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Methods for accurate registration and fusion of intraoperative cone-beam CT (CBCT) with endoscopic video have been developed and integrated into a system for surgical guidance that accounts for intraoperative anatomical deformation and tissue excision. The system is based on a prototype mobile C-Arm for intraoperative CBCT that provides low-dose 3D image updates on demand with sub-mm spatial resolution and soft-tissue visibility, and also incorporates subsystems for real-time tracking and navigation, video endoscopy, deformable image registration of preoperative images and surgical plans, and 3D visualization software. The position and pose of the endoscope are geometrically registered to 3D CBCT images by way of real-time optical tracking (NDI Polaris) for rigid endoscopes (e.g., head and neck surgery), and electromagnetic tracking (NDI Aurora) for flexible endoscopes (e.g., bronchoscopes, colonoscopes). The intrinsic (focal length, principal point, non-linear distortion) and extrinsic (translation, rotation) parameters of the endoscopic camera are calibrated from images of a planar calibration checkerboard (2.5×2.5 mm2 squares) obtained at different perspectives. Video-CBCT registration enables a variety of 3D visualization options (e.g., oblique CBCT slices at the endoscope tip, augmentation of video with CBCT images and planning data, virtual reality representations of CBCT [surface renderings]), which can reveal anatomical structures not directly visible in the endoscopic view - e.g., critical structures obscured by blood or behind the visible anatomical surface. Video-CBCT fusion is evaluated in pre-clinical sinus and skull base surgical experiments, and is currently being incorporated into an ongoing prospective clinical trial in CBCT-guided head and neck surgery.

esthetic appearance is one of the most important factors for reconstructive surgery. The current practice of maxillary reconstruction chooses radial forearm, fibula or iliac rest osteocutaneous to recreate three-dimensional complex structures of the palate and maxilla. However, these bone flaps lack shape similarity to the palate and result in a less satisfactory esthetic. Considering similarity factors and vasculature advantages, reconstructive surgeons recently explored the use of scapular tip myo-osseous free flaps to restore the excised site. We have developed a new method that quantitatively evaluates the morphological similarity of the scapula tip bone and palate based on a diagnostic volumetric computed tomography (CT) image. This quantitative result was further interpreted as a color map that rendered on the surface of a three-dimensional computer model. For surgical planning, this color interpretation could potentially assist the surgeon to maximize the orientation of the bone flaps for best fit of the reconstruction site. With approval from the Research Ethics Board (REB) of the University Health Network, we conducted a retrospective analysis with CT image obtained from 10 patients. Each patient had a CT scans including the maxilla and chest on the same day. Based on this image set, we simulated total, subtotal and hemi palate reconstruction. The procedure of simulation included volume segmentation, conversing the segmented volume to a stereo lithography (STL) model, manual registration, computation of minimum geometric distances and curvature between STL model. Across the 10 patients data, we found the overall root-mean-square (RMS) conformance was 3.71± 0.16 mm

Background: Limited follow-up data on aesthetic outcome and survival after microsurgical reconstruction of complex scalp and forehead defects are available. These data are important to improve reconstruction quality and patient counseling. The purpose of this study was to evaluate surgical, aesthetic, and oncologic outcome of free flap scalp and forehead reconstructions in the patient population of two academic centers. Methods: Retrospective data analysis of patients with a microsurgical reconstruction of the scalp or forehead between January of 1999 and June of 2008 was performed. Aesthetic outcome was assessed on a five-point Likert scale for flap color match, contour, and overall aesthetic result. Results: The group consisted of 84 patients with a mean follow-up time of 27 months (range, 1 to 95 months). Mean defect size was 134 cm(2) (range, 20 to 340 cm2), with 46 percent full-thickness bone defects and 16 percent dura defects. The most commonly used free flaps were latissimus dorsi (n = 34) and anterolateral thigh (n = 24). Total flap failure occurred in five patients (6 percent). Disease-free survival and overall survival rates at 5 years were 57 and 65 percent, respectively. Additional operations for aesthetic reasons were performed in 19 patients (23 percent). Panel scores showed a significant lower satisfaction with reconstruction of defects that were located over the frontal scalp compared with other locations (p = 0.004). Conclusions: Microsurgical reconstruction in complex scalp and forehead defects is a safe procedure. From the authors' experience, they suggest an algorithm for reconstruction of these complex reconstructive defects that will most likely result in the best aesthetic result. (Plast. Reconstr. Surg 126: 460, 2010.)

Made available in DSpace on 2013-08-28T14:11:27Z (GMT). No. of bitstreams: 1 WOS000273764100001.pdf: 671028 bytes, checksum: 64cd35202f41a38df5813a1ab726b57f (MD5) Made available in DSpace on 2013-09-30T18:37:53Z (GMT). No. of bitstreams: 2 WOS000273764100001.pdf: 671028 bytes, checksum: 64cd35202f41a38df5813a1ab726b57f (MD5) WOS000273764100001.pdf.txt: 26366 bytes, checksum: b4e9a375d4fd920a2ae084b8444b9546 (MD5) Previous issue date: 2009-12-23 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:50:28Z No. of bitstreams: 2 WOS000273764100001.pdf: 671028 bytes, checksum: 64cd35202f41a38df5813a1ab726b57f (MD5) WOS000273764100001.pdf.txt: 26366 bytes, checksum: b4e9a375d4fd920a2ae084b8444b9546 (MD5) Made available in DSpace on 2014-05-20T13:50:28Z (GMT). No. of bitstreams: 2 WOS000273764100001.pdf: 671028 bytes, checksum: 64cd35202f41a38df5813a1ab726b57f (MD5) WOS000273764100001.pdf.txt: 26366 bytes, checksum: b4e9a375d4fd920a2ae084b8444b9546 (MD5) Previous issue date: 2009-12-23 Canadian Institutes of Health Research (CIHR) Galloway Fund Wharton Head Neck Research Fund Unknown primary malignancy in the head and neck is not an infrequent diagnosis for patients with metastatic cervical lymph nodes. Although linked with a relatively good prognosis following radiation treatment, widespread radiation is coupled with significant morbidity. Altered microRNA (miRNA) expression has been associated with both cancer progression and metastasis. We sought to determine whether miRNA expression analysis could be used as a diagnostic tool to discover the primary site of malignancy, within the head and neck. We used quantitative real-time PCR to identify miRNA expression profiles of squamous cell carcinoma of the tonsil, base of tongue and post-nasal space, as well as their corresponding metastatic lymph nodes, from 6 patients. Our results revealed that each cancer maintained its expression profile between the primary site and the nodal metastasis (r = 0.82, p < 0.0001). In addition, each anatomical sub-site maintained a distinct miRNA profile between individual patients (r = 0.79, p < 0.0001). Finally, between sub-sites, the miRNA profiles were distinct (p < 0.0001). As proof of principle, our study provides an indication that miRNA expression analysis may be useful to compare the primary lesion and local metastatic disease. This may be clinically relevant to predict the primary site of origin of metastatic disease, when the primary site remains obscure. Princess Margaret Hosp, Dept Appl Mol Oncol, Ontario Canc Inst, Toronto, on M5G 2M9, Canada Princess Margaret Hosp, Dept Head & Neck Surg Oncol, Toronto, on M5G 2M9, Canada UNESP, Dept Genet, Biosci Inst, Botucatu, SP, Brazil Univ Toronto, Dept Lab Med & Pathobiol, Toronto, on M5S 1A8, Canada Princess Margaret Hosp, Dept Biostat, Toronto, on M5G 2M9, Canada Univ Hlth Network, Toronto Gen Hosp, Dept Pathol, Toronto, on M5G 2M9, Canada UNESP, Dept Genet, Biosci Inst, Botucatu, SP, Brazil CHIR: STP-53912

BACKGROUND: The authors compared the survival outcomes of radiotherapy +/− salvage surgery to surgery +/− postoperative radiotherapy for patients with squamous cell cancer of the hypopharynx. There was no evidence beyond observational studies and no consensus on the which treatment is most effective for this patient group. METHODS: The authors conducted a retrospective population-based study of 595 patients from Ontario Canada diagnosed between January 1, 1990 and December 31, 1999. Three different methodological approaches were used for the survival analysis including a restricted cohort study, a matched case-control study, and a natural experiment study across defined geographic regions. RESULTS: The authors found no survival advantage for either radiotherapy +/− salvage surgery or surgery +/− postoperative radiotherapy. CONCLUSIONS: This study set the baseline for clinical decisions that was not previously established there is no difference in survival for patients with hypopharynx comparing primary surgery to primary radiotherapy. This information is essential for the interpretation of current treatment results, the planning of future clinical studies and the treatment of patients who are not having chemoradiotherapy. Cancer 2009. © 2009 American Cancer Society.

Background. In this study, a meta-analysis of level IIb metastases in squamous cell carcinoma (SCC) of the oral cavity was conducted. Methods. Two independent reviewers screened abstracts and full text papers deemed potentially relevant. Data were pooled using a random intercept model. Results. In this analysis, 729 abstracts and 177 full text papers were screened (Kappa statistic 0.8 and 1.0, respectively). A total of 332 patients in 9 papers were included in the analysis. Twenty patients had level IIb metastases (mean, 6%; range, 0% to 10.4%). The pooled percentage of level IIb metastases was 6.0% (95% CI: 3.5–8.6). Only 3 patients with level IIb metastases had isolated nodal disease. Eighty-five percent of those with level IIb metastases had additional nodal disease (95% CI: 64.0–94.8), with IIa being a common denominator among all. Conclusion. Level IIb nodal metastases are relatively uncommon in previously untreated SCC of the oral cavity (6%). Furthermore, isolated level IIb nodal disease is uncommon. However, given the quality of evidence to date, it is recommended that dissection of level IIb remain the standard of care in oral cavity squamous cell cancer. © 2009 Wiley Periodicals, Inc. Head Neck, 2010

INTRODUCTION Despite the best preoperative care, meticulous surgical technique, and attentive postoperative management, complications frequently arise in the head and neck cancer patient. Many of these individuals are elderly with concomitant medical problems and pose a constant challenge for those involved in their care. Early recognition of the symptoms and signs of complications can prevent amplification of existing problems. The purpose of this chapter is to focus on the major surgical complications and how they are best avoided or treated once they occur.

Reconstruction of circumferential pharyngeal defects following total pharyngolaryngectomy presents major challenges with respect to surgical morbidity and restoration of functional deficits, which are often made more demanding by the increasing trend to utilize primary chemoradiation protocols with surgery reserved for salvage cases. The present review evaluates the reconstructive techniques described in the literature, including historical techniques as well as more recent innovative methods. Each technique is critically appraised with particular reference to postoperative morbidity and functional rehabilitation. Treatment recommendations are made based on the available evidence.

Background. The association between nodal ratio and survival in oral cavity carcinomas has recently been pro- posed, but no prospective evaluations exist. Methods. We sought to determine, using an institutional database, whether nodal ratio impacts survival in node-positive oral cavity squamous cell carcinoma. Results. Between 1994 and 2004, 143 new diagnoses of N1-2 squamous cell carcinoma of the oral cavity were identi- fied. The mean number of nodes identified was 41.6, and the mean nodal ratio was 9%. Nodal ratio was strongly statistically associated with overall and disease-specific survival in both univariate and multivariate analyses. No other prognostic indi- cator maintained that degree of statistical significance. Patients could be stratified into low (0% to 6%), moderate (6% to 13%), and high-risk (>13%) groups based on nodal ratio. Conclusions. In squamous cell carcinoma of the oral cavity, an increased nodal ratio is a strong predictor of decreased sur- vival. Risk of death can be stratified by nodal ratio. V C 2009 Wiley Periodicals, Inc. Head Neck 31: 1482-1488, 2009

Objectives To describe a cadaveric temporal bone model of labyrinthitis ossificans and investigate the utility of intraoperative cone-beam computed tomography (CBCT) in the facilitating cochlear implantation. Design Cadaveric temporal bone study. Methods Five cadaveric heads had cement introduced into the 10 cochleas. CBCT and a conventional CT scan were compared to assess the extent of cochlear obliteration. The cement was drilled-out (under CBCT guidance, if required) and cochlear implant electrode arrays (from 3 different manufacturers) inserted. Results CBCT images demonstrated temporal bone anatomy and the extent of cochlear obliteration as clearly as conventional CT in all cases. Intraoperative CBCT guided drilling and facilitated electrode placement in two of five heads (3 of 10 ears). Streak-artifact from the electrodes of two devices partially obscured image clarity. Conclusions The obliterated cochlear model reproduced a disease-ossified cochlear both radiographically and surgically. CBCT is useful for intraoperative imaging to facilitate electrode array placement in the obliterated or congenitally abnormal cochlea.

Surgical simulation has become a critical component of surgical practice and training in the era of high-precision image-guided surgery. While the ability to simulate surgery of the paranasal sinuses and skull base has been conventionally limited to 3D digital simulation or cadaveric dissection, we have developed novel methods employing rapid prototyping technology and 3D printing to create high-fidelity models from real patient images (CT or MR). Such advances allow creation of patient-specific models for preparation, simulation, and training before embarking on the actual surgery. A major challenge included the development of novel material formulations compatible with the rapid prototyping process while presenting anatomically realistic flexibility, cut-ability, drilling purchase, and density (CT number). Initial studies have yielded realistic models of the paranasal sinuses and skull base for simulation and training in image-guided surgery. The process of model development and material selection is reviewed along with the application of the phantoms in studies of high-precision surgery guided by C-arm cone-beam CT (CBCT). Surgical performance is quantitatively evaluated under CBCT guidance, with the high-fidelity phantoms providing an excellent test-bed for reproducible studies across a broad spectrum of challenging surgical tasks. Future work will broaden the atlas of models to include normal anatomical variations as well as a broad spectrum of benign and malignant disease. The role of high-fidelity models produced by rapid prototyping is discussed in the context of patient-specific case simulation, novel technology development (specifically CBCT guidance), and training of future generations of sinus and skull base surgeons.

A system for intraoperative cone-beam CT (CBCT) surgical guidance is under development and translation to trials in head and neck surgery. The system provides 3D image updates on demand with sub-millimeter spatial resolution and soft-tissue visibility at low radiation dose, thus overcoming conventional limitations associated with preoperative imaging alone. A prototype mobile C-arm provides the imaging platform, which has been integrated with several novel subsystems for streamlined implementation in the OR, including: real-time tracking of surgical instruments and endoscopy (with automatic registration of image and world reference frames); fast 3D deformable image registration (a newly developed multi-scale Demons algorithm); 3D planning and definition of target and normal structures; and registration / visualization of intraoperative CBCT with the surgical plan, preoperative images, and endoscopic video. Quantitative evaluation of surgical performance demonstrates a significant advantage in achieving complete tumor excision in challenging sinus and skull base ablation tasks. The ability to visualize the surgical plan in the context of intraoperative image data delineating residual tumor and neighboring critical structures presents a significant advantage to surgical performance and evaluation of the surgical product. The system has been translated to a prospective trial involving 12 patients undergoing head and neck surgery - the first implementation of the research prototype in the clinical setting. The trial demonstrates the value of high-performance intraoperative 3D imaging and provides a valuable basis for human factors analysis and workflow studies that will greatly augment streamlined implementation of such systems in complex OR environments.

Advances in image-guided surgery have led to minimally-invasive, high-precision procedures that increase the efficacy of treatment, minimize surgical complications, and reduce patient recovery time. A recent advance in intraoperative 3D imaging includes cone-beam CT (CBCT) implemented on a mobile C-arm. This paper investigates the effect of the number and configuration of fiducials on target registration error (TRE) and identifies fiducial configurations that minimize TRE for rigid point-based registration in CBCT-guided head and neck surgery. Best configurations were those that minimized the distance between the centroid of fiducials and the surgical target while maximizing fiducial separation (distance from principal axes). Configurations with as few as 4 fiducials could be identified that minimized TRE (e.g., TRE0.3 mm for the pituitary, cochlea, and nasion), with more fiducials (6 or more) providing improved TRE uniformity throughout the volume of clinical interest. If possible, fiducials affixed to the skin or cranium (e.g., 4-6 markers) should include a majority about the target (to minimize centroid-to-target distance) with others at a distance (to maximize separation). A greater number of fiducials distributed evenly can provide low, uniform TRE for all targets--e.g., 8 markers, TRE approximately 0.2-0.6 mm throughout the volume of interest. Such work helps guide the implementation of C-arm CBCT in head and neck surgery in a manner that maximizes surgical precision and exploits intraoperative image guidance to its full potential.

The computational and geometric performance of Demons deformable registration techniques were investigated in the application of cone-beam CT (CBCT) for intra-operative guidance of head and neck surgery. A prototype C-arm providing CBCT images of sub-mm spatial resolution and soft-tissue contrast was used to acquire images of a cadaveric head before and after surgical intervention. Four deformable registration methods were investigated both in terms of their convergence behavior (time and number of iterations required) and registration accuracy (correlation between deformed and target images and the corresponding target registration error, TRE). Rigid registration alone exhibited a TRE of (2.6 +/- 1.0) mm, compared to a TRE of (0.8 +/- 0.3) mm obtained with deformable registration. A fast symmetric demons implementation was identified as the most suitable for intra-operative use in terms of speed, image quality, and accuracy. Increasing the spatial resolution of CBCT images was found to increase registration accuracy at the cost of computational expense. Intra-operative CBCT combined with deformable registration offers to overcome conventional limitations of guidance by preoperative images alone and presents an accurate method of integrating imaging and planning data in a manner that properly reflects changes in the intra-operative state.

Background: the role of cone-beam CT (CBCT) in demonstrating anterior skull base defects (ASBDs), differing in size and location, was investigated. The study was designed to describe the potential advantage of CBCT in the setting of an intraoperative cerebrospinal fluid (CSF) leak. Methods: in all, 120 ASBD were evaluated in 5 cadaver heads. Orthogonal and oblique slices were reconstructed. Observer studies assessed the visibility of ASBD in each location as a function of defect size. Results: for 1-, 2-, and 4-mm defects, the percentage that were undetectable ranged from 20% to 33%, 0% to 14%, and 0% to 5%, respectively. Confident breach detection increased with defect size and was most challenging in the lateral lamella and cribriform. CBCT permitted confident detection of ASBD as small as about 2 mm in the fovea ethmoidalis and planum. Oblique views were found to be superior to orthogonal planes. Conclusions: the ability to identify ASBD depended on the size and location of defect. Oblique viewing planes were optimal for ASBD visualization

Background The purpose of this study was to identify prognostic factors associated with minor salivary gland malignancies. Method This was a retrospective study of 171 patients. Statistical analysis of both clinical and pathological parameters with survival outcomes was performed. Results Adenoid cystic carcinoma (46.8%), mucoepidermoid carcinoma (22.8%), and adenocarcinoma (18.7%) were the most common pathologies. The most frequent sites of primary tumor were in the oral cavity (44.4%) and nasal cavity (40.4%). The 5-year and 10-year overall survivals were 73.8% and 58.1%. Disease-specific survivals (DSS) were 78.2% and 66.7% and disease-free survivals (DFS) were 64.8% and 47.5%, respectively. Local recurrence rate was 26.9%, regional recurrence 7%, and distant failure was 18.7%. The grade of tumor was the only factor associated with DSS on multivariate analysis. Conclusion Overall and DSS of minor salivary gland malignancies were good. Surgery, either alone or in combination with radiation, was an efficacious treatment modality. High-grade tumors were associated with worse DSF. © 2008 Wiley Periodicals, Inc. Head Neck, 2009

Olfactory neuroblastoma is an uncommon neuroectodermal tumor of the sinonasal tract. It represents 2% to 3% of sinonasal neoplasms. Most olfactory neuroblastoma behave locally aggressive with 30% recurrence rates. A subset metastasizes to lymph nodes and/or distant sites. Grading of olfactory neuroblastoma involves a combination of factors with low-grade tumors having better survival than high-grade tumors. The grade does not always predict prognosis, however, as metastases can be seen in all grades of olfactory neuroblastoma. Trk-A, Trk-B, and p75NRT are neurotrophin receptors associated with numerous solid malignancies, particularly pediatric neuroblastoma. GRP78 is an endoplasmic reticulum protein, associated with differentiation of neuroblastic cells. Trk-A, p75NRT, and GRP78 overexpression are favorable prognostic factors in pediatric neuroblastoma, whereas Trk-B is associated with a poorer prognosis in these tumors. Olfactory neuroblastoma is clinically distinct from pediatric neuroblastoma but shares some histological features. Trk-A and p75NRT have been demonstrated in olfactory neuroblastoma previously. Trk-B and GRP78 have not been investigated in olfactory neuroblastoma. None of these markers have been correlated with grade or outcome in olfactory neuroblastoma. To investigate the role of Trk-A, Trk-B, p75NRT, and GRP78, a series of 20 olfactory neuroblastomas was stained with these antibodies. Trk-A and Trk-B stained most cases of olfactory neuroblastoma (90% and 85%). GRP78 stained most cases (90%), although weakly. P75NRT demonstrated focal membranous staining in a sustentacular pattern (60%). None of these markers correlated with Hyams grade. None of these markers definitively correlated with patient outcome. Neurotrophin receptors do not appear to have a prognostic role; however, Trk's may play an oncogenic role in olfactory neuroblastoma.

Objectives/Hypothesis: To provide the baseline information on the natural history of patients with squamous cell carcinoma of the hypopharynx to help clinicians, researchers, and patients assess the relative effectiveness of treatment options when the best treatment is not known and newer treatments are being proposed. Study Design: Retrospective population-based design. Methods: The patient descriptors, treatments, and outcomes for 595 patients across the province of Ontario, Canada from January 1990 to December 31, 1999 based on electronic data and chart review. Results: The typical patient is 65 years old, male, unemployed, and poor. They are heavy drinkers with significant comorbidity compromising functional status. The tumors are advanced (over 50% stage 4). After curative treatment 20% had residual disease, recurrences tended to appear in the first year and 50% of first recurrences included metastases. Overall, 47% of patients were disease free at 3 years but eventually 64% of patients died of their cancer. Conclusions: This information can be used by clinicians and researchers to understand the natural history of the patient group to critically assess both the selection bias and effectiveness of treatments.

A conventional approach to image-guided surgery relies on positional tracking relative to preoperative images. We investigated the performance of intraoperative cone-beam computed tomography (CBCT) on a mobile C-arm for real-time guidance of head and neck surgery. Objectives were as follows: (1) to quantify improvements in surgical performance achieved with intraoperative CBCT and (2) to investigate specific, challenging surgical tasks for which CBCT is essential for total target ablation and critical structure avoidance.Surgical performance was evaluated using a phantom model in which a simulated skull base lesion was excised with and without intraoperative CBCT guidance. Performance was quantified by means of statistical decision theory analysis for conservative and radical excision tasks, yielding measures of sensitivity and specificity for each surgical task. Cadaveric specimens were employed to demonstrate the efficacy of CBCT guidance in sinus and skull base surgery.Performance under CBCT guidance was significantly increased in all cases, particularly for radical excision tasks in proximity to critical normal structures. Cadaver studies demonstrated that CBCT-guided procedures yielded higher-quality surgical product and higher conformity to surgical margins with dramatically increased surgical confidence.Intraoperative CBCT quantifiably improved surgical performance in all excision tasks and significantly increased surgical confidence. CBCT offers an intraoperative three-dimensional imaging technology that provides exquisite, real-time visualization of sinus and skull base anatomy. Such intraoperative imaging in combination with real-time tracking and navigation should be of great benefit in delicate procedures in which excision must be executed in close proximity to critical structures.

Background. The purpose of this study was to describe the impact of partial lateral glossectomy on midsagittal tongue movement during speech. Methods. Using B-mode ultrasound, the midsagittal tongue movement of 10 patients with lateral partial glossectomy during a standardized reading passage was analyzed before and after surgery. Six normal adults served as control speakers. The main outcome measure was the tongue velocity during speech. The technique of defect reconstruction (local vs flap) was included as a covariate in the analysis. Results. Following the surgery, all patients significantly increased the velocity of the midsagittal tongue movements dur- ing the reading passage. Conclusion. The results demonstrated that the patients with partial glossectomy compensated for the lateral tongue resec- tions by increasing the velocity of the residual tongue during speech. The study provides first insights into the biomechanical aspects of spontaneous articulatory compensation following lat- eral tongue resections. V

Background Free flap reconstruction of head and neck cancer defects is complex with many factors that influence perioperative complications. The aim was to determine if there was an association between perioperative variables and postoperative outcome. Methods We evaluated 185 patients undergoing free flap reconstruction following ablation of head and neck cancer between 1999 and 2001. Demographic, laboratory, surgical and anesthetic variables were analyzed using univariate and multivariable techniques. Results Ninety-eight patients (53%) developed complications, of which 74 were considered major, giving a major morbidity rate of 40%. Predictors of major complications were increasing patient age, ASA class, and smoking. Predictors of medical complications were ASA class, smoking, age and crystalloid replacement. Predictors of surgical complications were tracheostomy, preoperative hemoglobin, and preoperative radiotherapy. Conclusion Patient age, comorbidity, smoking, preoperative hemoglobin, and perioperative fluid management are potential predictors of postoperative complications following free flap reconstruction for cancer of the head and neck. © 2007 Wiley Periodicals, Inc. Head Neck 2007

The Pidd (p53-induced protein with death domain) gene was shown to be induced by the tumour suppressor p53 and to mediate p53-dependent apoptosis in mouse and human cells, through interactions with components of both the mitochondrial and the death receptor signalling pathways. To study the role of Pidd in clinical tumours, we measured its expression by quantitative reverse transcription-PCR in microdissected oral squamous cell carcinomas (OSCC) with and without p53 mutation. Tumour cell apoptosis was assessed by in situ terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling. Tumour proliferation was assessed by immunohistochemical staining for the Ki-67 antigen. We found a wide range of Pidd expression among OSCC. Statistical analysis revealed an association between Pidd expression and apoptotic index (Mann–Whitney test, P

Objectif: II existe une grande variation dans le diagnostic et la prise en charge des nodules thyroidiens. Le but de cette etude etait d'investiguer les differences de pratique entre les medecins de famille et les specialistes dans la prescription de scintigraphies thyroidiennes dans la prise en charge initiale de patients avec un nodule thyroidien. Devis: Revue de dossiers (incluant le dossier electronique). Localisation: University Health Network de Toronto. Participants: Tous les patients ayant subi une thyroidectomie sur une periode de 2 ans. Intervention: Nous avons revu les test diagnostics prescrits avant l'intervention et les specialites des medecins-prescripteurs. Resultats: Nous avons evalue 194 patients. Soixante-trois patients (32.5%) ont ete investigue exclusivement par leur medecin de famille, 63 patients (32.5%) l'ont ete par un specialiste, et 68 (35%) par une combinaison des deux. Les medecins de famille ont prescrit une scintigraphie chez 51% des patients pendant que les specialistes ne l'utilisaient que dans 29% des cas (p

High-performance intraoperative imaging is essential to an ever-expanding scope of therapeutic procedures ranging from tumor surgery to interventional radiology. The need for precise visualization of bony and soft-tissue structures with minimal obstruction to the therapy setup presents challenges and opportunities in the development of novel imaging technologies specifically for image-guided procedures. Over the past ~5 years, a mobile C-arm has been modified in collaboration with Siemens Medical Solutions for 3D imaging. Based upon a Siemens PowerMobil, the device includes: a flat-panel detector (Varian PaxScan 4030CB); a motorized orbit; a system for geometric calibration; integration with real-time tracking and navigation (NDI Polaris); and a computer control system for multi-mode fluoroscopy, tomosynthesis, and cone-beam CT. Investigation of 3D imaging performance (noise-equivalent quanta), image quality (human observer studies), and image artifacts (scatter, truncation, and cone-beam artifacts) has driven the development of imaging techniques appropriate to a host of image-guided interventions. Multi-mode functionality presents a valuable spectrum of acquisition techniques: i.) fluoroscopy for real-time 2D guidance; ii.) limited-angle tomosynthesis for fast 3D imaging (e.g., ~10 sec acquisition of coronal slices containing the surgical target); and iii.) fully 3D cone-beam CT (e.g., ~30-60 sec acquisition providing bony and soft-tissue visualization across the field of view). Phantom and cadaver studies clearly indicate the potential for improved surgical performance - up to a factor of 2 increase in challenging surgical target excisions. The C-arm system is currently being deployed in patient protocols ranging from brachytherapy to chest, breast, spine, and head and neck surgery.

On page 2164, J. Chen, J.C. Irish, G. Zheng, and co-workers show how 64 Cu-porphysome nanoparticles enable superior delineation of neoplastic tissues, metastatic lymph nodes, and vascular drainage on a head and neck cancer orthotopic rabbit model by PET imaging. Their selective fluorescence activation in tumor and metastatic lymph nodes permits intraoperative fluorescence guided surgeries.

A subset of triple negative breast cancer (TNBC) is characterized by overexpression of the epidermal growth factor receptor (EGFR) and loss of PTEN, and patients with these factors have a poor prognosis. In addition, approximately half of all basal breast cancers show autocrine activation of EGFR by amphiregulin (AREG), resulting in altered receptor trafficking and downstream signaling. However, despite the strong rationale for targeting EGFR in the treatment of TNBC, EGFR inhibitors have performed poorly in clinical trials. To further analyze the signaling processes active in this subset of TNBC, we performed reverse-phase protein array (RPPA) analysis on SUM149 cells, a highly tumorigenic and metastatic PTEN-null cell line that expresses high levels of AREG and EGFR, and MCF10A cells, a non-transformed mammary epithelial cell line cultured in the presence of either EGF or AREG. This analysis identified a number of signaling components mediated specifically by amphiregulin, including marked changes in integrin expression and increased levels of fibronectin, which is known to be a mediator of invasive capacity via interaction with integrin β1. RPPA analysis also revealed elevated AKT activity in SUM-149 cells, which was not surprising given the lack of PTEN expression. Interestingly, this AKT activity is not abrogated by treatment with the EGFR inhibitor gefitinib, nor by treatment with PI3K inhibitors. These findings and the results of preliminary experiments in SUM149 cells re-expressing PTEN suggest that AKT activity in these cells is, at least partly, independent of EGFR and PI3K activity. In addition, expression profiling demonstrated that AREG-activated EGFR regulates gene expression differently than EGF-activated EGFR, and functional analysis via genome-scale shRNA screening identified a set of genes, including PLK1 and BIRC5, that are regulated by EGFR in MCF10A cells but uncoupled from EGFR signaling in SUM149 cells, although they are essential for the survival of SUM-149 cells. Thus, our results demonstrate that in cells with constitutive EGFR activation and PTEN loss, critical survival genes are uncoupled from regulation by EGFR, a mechanism that is likely to mediate resistance to EGFR inhibitors. Citation Format: Christiana S. Kappler, Stephen T. Guest, Ericka L. Smith, Jonathan C. Irish, Elizabeth Garrett-Mayer, Zachary Kratche, Stephen Ethier. Oncogenic signaling in amphiregulin- and EGFR-expressing PTEN-null human breast cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1949. doi:10.1158/1538-7445.AM2015-1949

Summary Background Avascular necrosis of the mandible or maxilla is being recognized with increasing frequency in patients who are being treated with bisphosphonates for metastatic cancers. Methods and results A patient who was treated for avascular necrosis following treatment with bisphosphonates for multiple myeloma is presented. Conclusion Prophylactic and preventative measures should be instituted prior to commencing treatment with bisphosphonates to minimize the risk of developing avascular necrosis.

Objectives: Laryngopharyngeal reconstruction continues to challenge in terms of operative morbidity and optimal functional results. The primary aim of this study is to determine whether complications can be predicted on the basis of reconstruction in patients undergoing pharyngectomy for tumors involving the hypopharynx. In addition, we detail a reconstructive algorithm for management of partial and total laryngopharyngectomy defects. Method: A retrospective review was performed of 153 patients undergoing flap reconstruction for 85 partial and 68 circumferential pharyngectomies at a single institution over a 10-year period. There were 118 males and 35 females, the median age was 62 years, and mean follow up was 3.1 years. Pharyngectomy was performed for recurrence after radiotherapy in 80 patients and as primary surgery in 73. Free flap reconstruction was used in 42%, with 30 jejunal, 15 radial forearm, 11 anterolateral thigh, five rectus abdominis, and three gastro-omental flaps. Gastric transposition and pectoralis major pedicle flap was used in 14% and 44% of patients, respectively. Morbidity was analyzed according to extent of defect, regional versus free flap, enteric versus fasciocutaneous free flap reconstruction, and the effect of laparotomy. Results: The total operative morbidity and mortality rate was 71% and 3%, respectively. The most common complications were hypocalcemia in 45%, pharyngocutaneous fistula in 33%, and wound complications in 25%. The late complication and stricture rate was 26% and 15%, respectively. On univariate analysis, circumferential defects were associated with increased total (P = .046) and flap-related morbidity (P = .037), hypocalcemia (P < .001), late complications (P = .003), and stricture (P = .009). Gastric transposition had increased total (P = .007), flap-related (P = .035), late complications (P = .034), and hypocalcemia (P = .001). Pharyngocutaneous fistula was increased in patients undergoing salvage pharyngectomy for radiation failure (P = .048) compared with primary surgery. On multivariate analysis, gastric transposition independently predicted for wound complications (P = .014) and fistula (P = .012). Circumferential defects predicted for flap-related morbidity (P = .030), hypocalcemia (P = .017), and late complications (P = .042). Tracheoesophageal speech was the method of voice restoration in 44% of patients. Oral diet was achieved in 93% of patients; however, 16% required gastrostomy tube feeds for either total or supplemental nutrition. Conclusion: The operative morbidity associated with pharyngeal reconstruction is substantial in terms of early and late complications. We were able to predict morbidity by defect extent and reconstruction type and initial treatment modality. Swallowing function is acceptable; however, less than half of the patients undergoing pharyngectomy had tracheoesophageal puncture voice restoration.

Objective/Hypothesis: A cone-beam CT (CBCT) imaging system based on a mobile C-arm (Siemens PowerMobil) incorporating a high-performance flat-panel detector (Varian PaxScan) has been developed in our laboratory. We hypothesize that intraoperative C-arm CBCT provides image quality and guidance performance sufficient to assist surgical approach to the frontal recess. Study Design: A preclinical prospective study was conducted using six cadaver heads to assess the performance characteristics and the potential clinical utility of this imaging system. Methods: The mobile C-arm was employed for intraoperative CBCT guidance of the endoscopic approach to twelve frontal recesses. Results: The imaging system is capable of sub-mm 3D spatial resolution with bone and soft-tissue visibility and a field of view sufficient for guidance of head and neck surgery. The system can generate intraoperative, volumetric CT images rapidly with an acceptably low radiation exposure to the patient and with image quality sufficient for most surgical tasks. Moreover, the system is portable and compatible with the surgical setup, providing excellent access to the patient. Finally, the accuracy of the system is not bound to a registration process. Conclusions: The ability to create updated images as surgery progresses introduces the concept of ‘near-real-time’ CT guidance for head and neck surgery. We found that the use of CBCT increased surgical confidence in accessing the frontal recess, resolved ambiguities with anatomical variations, and provided valuable teaching information to surgeons in training in both preoperative planning and correlation between tri

OBJECTIVES: To describe our preclinical experience with Cone Beam CT (CBCT) in image-guided surgery of the temporal bone.STUDY DESIGN AND SETTINGS: A mobile isocentric C-arm (PowerMobil, Siemens Medical Systems, Erlangen, Germany) modified to include a flat-panel detector (Varian Imaging Products, Palo Alto, CA) and a motorized orbit was developed to acquire multiple projections in rotation about a subject. Initial experiments imaging steel wire in air were used to investigate the system's spatial resolution in 3D image reconstruction. Subsequently temporal bone dissection was performed on five cadaver heads using the modified C-arm as an image guidance system.RESULTS: We obtained a spatial resolution of 0.85 mm. The image acquisition time was 120 seconds and the radiation dose approximately one-tenth of a conventional CT scan.CONCLUSION: CBCT provided submillimeter accuracy at high speed with low radiation dosage to offer utility as an intraoperative imaging system.SIGNIFICANCE: CBCT offers technology th...

The functional determinants for a good speech outcome after a partial tongue resection and reconstruction are not well established. The purpose of the present study was to assess the protrusion, grooving and symmetry of the tongue during sustained speech sound production using three-dimensional ultrasound. The participants were twelve normal speakers and one partial glossectomee. The three-dimensional ultrasound volumes of nine sustained speech sounds were measured in three sagittal planes. The data were re-plotted as three-dimensional surfaces. We calculated an anteriority index, a concavity index and an asymmetry index. The glossectomee's postoperative surface plots were characterized by asymmetry and convexity of the tongue surface. The anteriority index illustrated that the glossectomee's ability to protrude her tongue was not affected by the operation. The concavity index captured a decrease in midsagittal grooving in the glossectomee's tongue. The asymmetry index demonstrated height differences in the elevation of the right and left side of the tongue. We conclude that three-dimensional ultrasound offers us a practical tool for the detailed and concise assessment of the lingual shape and deformation in patients undergoing glossectomy surgery.

Purpose: This population-based study describes the treatment of early glottic cancer in Ontario, Canada and assesses whether treatment variations were associated with treatment effectiveness. Methods and Materials: We studied 491 T1N0 and 213 T2N0 patients. Data abstracted from charts included age, sex, stage, treatment details, disease control, and survival. Results: The total dose ranged from 50 to 70 Gy, and the daily dose ranged from 1.9 to 2.8 Gy. In 90%, treatment duration was between 25 and 50 days. Field sizes, field reductions, beam arrangement, and beam energy varied. Late treatment breaks occurred in 13.6% of T1N0 and 27.1% of T2N0 cases. Local control was comparable to other reports for T1N0 (82% at 5 years), but was only 63.2% in T2N0. Variables associated with local failure in T1N0 were age less than 49 years (relative risk [RR], 3.21; 95% confidence interval [CI], 1.49‐6.90) and >3 treatment interruption days (RR, 2.43; 95% CI, 1.00‐5.91). In T2N0, these were field reduction (RR, 2.33; 95% CI, 1.23‐4.42) and late treatment breaks (RR, 2.19; 95% CI, 1.09‐4.41). Conclusion: Some aspects of treatment for early glottic cancer were associated with worse local control. Problems with protracted treatment are of particular concern, underscoring the need for randomized studies to intensify radiotherapy. © 2006 Elsevier Inc. Laryngeal cancer, Practice variations, Survival, Local control, Population-based.

A promising imaging platform for combined low-dose fluoroscopy and cone-beam CT (CBCT) guidance ofinterventional procedures hasbeen developed in our laboratory. Based on a mobile isocentric C-arm (SiemensPowerMobil) incorporating a high-performance flat-panel detector (Varian PaxScan 4030CB), the system demonstratessub-mm 3D spatial resolution and soft-tissue vi sibility with field of view sufficient for head and body sites. For pre-clinical studies in head neck tumor su rgery, we hypothesize th at the 3D intraoperative info rmation provided by CBCTpermits precise, aggressive techniques with improved avoidance of critical structures. The objectives include: 1) quantify improvement in surgical performance achieved with CBCT guidance compared to open and endoscopictechniques; and 2) investigate specific, ch allenging surgical tasks under CBCT gui dance. Investigations proceed from anidealized phantom model to cadaveric specimens. A novel sur gical performance evaluation method based on statisticaldecision theory is applied to excision and avoidance tasks. Analogous to receiver operating characteristic (ROC) analysis in medical imaging, the method quantifies surgical performance in terms of Lesion-Excised (True-Positve),Lesion-Remaining (False-Negative), Normal-Excised (False-Positive), and Normal-Remaining (True-Negative)fractions. Conservative and aggressive excision and avoidance tasks are executed in 12 cadaveric specimens with and without CBCT guidance, including: dissecti on through dura, preservation of po sterior lamina, ethmoid air cells removal,exposure of peri-orbita, and excision of infiltrated bone in the skull base (cli vus). Intraoperative CBCT data was foundto dramatically improve surgical performance and confidence in the execution of such tasks. Pre-clinical investigation ofthis platform in head and neck surgery, as well as spinal, trauma, biopsy, and other non vascular procedures, is discussed.Keywords: cone-beam CT, fluoroscopy, flat-panel detector, imaging performance, 3D imaging, image-guided surgery,image-guided interven tions, head and neck surgery, C-arm, surgical performance, image guidance, endoscopy

The present study aimed at identifying underlying parameters that govern the shape of the tongue. A functional topography of the tongue surface was developed based on three-dimensional ultrasound scans of sustained speech sounds in ten normal subjects. A principal component analysis extracted three components that explained 89.2% of the variance at 33 measurement points on the tongue surface. The results from the principal component analysis supported a physiologically plausible three-component model of tongue movement. This model breaks tongue movement down into a protrusion and retraction component that is represented by the measurement points on the posterior tongue, a tongue tip control component that is represented by the measurement points on the tongue blade, and a dorsal height and position control component that is represented by the measurement points on the tongue dorsum. A case series of three patients with partial glossectomies illustrates how this measurement system can be applied to surgically altered tongues to allow a detailed analysis of post-surgical function.

To evaluate the effectiveness of oral communication about the risks of facial cosmetic procedures compared with oral and written communication.A prospective randomized study conducted in an ambulatory surgery center. One hundred twenty consecutive patients were included; they presented for consultation for rhinoplasty, rhytidectomy, or laser resurfacing. Patients were randomly assigned to 1 of 2 groups: (1) those receiving oral discussion of the risks of the procedure and (2) those receiving oral and written communication about the risks. Two weeks after the initial consultation, patients were surveyed for recall of the risks.The group that received a pamphlet had a better risk recall than the group that did not (2.5 vs1.5 of 5 risks; P.001). The recall rate in the following groups that received a pamphlet was also better: (1) university-educated patients (P =.02), (2) patients who underwent rhinoplasty (P.001), (3) patients who underwent laser resurfacing (P =.02), and (4) female patients (P.001).Written disclosure of the risks of cosmetic procedures enables patients to retain and understand more clearly those potential risks. They are, therefore, able to give an informed consent to the proposed procedure. This study also identifies patient groups who may require more intensive presurgical teaching. The medicolegal implications are apparent.

To examine the indications for, and the success of, free flap reconstruction in patients with forehead and scalp defects.Case series.Two tertiary referral university teaching hospitals. Patients Twenty-six consecutive patients, aged 31 to 85 years, presenting with 26 scalp defects, 5 forehead defects, and 1 combined defect (size, 70-672 cm(2)). Three patients required resection and repair of the dura at surgery. Intervention Patients were staged according to the size of the defect and the viability of surrounding tissue; free flap reconstruction was performed where indicated.Flap survival, complications, and disease-free and overall survival.Thirty-four free flap reconstructions were performed (24 latissimus dorsi free flaps, 4 scapular free flaps, 3 rectus abdominis free flaps, and 3 radial forearm free flaps). One failed 2 weeks postoperatively, and 2 required exploration (1 for arterial ischemia and 1 for a hematoma). There were 3 cases of donor site morbidity (2 early seromas and 1 late abdominal hernia). One patient died of a pulmonary embolus 1 week postoperatively. Disease-free survival was 48% at 5 years and overall survival was 59% at 5 years, with a median follow-up of 24 months.Free revascularized tissue transfer is a reliable and safe way of reconstructing large scalp or forehead defects after traumatic injury or neoplastic resection. The muscle-only latissimus dorsi free flap for scalp reconstruction and the cutaneous scapular free flap for the forehead have proved successful in selected patients with a low complication rate and satisfactory cosmesis.

Combination surgery and radiotherapy (RT) is frequently used in soft tissue sarcoma (STS). Because lower doses and smaller irradiation volumes are possible in preoperative RT (pre-op RT), this approach can be especially valuable in anatomic settings where critical organs are in close proximity to the RT target area. A recent multicenter phase III trial (SR.2 trial of the National Cancer Institute of Canada Clinical Trials Group) comparing pre-op RT against post-op RT for extremity STS has shown significantly higher major wound complication rates (35%) with pre-op RT. We postulated that wound complication rates may be less frequent in the head and neck with better vascularity and wider use of secondary wound reconstruction. Using a prospective database, we identified 40 consecutive patients with head and neck STS treated with pre-op RT (50 Gy) and subsequent (4 to 6 weeks later) resection between 1/89 and 8/99 in a single institution setting. Major wound complications (MWC) were classified by the identical criteria used in the SR.2 trial. Intracranial extension was evident in 5 patients, whereas 50% of the patients had large tumors (> 5 cm). Deep tumor was present in 34 (85%), and 6 (15%) were superficial to fascia. In this series, 31 patients (77.5%) had secondary reconstruction of the acquired soft tissue deficit. The actuarial 2-year local relapse-free rate was 80%, and the metastatic relapse-free rate was 85%. Major wound complications occurred in 8 of 40 patients (20%) within 120 days of surgery according to the SR.2 criteria: secondary wound surgery (3), readmission or prolonged hospital admission for wound care (2), deep packing (0), prolonged dressing changes (2), and invasive procedure for wound care (1). The latter was a minor wound management problem (a single outpatient drainage of a seroma) for the combined rate of 8/20 or 20%. Our findings show that (1) pre-op RT in head and neck STS is associated with lower rates of major wound complications compared to extremity cases; (2) pre-op RT provides high rates of local control in an adverse group of cases of adult head and neck STS; (3) the choice of scheduling of RT should be based on anatomic issues with emphasis on the trade-offs between RT doses and volumes versus wound morbidity for individual patients. This is especially important when tumor may be adjacent to critical head and neck structures which may be protected from the high-dose RT area.

Osteoradionecrosis (ORN) of the craniomaxillofacial skeleton is a serious and debilitating complication that can occur following radiation therapy in the head and neck. Patients require effective treatment, which eradicates diseased tissue and restores function with minimal additional morbidity in a single stage, a requirement fulfilled in many cases by free tissue transfer. In a 6-year period from 1994 to 1999, 21 patients with ORN were treated by wide resection and free-flap reconstruction. The median interval between radiation therapy and ORN was 4 years (range: 1-33 years). The median radiation dose was 6000cGy. The affected areas were the mandible (15 patients), the temporal bone (three patients), the maxilla (one patient), the cervical vertebrae (one patient) and the frontal bone (one patient). Clinical symptoms included pain, ulceration, a persistent draining fistula, exposure of bone or hardware, and pathological fracture or non-union of bone. Six patients had had previous unsuccessful attempts at conservative surgical resection. Ten patients had preoperative hyperbaric oxygen (HBO) therapy. A number of different flaps were used for reconstruction in these patients. These included free fibula flaps (13 patients), iliac crest flaps (two patients), scapula flaps (three patients) and rectus abdominis flaps (three patients). All patients achieved relief from their presenting symptoms and primary bone or wound healing. One flap (4.8%) was lost. This was successfully reconstructed in a subsequent procedure. There were three flap re-explorations, two for arterial thrombosis and one for venous thrombosis. Conservative measures, such as limited debridement and HBO therapy, may be effective in preventing the progression of ORN. However, they fail to eradicate established ORN, which requires radical surgical resection followed by functional reconstruction with well-vascularised tissue.

Purpose: We compared the management and outcome of supraglottic cancer in Ontario, Canada, with that in the Surveillance, Epidemiology, and End Results (SEER) Program areas in the United States. Methods: Electronic, clinical, and hospital data were linked to cancer registry data and supplemented by chart review where necessary. Stage-stratified analyses compared initial treatment and survival in the SEER areas (n = 1,643) with a random sample from Ontario (n = 265). We also compared laryngectomy rates at 3 years in those patients 65 years and older at diagnosis. Results: Radical surgery was more commonly used in SEER, with absolute differences increasing with increasing stage: I/II, 17%; III, 36%; and IV, 45%. The 5-year survival rates were 74% in Ontario and 56% in SEER for stage I/II disease (P = .01), 55.7% in Ontario and 46.8% in SEER for stage III disease (P = .40), and 28.5% in Ontario and 29.1% in SEER for stage IV disease (P = .28). Cancer-specific survival results mirrored the overall survival results with the exception of stage IV disease, for which 34.6% of Ontario patients survived their cancer compared with 38.1% in SEER (P = .10). This stage IV difference was more pronounced when we further controlled for possible cause of death errors by restricting the comparison to patients with a single primary cancer (P = .01). Three-year actuarial laryngectomy rates differed. In stage I/II, these rates were 3% in Ontario compared with 35% in SEER (P < 10−3). In stage III disease, the rates were 30% and 54%, respectively (P = .03), and in stage IV disease they were 33% and 64% (P = .002). Conclusion: There are large differences in the management of supraglottic cancer between the SEER areas of the United States and Ontario. Long-term larynx retention was higher in Ontario, where radiotherapy is widely regarded as the treatment of choice and surgery is reserved for salvage. In stages I to III, survival was similar in the two regions despite the differences in treatment policy. In stage IV, there may be a small survival advantage in the U.S. SEER areas related to the higher use of primary surgery.

Complications arising from intubation and other airway management procedures can have significant morbidity and mortality risks. With the increasing interventional techniques employed by the anesthesiologist to acquire and maintain an airway, there is a potential for increasing airway injury. Awareness of the potential "difficult" airway and employing the appropriate techniques to maximize airway visualization can minimize the risk of these complications.

To examine the effects of an educational intervention, in the form of printed material, on patient knowledge and recall of possible risks from parotidectomy or thyroidectomy.Prospective, randomized, controlled study conducted during a 9-month period.Head and neck surgery clinic of an academic tertiary care hospital.One hundred twenty-five consecutive patients older than 16 years who were undergoing thyroidectomy or parotidectomy at the head and neck surgery clinic were recruited. Four patients were excluded from analysis because their follow-up interview was not within the required limits.At the preoperative visit during the routine consent process, both groups received a verbally delivered checklist of risks specific for the surgery to be performed. The intervention group was also given a pamphlet with written information accompanied by illustrations.The effectiveness of the educational intervention was determined by comparing the average rate of risk recall between the intervention and control groups. The effects of age, sex, level of education, and time between the consent and recall interviews on recall rate were also assessed.The overall risk recall rate for both procedures was 39.1%. The recall rate of the intervention group was 50.3% compared with 29.5% for the control group (P.001).The intervention consistently improved risk recall for all patients regardless of age, sex, and level of education. Patients' ability to recall potential risks was significantly increased by an educational intervention; all patients would benefit from this intervention.