EGFR-targeted fluorescence molecular imaging for intraoperative margin assessment in oral cancer patients: a phase II trial

First-in-Human Study of ABY-029, a Novel Fluorescent Peptide that Targets EGFR, Applied to Soft-Tissue Sarcomas

ABY-029, an anti-EGFR Affibody molecule conjugated to IRDye 800CW, recently underwent first-in-human testing in soft-tissue sarcoma. The FDA Exploratory Investigational New Drug status was obtained for the phase 0 clinical trial in which study objectives were to determine whether a biological variance ratio (BVR) of 10 was achievable, whether fluorescence intensity correlated with EGFR expression, and whether doses were well tolerated. Patients (N = 12) with soft-tissue sarcoma were recruited based on positive EGFR IHC staining of diagnostic biopsies. ABY-029 was administered at a microdose (30 nmol, n = 3), medium dose (90 nmol, n = 3), or high dose (171 nmol, n = 6) 1 to 3 hours prior to surgery. Following tumor resection, ex vivo tissue was imaged to determine the mean fluorescence intensity, BVR, and other contrast measures. EGFR expression was correlated with IHC. For micro, medium, and high doses, mean BVR (SD) values in cross-sectional slices were 4 (4), 10 (6), and 7 (8) for the whole tumor region and 6 (5), 13 (11), and 8 (6) for pathology-confirmed regions of interest, respectively. Strong linear correlations were found between all ABY-029 contrast metrics and total EGFR (r≥ 0.86; P < 0.029) in cross-sectional tissue slices and between mean fluorescence intensity and EGFR percent area (r = 0.63; P < 0.0001) in excised region-of-interest tissue sections. No ABY-029-related adverse events were observed. When administered above the microdose, ABY-029 demonstrated a high correlation with EGFR expression and contrast values that were encouraging for translation to clinical practice. Contrast values were similar to those observed with antibody agents but with a substantially reduced imaging-to-resection time and no drug-related adverse events.

Background Tissue with Native Target Expression Can Determine Presence of Nodal Metastasis in Head and Neck Squamous Cell Carcinoma Patients Infused with Targeted Fluorescent Tracers

PURPOSE

Survival and treatment intensity in patients with head and neck squamous cell carcinoma (HNSCC) is determined by the presence of lymph node (LN) metastasis, and as a result surgical removal of potentially affected LN remains a mainstay practice. Fluorescence guided surgery (FGS) using targeted optical agents is an expanding field that shows great potential for aiding diagnosis of metastatic LN. Given variations in fluorescence background, a reference standard for regions of interest is necessary for cross patient comparison. The present study aims to determine whether tissue with native target expression can be used as a background to determine metastatic LN in patients with HNSCC infused with anti-epidermal growth factor receptor (EGFR) targeted imaging agents.

PROCEDURES

Twenty-two patients infused with panitumumab-IRDye800 or cetuximab-IRDye800 prior to surgery were included. Fluorescence imaging and analysis was performed on resected LNs (N = 843) using the submandibular glands (SMG) and skin as reference standard tissue with known EGFR antigen expression.

RESULTS

Sixteen patients (72.7%) had at least one positive LN on final pathology. The LN to SMG (LN/SMG) and LN to skin (LN/skin) ratios were significantly higher in metastatic LN compared to benign LN (p < 0.0001 for both). Using patient-specific ratios to determine an optimal LN/skin cutoff was the most sensitive (95.2%) and directly comparing the LN/skin ratio of all patients to determine a cutoff was the most specific (86.3%).

CONCLUSIONS

In HNSCC patients infused with a molecularly targeted fluorescent tracer, endogenous expression of the target antigen can be used as a reference standard to detect LN metastasis. Additionally, the performance of the background in determining metastatic LN can be improved by utilizing patient-specific reference standards.

Oncologic significance of the lateral margin in buccal cancer

OBJECTIVE

To evaluate the specific oncologic significance of the lateral margin (LM)- the marginal plane closest to skin- in resected buccal cancer.

MATERIALS AND METHODS

216 consecutive, treatment naïve patients undergoing primary surgery for buccal cancer were included. Cheek skin was resected based on clinical features of skin or subcutaneous involvement or proximity to oral commissure. Main outcomes were 1) frequency of LM ≤1 mm in relation to other (anterior, posterior, superior and inferior) margins and 2) association of LM ≤1 mm with LRFS and DFS. Secondary outcomes were rate of LM ≤1 mm and size of LM with and without skin resection.

RESULTS

A total of 67 (31 %) patients had one or more margin ≤1 mm, of which LM comprised 36 (54 %). LM ≤1 mm was disproportionately highest among the five marginal planes (p < 0.001) and was independently associated with LRFS and DFS. Both associations held in sensitivity analysis wherein patients with co-existent margin ≤1 mm at any of the other four marginal planes underwent group-wise exclusion. Skin resection and preservation was performed in 61 (28 %) and 155 (72 %) patients respectively. The latter had a higher rate of LM ≤1 mm and smaller LM size (both p < 0.05).

CONCLUSIONS

This cohort study of buccal cancer shows that LM is most prone for ≤1 mm size. LM ≤1 mm predicts worse LRFS and DFS independent of other margins and risk factors. As skin preservation is associated with a higher rate of LM ≤1 mm, surgeons must lower the threshold to encompass more tissue laterally, including skin where appropriate.

The Use of Fluorescent Markers to Detect and Delineate Head and Neck Cancer: A Scoping Review

OBJECTIVES

The aim of surgery for head and neck squamous cell carcinoma (HNSCC) is to achieve clear resection margins, whilst preserving function and cosmesis. Fluorescent markers have demonstrated potential in the intraoperative visualisation and delineation of tumours, such as glioma, with consequent improvements in resection. The purpose of this scoping review was to identify and compare the fluorescent markers that have been used to detect and delineate HNSCC to date.

METHODS

A literature search was performed using the Ovid MEDLINE, Ovid Embase, Cochrane CENTRAL, ClinicalTrials.gov and ICTRP databases. Primary human studies published through September 2023 demonstrating the use of fluorescent markers to visualise HNSCC were selected and reviewed independently by two authors.

RESULTS

The search strategy identified 5776 records. Two hundred and forty-four full texts were reviewed, and sixty-five eligible reports were included. The most used fluorescent markers in the included studies were indocyanine green (ICG) (n = 14), toluidine blue (n = 11), antibodies labelled with IRDye800CW (n = 10) and 5-aminolevulinic acid (5-ALA) (n = 8). Toluidine blue and ICG both have limited specificity, although novel targeted options derived from ICG may be more effective. 5-ALA has been demonstrated as a topical marker and, recently, via enteral administration but it is associated with photosensitivity reactions. The fluorescently labelled antibodies cetuximab-IRDye800CW and panitumumab-IRDye800CW are promising options being investigated by ongoing trials.

CONCLUSION

Multiple safe fluorescent markers have emerged which may aid the surgical resection of HNSCC. Further research in larger cohorts is required to identify which marker should be considered gold standard.

Perspectives on the Application of Biosensors for the Early Detection of Oral Cancer

Oral cancer continues to cause profound suffering and is associated with high mortality rates. Early detection techniques are crucial in enhancing patient outcomes. This review paper thoroughly evaluates the significance of biomarkers and recent advancements in oral cancer detection, emphasizing cutting-edge electrochemical methods. The paper provides an epidemiological and etiological overview, outlining its clinical importance and reviewing the current state of the art in detection methods. Despite considerable progress, conventional methods exhibit limitations such as invasiveness, long wait times, and a lack of accuracy, creating a critical need for more robust technologies. This review emphasizes the significance of oral cancer biomarkers, which are considered promising cues for early detection, facilitating the development of innovative biosensing technologies. This review seeks to illuminate the recent advances in early detection and precision diagnostics, along with the usage of artificial intelligence strategies, ultimately contributing to significant progress in the battle against oral cancer.

Optical imaging guidance in oncologic surgery and interventional oncology

Over recent decades, optical imaging (OI) has become an integral part of medical imaging, offering significant advantages over other modalities, such as computed tomography (CT) and magnetic resonance imaging (MRI). OI is distinguished by its real-time imaging capability, cost-effectiveness, portability, absence of ionizing radiation, and high patient acceptability. The introduction of advanced optical dyes (including FDA-approved agents like indocyanine green, Cytalux, and Gleolan) has greatly enhanced its clinical utility. OI has shown clear benefits in the management of patients with cancer, originally by open surgery and now extending to minimally invasive, image-guided interventional procedures. This review highlights recent developments in OI for oncology, emphasizing its benefits for clinicians in guiding surgical and interventional procedures.

Deep learning-enabled fluorescence imaging for surgical guidance: in silico training for oral cancer depth quantification

Significance

Oral cancer surgery requires accurate margin delineation to balance complete resection with post-operative functionality. Current in vivo fluorescence imaging systems provide two-dimensional margin assessment yet fail to quantify tumor depth prior to resection. Harnessing structured light in combination with deep learning (DL) may provide near real-time three-dimensional margin detection.

Aim

A DL-enabled fluorescence spatial frequency domain imaging (SFDI) system trained with in silico tumor models was developed to quantify the depth of oral tumors.

Approach

A convolutional neural network was designed to produce tumor depth and concentration maps from SFDI images. Three in silico representations of oral cancer lesions were developed to train the DL architecture: cylinders, spherical harmonics, and composite spherical harmonics (CSHs). Each model was validated with in silico SFDI images of patient-derived tongue tumors, and the CSH model was further validated with optical phantoms.

Results

The performance of the CSH model was superior when presented with patient-derived tumors ( P -value < 0.05 ). The CSH model could predict depth and concentration within 0.4 mm and 0.4    μ g / mL , respectively, for in silico tumors with depths less than 10 mm.

Conclusions

A DL-enabled SFDI system trained with in silico CSH demonstrates promise in defining the deep margins of oral tumors.

Intraoperative fluorescence redefining neurosurgical precision

Surgical resection is essential for treating solid tumors, with success largely dependent on the complete excision of neoplastic cells. However, neurosurgical procedures must delicately balance tumor removal with the preservation of surrounding tissue. Achieving clear margins is particularly challenging in cases like glioblastoma due to the limitations of traditional white light visualization. These limitations often result in incomplete resections, leading to frequent recurrences, or excessive resection that harms vital neural structures, causing iatrogenic nerve damage, which can lead to sensory and functional deficits. Current statistics reveal a 90% recurrence rate for malignant gliomas. Similarly, an 8% incidence of iatrogenic nerve trauma contributes to an estimated 25 million cases of peripheral nerve injury globally each year. These figures underscore the urgent need for improved intraoperative techniques for lesion margin and nerve identification and visualization. Recent advances in neurosurgical imaging, such as fluorescence-guided surgery (FGS), have begun to address these challenges. Fluorescent agents used in FGS illuminate target tissues, although not all do so selectively. Despite the promising results of agents such as 5-aminolevulinic acid and indocyanine green, their applications are mainly limited by issues of sensitivity and specificity. Furthermore, these agents do not effectively address the need for precise nerve visualization. Nerve Peptide 41, a novel systemically administered fluorescent nerve-targeted probe, shows promise in filling this gap. This review assesses the major fluorescent imaging modalities in neurosurgery, highlighting each of their benefits, limitations, and potential.

Cutting-edge insights: near-infrared imaging for surgical margin assessment in head and neck tumor resection: a systematic review and meta-analysis

BACKGROUND

In head and neck cancer (HNC), real-time evaluation of tumor margin status following surgical excision of the tumor is of critical importance. This systematic review aimed to assess the effectiveness of near-infrared fluorescence (NIRF) imaging for the real-time delineation of tumor margins in HNC resections.

METHODS

Two investigators independently conducted a comprehensive search following the Preferred Reporting Items for a Systematic Review and Meta-analysis of Diagnostic Test Accuracy Studies (PRISMA-DTA) guidelines across the PubMed, Scopus, Embase, and China National Knowledge Infrastructure (CNKI) databases until August 1st, 2023. Observational studies were included, while other studies with inappropriate study design were excluded. The primary outcomes included the specificity, sensitivity, and area under the summary receiver operating characteristic (SROC) curve when using NIRF imaging to assess surgical margins. We compared fluorescence in the resection specimen margins and residual fluorescence in the surgical cavity margins as methods of utilizing NIRF to evaluate surgical margins. Diagnostic trial quality was assessed, and statistical heterogeneity was determined.

RESULTS

The initial search yielded 1,607 articles. After reviewing the full texts, seven articles with 103 patients were included, among which five were incorporated for quantitative analysis. The selected studies had an average score of 10.1 of quality. Heterogeneity analysis revealed I2 values of 26% [95% confidence interval (CI): 0-100%] and 78% (95% CI: 52-100%) for NIRF specimen imaging with close margin considered positive or negative. Comparing NIRF imaging to the gold standard of pathology for surgical margin diagnosis, with close margin considered positive, sensitivity and specificity in excised specimens were 0.84 (95% CI: 0.39-0.98) and 0.96 (95% CI: 0.80-0.99), respectively. When a close margin was considered negative, sensitivity and specificity were 0.98 (95% CI: 0.10-1.00) and 0.96 (95% CI: 0.45-1.00), respectively. The areas under the SROC curves were 0.97 (95% CI: 0.95-0.98) and 0.99 (95% CI: 0.98-1.00), respectively. A quantitative analysis of residual fluorescence at surgical cavity margins was not performed due to an insufficient number of studies.

CONCLUSIONS

NIRF imaging is a promising method for real-time surgical margin assessment of HNC. With its robust diagnostic capabilities in excised tumor specimens, it is also an effective technique for detecting residual tumor fluorescence in the surgical cavity for supplementary assessment. But the results should be interpreted with caution.

Tumour Marker Expression in Head and Neck Malignancies to Identify Potential Targets for Intraoperative Molecular Near-Infrared Imaging

BACKGROUND

Oral and laryngeal squamous cell carcinoma (OSCC and LSCC) and papillary thyroid carcinoma (PTC) are common head and neck cancers (HNCs) typically treated surgically. Challenges in tumour delineation often lead to inadequate resection margins in OSCC and LSCC, and missed multifocality in PTC. Fluorescence imaging (FLI) using near-infrared tumour-targeting tracers may improve intraoperative identification of malignancy, facilitating precise excision. This study evaluates six potential FLI targets in OSCC, LSCC and PTC.

MATERIALS AND METHODS

Immunohistochemical staining was performed on OSCC (n = 20), LSCC (n = 10) and PTC (n = 10), assessing CEA, c-Met, EpCAM, EGFR, integrin αvβ6 and VEGF-α. Expression was scored (0-12) using the total immunostaining score (TIS) system, and categorized into absent (TIS 0), low (TIS 1-5), moderate (TIS 6-8) or high (TIS 9-12).

RESULTS

Integrin αvβ6 showed significant overexpression in OSCC (TIS: 12; p < 0.001) and LSCC (TIS: 8; p = 0.002), with 80% of OSCC and 90% of LSCC exhibiting moderate-high expression. Similarly, EGFR expression was moderate-high in most OSCC (87.5%; TIS: 8) and universally high in LSCC (100%; TIS: 12). In PTC, EGFR and VEGF-α expressions were low-moderate, but significantly higher than in healthy tissue (TIS: 6; p < 0.006).

CONCLUSION

This study highlights integrin αvβ6 and EGFR as viable FLI targets in OSCC and LSCC, especially integrin αvβ6 for tumour margin delineation. In PTC, despite lower expressions, the significant overexpression of VEGF-α, c-MET, and EGFR suggests their potential as FLI targets. Our findings support the development of tumour-targeted FLI tracers to improve surgical precision in HNC.

Enzymatically Cyclic Activated Biosensor Based on a Tetrahedral DNA Framework for Precise Tumor in Situ Molecular Imaging

The development of stimulus-responsive and amplification-based strategies is crucial for achieving improved spatial specificity and enhanced sensitivity in tumor molecular imaging, addressing challenges such as off-tumor signal leakage and limited biomarker content. Therefore, a cyclically activated enzymatic biosensor based on the modification of an AP site within a tetrahedral framework DNA (AP-tFNA) was rationally developed for tumor cell-specific molecular imaging using the endogenous enzyme apurinic/apyrimidinic endonuclease 1 (APE1) as a target, exhibiting superior spatial specificity and high sensitivity. APE1, which predominantly localizes within the nucleus in normal cells but exhibits cytosolic and nucleus expression in cancer cells, can specifically recognize and cleave the AP site in AP-tFNA, resulting in the separation of the fluorophore and quenching group, thereby inducing a fluorescence signal. Additionally, upon completion of the excision of one AP site in AP-tFNA, APE1 is released, thereby initiating a subsequent cycle of hydrolytic cleavage reactions. The experimental results demonstrated that AP-tFNA enables precise differentiation of tumor cells both in vitro and in vivo. In particular, the AP-tFNA can monitor drug resistance in neuroblastoma cells and classify the risk for neuroblastoma patients at the clinical plasma level.

Intraoperative Molecular Imaging With Pafolacianine in Resection of Occult Pulmonary Malignancy in the ELUCIDATE Trial

BACKGROUND

Clinical studies have demonstrated that intraoperative molecular imaging (IMI) with pafolacianine identifies occult pulmonary lesions that are not identified by preoperative computed tomography or by intraoperative inspection techniques in ∼20% of patients. This study describes occult lesion clinical data and evaluates characteristics so that surgeons can better incorporate this emerging technology into clinical decision making.

METHODS

Participants (n = 100) enrolled in a phase 3 trial of IMI with pafolacianine during pulmonary resection (Enabling Lung Cancer Identification Using Folate Receptor Targeting [ELUCIDATE]; NCT04241315) were identified. Participants underwent preoperative computed tomography with 1.25-mm slices. Patient and lesion characteristics were analyzed. Positive predictive value and false positive rates were tabulated for IMI fluorescent lesions, with predictors of malignant vs benign occult lesions described.

RESULTS

IMI identified 29 occult lesions in 23 (23%) participants. Seventeen of 29 (58%) lesions were identified within the same lobe as known lesions; 12 of 29 (42%) were identified in a different lobe from the suspicious nodule known by preoperative assessment. Twenty-three of 29 (79%) of occult lesions found by IMI were resected with an additional wedge resection. Ten of 29 (34%) lesions identified by IMI were malignant. There was no additional morbidity in participants with lesions resected. With pafolacianine, 7 participants had a synchronous primary stage I lung cancer identified, and 1 participant had additional metastases identified.

CONCLUSIONS

IMI with pafolacianine identifies occult malignant lesions during pulmonary resection despite thorough preoperative imaging and intraoperative assessment by experienced surgeons.

Imaging Modalities for Head and Neck Cancer: Present and Future

Several imaging modalities are utilized in the diagnosis, treatment, and surveillance of head and neck cancer. First-line imaging remains computed tomography (CT); however, MRI, PET with CT (PET/CT), and ultrasound are often used. In the last decade, several new imaging modalities have been developed that have the potential to improve early detection, modify treatment, decrease treatment morbidity, and augment surveillance. Among these, molecular imaging, lymph node mapping, and adjustments to endoscopic techniques are promising. The present review focuses on existing imaging, novel techniques, and the recent changes to imaging practices within the field.

Interim Phase II Results Using Panitumumab-IRDye800CW during Transoral Robotic Surgery in Patients with Oropharyngeal Cancer

PURPOSE

The incidence of oropharyngeal squamous cell carcinoma (OPSCC) has continually increased during the past several decades. Using transoral robotic surgery (TORS) significantly improves functional outcomes relative to open surgery for OPSCC. However, TORS limits tactile feedback, which is often the most important element of cancer surgery. Fluorescence-guided surgery (FGS) strategies to aid surgeon assessment of malignancy for resection are in various phases of clinical research but exhibit the greatest potential impact for improving patient care when the surgeon receives limited tactile feedback, such as during TORS. Here, we assessed the feasibility of intraoperative fluorescence imaging using panitumumab-IRDye800CW (PAN800) during TORS in patients with OPSCC.

PATIENTS AND METHODS

Twelve consecutive patients with OPSCC were enrolled as part of a nonrandomized, prospective, phase II FGS clinical trial using PAN800. TORS was performed with an integrated robot camera for surgeon assessment of fluorescence. Intraoperative and ex vivo fluorescence signals in tumors and normal tissue were quantified and correlated with histopathology.

RESULTS

Intraoperative robot fluorescence views delineated OPSCC from normal tissue throughout the TORS procedure (10.7 mean tumor-to-background ratio), including in tumors with low expression of the molecular target. Tumor-specific fluorescence was consistent with surgeon-defined tumor borders requiring resection. Intraoperative robot fluorescence imaging revealed an OPSCC fragment initially overlooked during TORS based on brightfield views, further substantiating the clinical benefit of this FGS approach.

CONCLUSIONS

The results from this patient with OPSCC cohort support further clinical assessment of FGS during TORS to aid resection of solid tumors.

Illuminating the future of precision cancer surgery with fluorescence imaging and artificial intelligence convergence

Real-time and accurate guidance for tumor resection has long been anticipated by surgeons. In the past decade, the flourishing material science has made impressive progress in near-infrared fluorophores that may fulfill this purpose. Fluorescence imaging-guided surgery shows great promise for clinical application and has undergone widespread evaluations, though it still requires continuous improvements to transition this technique from bench to bedside. Concurrently, the rapid progress of artificial intelligence (AI) has revolutionized medicine, aiding in the screening, diagnosis, and treatment of human doctors. Incorporating AI helps enhance fluorescence imaging and is poised to bring major innovations to surgical guidance, thereby realizing precision cancer surgery. This review provides an overview of the principles and clinical evaluations of fluorescence-guided surgery. Furthermore, recent endeavors to synergize AI with fluorescence imaging were presented, and the benefits of this interdisciplinary convergence were discussed. Finally, several implementation strategies to overcome technical hurdles were proposed to encourage and inspire future research to expedite the clinical application of these revolutionary technologies.

Development of a plant-based surgical training model for fluorescence-guided cancer surgery

BACKGROUND

Fluorescence-guided surgery (FGS) can help surgeons to discriminate tumor tissue from adjacent normal tissues using fluorescent tracers.

METHODS

We developed a surgical training model, manufactured using sustainable vegetable organic material with indocyanine green (ICG)-containing "tumor." Surgeons evaluated the model with both the closed-field and endoscopic fluorescence imaging devices and assessed its efficacy to identify residual tumor after enucleation using electrocautery.

RESULTS

Strong correlations of fluorescence were obtained at all working distance (3, 5, 7, and 10 cm), showing the robustness of fluorescence signal for the closed-field and endoscopic fluorescence imaging devices. The higher fluorescence signals were obtained in the wound bed in the closed-field fluorescence imaging device and the residual tumor could be clearly identified by fluorescence endoscopy.

CONCLUSIONS

Our FGS training model may provide experience for surgeons unfamiliar with optical surgery and subsequent tissue interactions. The model seemed particularly helpful in teaching surgeons the principles of FGS.

Multispectral fluorescence imaging of EGFR and PD-L1 for precision detection of oral squamous cell carcinoma: a preclinical and clinical study

BACKGROUND

Early detection and treatment are effective methods for the management of oral squamous cell carcinoma (OSCC), which can be facilitated by the detection of tumor-specific OSCC biomarkers. The epidermal growth factor receptor (EGFR) and programmed death-ligand 1 (PD-L1) are important therapeutic targets for OSCC. Multispectral fluorescence molecular imaging (FMI) can facilitate the detection of tumor multitarget expression with high sensitivity and safety. Hence, we developed Nimotuzumab-ICG and Atezolizumab-Cy5.5 imaging probes, in combination with multispectral FMI, to sensitively and noninvasively identify EGFR and PD-L1 expression for the detection and comprehensive treatment of OSCC.

METHODS

The expression of EGFR and PD-L1 was analyzed using bioinformatics data sources and specimens. Nimotuzumab-ICG and Atezolizumab-Cy5.5 imaging probes were developed and tested on preclinical OSCC cell line and orthotopic OSCC mouse model, fresh OSCC patients' biopsied samples, and further clinical mouthwash trials were conducted in OSCC patients.

RESULTS

EGFR and PD-L1 were specifically expressed in human OSCC cell lines and tumor xenografts. Nimotuzumab-ICG and Atezolizumab-Cy5.5 imaging probes can specifically target to the tumor sites in an in situ human OSCC mouse model with good safety. The detection sensitivity and specificity of Nimotuzumab-ICG in patients were 96.4% and 100%, and 95.2% and 88.9% for Atezolizumab-Cy5.5.

CONCLUSIONS

EGFR and PD-L1 are highly expressed in OSCC, the combination of which is important for a precise prognosis of OSCC. EGFR and PD-L1 expression can be sensitively detected using the newly synthesized multispectral fluorescence imaging probes Nimotuzumab-ICG and Atezolizumab-Cy5.5, which can facilitate the sensitive and specific detection of OSCC and improve treatment outcomes.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR2100045738. Registered 23 April 2021, https://www.chictr.org.cn/bin/project/edit?pid=125220.

Fluorescence-guided surgery using cetuximab-800CW in patients with penile carcinoma

OBJECTIVE

To investigate the feasibility of fluorescence molecular imaging (FMI), using cetuximab-800CW, as an intraoperative tool to determine surgical margins in penile squamous cell carcinoma (PSCC).

PATIENTS AND METHODS

A total of 11 patients with PSCC received 75 mg cetuximab followed by 15 mg cetuximab-800CW 2 days before surgery. FMI of the whole excision specimen and tissue slices was performed. Fluorescence visualisation was correlated to histopathology. Based on tumour and healthy tissue regions of interest, mean fluorescence intensity was calculated for each individual patient.

RESULTS

Significant differences between tumour and healthy mean fluorescence intensity were found with tumour-to-background ratios of a median (IQR) of 1.51 (0.99) and a mean (SD) of 1.51 (0.32) in the excision specimen and tissue slices, respectively. One patient showed a high relative fluorescence intensity with a signal-to-background ratio of 1.79, corresponding to a tumour-positive margin on fresh frozen sectioning.

CONCLUSION

In this Phase I study we showed that cetuximab-800CW seems suitable to discriminate PSCC from background tissue. The tracer was well tolerated, and no false positive spots were seen.

Infrared Fluorescence-guided Surgery for Tumor and Metastatic Lymph Node Detection in Head and Neck Cancer

In patients with head and neck cancer (HNC), surgical removal of cancerous tissue presents the best overall survival rate. However, failure to obtain negative margins during resection has remained a steady concern over the past 3 decades. The need for improved tumor removal and margin assessment presents an ongoing concern for the field. While near-infrared agents have long been used in imaging, investigation of these agents for use in HNC imaging has dramatically expanded in the past decade. Targeted tracers for use in primary and metastatic lymph node detection are of particular interest, with panitumumab-IRDye800 as a major candidate in current studies. This review aims to provide an overview of intraoperative near-infrared fluorescence-guided surgery techniques used in the clinical detection of malignant tissue and sentinel lymph nodes in HNC, highlighting current applications, limitations, and future directions for use of this technology within the field. Keywords: Molecular Imaging-Cancer, Fluorescence © RSNA, 2024.

Rapid Glutathione Analysis with SERS Microneedles for Deep Glioblastoma Tissue Differentiation

Rapid tissue differentiation at the molecular level is a prerequisite for precise surgical resection, which is of special value for the treatment of malignant tumors, such as glioblastoma (GBM). Herein, a SERS-active microneedle is prepared by modifying glutathione (GSH)-responsive molecules, 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB), on the surface of Au@Ag substrates for the distinction of different GBM tissues. Since the Raman signals on the surface of the DTNB@Au@Ag microneedle can be collected by both portable and benchtop Raman spectrometers, the distribution of GSH in different tissues at centimeter scale can be displayed through Raman spectroscopy and Raman imaging, and the entire analysis process can be accomplished within 12 min. Accordingly, in vivo brain tissues of orthotopic GBM xenograft mice and ex vivo tissues of GBM patients are accurately differentiated with the microneedle, and the results are well consistent with tissue staining and postoperative pathological reports. In addition, the outline of tumor, peritumoral, and normal tissues can be indicated by the DTNB@Au@Ag microneedle for at least 56 days. Considering that the tumor tissues are quickly discriminated at the molecular level without the restriction of depth, the DTNB@Au@Ag microneedle is promising to be a powerful intraoperative diagnostic tool for surgery navigation.

Beneath the surface: A systematic review on intraoperative imaging techniques for deep margin assessment in oral squamous cell carcinoma

Resection margins of oral squamous cell carcinoma (SCC) are often inadequate. A systematic review on clinical intraoperative whole-specimen imaging techniques to obtain adequate deep resection margins in oral SCC is lacking. Such a review may render better alternatives for the current insufficient intraoperative techniques: palpation and frozen section analyses (FSA). This review resulted in ten publications investigating ultrasound (US), four investigating fluorescence, and three investigating MRI. Both US and fluorescence were able to image the tumor intraorally and perform ex-vivo imaging of the resection specimen. Fluorescence was also able to image residual tumor tissue in the wound bed. MRI could only be used on the ex-vivo specimen. The 95 % confidence intervals for sensitivity and specificity were large, due to the small sample sizes for all three techniques. The sensitivity and specificity of US for identifying < 5 mm margins ranged from 0 % to 100 % and 60 % to 100 %, respectively. For fluorescence, this ranged from 0 % to 100 % and 76 % to 100 %, respectively. For MRI, this ranged from 7 % to 100 % and 81 % to 100 %, respectively. US, MRI and fluorescence are the currently available imaging techniques that can potentially be used intraoperatively and which can image the entire tumor-free margin, although they have insufficient sensitivity for identifying < 5 mm margins. Further research on larger cohorts is needed to improve the sensitivity by determining cut-off points on imaging for inadequate margins. This improves the number of adequate resections of oral SCC's and pave the way for routine clinical implementation of these techniques.

Identification of new head and neck squamous cell carcinoma molecular imaging targets

OBJECTIVES

Intraoperative fluorescence imaging (FI) of head and neck squamous cell carcinoma (HNSCC) is performed to identify tumour-positive surgical margins, currently using epidermal growth factor receptor (EGFR) as imaging target. EGFR, not exclusively present in HNSCC, may result in non-specific tracer accumulation in normal tissues. We aimed to identify new potential HNSCC FI targets.

MATERIALS AND METHODS

Publicly available transcriptomic data were collected, and a biostatistical method (Transcriptional Adaptation to Copy Number Alterations (TACNA)-profiling) was applied. TACNA-profiling captures downstream effects of CNAs on mRNA levels, which may translate to protein-level overexpression. Overexpressed genes were identified by comparing HNSCC versus healthy oral mucosa. Potential targets, selected based on overexpression and plasma membrane expression, were immunohistochemically stained. Expression was compared to EGFR on paired biopsies of HNSCC, adjacent macroscopically suspicious mucosa, and healthy mucosa.

RESULTS

TACNA-profiling was applied on 111 healthy oral mucosa and 410 HNSCC samples, comparing expression levels of 19,635 genes. The newly identified targets were glucose transporter-1 (GLUT-1), placental cadherin (P-cadherin), monocarboxylate transporter-1 (MCT-1), and neural/glial antigen-2 (NG2), and were evaluated by IHC on samples of 31 patients. GLUT-1 was expressed in 100 % (median; range: 60-100 %) of tumour cells, P-cadherin in 100 % (50-100 %), EGFR in 70 % (0-100 %), MCT-1 in 30 % (0-100 %), and NG2 in 10 % (0-70 %). GLUT-1 and P-cadherin showed higher expression than EGFR (p < 0.001 and p = 0.015).

CONCLUSIONS

The immunohistochemical confirmation of TACNA-profiling results showed significantly higher GLUT-1 and P-cadherin expression than EGFR, warranting further investigation as HNSCC FI targets.

Development and validation of a cadaveric porcine Pseudotumor model for Oral Cancer biopsy and resection training

OBJECTIVE

The gold standard of oral cancer (OC) treatment is diagnostic confirmation by biopsy followed by surgical treatment. However, studies have shown that dentists have difficulty performing biopsies, dental students lack knowledge about OC, and surgeons do not always maintain a safe margin during tumor resection. To address this, biopsies and resections could be trained under realistic conditions outside the patient. The aim of this study was to develop and to validate a porcine pseudotumor model of the tongue.

METHODS

An interdisciplinary team reflecting various specialties involved in the oncological treatment of head and neck oncology developed a porcine pseudotumor model of the tongue in which biopsies and resections can be practiced. The refined model was validated in a final trial of 10 participants who each resected four pseudotumors on a tongue, resulting in a total of 40 resected pseudotumors. The participants (7 residents and 3 specialists) had an experience in OC treatment ranging from 0.5 to 27 years. Resection margins (minimum and maximum) were assessed macroscopically and compared beside self-assessed margins and resection time between residents and specialists. Furthermore, the model was evaluated using Likert-type questions on haptic and radiological fidelity, its usefulness as a training model, as well as its imageability using CT and ultrasound.

RESULTS

The model haptically resembles OC (3.0 ± 0.5; 4-point Likert scale), can be visualized with medical imaging and macroscopically evaluated immediately after resection providing feedback. Although, participants (3.2 ± 0.4) tended to agree that they had resected the pseudotumor with an ideal safety margin (10 mm), the mean minimum resection margin was insufficient at 4.2 ± 1.2 mm (mean ± SD), comparable to reported margins in literature. Simultaneously, a maximum resection margin of 18.4 ± 6.1 mm was measured, indicating partial over-resection. Although specialists were faster at resection (p < 0.001), this had no effect on margins (p = 0.114). Overall, the model was well received by the participants, and they could see it being implemented in training (3.7 ± 0.5).

CONCLUSION

The model, which is cost-effective, cryopreservable, and provides a risk-free training environment, is ideal for training in OC biopsy and resection and could be incorporated into dental, medical, or oncologic surgery curricula. Future studies should evaluate the long-term training effects using this model and its potential impact on improving patient outcomes.

A Raman topography imaging method toward assisting surgical tumor resection

Achieving complete tumor resection upon initial surgical intervention can lead to better patient outcomes by making adjuvant treatments more efficacious and reducing the strain of repeat surgeries. Complete tumor resection can be difficult to confirm intraoperatively. Methods like touch preparation (TP) have been inconsistent for detecting residual malignant cell populations, and fatty specimens like breast cancer lumpectomies are too fatty to process for rapid histology. We propose a novel workflow of immunostaining and topographic surface imaging of freshly excised tissue to ensure complete resection using highly sensitive and spectrally separable surface-enhanced Raman scattering nanoparticles (SERS NPs) as the targeted contrast agent. Biomarker-targeting SERS NPs are ideal contrast agents for this application because their sensitivity enables rapid detection, and their narrow bands enable extensive intra-pixel multiplexing. The adaptive focus capabilities of an advanced Raman instrument, combined with our rotational accessory device for exposing each surface of the stained specimen to the objective lens, enable topographic mapping of complete excised specimen surfaces. A USB-controlled accessory for a Raman microscope was designed and fabricated to enable programmatic and precise angular manipulation of specimens in concert with instrument stage motions during whole-surface imaging. Specimens are affixed to the accessory on an anti-slip, sterilizable rod, and the tissue surface exposed to the instrument is adjusted on demand using a programmed rotating stepper motor. We demonstrate this topographic imaging strategy on a variety of phantoms and preclinical tissue specimens. The results show detail and texture in specimen surface topography, orientation of findings and navigability across surfaces, and extensive SERS NP multiplexing and linear quantitation capabilities under this new Raman topography imaging method. We demonstrate successful surface mapping and recognition of all 26 of our distinct SERS NP types along with effective deconvolution and localization of randomly assigned NP mixtures. Increasing NP concentrations were also quantitatively assessed and showed a linear correlation with Raman signal with an R2 coefficient of determination of 0.97. Detailed surface renderings color-encoded by unmixed SERS NP abundances show a path forward for content-rich, interactive surgical margin assessment.

Recent advances in head and neck surgical oncology

In recent years, the field of head and neck oncology has witnessed a remarkable transformation with unprecedented advances that have revolutionized the management of complex tumors in this region. As an intricate subspecialty within oncology, head and neck surgical procedures demand detailed knowledge of the complex anatomy meticulous precision in surgical technique, and expertise to preserve vital functions while ensuring optimal oncological outcomes. With the relentless pursuit of improved patient outcomes, the integration of innovative technologies has significantly enhanced the surgical armamentarium. Robotics, endoscopic platforms, and image-guided navigation have revolutionized the surgical approach, enabling precise tumor resection and sparing healthy tissues. Furthermore, the application of advanced imaging modalities and molecular biomarker profiling has opened new avenues for personalized treatment strategies. From targeted therapies and immunotherapies to adaptive radiation techniques, clinicians are now equipped with an array of tailored options, ushering in a new era of personalized care for patients with head and neck malignancies. This article delves into the unfolding narratives of clinical triumphs, exploring the transformative potential of emerging therapies and the collaborative efforts propelling head and neck surgical oncology toward a future of hope and healing.

Improved intraoperative identification of close margins in oral squamous cell carcinoma resections using a dual aperture fluorescence ratio approach: first in-human results

Significance

Surgical excision is the main treatment for solid tumors in oral squamous cell carcinomas, where wide local excision (achieving a healthy tissue margin of > 5    mm around the excised tumor) is the goal as it results in reduced local recurrence rates and improved overall survival.

Aim

No clinical methods are available to assess the complete surgical margin intraoperatively while the patient is still on the operating table; and while recent intraoperative back-bench fluorescence-guided surgery approaches have shown promise for detecting "positive" inadequate margins (< 1    mm ), they have had limited success in the detection of "close" inadequate margins (1 to 5 mm). Here, a dual aperture fluorescence ratio (dAFR) approach was evaluated as a means of improving detection of close margins.

Approach

The approach was evaluated on surgical specimens from patients who were administered a tumor-specific fluorescent imaging agent (cetuximab-800CW) prior to surgery. The dAFR approach was compared directly against standard wide-field fluorescence imaging and pathology measurements of margin thickness in specimens from three patients and a total of 12 margin locations (1 positive, 5 close, and 6 clear margins).

Results

The area under the receiver operating characteristic curve, representing the ability to detect close compared to clear margins (> 5    mm ) was found to be 1.0 and 0.57 for dAFR and sAF, respectively. Improvements in dAFR were found to be statistically significant (p < 0.02 ).

Conclusions

These results provide evidence that the dAFR approach potentially improves detection of close surgical margins.