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British Journal of Oral and Maxillofacial Surgery 54 (2016) 694–696
Short communication
Augmented reality visualization in head and neck surgery: an overview of recent findings in sentinel node biopsy and future perspectives Andrea Corrado Profeta ∗ , Clare Schilling, Mark McGurk Guy’s and St Thomas’s Hospital NHS Foundation Trust, Department of Oral and Maxillofacial Surgery, Floor 23, Guy’s Tower, Guy’s Hospital, London, SE1 9RT, UK Accepted 11 November 2015 Available online 22 January 2016
Abstract “Augmented reality visualisation”, in which the site of an operation is merged with computer-generated graphics, provides a way to view the relevant part of the patient’s body in better detail. We describe its role in relation to sentinel lymph node biopsy (SLNB), current advancements, and future directions in the excision of tumours in early-stage cancers of the head and neck. © 2016 Published by Elsevier Ltd on behalf of The British Association of Oral and Maxillofacial Surgeons.
Keywords: Augmented reality; head and neck surgery; fhSPECT
Introduction During the 1990s, we began to develop prototypes of “augmented reality” as components of personalised medicine.1 Augmented reality adds information that has been processed by a computer system to aid the surgeon. Such additional information can be linked spatially and temporally to the site of the operation using tracking technology, which continuously records the position of the patient and surgical instruments through sensors (computer-aided navigation).2 This innovation improves outcome and safety in a wide range of medical applications, and can be used to repair defects after trauma, in osteotomies of the facial skeleton, orthognathic surgery, distraction osteogenesis, arthroscopy
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Corresponding author. E-mail addresses: andrea.profeta@kcl.ac.uk (A.C. Profeta), clare.schilling@kcl.ac.uk (C. Schilling), mark.mcgurk@kcl.ac.uk (M. McGurk).
of the temporomandibular joint, removal of foreign bodies, image-guided biopsies, and dental implants.3 We focus on the application of freehand single photon emission computed tomography (SPECT), which promises to improve outcomes by detecting the involvement of sentinel lymph nodes.
Freehand SPECT Most 3-dimensional nuclear imaging systems are used only for diagnosis because of their size and time constraints in the operating room. The concept behind freehand SPECT is to combine a gamma probe (similar to conventional radioguided surgery) with a tracking system (as used for neurosurgical navigation) to scan the relevant area (Fig. 1). “Scanning” here means moving a handheld detector freely from different directions - for example, “painting” the surface of the body with the gamma probe - the position, or orientation of which, is monitored stereotactically and the readings synchronised.
http://dx.doi.org/10.1016/j.bjoms.2015.11.008 0266-4356/© 2016 Published by Elsevier Ltd on behalf of The British Association of Oral and Maxillofacial Surgeons.
A.C. Profeta et al. / British Journal of Oral and Maxillofacial Surgery 54 (2016) 694–696
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Results
Fig. 1. Freehand SPECT (single photon emission computed tomography): scanning immediately after injection (published with the patient’s permission).
The first results using this technology for 3-dimensional image-guided sentinel lymph node biopsy (SLNB) in the head and neck have been described.6 This approach overcomes the limitation of the shine-through phenomenon in tumours of the floor of the mouth, resulting in the reduction in false-negatives. Further studies have reaffirmed the feasibility and high sensitivity of 3-dimensional image-guided SLNB, and confirmed that it allows detection of SLN in the most challenging setting with close proximity to the injection site.7,8 Another preliminary study highlighted the value of freehand SPECT for detection of metastases in SLN in patients with squamous cell carcinoma of the head and neck at different sites.9 Occult disease was not detected during subsequent selective neck dissection in any patient, and no residual radioactivity was found after the SLN had been excised. Recently, Heuveling et al.,8 demonstrated a detection rate of 94% in comparison with preoperative lymphoscintigraphy, and the SLNB was facilitated in a quarter of patients.
Discussion
Fig. 2. Freehand SPECT (single photon emission computed tomogram) of sentinel nodes.
Augmented reality has huge potential, and maxillofacial surgeons are well positioned to lead research by integrating technology into their work. The transmission of preoperative planning and simulation data supported by lightweight head-mounted displays, realtime infrared fluorescence, and microendoscopy may help to identify the margins of tumours, to excise them more accurately while preserving normal tissues, and to transfer acquired data wirelessly for remote analysis.10 We think that it will also open up the possibility of SLNB in the routine management of other tumours of the head and neck, such as the salivary glands, thyroid, and larynx, and in doing so will allow a safer and less invasive approach.
Conflict of interest Fig. 3. Real-time projection of hot spots detected by freehand SPECT (single photon emission computed tomography) on to intraoperative image of patient (published with the patient’s permission).
We have no conflicts of interest.
Ethics statement/confirmation of patient permission From this combination and using an algorithm, we reconstruct the distribution of radioactivity 3-dimensionally with minimal disruption during operation (Fig. 2). High resolution images are then superimposed on a conventional video of the body surface, which is also recorded. The superimposition uses augmented reality, in which 3-dimensional virtual data are overlaid on the live video to allow calculation and display of the depth of target structures (Fig. 3).4,5
The patient gave permission for use of the information.
References 1. Tabatabaeifar S, Kruse TA, Thomassen M, et al. Use of next generation sequencing in head and neck squamous cell carcinomas: a review. Oral Oncol 2014;50:1035–40.
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2. Cabrilo I, Sarrafzadeh A, Bijlenga P, et al. Augmented reality-assisted skull base surgery. Neurochirurgie 2014;60:304–6. 3. Zinser MJ, Mischkowski RA, Dreiseidler T, et al. Computer-assisted orthognathic surgery: waferless maxillary positioning, versatility, and accuracy of an image-guided visualisation display. Br J Oral Maxillofac Surg 2013;51:827–33. 4. Schilling C, Gnanasegaran G, McGurk M. Three-dimensional imaging and navigated sentinel node biopsy for primary parotid malignancy: new application in parotid cancer management. Head Neck 2014;36:E91–3. 5. Bluemel C, Schnelzer A, Okur A, et al. Freehand SPECT for imageguided sentinel lymph node biopsy in breast cancer. Eur J Nucl Med Mol Imaging 2013;40:1656–61. 6. Heuveling DA, Karagozoglu KH, van Schie A, et al. Sentinel node biopsy using 3D lymphatic mapping by freehand SPECT in early stage oral cancer: a new technique. Clin Otolaryngol 2012;37:89–90.
7. Bluemel C, Herrmann K, Müller-Richter U, et al. Freehand SPECTguided sentinel lymph node biopsy in early oral squamous cell carcinoma. Head Neck 2014;36:E112–6. 8. Heuveling DA, van Weert S, Karagozoglu KH, et al. Evaluation of the use of freehand SPECT for sentinel node biopsy in early stage oral carcinoma. Oral Oncol 2015;51:287–90. 9. Mandapathil M, Teymoortash A, Heinis J, et al. Freehand SPECT for sentinel lymph node detection in patients with head and neck cancer: first experiences. Acta Otolaryngol 2014;134: 100–4. 10. Liu Y, Njuguna R, Matthews T, et al. Near-infrared fluorescence goggle system with complementary metal-oxide-semiconductor imaging sensor and see-through display. J Biomed Opt 2013;18:101303.