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| Dr. Mangham's curriculum vitae contains a list of publications and presentations on acoustic tumors. To go the curriculum vitae page, click here |
|
.Expert
Opinion on the Diagnosis of Acoustic Tumors,
by Charles A. Mangham, MD, MS, Seattle, Washington |
| Ideally, clinicians recommend diagnostic tests when the patient's risk of disease is sufficient to justify putting numerous similar patients through the morbidity required to diagnose disease in one patient. In the case of acoustic tumor diagnosis, there are few published data available to the clinician to help assess risk in an individual patient. The purpose of this study was to obtain information by an opinion poll of a group of experts. We used the Delphi method to poll clinicians trained at the House Ear Clinic. We asked these experts 20 questions related to acoustic tumor diagnosis. Some of the expert opinion presented herein is the only data related to acoustic tumor diagnosis available to clinicians. These data are a first step in elevation of decision-making for tumor diagnosis above the level of speculation. However, the experts' responses displayed a pattern of inaccuracy that limits the clinical application of their opinion. Exposing this pattern was instructive for identifying desirable features of protocols for diagnosing tumors. We recommend that protocols not depend on clinicians estimating probability of tumor. Instead, protocols may list specific findings, such as unilateral distortion on the telephone, to indicate, when present, that the risk of tumor is sufficient to order a diagnostic test. (Otolaryngol Head Neck Surg 1 997:1 1 7 6227 ) |
| If you would like to read the full text of the paper, click here: full text of "Expert Opinion ..." paper |
| Hearing Threshold Difference Between Ears and Risk of Acoustic Tumor, by Charles A. Mangham, MD, Seattle, Washington (abstract) |
| Reprinted from OTOLARYNGOLOGY: HEAD AND NECK SURGERY, St. Louis Vol. 105, No. 6, PP. 814817, December, 1991 (Printed in the U.S.A.) (Copyright 1991 by the American Academy of Otolaryngology Head and Neck Foundation, Inc.) |
| This is the abstract from the paper. Click below for the full text of the paper. |
| This study addresses the question, what difference in hearing between ears puts a patient at sufficient risk of acoustic tumor to warrant further diagnostic tests? The subjects were 210 patients with surgically confirmed unilateral acoustic tumors and a control group comprised of 112 patients referred for audiometry. Hearing thresholds were determined at octave intervals from 250 Hz to 8 kHz. The threshold in the nonsuspect ear was subtracted from the threshold in the suspect ear. The rank order in effectiveness for threshold difference was: 2 kHz, 4 kHz, 1 kHz, 8 kHz, 500 Hz, and 250 Hz. We found that the most effective diagnostic strategy was to refer patients for magnetic resonance imaging if their average threshold difference at 1 to 8 kHz was 20 dB or greater and refer patients for auditory brainstem response testing if their average threshold was 5 to 20 dB. (OTOLARYNGOL HEAD NECK SURG 1991;105:814.) |
| If you would like to read the full text of the paper, click here: full text of "Hearing threshold difference ..." paper. |
| Indications
for hearing preservation in acoustic tumor surgery,
Charles A. Mangham, MD., MS. and Theresa A. Skalabrin, M.A. |
| From: The American Journal of Otology/Volume 13, Number 2, March 1992 |
|
This study addresses the problem of how to counsel patients with acoustic tumors concerning the issue of hearing preservation. Rather than the traditional yes or no answer, we wish to give the patient the probability that hearing can be preserved given the size of the tumor and the patient's preoperative hearing level. The subjects were 77 patients of the Seattle Ear Clinic who underwent total removal of unilateral acoustic tumors with attempted hearing preservation using a suboccipital approach. Other criteria for inclusion in the study were: tumor size, measured from a preoperative diagnostic image, and availability of pre and postoperative hearing test results. We reviewed published data from other centers using similar inclusion criteria to determine if our findings were representative of the experience of surgeons at other institutions. We found a significant relationship between hearing preservation success and tumor size, but not between success and preoperative hearing level. The probability of success varied from 78 percent for 0.5cm tumors to about 15 percent for tumors 2.0 cm and larger. If surgery was successful, 82 percent of patients had hearing that was the same or better than their preoperative hearing level. |
| If you would like to read the full text of the paper, click here: full text of "Indications for Hearing Preservation ..." paper. |
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