Assessment Of Surgical Margins Research Articles

Oral ID® as an adjunctive tool for surgical margin assessment in patients with oral squamous cell carcinoma: a comparative study

Objective: The condition of the resected margin in oral squamous cell carcinoma continues to be an importantprognostic factor; the use of optic technology could help surgeons in determining the margin status at real time.This study aims to evaluate Oral ID, a hand held device that uses the principal of auto-fluorescence to determinesurgical safe margins in patients with oral squamous cell carcinoma, and to compare the results with those of theconventional 1 cm margin method. Material and Methods: This study was a descriptive, comparative analyticalstudy carried out at Khartoum Dental Teaching Hospital and Oral Histopathology Diagnostic Laboratory, Facultyof Dentistry, University of Khartoum. A total of 92 margins obtained from 31 patients, 46 margins were taken byOral ID and the other 46 were taken by the traditional 1cm method. All margins were examined histologicallywith conventional Hematoxylin and Eosin stain. Results: It was found that all tumors showed fluorescence loss; Asignificant association was found between the use of Oral ID and obtaining a free margin P (0.02) the sensitivityof Oral ID was found to be 74% the specificity was found to be 89%. Ten out of the 46 margins obtained byfluorescence showed mild dysplasia and two margins showed high grade dysplasia. The 46 margins obtainedby the traditional 1cm margin showed different field alterations two were involved, one was close, five showedhigh grade dysplasia and 14 showed mild dysplasia yielding a specificity of 52.2%. Conclusion: Using Oral IDfor surgical margin assessment increases the accuracy to 74% compared to the conventional method which wasfound to be 52.2%. The results of the device are comparable to other auto-fluorescence devices of differenttrademarks. Further development of the device to help overcome its limitations is strongly advised. KEYWORDSOral ID; Auto-fluorescence; Cancer; Diagnosis; Oral squamous cell carcinoma.

Prospective Non-Randomized Study of Intraoperative Assessment of Surgical Resection Margin of Colo-Rectal Liver Metastases.

Introduction: More than 50% of patients with colorectal cancer (CRC) develop liver metastases during the natural course of disease. Surgical resection is currently the most potentially curative method in the treatment of colorectal liver metastases (CRLM). The goal of surgery is to achieve a negative resection margin (RM) of at least 1 mm, which provides the best prognosis for patients. The RM can be assessed by the pathologist of the resected liver specimen (RLS) and by the surgeon intraoperatively. The aim of this research paper is to determine the degree of agreement on intraoperative assessment of the RM by the surgeon and histopathological RM assessment by the pathologist.Material and methods: This prospective non-randomized double-blind study was approved by the Ethics Committee of the Oncology Institute of Vojvodina and registered on ClinicalTrials.gov #NCT04634526. The study was conducted at the Oncology Institute of Vojvodina, Sremska Kamenica, Serbia. An experienced hepatobiliary surgeon assessed RM for every specimen intra-operatively, immediately after CRLM resection. Resected CRLM lesions were analyzed by two experienced pathologists. These data were compared with pathological RM assessment as a “gold standard”. RM of 1 mm or more was rated as negative RM (RM-). Disease-free survival (DFS) and recurrence rate was calculated by RM status defined by surgeon and by pathologist.Results: From 01 January 2015 to 31 August 2019, 98 patients were enrolled in the study. There were 219 RLS with 245 CRLM. The surgeon registered positive RM (RM+) of <1mm in 41 (18.7%) RLS. Taking the result of the histopathological assessment (HPA) as the “gold standard”, it was determined that RM was true positive in 32 (14.6%) cases. False positive RM was found in 9 (4.1%) cases. False negative RM was found in 20 (9.1%) cases. True negative RM was found in 158 (72.2%) cases. Sensitivity of surgical assessment (SA) of RM+ was 61.5% (32/52). Specificity of SA of RM+ was 94.6% (158/167). The positive predictive value (PPV) was 78.0% (32/41), while the negative predictive value (NPV) was 88.8% (158/178). The overall accuracy of the RM+ SA was 86.8% (190/219). There was no statistically significant difference in the assessment of RM+ per RLS by surgeon and pathologists (p=0.061), but it was significant when analyses per patients was performed (p=0.017). Recurrence rate for RM+ patients was 48.1% (13/27, p=0.05) for SA and 35.0% (14/40, p=0.17) for HPA. Three year DFS for RM- and RM+ was 66.5% and 27.9% (p=0.04), respectively, by SA, and 64.8% and 42.1% (p=0.106), respectively, by HPA.Conclusion: Intraoperative assessment of RM- by surgeon of RLS is clinically meaningful. There is not a statistically significant difference in the assessment of RM+ by surgeon and pathologists per RLS, but it was statically significant on a per patient basis. RM determined by surgeon has better prognostic impact on recurrence rate and 1- and 3-year DFS than standard histopathological assessment.

Prospective non-randomized study of intraoperative assessment of surgical resection margin of colo-rectal liver metastases

More than 50.0% of patients with colorectal cancer (CRC) develop liver metastases (CRLM) during the natural course of disesae. Surgical resection of the liver is the most potentially curative treatment. The goal of surgical treatment is to achieve a negative resection margin (RM-) of 1 mm, and thus provide the best prognosis for patients. The resection margin (RM) can be assessed by a pathologist (PA) on the resected liver specimen (RLS) and by surgeon intraoperatively (SA). The aim of this study was to determine the degree of agreement between SA and PA of RM and to compare their clinical significance. The study was double-blind, prospective, and nonrandomized. The surgeons assessed the RM for each RLS intraoperatively after resection. Liver resections were performed by four hepatobiliary surgeons. Their assessment of RM was compared with the assessment of RM performed by pathologists as the "gold standard". RM of 1 mm and more was rated as negative. Sensitivity, specificity, positive and negative predictive value were calculated, as well as the overall accuracy of the surgical assessment (SA) of RM in relation to the assessment of RM by the pathologist (PA). The influence of clinical outcome of SA and PA of RM were also analyzed. In the period from 1.1.2015 to 31.8.2019, 150 patients with resected CRLM were included in the study. A total of 337 RLS with 407 CRLMs were removed. There were 62 (18.4%) RLS with RM+ by SA. Pathologists agreed with surgeons in 48 (77.4%) cases, while in 14 (22.6%) cases they considered otherwise. Pathologists registered RM + in 83 (24.6%) cases. Surgeons agreed in 48 (57.8%) cases, while in 35 (42.2%) they considered otherwise. The sensitivity of the surgical assessment of RM + of 57.8%, specificity of 94.5%, positive predictive value of 77.4%, negative predictive value of 87.3%, and overall accuracy of 85.5% were obtained. Recurrence rate for RM+ patients was 42.9% (15/35, p=0.017) for SA and 32.7% (18/55, p=0.216) for PA. Three-year disease-free survival for RM-: RM+ was 64.5% and 36.1% (p = 0.01) by SA of RM, and 63.1%: 49.6% (p = 0.181) by PA of RM. Intraoperative assessment of RM is satisfactory, which is the goal of surgical treatment. However, there is a statistically significant difference in the assessment of RM + between surgeons and pathologists. In fact, RM + determined by the surgeon has a better prognostic effect on recurrence rate and DFS, compared to the assessment made by the pathologist.

Rapid and Sensitive Detection of Cancer Cells with Activatable Fluorescent Probes for Enzyme Activity.

Fluorescence (FL)-guided detection of cancer is one of the most promising approaches to achieve intraoperative assessment of surgical margins. Enzymes, such as aminopeptidase, carboxypeptidase, and glycosidase, whose activities are increased in cancer, have attracted great interest as imaging targets for rapid and sensitive visualization of cancerous tissues with fluorescent probes. Activatable probes, which are initially nonfluorescent but become strongly fluorescent upon rapid one-step cleavage of their substrate moiety by the target enzyme, are especially promising for practical clinical application during surgical or endoscopic procedures due to the highly amplified FL change generated by enzyme-catalyzed turnover at lesion sites. Here, we describe robust protocols for using activatable fluorescent probes targeting cancer-associated enzyme activities to visualize cultured cancer cells, metastatic cancer in a mouse model, and cancerous lesions in surgical specimens from patients.

Evaluation of different haematoxylin stain subtypes for the optimal microscopic interpretation of cutaneous malignancy in Mohs frozen section histological procedure

ABSTRACT Background The Mohs technique employs mainly H&E-stained frozen sections for surgical margin assessment of cutaneous excisions, utilising microscopic evaluation of the complete, circumferential, peripheral and deep margins. This study aimed to determine which mordant based haematoxylin (Ehrlich’s, Cole’s, Mayer’s, Gill’s I, Gill’s II, Gill’s III, Weigert’s, Harris’ or Carazzi’s) produced the optimal morphological clarity of staining for the identification of cellular and tissue morphology of cutaneous basal cell carcinoma (BCC). Material and methods In total, 100 anonymised patient cases were selected, sectioned and stained with each haematoxylin subtype. The slides were independently evaluated microscopically by two assessors. A combined score was generated to determine the sensitivity (defined as the intensity of haematoxylin staining being too weak or too strong and the colour appearance of the haematoxylin not being blue/black) and specificity (defined as the appearance of background staining with haematoxylin, uneven staining and staining deposits) for each of the nine haematoxylin subtypes. The scoring criteria were based on the UKNEQAS CPT Mohs procedure assessment criteria. Results The scores generated for specificity identified Carazzi’s haematoxylin as best performing (99.2%) followed by Gill’s III (98.4%), Ehrlich’s (98.2%) and Harris’ (85.0%). The sensitivity score again identified Carazzi’s as producing the best result (85.0%) followed by Weigert’s (83.4%), Ehrlich’s (81.6%) and Gill’s III (80.4%). Discussion Carazzi’s haematoxylin is the most optimal staining dye for the identification of BCC tumour for use as part of the Mohs micrographic surgery procedure.

Real-time surgical margin assessment using ICG-fluorescence during laparoscopic and robot-assisted resections of colorectal liver metastases.

BackgroundAlmost a third of the resections in patients with colorectal liver metastases (CRLM) undergoing curative surgery, end up being tumor-margin positive (≤1 mm margin). Near-infrared fluorescent (NIRF) imaging using the fluorescent contrast agent indocyanine green (ICG) has been studied for many different applications. When administered in a relatively low dose (10 mg) 24 hours prior to surgery, ICG accumulated in hepatocytes surrounding the CRLM. This results in the formation of a characteristic fluorescent ‘rim’ surrounding CRLM when located at the periphery of the liver. By resecting the metastasis with the entire surrounding fluorescent rim, in real-time guided by NIRF imaging, the surgeon can effectively acquire margin-negative (>1 mm) resections. This pilot study aims to describe the surgical technique for using near-infrared fluorescence imaging to assess tumor-margins in vivo in patients with CRLM undergoing laparoscopic or robot-assisted resections.MethodsOut of our institutional database we selected 16 CRLM based on margin-status (R0; n=8, R1; n=8), which were resected by a minimally-invasive approach using ICG-fluorescence. NIRF images acquired during surgery, from both the resection specimen and the wound bed, were analysed for fluorescent signal. We hypothesized that a protruding fluorescent rim at the parenchymal side of the resection specimen could indicate a too close proximity to the tumor and could be predictive for a tumor-positive surgical margin. NIRF images were correlated to final histopathological assessment of the resection margin.ResultsAll lesions with a NIRF positive resection plane in vivo were reported as having a tumor-positive margin. Lesions that showcased no protruding rim in the wound bed in vivo were diagnosed as having a tumor-negative margin in 88% of cases. A 5-step surgical workflow is described to document the NIRF signal was used assess the resection margin in vivo for future clinical studies.ConclusionsThe pilot study shows that image-guided surgery using real-time ICG-fluorescence has the potential to aid surgeons in achieving a tumor-negative margin in minimally invasive liver metastasectomies. The national multi-centre MIMIC-Trial will prospectively study the effect of this technique on surgical tumor-margins (Dutch Trial Register number NL7674).

Impact of resection margin status and revision transoral laser microsurgery in early glottic cancer: analysis of organ preservation and local disease control on a cohort of 153 patients

IntroductionTransoral laser microsurgery represents the treatment of choice for early glottic cancer. Its use and effectiveness are mainly related to laryngeal exposure and deep extension of tumor. Histopathologic assessment of surgical margin presents a main issue about transoral laser microsurgery and complete oncological excision. ObjectiveThe aim was to analyze the impact of revision surgery on organ preservation and local disease control in patients with early glottic cancer treated by transoral laser microsurgery. MethodsWe carried out a retrospective study on a cohort of 153 patients with early glottic cancer (Tis, T1, T2) treated by transoral laser microsurgery. Resection margins were classified as follows: “free” if macroscopic margin-tumor distance was at least 2mm, as “close” if it was less than 2mm and “positive” if the margin was involved by carcinoma. Patients were divided into two groups: patients with free resection margins (Group A) and patients with positive, close or not-evaluable resection margins (Group B). Group A (36) underwent periodic followup. Group B (117) underwent a second look laser CO2 2 months after surgery. Fifteen patients of Group A with suspected persistence of carcinoma during followup underwent a second laser resection after a time interval of 4–8 months after first surgery. Overall survival, disease-free survival, disease-specific survival, ultimate local control with laser alone and organ preservation rates were estimated. ResultsFive-year overall survival rate and 5-year disease-specific survival were 100% in both groups. The five-year laryngeal preservation rate was 100% in Group A and 95.2% in Group B. Five-year disease-free survival was 92.15% and 5-year ultimate local control with laser alone in 92.15% of patients. ConclusionThis study has demonstrated that revision Transoral Laser Microsurgery is able to confirm the oncological radicality in most cases, even in the case of positive, close or non-evaluable margins. Considering our results, according to our experience, the second look with CO2 laser is a therapeutic strategy to consider, even in the case of close or non-evaluable as well as positive margins.

Absence of residual fluorescence in the surgical bed at near-infrared fluorescence imaging predicts negative margins at final pathology in patients treated with breast-conserving surgery for breast cancer

IntroductionPositive margins after breast-conserving surgery (BCS) for breast cancer (BC) remain a major concern. In this study we investigate the feasibility and accuracy of indocyanine green (ICG) fluorescence imaging (FI) for the in vivo assessment of surgical margins during BCS. Materials and methodsPatients with BC admitted for BCS from October 2015 to April 2016 were proposed to be included in the present study (NCT02027818). ICG (0.25 mg/kg) was intravenously injected at induction anesthesia and ICG-FI of the surgical beds was correlated with final pathology results. ResultsFifty patients consented to participate and thirty-five patients were retained for final analysis, 15 patients having been excluded for, respectively, incomplete video records data for signal to background ratio (SBR) calculation (11) and in situ tumors (4). The final pathological assessment of 35 breast specimens identified 5 (14.7%) positive margins. Intraoperative ICG-FI revealed hyperfluorescent signals in 15 (42.9%) patients and an absence of fluorescent signals in 20 (57.1%). Median SBR in patients with involved margins was 1.8 (SD 0.7) and was 1.25 (SD 0.6) in patients with clear margins (p = 0.05). The accuracy, specificity, positive and negative predictive value of ICG-FI for breast surgical margin assessment were 71%, 60%, 29% and 100%, respectively. ConclusionICG-FI of BC surgical beds has a high negative predictive value for surgical margin assessment during BCS. The absence of residual fluorescence in the surgical bed of patients with fluorescent tumors predicts negative margins at final pathology and allows the surgeon to avoid further intraoperative analysis.

Biophotonic technologies for assessment of breast tumor surgical margins-A review.

Breast conserving surgery (BCS) offering similar surgical outcomes as mastectomy while retaining breast cosmesis is becoming increasingly popular for the management of early stage breast cancers. However, its association with reoperation rates of 20% to 40% following incomplete tumor removal warrants the need for a fast and accurate intraoperative surgical margin assessment tool that offers cellular, structural and molecular information of the whole specimen surface to a clinically relevant depth. Biophotonic technologies are evolving to qualify as such an intraoperative tool for clinical assessment of breast cancer surgical margins at the microscopic and macroscopic scale. Herein, we review the current research in the application of biophotonic technologies such as photoacoustic imaging, Raman spectroscopy, multimodal multiphoton imaging, diffuse optical imaging and fluorescence imaging using medically approved dyes for breast cancer detection and/or tumor subtype differentiation toward intraoperative assessment of surgical margins in BCS specimens, and possible challenges in their route to clinical translation.

The feasibility and utility of optical coherence tomography directed histopathology for surgical margin assessment of canine mast cell tumours.

Histopathologic surgical margin assessment in veterinary patients is an imprecise science with assessment limited to a small proportion of the surgical margin due to time and finances. Incomplete excision of canine mast cell tumours (MCTs) alters treatment recommendations and prognosis. Optical coherence tomography (OCT) is a novel imaging modality that has been reported in a single veterinary study for surgical margin assessment. Twenty-five dogs with 34 MCTs were enrolled in a prospective pilot-study to assess the imaging characteristics of canine MCTs with OCT and to evaluate the feasibility and utility of OCT-guided histopathology. All dogs underwent routine surgical excision of MCTs. OCT imaging was used to assess the entire surgical margin prior to placement in formalin. Either normal areas or areas suspected of incomplete MCT excision were inked. Standard histopathologic sectioning and tangential sectioning of inked areas were performed and compared to OCT results. OCT identified MCT near the surgical margin in 10 of 26 specimens (38.4%). Four specimens suspicious for incomplete margins on OCT had incomplete MCT excision that was missed on standard histopathologic sectioning. Six specimens had OCT-guided sections taken as suspicious, which did not show MCT on histopathology. OCT-guided pathology sections were able to detect incompletely excised MCT near the surgical margin with a sensitivity of 90% and specificity of 56.2% in this preliminary study. OCT imaging shows promise for guiding pathologists to areas of interest to improve the diagnostic accuracy of surgical margin assessment in excised canine MCTs.

200 Poster - Importance of intraoperatory surgical margin assessment for positive margin diagnosis in breast cancer-conserving surgery

Background: Surgical margin status is an important prognostic factor. We studied the accuracy of our intraoperative specimen evaluation protocol as a positive margins diagnostic probe.

Fluorescent image-guided surgery in breast cancer by intravenous application of a quenched fluorescence activity-based probe for cysteine cathepsins in a syngeneic mouse model

PurposeThe reoperation rate for breast-conserving surgery is as high as 15–30% due to residual tumor in the surgical cavity after surgery. In vivo tumor-targeted optical molecular imaging may serve as a red-flag technique to improve intraoperative surgical margin assessment and to reduce reoperation rates. Cysteine cathepsins are overexpressed in most solid tumor types, including breast cancer. We developed a cathepsin-targeted, quenched fluorescent activity-based probe, VGT-309, and evaluated whether it could be used for tumor detection and image-guided surgery in syngeneic tumor-bearing mice.MethodsBinding specificity of the developed probe was evaluated in vitro. Next, fluorescent imaging in BALB/c mice bearing a murine breast tumor was performed at different time points after VGT-309 administration. Biodistribution of VGT-309 after 24 h in tumor-bearing mice was compared to control mice. Image-guided surgery was performed at multiple time points tumors with different clinical fluorescent camera systems and followed by ex vivo analysis.ResultsThe probe was specifically activated by cathepsins X, B/L, and S. Fluorescent imaging revealed an increased tumor-to-background contrast over time up to 15.1 24 h post probe injection. In addition, VGT-309 delineated tumor tissue during image-guided surgery with different optical fluorescent imaging camera systems.ConclusionThese results indicate that optical fluorescent molecular imaging using the cathepsin-targeted probe, VGT-309, may improve intraoperative tumor detection, which could translate to more complete tumor resection when coupled with commercially available surgical tools and techniques.

A retrospective cohort study of comprehensive peripheral and deep margin assessment in Merkel cell carcinoma: Standard margins may be unreliable

To the Editor: The National Comprehensive Cancer Network (NCCN) guidelines recommend wide excision with 1- to 2-cm margins to investing muscular fascia or pericranium for Merkel cell carcinoma (MCC) treatment. The ideal method of excision and surgical margin assessment has not been established. The goal of this study was to assess the adequacy of currently recommended surgical margins using complete histopathologic margin evaluation methods: Mohs micrographic surgery (MMS) or wide local excision with complete circumferential peripheral and deep margin assessment with intraoperative en face frozen sections.

Real Time Tissue Identification From Diathermy Smoke by Differential Mobility Spectrometry

Current methods for intraoperative surgical margin assessment are inadequate in terms of diagnostic accuracy, ease-of-use, and speed of analysis. Molecular analysis of tissues could potentially overcome these issues. A system based on differential ion mobility spectrometry (DMS) analysis of surgical smoke has been proposed as one potential method, but to date, it has been able to function in a relatively slow and heavily controlled manner that is inadequate for clinical use. In this study, we present an integrated sensor system that can measure a surgical smoke sample in seconds and relay the information of the tissue type to the user in near real time in simulated surgical use. The system was validated by operating porcine adipose tissue and muscle tissue. The differentiation of these tissues based on their surgical smoke profile with a cross-validated linear discriminant analysis model produced a classification accuracy of 93.1% (N = 1059). The measurements were also classified with a convolutional neural network model, resulting in a classification accuracy of 93.2%. These results indicate that the DMS-based smoke analysis system is capable of rapid tissue identification from surgical smoke produced in freehand surgery.

Evaluating optical coherence tomography for surgical margin assessment of canine mammary tumours.

Optical coherence tomography (OCT) uses near-infrared light waves to generate real-time, high-resolution images on the microscopic scale similar to low power histopathology. Previous studies have demonstrated the use of OCT for real-time surgical margin assessment for human breast cancer. The use of OCT for canine mammary tumours (CMT) could allow intra-operative visualisation of residual tumour at the surgical margins. The purpose of this study was to assess OCT imaging for the detection of incomplete tumour resection following CMT surgery. We hypothesized that the OCT images would have comparable features to histopathological images of tissues at the surgical margins of CMT resections along with a high sensitivity of OCT detection of incomplete surgical excision of CMT. Thirty surgical specimens were obtained from nineteen client-owned dogs undergoing surgical resection of CMT. OCT image appearance and characteristics of adipose tissue, skin, mammary tissue and mammary tumour at the surgical margins were distinct and different. The OCT images of normal and abnormal tissues at the surgical margins were utilized to develop a dataset of OCT images for observer evaluation. The sensitivity and specificity for ex vivo images were 83.3% and 82.0% (observer 1) and 70.0% and 67.9% (observer 2). The sensitivity and specificity for in vivo images were 70.0% and 89.3% (observer 1) and 76.7% and 67.9% (observer 2). These results indicate a potential use of OCT for surgical margin assessment for CMT to optimize surgical intervention and clinical outcomes. Improved training and experience of observers may improve sensitivity and specificity.

Vacuum intraoperative specimen mammography: A novel technique

ObjectiveIntraoperative specimen mammography (ISM) is a diffuse technique that allows surgeons to check specimens immediately after lumpectomy. Although the specimen is slightly compressed, the radiological image can be distorted by tissue overlap, and this may affect the evaluation of tumour borders, resulting in extension of the lumpectomy. As ISM may be less precise due to inadequate compression, a vacuum effect was applied to the specimen to increase the precision of margin detection. Study designThis study was conducted at St. Anna Hospital Breast Unit, Turin, Italy. Women who underwent lumpectomy for cancer were eligible for inclusion. Both standard ISM (sISM) and vacuum ISM (vISM) were performed. Eighteen specimens obtained after lumpectomy from 1 April 2018 to 31 April 2018 were scanned. sISM (two orthogonal projections) was performed. Next, the specimen was placed in a vacuum, and vISM was performed. The examination was completed with a second orthogonal projection after removal of the vacuum, replacement of the specimen and repositioning of the vacuum. Additional tissue was removed if the surgeon considered that excision was inadequate. Finally, the specimen was sent for definitive histopathological analysis, which is the gold standard for the assessment of surgical margins. Intraoperative histological margin assessment was not performed. The sISM and vISM images and final histopathology reports were compared. ResultsFor sISM, specificity was 47 % [95 % confidence interval (CI) 25–70], sensitivity was 67 % (95 % CI 21–94), positive predictive value (PPV) was 20 % (95 % CI 6–51) and negative predictive value (NPV) was 88 % (95 % CI 53–98). For vISM, specificity was 100 % (95 % CI 80–100), sensitivity was 67 % (95 % CI 21–94), PPV was 100 % (95 % CI 34–100) and NPV was 94 % (95 % CI 72–99). ConclusionThese data suggest that the vacuum technique is feasible, cost-saving and yields results that are similar to those from frozen sections but without the limitations, such as prolonged operating time, high variability in sensitivity due to pathologists’ abilities, risk of compromising the histological report, and unreliability for small lumps and ductal carcinoma in situ.

The Head and Neck Oncology Specimen: The Gross Examination as an Essential Component to Diagnosis and Optimal Patient Outcomes

Abstract Achieving complete resection in head and neck oncologic cancer surgeries without leaving behind residual disease is the most significant factor to minimize the risk of locoregional recurrence and overall survival. Approaches regarding how to handle en bloc specimens for margin assessment also impact patients' long-term outcomes. Although sampling the tumor bed to evaluate for residual tumor at surgical margins (excision edges) is the most commonly practiced technique, some studies have shown that separately submitted tumor bed margins have lower sensitivity for tumor assessment compared with detection of those positive margins from direct sampling of the en bloc specimen. Close collaboration between the surgeon and pathologist is fundamental to optimize surgical margin assessment and reporting. Current American Joint Committee on Cancer (eighth edition) and National Comprehensive Cancer Network guidelines recommend the en bloc specimen sampling for intraoperative assessment of surgical margins. Cutoffs less than 5 mm between tumor and the surgical margin had been considered adequate in specific subsites in head and neck region. Emerging in situ imaging modalities and molecular testing may help to reduce inadequate surgical margins during tumor resections; however, further studies and validation are needed. This article presents a review of recent publications and guidelines of general grossing principles and recent updates to optimize cancer-free surgical margins and to emphasize the limitation issues encountered in routine practice.

Feasibility of integrated high‐wavenumber Raman imaging and fingerprint Raman spectroscopy for fast margin assessment in breast cancer surgery

AbstractIntraoperative assessment of surgical margins remains one of the main challenges in cancer surgery. Raman spectroscopy can detect cancer cells with high accuracy, but it is time‐consuming. In this paper, we investigated a selective‐sampling Raman spectroscopy approach, based on high wavenumber (HW) Raman imaging (spectral range 2,500–3,500 cm−1) and fingerprint Raman spectroscopy (spectral range 600–1,800 cm−1), to reduce the overall tissue analysis time while maintaining high diagnostic accuracy. HW Raman mapping was used as a first step to identify the adipose tissue regions based on the C–H stretching bands at 2,700–2,950 cm−1. As residual tumors are typically found in nonadipose tissue, an algorithm was developed to allocate sampling points for fingerprint Raman spectroscopy at locations corresponding to low intensity in the HW‐Raman maps. Preliminary results show that HW‐Raman imaging based on a 671 nm laser is effective and fast for mapping of adipose tissue in breast resections, with typical imaging times of 2 min for tissue areas as large as 2 × 2 cm2 areas. Albeit the remaining high fluorescence background in the fingerprint region prevents the use of single 671‐nm laser, the HW Raman imaging can be still exploited in combination with 785‐nm excitation Raman spectroscopy for identifying residual tumor. Although this study demonstrates the feasibility of this approach, further improvements, such as using single element detectors for HW Raman imaging, are required to increase the analysis speed further towards intraoperative use in the routine clinical setting.

Imprint Cytology for Intra-operative Assessment of Surgical Margins for Skeletal Tumours in COVID-19 Pandemic.

In the current COVID-19 pandemic, tremendous pressure is been exerted on the existing health infrastructure of many developing nations. Limb salvage surgeries in bone and soft tissue sarcomas cannot be delayed beyond a certain time-period and constitute an orthopaedic emergency in certain situations. Evaluation of intra-operative surgical margins forms an important step especially in cases with planned close margins or intercalary resections. Techniques such as imprint cytology can be preferred over frozen sections for evaluation of the surgical margins especially in COVID-19 positive patients. The advantages it offers such as completion of the procedure within the operation room complex, no generation of aerosols, and almost equal sensitivity and specificity when compared with frozen section method do warrant a modification of current surgical practice in the current health crisis especially in resource-constrained nations. Awareness and better communication regarding the same from the pathologist to the surgical team will go a long way in conserving resources and avoid unnecessary exposure to potentially infected aerosols.

Feasibility of multimodal multiphoton microscopy to facilitate surgical margin assessment in pancreatic cancer: erratum

After publication of our original paper Appl. Opt. 59, G1 (2020)APOPAI0003-693510.1364/AO.391315, it came to the authors’ attention that there were missing labels on Fig. 5. The labels are important for our readers to understand the figure.