Intraoperative Margin Assessment Research Articles

The utility of intraoperative marrow margin frozen section in extremity bone sarcoma resection.

Intraoperative frozen section analysis is commonly used to evaluate marrow margins during extremity bone sarcoma resections, but its efficacy in the era of magnetic resonance imaging is debated. This study aimed to compare the accuracy of intraoperative frozen section assessment with final pathology, assess its correlation with gross intraoperative margin assessment, and evaluate its impact on surgical decision making. Consecutive patients undergoing extremity bone sarcoma resections from 2010 to 2022 at a single sarcoma center were included. Intraoperative frozen section and gross margin assessments were compared to final pathology using positive predictive values (PPV) and negative predictive values (NPV). Changes in surgical decisions due to positive intraoperative margins were recorded. Of 166 intraoperative frozen section marrow margins, four were indeterminant/positive, with two false positive/indeterminant findings and two false negatives compared to final pathology. Gross intraoperative assessment had no false positives and two false negatives. Frozen section analysis yielded a PPV of 50% (95% confidence interval [CI]: 16%-84%) and NPV of 98.8% (95% CI: 97%-100%), while gross assessment had a PPV of 100% (95% CI: 16%-100%) and NPV of 98.8% (95% CI: 97%-100%). Positive frozen section margins led to additional resections in three of four cases. Intraoperative frozen section analysis did not offer added clinical value beyond gross margin assessment in extremity bone sarcoma resections. It exhibited a low PPV and led to unnecessary additional resections. Gross intraoperative assessment proved adequate for margin evaluation, potentially saving time and resources.

Enhancing Intraoperative Tissue Identification: Investigating a Smart Electrosurgical Knife's Functionality During Electrosurgery.

Detecting the cancerous growth margin and achieving a negative margin is one of the challenges that surgeons face during cancer procedures. A smart electrosurgical knife with integrated optical fibers has been designed previously to enable real-time use of diffuse reflectance spectroscopy for intraoperative margin assessment. In this paper, the thermal effect of the electrosurgical knife on tissue sensing is investigated. Porcine tissues and phantoms were used to investigate the performance of the smart electrosurgical knife after electrosurgery. The fat-to-water content ratio (F/W-ratio) served as the discriminative parameter for distinguishing tissues and tissue mimicking phantoms with varying fat content. The F/W-ratio of tissues and phantoms was measured with the smart electrosurgical knife before and after 14 minutes of electrosurgery. Additionally, a layered porcine tissue and phantom were sliced and measured from top to bottom with the smart electrosurgical knife. Mapping the thermal activity of the electrosurgical knife's electrode during animal tissue electrosurgery revealed temperatures exceeding 400 °C. Electrosurgery for 14 minutes had no impact on the device's accurate detection of the F/W-ratio. The smart electrosurgical knife enables real-time tissue detection and predicts the fat content of the next layer from 4 mm ahead. The design of the smart electrosurgical knife outlined in this paper demonstrates its potential utility for tissue detection during electrosurgery. In the future, the smart electrosurgical knife could be a valuable intraoperative margin assessment tool, aiding surgeons in detecting tumor borders and achieving negative margins.

The potential of indocyanine green fluorescence detection in surgical cut margin of breast conserving surgery.

Fluorescence-guided surgery (FGS) is a cutting-edge technology that uses near-infrared (NIR) fluorescence imaging to guide surgeons in surgery. Indocyanine green (ICG) is a fluorescent dye, which can be used for in vivo imaging of tumor cells. We aimed to explore the use of ICG fluorescence-guided technology as a rapid intraoperative margin assessment method for breast cancer surgery. In addition, we also compared the dose selection of ICG. This was a non-randomized prospective cohort study. Data were collected between August 2021 and October 2022 in the Division of Breast Surgery, Department of General Surgery, Nanjing Drum Tower Hospital, the Affiliated Hospital of Medical School, Nanjing University. Upon specimen removal, tumor margins were immediately analyzed by ICG fluorescence detection and then sent to the pathology department for intraoperative frozen section analysis and subsequent routine pathological examination. Abnormal margin rates were calculated and compared using intraoperative frozen section analysis and under the guidance of ICG fluorescence. The study included 69 cases of breast cancer patients who underwent tumor resection assisted by ICG fluorescence-guided technology, including 18 patients with a 0.5 mg/kg dose and 51 patients with a 1.0 mg/kg dose. According to the study findings, the ICG test achieved a sensitivity of 81.82% and a specificity of 75.82%. At a dose of 0.5 mg/kg, the sensitivity was 66.67% whereas the specificity was 93.33%. At the dose of 1 mg/kg, the sensitivity was 87.5%, and the specificity was 74.42%. Similarly, for intraoperative frozen section analysis, the sensitivity was 81.82%, but the specificity was enhanced to 94.83%. Positive surgical cut margin was not identified in 2/69 by ICG fluorescence and frozen section analysis respectively. The sensitivity of ICG fluorescence detection is comparable to that of frozen section analysis, but the specificity is poor. The sensitivity increased and the specificity decreased at 1 mg/kg compared to the 0.5 mg/kg dose. ICG fluorescence can be used as a supplementary tool for frozen section analysis. These findings support further development and clinical performance assessment of ICG fluorescence.

Cerenkov Luminescence Imaging and Flexible Autoradiography for specimen margin assessment during breast-conserving cancer surgery

Abstract Background Among women with breast cancer who undergo breast-conserving surgery (BCS), 20-25% require further surgery due to close or involved margins. Improved techniques are needed to assess resection margins. Purpose The study aims were to assess the feasibility of the combined techniques of Cerenkov Luminescence Imaging—Flexible AutoRadiography (CLI-FAR) to assess excision specimen margins in women undergoing breast-conserving surgery (BCS) and to determine the diagnostic performance of intraoperative CLI-FAR imaging with postoperative histopathology as the reference standard. Materials and Methods Women undergoing BCS were recruited prospectively at a single centre over thirteen months. Patients were injected with 250MBq +/- 10MBq of 18F-fluorodeoxyglucose (18F-FDG), 145 minutes before surgery and the excised specimens were imaged intraoperatively. The surgically excised tumour was initially imaged using conventional x-ray, and margins suspected to be involved by tumor were then imaged using CLI-FAR. CLI-FAR imaging was performed using the LightPath system® (Lightpoint®), an in vitro diagnostic device designed to identify and locate positron-emitting radionuclides. Any suspicious margin underwent an immediate re-excision in the form of cavity shavings. Sensitivity, specificity, positive and negative predictive value whilst considering histopathological assessment as the golden standard were used to assess the performance of CLI-FAR. Results In all, 54 specimens were imaged in 52 patients with a total of 104 margins reviewed using CLI-FAR. The results showed a specificity of 97.8% (89/91, 95% CI: 95.0%, 100.6%), sensitivity of 76.9% (10/13, 95% CI: 68.3%, 85.0%), positive predictive value (PPV) of 83.3% (10/12, 95% CI: 76.2%, 90.5%) and negative predictive value (NPV) of 96.7% (89/92, 95% CI: 93.3%, 100.2%). In all, 8 patients had 10 positive margins on CLI-FAR imaging and were treated accordingly. CLI-FAR imaging reduced the re-excision rate by (17.3/25) 69%. Conclusion CLI-FAR imaging is a promising technique for intraoperative margin assessment in women undergoing BCS for invasive breast cancer.

Diagnostic accuracy of autofluorescence-Raman spectroscopy for surgical margin assessment during Mohs micrographic surgery of basal cell carcinoma.

Autofluorescence (AF) - Raman spectroscopy is a technology that can detect residual basal cell carcinoma (BCC) on the resection margin of fresh surgically excised tissue specimens. The technology does not require tissue fixation, staining, labelling, or sectioning, and provides quantitative diagnosis maps of the surgical margins in 30 minutes. To determine the accuracy of the AF-Raman instrument to detect incomplete excisions of BCC during Mohs micrographic surgery, using histology as reference standard. Skin layers from 130 patients undergoing Mohs surgery at the Nottingham University Hospitals NHS Trust (September 2022 to July 2023) were investigated with the AF-Raman instrument. The layers were measured fresh, immediately after excision. The AF-Raman results and the intra-operative assessment by Mohs surgeons were compared to a post-operative consensus-derived reference produced by three dermatopathologists. The sensitivity, specificity, positive predictive value, and negative predictive value were calculated. The AF-Raman analysis was successfully completed for 125 out of the 130 layers. The AF-Raman analysis covered 91% of the specimen surface area on average, with the lowest being 87% for eyelid and the highest being 94% for forehead specimens. The AF-Raman instrument identified positive margins in 24 out of 36 BCC-positive cases, resulting in a 67% sensitivity (95% confidence intervals (CI): 49%-82%) and negative margins in 65 out of 89 BCC-negative cases, resulting in a 73% specificity (95% CI 63%-82%). Only one out of the 12 false negative cases was caused by misclassification by the AF-Raman algorithm. The other 11 false negatives cases were produced because no valid Raman signal was recorded at the location of the residual BCC due to either occlusion by blood or poor contact between tissue and cassette window. The intra-operative diagnosis by Mohs surgeons identified positive margins in 31 out of 36 BCC-positive cases, 86% sensitivity (95% CI: 70%-95%), and negative margins in 79 out of 89 BCC-negative cases, 89% specificity (95% CI: 81%-95%). This study shows that the AF-Raman instrument has potential for intra-operative microscopic assessment of surgical margins in surgery of BCC. Further improvements are required for tissue processing to ensure complete coverage of the surgical specimens. ClinicalTrials.gov ID NCT03482622.

Abstract PO2-23-07: Three-dimensional navigated mass spectrometry for intraoperative margin assessment during breast cancer surgery

Abstract Positive resection margins occur in approximately 25% of breast cancer (BCa) surgeries, requiring re-operation. Margin status is not routinely available during surgery; thus, technologies that identify residual cancer on the specimen or cavity are needed to provide intraoperative decision support that may reduce positive margin rates. Rapid evaporative ionization mass spectrometry (REIMS) is an emerging technique that chemically profiles the plume generated by tissue cauterization to classify the ablated tissue as either cancerous or non-cancerous, on the basis of detected lipid species. Although REIMS can distinguish cancer and non-cancerous breast tissue by the signals generated, it does not indicate the location of the classified tissue in real-time. Our objective was to combine REIMS with spatio-temporal navigation (navigated REIMS), and to compare performance of navigated REIMS with conventional histopathology examination (gold standard) to assess margin status (positive or negative) in patients undergoing surgery for BCa. A multivariate model was trained using pathology-validated mass spectra from ex vivo resection specimens from 11 patients, including 36 spectra from invasive cancer, and 118 spectra from normal breast adipose. This model was subsequently tested retrospectively on intraoperative data from 25 BCa cases that were conducted using navigated REIMS. Navigation was facilitated by an electromagnetic sensor placed on the cautery. To record the position of the tumor, a localization wire fitted with an electromagnetic sensor was placed into the tumor using ultrasound prior to surgery, and a 3D map of the tumor was created. This enabled real-time knowledge of the cautery position relative to the tumor during surgery. Spectra from the plume classified as BCa were mapped onto a display of the tumor region and compared with the pathology report. Our multivariate classifier exhibited >90% accuracy on cross-validation, driven by an elevated ratio of glycerophospholipid:triglyceride in cancer as compared with normal adipose. In the intraoperative testing cohort, 4/150 margins were assessed by pathology as positive, all of which were correctly identified by REIMS (Sensitivity=100%). Notably, two of these cases were positive for ductal carcinoma in situ. 146/150 margins were negative, of which 131/146 negative margins were consistent with histopathology (Specificity=90%). There were 13 negative margins that were determined to be positive by REIMS (false positive), of which 8 margins were noted as either ‘close margins’ (with cancer cells being detected within 1 mm of the inked margin on histopathology), or as high-density normal breast tissue. Other normal tissue such as skin and muscle also exhibited high phospholipid content but these spectra could be rationalized by relative distance from the tumor region using the navigation data and/or information provided by the surgeon in real-time. We have demonstrated the importance of spatio-temporal tracking and histopathology to validate intraoperative REIMS. Furthermore, we have shown the feasibility of navigated REIMS in identifying margins containing cancer in real-time during BCa surgery, where a wider excision may be desirable. Citation Format: Martin Kaufmann, Amoon Jamzad, Tamas Ungi, Jessica R Rodgers, Teaghan Koster, Chris Yeung, Josh Ehrlich, Alice Santilli, Mark Asselin, Natasja Janssen, Julie McMullen, Kathryn Solberg, Joanna Cheesman, Alessia Di Carlo, Kevin Yi Mi Ren, Sonal Varma, Shaila Merchant, Cecil Jay Engel, G Ross Walker, Andrea Gallo, Doris Jabs, Parvin Mousavi, Gabor Fichtinger, John F Rudan. Three-dimensional navigated mass spectrometry for intraoperative margin assessment during breast cancer surgery [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-23-07.

Abstract PO1-23-07: The effect of intra-operative margin assessment during breast conserving surgery for breast cancer in a Dutch cohort

Abstract Background Pre-operative tumour localisation and intraoperative specimen radiography are necessary to perform adequate resection of non-palpable breast tumours. Intraoperative digital specimen mammography (IDSM), is an alternative to conventional specimen radiography (CSR) and has the benefit of providing immediate specimen evaluation and the potential of decreasing operation time. IDSM may also reduce positive margins and re-excision rates. IDSM was implemented in our hospital in 2018. The study objective was to evaluate the surgery time, radicality and re-excisions in IDSM and CSR. Methods A single centre retrospective cohort study with two cohorts: CSR (n=532) and IDSM (n=475). The primary outcome was duration of surgery. Secondary outcomes were margin status of the primary surgery, the perioperative cavity shave rate and the re-excision rate. Differences between cohorts were compared using univariate statistics and multiple regression to adjust for variables that were statistically significantly associated with duration of surgery. Results IDSM use was associated with 8 minutes shorter surgery time (B -8.242, p < 0.001). Treatment variables independently associated with the duration of surgery were use of IDSM, type of (axillary) surgery and the performance of cavity shaving. Cavity shaves were more often performed when IDSM was used (24% versus 14% in CSR group, p < 0.001), while the proportion of radical first surgeries (93% versus 96% respectively, p = 0.070) was comparable. Conclusion IDSM was associated with a modest reduction in duration of surgery. Surgeons performed more cavity shaves since IDSM but this was not reflected by a lower proportion of patients with positive margins. Table 1. Baseline characteristics of the CSR versus the IDSM cohort Table 2. Results of surgery in the CSR versus the IDSM cohort. Citation Format: Sophie Wooldrik, Elles van de Voort, Taco Klem, Thijs van Dalen, Cornelis Verhoef, Gerson Struik, Erwin Birnie. The effect of intra-operative margin assessment during breast conserving surgery for breast cancer in a Dutch cohort [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-23-07.

Intra-operative margin assessment – Can technology alone improve outcomes?

Intra-operative margin assessment – Can technology alone improve outcomes?

Combined multi-separation diffuse reflectance and intrinsic fluorescence spectroscopy: A tool for rapid diagnostics and intraoperative margin assessment in breast surgery

Combined multi-separation diffuse reflectance and intrinsic fluorescence spectroscopy: A tool for rapid diagnostics and intraoperative margin assessment in breast surgery

Cerenkov Luminescence Imaging and flexible autoradiography – A first-in-human novel imaging study for intra-operative margin assessment in women undergoing breast-conserving surgery for cancer

Cerenkov Luminescence Imaging and flexible autoradiography – A first-in-human novel imaging study for intra-operative margin assessment in women undergoing breast-conserving surgery for cancer

Comparative Study of Indocyanine Green Intravenous Injection and the Inflation-Deflation Method for Assessing Resection Margins in Segmentectomy for Lung Cancer: A Single-Center Retrospective Study.

The inflation-deflation (ID) method has long been the standard for intraoperative margin assessment in segmentectomy. However, with advancements in vision technology, the use of near-infrared mapping with indocyanine green (ICG) has become increasingly common. This study was conducted to compare the perioperative outcomes and resection margins achieved using these methods. This retrospective study included patients who underwent direct segmentectomy for clinical stage I lung cancer between January 2018 and September 2022. We compared perioperative factors, including bronchial and parenchymal resection margins, according to the margin assessment method and the type of segmentectomy performed. Since the ICG approach was adopted in April 2021, we also examined a recent subgroup of patients treated from then onward. A total of 319 segmentectomies were performed. ID and ICG were utilized for 261 (81.8%) and 58 (18.2%) patients, respectively. Following April 2021, 61 patients (51.3%) were treated with ID, while 58 (48.7%) received ICG. We observed no significant difference in resection margins between ID and ICG for bronchial (2.7 cm vs. 2.3 cm, p=0.07) or parenchymal (2.5 cm vs. 2.3 cm, p=0.46) margins. Additionally, the length of hospitalization and the complication rate were comparable between groups. Analysis of the recent subgroup confirmed these findings, showing no significant differences in resection margins (bronchial: 2.6 cm vs. 2.3 cm, p=0.25; parenchymal: 2.4 cm vs. 2.3 cm, p=0.75), length of hospitalization, or complication rate. The perioperative outcomes and resection margins achieved using ID and ICG were comparable, suggesting that both methods can safely guide segmentectomy procedures.

Intraoperative Evaluation of Breast Tissues During Breast Cancer Operations Using the MasSpec Pen

Surgery with complete tumor resection remains the main treatment option for patients with breast cancer. Yet, current technologies are limited in providing accurate assessment of breast tissue in vivo, warranting development of new technologies for surgical guidance. To evaluate the performance of the MasSpec Pen for accurate intraoperative assessment of breast tissues and surgical margins based on metabolic and lipid information. In this diagnostic study conducted between February 23, 2017, and August 19, 2021, the mass spectrometry-based device was used to analyze healthy breast and invasive ductal carcinoma (IDC) banked tissue samples from adult patients undergoing breast surgery for ductal carcinomas or nonmalignant conditions. Fresh-frozen tissue samples and touch imprints were analyzed in a laboratory. Intraoperative in vivo and ex vivo breast tissue analyses were performed by surgical staff in operating rooms (ORs) within 2 different hospitals at the Texas Medical Center. Molecular data were used to build statistical classifiers. Prediction results of tissue analyses from classification models were compared with gross assessment, frozen section analysis, and/or final postoperative pathology to assess accuracy. All data acquired from the 143 banked tissue samples, including 79 healthy breast and 64 IDC tissues, were included in the statistical analysis. Data presented rich molecular profiles of healthy and IDC banked tissue samples, with significant changes in relative abundances observed for several metabolic species. Statistical classifiers yielded accuracies of 95.6%, 95.5%, and 90.6% for training, validation, and independent test sets, respectively. A total of 25 participants enrolled in the clinical, intraoperative study; all were female, and the median age was 58 years (IQR, 44-66 years). Intraoperative testing of the technology was successfully performed by surgical staff during 25 breast operations. Of 273 intraoperative analyses performed during 25 surgical cases, 147 analyses from 22 cases were subjected to statistical classification. Testing of the classifiers on 147 intraoperative mass spectra yielded 95.9% agreement with postoperative pathology results. The findings of this diagnostic study suggest that the mass spectrometry-based system could be clinically valuable to surgeons and patients by enabling fast molecular-based intraoperative assessment of in vivo and ex vivo breast tissue samples and surgical margins.

185 (PB-092) Poster - Cerenkov Luminescence Imaging and Flexible AutoRadiography – a first-in-human novel imaging study for intra-operative margin assessment in women undergoing breast-conserving surgery for cancer

185 (PB-092) Poster - Cerenkov Luminescence Imaging and Flexible AutoRadiography – a first-in-human novel imaging study for intra-operative margin assessment in women undergoing breast-conserving surgery for cancer

Tenascin-C as a target for Intra-operative margin assessment in patients after neo-adjuvant chemotherapy.

Tenascin-C as a target for Intra-operative margin assessment in patients after neo-adjuvant chemotherapy.

Mutation Endmember Library Sparse Mixed Abundance Estimation Model for Glioma Margin Determination with Raman Spectroscopy.

The glioma margin is a region of brain tissue where glioblastoma tissue transitions to normal tissue with varying levels of cancer cell concentration. This article uses Raman spectroscopy to detect the glioma margin, which is a fuzzy and uncertain substance that cannot be accurately identified by conventional pattern recognition algorithms. This article applies abundance estimation to Raman spectral unmixing of glioma marginal tissues for the accurate and real-time determination of the tumor surgical boundary during an operation. This article introduces a novel method: the mutation endmember library sparse mixed abundance estimation model. This method adds different representative Raman spectra to each endmember library to account for its dynamic properties, thus reducing errors from such variations and fully capturing the diversity within the substance. Moreover, it uses group sparse endmember bundle decomposition, where each substance endmember library consists of multiple Raman spectra. Fractionally mixed norms are used to ensure intergroup and intragroup sparsity, eliminate redundant spectra, and enhance the generalization ability of the abundance estimation. This method was compared with conventional abundance estimation methods. The experimental results of 112 human glioma margin tissues demonstrate that this method outperforms other methods in terms of accuracy, stability, and generalization ability. This article demonstrates the potential of miniature Raman spectroscopy as a new approach to in vivo and noninvasively determining intraoperative margin assessment.

A blinded study using laser induced endogenous fluorescence spectroscopy to differentiate ex vivo spine tumor, healthy muscle, and healthy bone

Ten patients undergoing surgical resection for spinal tumors were selected. Samples of tumor, muscle, and bone were resected, de-identified by the treating surgeon, and then scanned with the TumorID technology ex vivo. This study investigates whether TumorID technology is able to differentiate three different human clinical fresh tissue specimens: spine tumor, normal muscle, and normal bone. The TumorID technology utilizes a 405 nm excitation laser to target endogenous fluorophores, thereby allowing for the detection of tissue based on emission spectra. Metabolic profiles of tumor and healthy tissue vary, namely NADH (bound and free emission peak, respectively: 487 nm, 501 nm) and FAD (emission peak: 544) are endogenous fluorophores with distinct concentrations in tumor and healthy tissue. Emission spectra analyzed consisted of 74 scans of spine tumor, 150 scans of healthy normal bone, and 111 scans of healthy normal muscle. An excitation wavelength of 405 nm was used to obtain emission spectra from tissue as previously described. Emission spectra consisted of approximately 1400 wavelength intensity pairs between 450 and 750 nm. Kruskal–Wallis tests were conducted comparing AUC distributions for each treatment group, α = 0.05. Spectral signatures varied amongst the three different tissue types. All pairwise comparisons among tissues for Free NADH were statistically significant (Tumor vs. Muscle: p = 0.0006, Tumor vs. Bone: p < 0.0001, Bone vs. Muscle: p = 0.0357). The overall comparison of tissues for FAD (506.5–581.5 nm) was also statistically significant (p < 0.0001), with two pairwise comparisons being statistically significant (Tumor vs. Muscle: p < 0.0001, Tumor vs. Bone: p = 0.0045, Bone vs. Muscle: p = 0.249). These statistically significant differences were maintained when stratifying tumor into metastatic carcinoma (N = 57) and meningioma (N = 17). TumorID differentiates tumor tissue from normal bone and normal muscle providing further clinical evidence of its efficacy as a tissue identification tool. Future studies should evaluate TumorID’s ability to serve as an adjunctive tool for intraoperative assessment of surgical margins and surgical decision-making.

Current clinical applications of Cerenkov luminescence for intraoperative molecular imaging.

Cerenkov luminescence imaging (CLI) is a new emerging technology that can be used for optical imaging ofapproved radiotracers, both in a preclinical, and even more recently, in a clinical context with rapid imaging times,low costs, and detection in real-time (Grootendorst et al. Clin Transl Imaging 4(5):353-66, 2016); Wang et al.Photonics 9(6):390, 2022). This brief review provides an overview of clinical applications of CLI with a focuson intraoperative margin assessment (IMA) to address shortcomings and provide insight for future work in thisapplication. A literature review was performed using PubMed using the search words Cerenkov luminescence imaging (CLI),intraoperative margin assessment (IMA), and image-guided surgery. Articles were selected based on title, abstract,content, and application. Original research was summarized to examine advantages and limitations of CLI compared to other modalities forIMA. The characteristics of Cerenkov luminescence (CL) are defined, and results from relevant clinical trials arediscussed. Prospects of ongoing clinical trials are reviewed, along with technological advancements related to CLI. CLI is a proven method for molecular imaging and shows feasibility for determining intraoperative margins if futurework involves establishing quantitative approaches for attenuation and scattering, depth analysis, and radiationsafety for CLI at a larger scale.

Correlation of intra operative specimen imaging with final histopathology in breast conserving surgery for breast cancer.

To determine the effectiveness of specimen mammography in breast conserving surgery cases with respect to reduction in margin positivity rate, and to see whether the rate of secondary surgeries is decreased by intra-operative excision based on specimen mammography evaluation. The retrospective study was conducted at the Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore, Pakistan, and comprised data from January 2018 to December 2019 related to all female breast cancer patients who underwent mastectomy or breast conserving surgery with the involvement of specimen mammography. Sensitivity, specificity, positive predictive value and negative predictive value of specimen mammography were calculated. Data was analysed using SPSS 20. Of the 226 patients initially assessed, 65(28.7%) were excluded, and the final sample comprised 161(71.2%) women with mean age 46.71±10.47 years. The sensitivity, specificity, positive predictive value and negative predictive value of specimen mammography for the sample were 65.8%, 80.8%, 54% and 87.3%, respectively. Performing specimen mammography for intra-operative margin assessment in 12 patients was likely to spare one patient from re-excision. Intra-operative specimen mammography was found to be a reliable tool for assessing margin status.

Role of Intraoperative Frozen Section Assessment of Proximal Bile Duct Margins and the Impact of Additional Re-Resection in Perihilar Cholangiocarcinomas.

Intraoperative frozen section (FS) analysis to assess the bile duct margin status is commonly used to assess the completeness of resection during surgery for perihilar cholangiocarcinoma (pCCA) resection. However, the impact of additional re-section on the long-term outcome after obtaining an initial positive margin remains unclear. Patients diagnosed as pCCA on preoperative imaging and subjected to curative intent surgery from May 2013 to June 2021 with a minimum follow-up of 2years were included. Intraoperative FS analysis of the proximal bile duct margin was performed in all patients. A positive margin was defined by the presence of invasive cancer. Out of the 62 patients with a preoperative diagnosis of pCCA on imaging, 35 patients were included for final analyses after excluding patients with inoperable disease (on staging laparoscopy or local exploration) and other/benign pathology on the final histopathology report. Out of the 35 patients, patients with postoperative 90-day mortality were excluded from the final survival analysis. FS analysis revealed an initial positive margin in 10 (28.5%) patients. Among 10 patients who underwent re-resection to achieve negative proximal margins, only 5 patients achieved a negative margin (secondary R0). An initial positive margin was associated with poor long-term outcomes. Median disease-free survival (DFS) and overall survival (OS) were 16 and 19.6months for patients with an initial positive margin, but 36 and 58.2months for patients with an initial negative margin, respectively (p = 0.012). The median DFS and OS were significantly lower for those with secondary R0 as compared to primary R0 (16 vs. 36months for DFS, p = 0.117 and 19.6 vs. 58.2months for OS, p = 0.027, respectively). An intraoperative FS positive proximal hepatic duct margin dictates poor long-term outcomes for patients with resectable pCCA. Additional resection has a questionable benefit on survival, when a secondary negative margin is achieved.

Intraoperative margin assessment for basal cell carcinoma with deep learning and histologic tumor mapping to surgical site

Successful treatment of solid cancers relies on complete surgical excision of the tumor either for definitive treatment or before adjuvant therapy. Intraoperative and postoperative radial sectioning, the most common form of margin assessment, can lead to incomplete excision and increase the risk of recurrence and repeat procedures. Mohs Micrographic Surgery is associated with complete removal of basal cell and squamous cell carcinoma through real-time margin assessment of 100% of the peripheral and deep margins. Real-time assessment in many tumor types is constrained by tissue size, complexity, and specimen processing / assessment time during general anesthesia. We developed an artificial intelligence platform to reduce the tissue preprocessing and histological assessment time through automated grossing recommendations, mapping and orientation of tumor to the surgical specimen. Using basal cell carcinoma as a model system, results demonstrate that this approach can address surgical laboratory efficiency bottlenecks for rapid and complete intraoperative margin assessment.