HEAD & NECK SURGERY - Stanford University School of Medicine

More documents

Recommendations

Info

S T ANFORD U NIVERSITY D EPARTMENT OF O TOLARYNGOLOGY – HEAD & N ECK S URGERY R ESEARCH P ROGRAMS Figure 2 – Generation of the Nyquist plot, an objective representation of normal vocal fold vibration. form of high-resolution MRI imaging for the detection of early invasive cancer of the vocal cords (Figure 3). High-resolution MRI scanning may allow images of the larynx at 8 to 10 times the resolution of standard MRI, and a clinical trial is currently underway to determine its role in predicting invasion of the cartilage by cancer. Earlier detection of advanced disease may afford higher rates of laryngeal conservation in the future. Figure 3 – High-resolution MRI of the human larynx. 14 CLINICAL RESEARCH IN OTOLOGY-NEUROTOLOGY Nikolas H. Blevins and Robert K. Jackler Planned Subtotal Resection and Stereotactic Radiotherapy for Acoustic Neuroma The advent of stereotactic radiosurgery has provided the clinician with a nonsurgical option to control the growth of acoustic tumors. With the development of the Cyberknife linear accelerator system, Stanford has long been a pioneer in the non-surgical management of skull base disease. Despite considerable experience with small acoustic tumors, the role of radiosurgery into the treatment of large tumors remains to be fully defined. The potentially synergistic effect of combined microsurgical resection and stereotactic radiotherapy could offer effective new options to individuals who remain at most risk given conventional treatment. The Stanford Department of Otolaryngology in collaboration with the departments of Neurosurgery and Radiation Oncology, is leading a prospective multicenter trial to assess the efficacy of managing large acoustic neuromas (over 3 cm) with a combination of planned subtotal resection followed by stereotactic radiosurgery. Patients enrolled in the protocol will undergo planned subtotal resection avoiding potentially injurious dissection of the facial nerve from the tumor capsule. Patients will be followed with serial MRI scans, and will receive stereotactic radiation to the tumor remnant if growth is detected. The prospective nature of this study will provide valuable data towards establishing optimal treatment of advanced disease, while minimizing the risk of postoperative facial nerve dysfunction. Planned subtotal resection of an acoustic neuroma The Stanford Cyberknife. The Use of Stacked ABR for the Assessment of Hearing Preservation in Acoustic Neuroma Resection Patients with small acoustic neuromas and good hearing are faced with a choice of treatment options. Whether they choose to undergo microsurgical resection or stereotactic radiotherapy (such as with Cyberknife) can be largely influenced by the likelihood of hearing preservation. The short-term rates of hearing preservation with stereotactic radiation are excellent, but given the persistence of tumor and possible long-term neurovascular changes, hearing levels may deteriorate with time. Microsurgery in contrast, often places additional risks to hearing in the short term. However, the expectation for maintaining hearing that is present post-operatively is quite favorable. Unfortunately, there is a current lack of preoperative predictors of which patients are more likely to retain hearing through a surgical procedure. The Stanford Departments of Otolaryngology and Audiology are engaged in a prospective clinical trial to assess innovative of electrophysiologic testing to predict the success of hearing-preservation attempts. The study applies highly sensitive auditory brainstem response techniques (“stacked ABR”) that may be an accurate predictor of the potential for an involved cochlear nerve to withstand surgical manipulation and tumor extraction. The development of such non-invasive preoperative predictors will substantively assist with patient counseling and treatment planning in patients with acoustic neuromas. Given this additional information, patients and their clinicians may make better-informed decisions about the pursuit of treatment options.
Non-invasive Diagnosis of Cholesteatoma using High-Resolution Diffusion-Weighted MRI Sequences The Department of Otolaryngology, in conjunction with the Department of Radiology, is engaged in a prospective study to establish the efficacy of innovative MRI techniques in the diagnosis of cholesteatoma. Standard diffusion-weighted MRI is capable of detecting intratemporal squamous epithelium. However, it is suboptimal in its anatomic resolution and is subject to significant artifacts, both of which limit its clinical utility. Our protocol involves the use of new signal processing techniques (SENSE-DWI). The resulting improved images have the potential to make MRI clinically useful in treatment planning for patients with possible occult cholesteatoma. Patients in whom a second-look procedure is contemplated may benefit greatly from this non-invasive imaging modality. Innovations in Cochlear Implant Technology In 1964, the first human multichannel cochlear implant was placed at Stanford. The Department of Otolaryngology continues this long history of innovation in the development and application of inner ear prostheses. Related basic science projects include the application of stem-cells for inner ear regeneration, computational modeling of inner ear function, and inner ear microendoscopy for therapeutics and inner ear microrobotics. The LPCH/Stanford Cochlear Implant Center is actively involved in clinical trials for cochlear implants. We are a center for the clinical trial of the Nucleus Electrical-Acoustic Hybrid implant.These devices offer the potential benefits of cochlear implantation to the vast number of individuals who suffer from high frequency hearing loss, since residual acoustic hearing in the lower frequencies can be maintained. CLINICAL RESEARCH IN AUDIOLOGY Gerald Popelka, PhD Clinical research in Audiology complements the services that are provided and consequently covers both diagnostics and rehabilitation. All clinical audiology research is performed under strict IRB protocols with patients providing signed consents and receiving compensation in most cases and complete protection of patient privacy Our current auditory diagnostic research projects center around the development and improvement of clinical information derived from auditory evoked potentials. A new auditory evoked potential measure reported last year has the possibility of indicating whether cochlear fluid pressure is abnormally high. The measure is based on the theory that a prominent peak in the waveform of the auditory brainstem response will shift in latency (about 1 msec) with selective stimulation of different portions of the basilar membrane. This latency shift is due primarily to the normal stiffness gradient along the length of the basilar membrane. High fluid pressure such as that associated with endolymphatic hydrops is expected to eliminate this gradient stiffness and therefore eliminate the latency shift. Currently, several parametric variables are being investigated including electrode location, automated response quantification, methods for reducing electromyogenic artifacts, and other practical considerations before the method can be deemed reliable Fall 2006 enough for routine clinical use. It is hoped that the improved procedure will provide a repeatable and useful indication of cochlear fluid pressure. Our current rehabilitative research projects center on the development of advanced digital signal processing that can be implemented with contemporary digital hearing aids. These advanced hearing aids now constitute over 90% of all hearing aids sold nationally and 100% of those dispensed in our clinic and continue to add new functionality such as incorporating cell phone capability. Current research projects involve both the development of new digital processing for improving speech understanding in noise and measuring and understanding the sources of alterations in other auditory tasks caused by the specific digital processing such as errors in locating sounds in the environment. We wish to make sure that an enhancement in one type of auditory performance, improved understanding in noise, eg, is not obtained at the expense of a detriment in another type of auditory performance, poor speech understanding through the internal cell phone function, eg. We also wish to determine if the particular digital processing interacts with the individual hearing status such that a particular processing may be beneficial for certain types of hearing impairment but detrimental for other types of hearing impairment. Patients with well documented hearing loss are recruited to listen to speech and other sounds processed digitally under highly-controlled conditions either in real time or with prerecordedrecordings. It is hoped that this systematic approach will result in an understanding of the optimal digital processing for individual patients allowing us to fulfill our goal of providing customized and optimized solutions for our hearing impaired patients. 15
Page 1 and 2: Stanford University Medical Center
Page 3 and 4: I NTRODUCING O UR FACULTY (Fall 200
Page 5 and 6: STANFORD FACULTY AT SANTA CLARA VAL
Page 7 and 8: may act to amplify low levels of so
Page 9 and 10: These microRNAs (miRNA) are normal,
Page 11 and 12: of maternal senescent red blood cel
Page 13: EVIDENCE-BASED MEDICINE IN FACIAL P

HEAD & NECK SURGERY - Stanford University School of Medicine

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?