combinations containing copanlisib or romidepsin were most effective against B cell NHL and NK/T cell NHL samples, respectively. Off-label QPOP-guided therapy offered at physician discretion in the absence of standard options (n = 17) resulted in five complete responses. Among patients with more than two prior lines of therapy, the rates of progressive disease were lower with QPOP-guided treatments than with conventional chemotherapy. Overall, this study shows that the identification of patient-specific drug combinations through ex vivo analysis was achievable for RR-NHL in a clinically applicable time frame. These data provide the basis for a prospective clinical trial evaluating ex vivo-guided combination therapy in RR-NHL.

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.

Navigation-Guided Transnasal Endoscopic Delineation of the Posterior Margin for Maxillary Sinus Cancers: A Preclinical Study.

BACKGROUND: The resection of advanced maxillary sinus cancers can be challenging due to the anatomical proximity to surrounding critical anatomical structures. Transnasal endoscopy can effectively aid the delineation of the posterior margin of resection. Implementation with 3D-rendered surgical navigation with virtual endoscopy (3D-SNVE) may represent a step forward. This study aimed to demonstrate and quantify the benefits of this technology. MATERIAL AND METHOD: Four maxillary tumor models with critical posterior extension were created in four artificial skulls (Sawbones®). Images were acquired with cone-beam computed tomography and the tumor and carotid were contoured. Eight head and neck surgeons were recruited for the simulations. Surgeons delineated the posterior margin of resection through a transnasal approach and avoided the carotid while establishing an adequate resection margin with respect to tumor extirpation. Three simulations were performed: 1) unguided: based on a pre-simulation study of cross-sectional imaging; 2) tumor-guided: guided by real-time tool tracking with 3D tumor and carotid rendering; 3) carotid-guided: tumor-guided with a 2-mm alert cloud surrounding the carotid. Distances of the planes from the carotid and tumor were classified as follows and the points of the plane were classified accordingly: "red": through the carotid artery; "orange": <2 mm from the carotid; "yellow": >2 mm from the carotid and within the tumor or <5 mm from the tumor; "green": >2 mm from the carotid and 5-10 mm from the tumor; and "blue": >2 mm from the carotid and >10 mm from the tumor. The three techniques (unguided, tumor-guided, and carotid-guided) were compared. RESULTS: 3D-SNVE for the transnasal delineation of the posterior margin in maxillary tumor models significantly improved the rate of margin-negative clearance around the tumor and reduced damage to the carotid artery. "Green" cuts occurred in 52.4% in the unguided setting versus 62.1% and 64.9% in the tumor- and carotid-guided settings, respectively (p < 0.0001). "Red" cuts occurred 6.7% of the time in the unguided setting versus 0.9% and 1.0% in the tumor- and carotid-guided settings, respectively (p < 0.0001). CONCLUSIONS: This preclinical study has demonstrated that 3D-SNVE provides a substantial improvement of the posterior margin delineation in terms of safety and oncological adequacy. Translation into the clinical setting, with a meticulous assessment of the oncological outcomes, will be the proposed next step.

Augmented Reality and Intraoperative Navigation in Sinonasal Malignancies: A Preclinical Study.

OBJECTIVE: To report the first use of a novel projected augmented reality (AR) system in open sinonasal tumor resections in preclinical models and to compare the AR approach with an advanced intraoperative navigation (IN) system. METHODS: Four tumor models were created. Five head and neck surgeons participated in the study performing virtual osteotomies. Unguided, AR, IN, and AR + IN simulations were performed. Statistical comparisons between approaches were obtained. Intratumoral cut rate was the main outcome. The groups were also compared in terms of percentage of intratumoral, close, adequate, and excessive distances from the tumor. Information on a wearable gaze tracker headset and NASA Task Load Index questionnaire results were analyzed as well. RESULTS: A total of 335 cuts were simulated. Intratumoral cuts were observed in 20.7%, 9.4%, 1.2,% and 0% of the unguided, AR, IN, and AR + IN simulations, respectively (p < 0.0001). The AR was superior than the unguided approach in univariate and multivariate models. The percentage of time looking at the screen during the procedures was 55.5% for the unguided approaches and 0%, 78.5%, and 61.8% in AR, IN, and AR + IN, respectively (p < 0.001). The combined approach significantly reduced the screen time compared with the IN procedure alone. CONCLUSION: We reported the use of a novel AR system for oncological resections in open sinonasal approaches, with improved margin delineation compared with unguided techniques. AR improved the gaze-toggling drawback of IN. Further refinements of the AR system are needed before translating our experience to clinical practice.

Defining a cohort of oligometastatic nasopharyngeal carcinoma patients with improved clinical outcomes.

OBJECTIVES: To compare the clinical outcomes of oligometastatic versus widely metastatic NPC patients. MATERIALS AND METHODS: Retrospective review of 157 patients with metastatic NPC at a tertiary hospital was performed. Multivariate analysis was carried out to compare the overall and progression-free survival (OS and PFS) of these two cohorts of NPC patients. The number of organ involvement and discrete metastatic lesions associated with improved OS and PFS were ascertained. RESULTS: Patients with oligometastatic NPC (single organ, less than six discrete metastatic lesions) had a better median OS than patients with widespread metastasis (24.8 versus 12.8 months, P < .001). Similarly, the median PFS of oligometastatic NPC was better than that of polymetastatic NPC (11.7 versus 7.3 months, P < .001). CONCLUSION: Single organ disease with less than six discrete lesions is a good indicator of limited metastatic load in NPC, and is associated with improved survival.