A case of a dermoid cyst compressing the airway.

INTRODUCTION: In this report we discuss the etiology, common locations, diagnostic approach, and treatment of a dermoid cyst. CASE PRESENTATION: A 22-year-old man arrived at the emergency department complaining of submental fullness, an increase in snoring, choking, gagging, and difficulty breathing. The patient was taken to the operating room for a complete resection of a large dermoid cyst that was compressing his airway. DISCUSSION: Dermoid cysts are uncommon head and neck tumors mainly presenting in patients aged 15 to 35. The origin of dermoid cysts is thought to be congenital in most cases, but they can also develop from acquired factors such as trauma or surgical implantation that forces epithelial cells into deep tissues. CONCLUSION: Although benign and often asymptomatic, dermoid cysts may cause other associated symptoms due to compression of structures in the head and neck.

Comparison of physical examination and fluorodeoxyglucose positron emission tomography/computed tomography 4-6 months after radiotherapy to assess residual head-and-neck cancer.

PURPOSE: To retrospectively compare fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) and physical examination 4-6 months after radiotherapy for assessing residual head-and-neck cancer (HNC). METHODS AND MATERIALS: From July 2002 through March 2006, 52 HNC patients underwent definitive radiotherapy or chemoradiotherapy. Categoric assessments of residual tumor by PET/CT and physical examination 4-6 months after therapy were correlated and compared with clinical outcomes. Pretreatment data, including tumor stage and primary site standardized uptake value, were also gathered retrospectively and correlated with clinical outcomes. Median follow-up time was 58 months. RESULTS: Twenty-one patients had either locoregionally "positive" (17 of 21) or "equivocal" (4 of 21) PET/CT scans, whereas 31 patients had locoregionally negative scans. Four patients failed treatment and had biopsy-confirmed residual or recurrent local disease. All patients, including patients with locally suspicious scans or examinations who refused biopsies, were followed clinically for a minimum of 29 months after therapy, with no other cases of treatment failure detected during this time. No patient had residual nodal disease after therapy. Sensitivities of PET/CT vs. physical examination for early detection of treatment failure were 100% vs. 50%, whereas the specificities of the two modalities were 64.6% vs. 89.6%, respectively. Higher initial T stage and American Joint Commission on Cancer stage correlated with increased incidence of positive/equivocal PET/CT results and treatment failure. Maximal standardized uptake value was not predictive of any clinical outcome. CONCLUSIONS: A negative result on PET/CT obtained 4-6 months after radiotherapy is highly sensitive and correlates with successful locoregional control. Patients with negative scans may reasonably be spared invasive diagnostic procedures, such as biopsy and neck dissection, unless recurrent disease is suspected on clinical grounds. Close follow-up is prudent for HNC patients with abnormal findings on posttherapy PET/CT scan.

Gamma knife surgery of vestibular schwannomas: volumetric dosimetry correlations to hearing loss suggest stria vascularis devascularization as the mechanism of early hearing loss.

OBJECTIVE: Determine which variables are correlated with early hearing changes after gamma knife surgery of vestibular schwannomas (VSs). STUDY DESIGN: Prospective clinical study of hearing outcomes, radiation dosimetry, conformity, and tumor size of all sporadic unilateral VS patients treated between June 2000 and July 2009. SETTING: Tertiary referral center. PATIENTS: : Fifty-nine VS patients with at least 6 months of follow-up data were studied. INTERVENTIONS: Audiometry and imaging were performed to determine auditory thresholds, speech discrimination, and tumor size. Radiation doses to 5 volumes were measured. MAIN OUTCOME MEASURES: Pretreatment and posttreatment comparisons were performed with regard to change in tumor size; radiation dose to specific volumes including the internal auditory canal, cochlea, basal turn of the cochlea, and modiolus; and conformity of the treatment. RESULTS: The mean follow-up was 63.76 months (standard deviation, ±29.02 mo; range, 9-109 mo). The median follow-up was 65.5 months. A statistically significant association between maximum radiation dose to the cochlea volume and 3-frequency pure-tone average in patients starting with 50 dB or lesser PTA3 was demonstrated using linear regression analysis. CONCLUSION: Longitudinal changes in hearing occur over time, with the largest changes seen in the first 12 months after treatment. With our study outcomes as basis, limiting the dose of radiation to the cochlea to no more than 4 Gy would likely reduce vascular injury to the stria vascularis and improve hearing outcomes. Shielding the cochlea during the treatment planning process would be one mechanism to accomplish this goal.

Recurrent contralateral abducens nerve palsy in acute unilateral sphenoiditis.

OBJECTIVE: We describe a patient who presented with recurrent, contralateral abducens nerve palsy resulting from acute sphenoiditis. METHODS: Patient medical record and imaging studies were reviewed. A literature review of complications of sphenoiditis was performed. RESULTS: Our patient presented with symptoms consistent with an upper respiratory tract infection, as well as severe headache, disequilibrium, and diplopia. Physical examination demonstrated left-sided sixth cranial nerve palsy. Imaging studies were consistent with right sphenoid sinus inflammatory disease. Her medical history was significant for a similar episode 9 years previously, which was managed medically. The current episode was treated acutely with antibiotics and prednisone. Upon resolution of her symptoms, she underwent an endoscopic sphenoidotomy. CONCLUSIONS: Although cranial nerve palsies associated with isolated sphenoiditis have been reported, we describe a unique case of recurrent isolated sphenoiditis causing contralateral abducens nerve palsy. Acute management can be medical, with surgical therapy reserved for refractory cases or to prevent future episodes.

Peripheral cysts: a distinguishing feature of esthesioneuroblastoma with intracranial extension.

Esthesioneuroblastoma is a rare malignancy that arises in the olfactory epithelium. We report an interesting case of esthesioneuroblastoma in an 82-year-old man that included an unusual but characteristic imaging feature of this tumor: cysts at the tumor-brain interface. The patient declined primary surgical resection and elected to undergo primary radiation therapy. At 2 years of follow-up, he remained disease-free. The rarity of this tumor and its unique natural history can lead to a complicated assessment of the clinical picture. We review the diagnostic and treatment alternatives.

Bisphosphonate-related osteonecrosis of the mandible and maxilla: clinical and imaging features.

OBJECTIVE: Bisphosphonate-related osteonecrosis of the jaws is a rare, but morbid, condition. We present the clinical and imaging features of 19 patients. METHODS: A review of 19 bisphosphonate-related osteonecrosis patients was performed. Patient demographics, diagnosis, dental procedures, symptoms and clinical findings, location and pattern of involvement, and presence of fractures, sequestra, and fistulae were documented. RESULTS: Patients included 14 women and 5 men aged 48 to 80 years. Diagnoses included breast carcinoma (n = 11), multiple myeloma (n = 4), osteoporosis (n = 4), prostate carcinoma (n = 2), and lymphoma (n = 1). Seventeen patients received intravenous and 2 received oral bisphosphonates for 2 to 5 years. Bone involvement was noted in the mandible (74%), maxilla (16%), and both (10%). A lytic and sclerotic pattern was most common (58%). Additional findings included fractures (n = 5), sequestra (n = 4), and oroantral fistulae (n = 2). CONCLUSIONS: Bisphosphonate-related osteonecrosis is a rare, but morbid, condition, and imaging features can mimic other conditions. It is important for the radiologist to consider this entity in the appropriate clinical setting.

Clinical outcomes of patients receiving integrated PET/CT-guided radiotherapy for head and neck carcinoma.

PURPOSE: We previously reported the advantages of (18)F-fluorodeoxyglucose-positron emission tomography (PET) fused with CT for radiotherapy planning over CT alone in head and neck carcinoma (HNC). The purpose of this study was to evaluate clinical outcomes and the predictive value of PET for patients receiving PET/CT-guided definitive radiotherapy with or without chemotherapy. METHODS AND MATERIALS: From December 2002 to August 2006, 42 patients received PET/CT imaging as part of staging and radiotherapy planning. Clinical outcomes including locoregional recurrence, distant metastasis, death, and treatment-related toxicities were collected retrospectively and analyzed for disease-free and overall survival and cumulative incidence of recurrence. RESULTS: Median follow-up from initiation of treatment was 32 months. Overall survival and disease-free survival were 82.8% and 71.0%, respectively, at 2 years, and 74.1% and 66.9% at 3 years. Of the 42 patients, seven recurrences were identified (three LR, one DM, three both LR and DM). Mean time to recurrence was 9.4 months. Cumulative risk of recurrence was 18.7%. The maximum standard uptake volume (SUV) of primary tumor, adenopathy, or both on PET did not correlate with recurrence, with mean values of 12.0 for treatment failures vs. 11.7 for all patients. Toxicities identified in those patients receiving intensity modulated radiation therapy were also evaluated. CONCLUSIONS: A high level of disease control combined with favorable toxicity profiles was achieved in a cohort of HNC patients receiving PET/CT fusion guided radiotherapy plus/minus chemotherapy. Maximum SUV of primary tumor and/or adenopathy was not predictive of risk of disease recurrence.

Initial experience of FDG-PET/CT guided IMRT of head-and-neck carcinoma.

PURPOSE: The purpose of this study is to evaluate the impact of (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) fused with planning computed tomography (CT) on tumor localization, which guided intensity-modulated radiotherapy (IMRT) of patients with head-and-neck carcinoma. METHODS AND MATERIALS: From October 2002 through April 2005, we performed FDG-PET/CT guided IMRT for 28 patients with head-and-neck carcinoma. Patients were immobilized with face masks that were attached with five fiducial markers. FDG-PET and planning CT scans were performed on the same flattop table in one session and were then fused. Target volumes and critical organs were contoured, and IMRT plans were generated based on the fused images. RESULTS: All 28 patients had abnormal increased uptake in FDG-PET/CT scans. PET/CT resulted in CT-based staging changes in 16 of 28 (57%) patients. PET/CT fusions were successfully performed and were found to be accurate with the use of the two commercial planning systems. Volume analysis revealed that the PET/CT-based gross target volumes (GTVs) were significantly different from those contoured from the CT scans alone in 14 of 16 patients. In addition, 16 of 28 patients who were followed for more than 6 months did not have any evidence of locoregional recurrence in the median time of 17 months. CONCLUSION: Fused images were found to be useful to delineate GTV required in IMRT planning. PET/CT should be considered for both initial staging and treatment planning in patients with head-and-neck carcinoma.

Cranial thickness in superior canal dehiscence syndrome: implications for canal resurfacing surgery.

OBJECTIVE: To use morphometric analyses of cranial thickness to investigate 2 cases of unanticipated calvarial bone resorption in superior canal dehiscence (SCD) resurfacing surgery. DESIGN: Retrospective morphometric analysis of high-resolution computed tomography (CT) temporal bone scans in normal and control subjects with accompanying case reports. SETTING: Tertiary care referral center. PATIENTS: Two patients with SCD and failed resurfacing because of bone resorption. Temporal bone CT scans from 30 sex-matched controls. INTERVENTION: Resurfacing of SCD via a middle fossa approach using a split thickness calvarial graft from the craniotomy site. MAIN OUTCOME MEASURE: Mean cross-sectional area of the middle fossa craniotomy bone flap and mean cranial thickness at 30 and 45 degrees above the middle fossa floor. RESULTS: Two patients had delayed failure of SCD resurfacing surgery as manifested by return of symptoms. High-resolution CT scans in both, and intraoperative confirmation in one, confirmed resorption of the bone graft. Measurements of cross-sectional area of the middle fossa craniotomy on high-resolution CT scans demonstrated significantly reduced values in the two SCD patients as compared with normal controls (Mann-Whitney U test, p<0.05). Cranial thickness outside the squamous temporal bone was reduced but did not reach statistical significance. CONCLUSION: Morphometric measurements of the calvarium have demonstrated that the squamous temporal bone is thinner in patients with SCD as compared with controls. Thus, the process leading to defects in the tegmen extends beyond the petrous pyramid. This suggests that there may be extratemporal factors leading to the development of a dehiscence. These findings also have implications for the surgical treatment of this disorder. Resurfacing methods may have a higher failure rate as the bone graft has reduced mass and maybe prone to resorption. Canal plugging methods may provide a more definitive means of addressing the dehiscent labyrinth than resurfacing.

Gamma knife radiosurgery for acoustic neuromas performed by a neurotologist: early experiences and outcomes.

OBJECTIVE: To assess early outcomes after Gamma knife radiosurgery of acoustic neuromas and other skull base tumors. BACKGROUND: Gamma knife radiosurgery is one of the available methods to treat acoustic neuromas, in addition to micro-surgical resection. Neuro-otologists have long been associated with microsurgical resection of these tumors; however, the application of Gamma knife radiosurgery to the treatment of these tumors by neuro-otologists has not been previously described. SETTING: Acoustic Neuroma and Skull Base Surgery Program / Tertiary Referral Center. STUDY DESIGN/PATIENTS/INTERVENTION: Prospective clinical study of all patients treated by the senior author and our gamma knife team beginning in June 2000. MAIN OUTCOME MEASURES: Preoperative MRI, audiometry, vestibular testing and facial nerve electromyography were completed. At six-month intervals postoperatively, audiometry, caloric testing and MRI were performed to determine thresholds and speech discrimination ability, vestibular function, and the size of the tumor. RESULTS: From June 2000 until March 2004, 38 patients were treated, and these included 33 acoustic neuromas, two meningiomas, one glomus jugulare tumor, and two facial neuromas. Greater than 36 month follow-up was available in 7 patients, > 24 months in 24, > 12 months in 31, and > 6 months in 34 patients. Statistically significant reduction in tumor size was seen over time, and tumor control was achieved in all but two patients. Various patterns of changes in auditory function, both in threshold and speech discrimination were observed in either positive or negative directions. CONCLUSIONS: Preliminary experience with Gamma knife radiosurgery indicates that this treatment method represents another option for neuro-otologists to use in managing patients with skull base tumors.

Effect of magnetic resonance imaging on internal magnet strength in Med-El Combi 40+ cochlear implants.

OBJECTIVE: Magnetic resonance imaging (MRI) has been contraindicated when cochlear implants containing an internal magnet are in place because of concerns regarding torque, force, demagnetization, artifacts, induced voltages, and heating. The objective was to determine the magnetic field strength of Med-El Combi 40+ cochlear implant internal magnets after MRI studies. STUDY DESIGN/METHODS: Two fresh cadavers were used to study demagnetization using a repeated measures design and a magnetometer. Pre- and postMRI measurement of magnetic field strength was completed. Five sets of sagittal T1-weighted, axial T1-weighted, and axial T2-weighted sequences were performed on a cadaver at 0.2 Tesla in the device-up and device-down positions. In the other cadaver, 15 sets of sagittal T1-weighted, axial T1-weighted, and axial T2-weighted sequences were performed on a cadaver at 1.5 Tesla were conducted, 5 each with the head oriented at 80, 90, and 100 degrees rotated around the yaw plane (rotated around the z-axis). Subsequently, three cochlear implant patients completed 0.2 Tesla MRIs. For these patients, subjective and objective assessment of cochlear implant performance was performed. SETTING: Academic medical center. RESULTS: In the cadaver studies, analysis of variance showed no significant difference in the magnetic field strength after the 0.2 or 1.5 Tesla scans. There was no significant difference in the magnetic field strength for the three patients undergoing 0.2 Tesla MRIs and no adverse consequences, including no changes in telemetry, auditory sensations, nonauditory sensations, and sound quality. CONCLUSIONS: No significant demagnetization of the internal magnet occurred during repeated 1.5 Tesla MRI scans with the head orientations used in this study. In the cochlear implant patients, no significant demagnetization of the internal magnet occurred after a 0.2 Tesla MRI.

Computed tomography technique for evaluation of the nasal valve.

OBJECTIVE: To compare measurements of the nasal valve on computed tomographic images obtained in the traditional coronal imaging plane with those obtained using the Nasal Base View (NBV) for evaluation of the sinonasal cavities. METHODS: Thirty computed tomograms of the sinuses were evaluated retrospectively. Coronal re-formations were performed in a plane perpendicular to the hard palate at the most anterior aspect of the nasal bones at the nasal dorsum. Re-formations of the NBVwere performed in a plane perpendicular to the anterior aspect of the estimated acoustic axis. Measurements of the nasal valve angle were performed for both imaging planes in each patient. RESULTS: Nasal valve angles measured in the traditional, coronal plane were found to have an angle of 8.3 degrees +/- 2.0 degrees (mean +/- SD). Nasal valve angles measured in the NBV had an angle of 11.4 degrees +/- 2.6 degrees. A significant difference was demonstrated (P<.001). CONCLUSIONS: The traditional coronal computed tomograms of the sinonasal cavities may underestimate the true nasal valve angle. The NBV may provide a more accurate assessment of the nasal valve, as the measured angles of the nasal valve in this plane were found to be more consistent with classic descriptions of 10 degrees to 15 degrees.