The computer-aided design margin: Ex vivo 3D specimen mapping to improve communication between surgeons and pathologists

Trends and Future Directions in Margin Analysis for Head and Neck Cancers

Margin status in head and neck cancer has important prognostic implications. Currently, resection is based on manual palpation and gross visualization followed by intraoperative specimen or tumor bed-based margin analysis using frozen sections. While generally effective, this protocol has several limitations including margin sampling and close and positive margin re-localization. There is a lack of evidence on the association of use of frozen section analysis with improved survival in head and neck cancer. This article reviews novel technologies in head and neck margin analysis such as 3-dimensional scanning, augmented reality, molecular margins, optical imaging, spectroscopy, and artificial intelligence.

Visual pathology reports for improved collaboration at multidisciplinary head and neck tumor board

PURPOSE

Multidisciplinary tumor boards (TB) are the standard for discussing complex head and neck cancer cases. During TB, imaging and microscopic pathology is reviewed, but there is typically no visualization of the resected cancer.

METHODS

A pilot study was conducted to investigate the utility of visual pathology reports at weekly TB for 10 consecutive weeks. Faculty-level participants completed a pre-survey and post-survey to assess understanding of resected cancer specimens.

RESULTS

Providers (n = 25) across seven medical specialties completed pre-survey and post-survey. Following intervention, providers reported significant improvement in understanding of anatomic orientation of the specimen and sites of margin sampling (mean 47.4-96.1, p < 0.001), ability to locate the site of a positive margin (mean 69.5-91.1, p < 0.001), and confidence in treatment plans created (mean 69.5-89.2, p < 0.001) with the addition of visual pathology reports.

CONCLUSIONS

Visual pathology reports improve provider understanding of resected cancer specimens at multidisciplinary TB.

Improving Interdisciplinary Communication and Pathology Reporting for Head and Neck Cancer Resections: 3D Visualizations and Margin Reconciliation

PURPOSE

Surgical pathology reports play an integral role in postoperative management of head and neck cancer patients. Pathology reports of complex head and neck resections must convey critical information to all involved clinicians. Previously, we demonstrated the utility of 3D specimen and defect scanning for communicating margin status and documenting the location of supplemental margins. We introduce a newly designed permanent pathology report which improves documentation of intraoperative margin mapping and extent of corresponding supplemental margins harvested.

METHODS

We test the hypothesis that gaps in understanding exist for head and neck resection pathology reports across providers. A cross-sectional exploratory study using human-centered design was implemented to evaluate the existing permanent pathology report with respect to understanding margin status. Pathologists, surgeons, radiation oncologists, and medical oncologists from United States-based medical institutions were surveyed. The results supported a redesign of our surgical pathology template, incorporating 3D specimen / defect scans and annotated radiographic images indicating the location of inadequate margins requiring supplemental margins, or indicating frankly positive margins discovered on permanent section.

RESULTS

Forty-seven physicians completed our survey. Analyzing surgical pathology reports, 28/47 (60%) respondents reported confusion whether re-excised supplemental margins reflected clear margins, 20/47 (43%) reported uncertainty regarding final margin status, and 20/47 (43%) reported the need for clarity regarding the extent of supplemental margins harvested intraoperatively. From this feedback, we designed a new pathology report template; 61 permanent pathology reports were compiled with this new template over a 12-month period.

CONCLUSION

Feedback from survey respondents led to a redesigned permanent pathology report that offers detailed visual anatomic information regarding intraoperative margin findings and exact location/size of harvested supplemental margins. This newly designed report reconciles frozen and permanent section results and includes annotated radiographic images such that clinicians can discern precise actions taken by surgeons to address inadequate margins, as well as to understand the location of areas of concern that may influence adjuvant radiation planning.

How far are we off? Analyzing the accuracy of surgical margin relocation in the head and neck

BACKGROUND

Positive surgical margin rates remain high in head and neck cancer surgery. Relocation is challenging given the complex, three-dimensional (3D) anatomy.

METHODS

Prospective, multi-institutional study to determine accuracy of head and neck surgeons and pathologists relocating margins on virtual 3D specimen models using written descriptions from pathology reports. Using 3D models of 10 head and neck surgical specimens, each participant relocated 20 mucosal margins (10 perpendicular, 10 shave).

RESULTS

A total of 32 participants, 23 surgeons and 9 pathologists, marked 640 margins. Of the 320 marked perpendicular margins, 49.7% were greater than 1 centimeter from the true margin with a mean relocation error of 10.2 mm. Marked shave margins overlapped with the true margin a mean 54% of the time, with no overlap in 44 of 320 (13.8%) shave margins.

CONCLUSIONS

Surgical margin relocation is imprecise and challenging even for experienced surgeons and pathologists. New communication technologies are needed.

3D Specimen Scanning and Mapping in Musculoskeletal Oncology: A Feasibility Study

BACKGROUND

Surgical resection is the primary treatment for bone and soft tissue tumors. Negative margin status is a key factor in prognosis. Given the three-dimensional (3D) anatomic complexity of musculoskeletal tumor specimens, communication of margin results between surgeons and pathologists is challenging. We sought to perform ex vivo 3D scanning of musculoskeletal oncology specimens to enhance communication between surgeons and pathologists.

METHODS

Immediately after surgical resection, 3D scanning of the fresh specimen is performed prior to frozen section analysis. During pathologic grossing, whether frozen or permanent, margin sampling sites are annotated on the virtual 3D model using computer-aided design (CAD) software.

RESULTS

3D scanning was performed in seven cases (six soft tissue, one bone), with specimen mapping on six cases. Intraoperative 3D scanning and mapping was performed in one case in which the location of margin sampling was shown virtually in real-time to the operating surgeon to help achieve a negative margin. In six cases, the 3D model was used to communicate final permanent section analysis. Soft tissue, cartilage, and bone (including lytic lesions within bone) showed acceptable resolution.

CONCLUSIONS

Virtual 3D scanning and specimen mapping is feasible and may allow for enhanced documentation and communication. This protocol provides useful information for anatomically complex musculoskeletal tumor specimens. Future studies will evaluate the effect of the protocol on positive margin rates, likelihood that a re-resection contains additional malignancy, and exploration of targeted adjuvant radiation protocols using a patient-specific 3D specimen map.

The art of specimen orientation: Two-dimensional maps for oropharynx squamous cell carcinoma

The goal of surgical treatment for oropharynx squamous cell carcinoma (SCCa) is resection to negative margins. Current methods of orienting resection specimens often do not give a comprehensive view, especially in oropharynx SCCa where specimens can lack anatomic landmarks. We created standardized two-dimensional maps of oropharynx anatomy drawn to scale to improve communication between surgeons and pathologists. Notes regarding surgery including anatomic landmarks, areas of concern, additional margins, and relevant clinical information were added to the map. The maps guided pathology work-up, and the pathologist could communicate details back to the surgeon on how the specimen was sectioned or locations of microscopic foci to direct future treatment and clinical monitoring. The use of two-dimensional maps for oropharynx SCCa specimens offers a standardized solution to address the challenges of anatomic orientation. These maps summarized key pathological information, preserved clinical details from the specimens, and guided multidisciplinary conferences when planning adjuvant treatment.

Surgical Margins in Musculoskeletal Sarcoma

» Negative margin resection of musculoskeletal sarcomas is associated with reduced risk of local recurrence.» There is limited evidence to support an absolute margin width of soft tissue or bone that correlates with reduced risk of local recurrence.» Factors intrinsic to the tumor, including histologic subtype, grade, growth pattern and neurovascular involvement impact margin status and local recurrence, and should be considered when evaluating a patient's individual risk after positive margins.» Appropriate use of adjuvant therapy, critical analysis of preoperative advanced cross-sectional imaging, and the involvement of a multidisciplinary team are essential to obtain negative margins when resecting sarcomas.

Virtual 3D Specimen Mapping in Head & Neck Oncologic Surgery

OBJECTIVES

Virtual 3D specimen mapping of oncologic surgical specimens provides a visual record of the specimen and margin sampling sites which can be utilized in a variety of cancer care settings. Our objective was to perform a retrospective review of head and neck surgical oncology cases where the specimen was mapped post-operatively and to evaluate the utility of these 3D specimen maps amongst the multidisciplinary cancer care team.

METHODS

A retrospective review of our 3D specimen model biorepository was performed. Surgical specimens were 3D scanned and then graphically annotated (or "mapped") during routine pathologic processing. The resulting 3D specimen maps were distributed to the multidisciplinary oncologic care team. Final margin status and any use of the 3D specimen maps were recorded.

RESULTS

A total of 28 cases were included. Virtual 3D specimen maps were utilized by the cancer care team in 8 cases (29%), including 2 positive margin cases, 2 close margin cases, and 4 indeterminate margin cases. 3D specimen maps were used to visualize positive margin sites for pathologist-surgeon communication as a visual reference during tumor board discussions and to inform radiation treatment planning.

CONCLUSION

Post-operative virtual 3D specimen mapping of oncologic specimens creates a permanent visual record of the specimen and the margins sampled and may serve as a beneficial tool for communication amongst the multidisciplinary cancer care team.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:191-197, 2024.

Virtual Resection Specimen Interaction Using Augmented Reality Holograms to Guide Margin Communication and Flap Sizing

Head and neck surgeons often have difficulty in relocating sites of positive margins due to the complex 3-dimensional (3D) anatomy of the head and neck. We introduce a new technique where resection specimens are 3D scanned with a smartphone, annotated in computer-assisted design software, and immediately visualized on augmented reality (AR) glasses. The 3D virtual specimen can be accurately superimposed onto surgical sites for orientation and sizing applications. During an operative workshop, a surgeon using AR glasses projected virtual, annotated specimen models back into the resection bed onto a cadaver within approximately 10 minutes. Colored annotations can correspond with pathologic annotations and guide the orientation of the virtual 3D specimen. The model was also overlayed onto a flap harvest site to aid in reconstructive planning. We present a new technique allowing interactive, sterile inspection of tissue specimens in AR that could facilitate communication among surgeons and pathologists and assist with reconstructive surgery.

Augmented-Reality Surgery to Guide Head and Neck Cancer Re-resection: A Feasibility and Accuracy Study

BACKGROUND

Given the complex three-dimensional (3D) anatomy of head and neck cancer specimens, head and neck surgeons often have difficulty relocating the site of an initial positive margin to perform re-resection. This cadaveric study aimed to determine the feasibility and accuracy of augmented reality surgery to guide head and neck cancer re-resections.

METHODS

This study investigated three cadaveric specimens. The head and neck resection specimen was 3D scanned and exported to the HoloLens augmented reality environment. The surgeon manually aligned the 3D specimen hologram into the resection bed. Accuracy of manual alignment and time intervals throughout the protocol were recorded.

RESULTS

The 20 head and neck cancer resections performed in this study included 13 cutaneous and 7 oral cavity resections. The mean relocation error was 4 mm (range, 1-15 mm) with a standard deviation of 3.9 mm. The mean overall protocol time, from the start of 3D scanning to alignment into the resection bed, was 25.3 ± 8.9 min (range, 13.2-43.2 min). Relocation error did not differ significantly when stratified by greatest dimension of the specimen. The mean relocation error of complex oral cavity composite specimens (maxillectomy and mandibulectomy) differed significantly from that of all the other specimen types (10.7 vs 2.8; p < 0.01).

CONCLUSIONS

This cadaveric study demonstrated the feasibility and accuracy of augmented reality to guide re-resection of initial positive margins in head and neck cancer surgery.

Frozen Section Analysis in Head and Neck Surgical Pathology: A Narrative Review of the Past, Present, and Future of Intraoperative Pathologic Consultation

Frozen section has remained the diagnostic gold standard for intraoperative pathological evaluation of surgical margins for head and neck specimens. While achieving tumor-free margins is of utmost importance to all head and neck surgeons, in practice, there are numerous debates and a lack of standardization for the role and method of intraoperative pathologic consultation. This review serves as a summary guide to the historical and contemporary practice of frozen section analysis and margin mapping in head and neck cancer. In addition, this review discusses current challenges in head and neck surgical pathology, and introduces 3D scanning as a groundbreaking technology to bypass many of the pitfalls in the current frozen section workflow. The ultimate goal for all head and neck pathologists and surgeons should be to modernize practices and take advantage of new technology, such as virtual 3D specimen mapping techniques, that improves the workflow for intraoperative frozen section analysis.

Immediate resection of positive margins improves local control in oral tongue cancer

OBJECTIVES

This study investigates the impact of immediate resection of positive margins on local control of oral tongue cancer.

MATERIALS AND METHODS

We analyzed 273 consecutive oral tongue cancers resected from 2013 to 2018. Additional resection was performed in cases during the initial operation based on surgeon inspection of the specimen and/or frozen margins. Positive margins were defined as invasive carcinoma/high-grade dysplasia < 1 mm from the inked edge. Patients were grouped as follows: negative margin (Group 1); positive margin with immediate additional tissue resection (Group 2); and positive margin without additional tissue resection (Group 3).

RESULTS

Overall, the rate of local recurrence was 7.7 % (21/273), and the rate of positive main specimen margin was 17.9 %. Of these patients, 38.8 % (19/49) underwent immediate additional resection of the presumed positive margin. Group 3 had higher local recurrence rates than Group 1 after adjustment for T-stage (aHR 2.8 [95 % CI 1.0-7.7], p = 0.04). Group 2 had similar rates of local recurrence (aHR 0.45 [95 % CI 0.06-3.6], p = 0.45). Three year local recurrence free survival for Groups 1, 2, and 3 were 91 %, 92 % and 73 %, respectively. Compared to the main specimen margin, sensitivity of intraoperative frozen tumor bed margins was 17.4 %, and specificity was 95 %.

CONCLUSION

In patients with positive main specimen margins, anticipation and detection in real-time with immediate additional tissue resection reduced local recurrence to rates similar to those with negative main specimen margins. These findings support the use of technology to provide real-time intraoperative margin data and guide additional resection for improved local control.