Coudeville L, Dubrulle F, Kiaei A, Vaneecloo FM, Lemaitre L, Lebrun T; International Society of Technology Assessment in Health Care. Meeting.

Annu Meet Int Soc Technol Assess Health Care Int Soc Technol Assess Health Care Meet. 1999; 15: 139.

Cresge-Labores, France.

OBJECTIVE: To determine the indications of low-field (0.2T) and high-field (1.5T) magnetic resonance imaging (MRI) in retrocochlear pathology detection. METHODS: Following cost-effective resource allocation rules, the level of risk from which detection is considered as justified can be used to determine the willingness-to-pay for the detection of a pathology. This property is used for identification of the optimal diagnostic strategy regarding the retrocochlear pathology risk of the patient. Three strategies are compared: not to achieve detection (ND), low-field MRI + high-field MRI in case of non-conclusive result or detection of small vestibular schwannomas (grade 1 or 2) with low-field MRI (LF), systematic high-field MRI (HF). A probabilistic sensitivity analysis, based on Monte-Carlo simulations, is performed to determine the probability for a strategy to be optimal regarding the risk of the patient. DATA: The performances of low-field and high-field MRI for detection of tumoral retrocochlear lesions (TRL) and other retrocochlear pathologies (ORP) are based on results of a clinical trial (281 patients). Four subgroups of patients were identified in this trial according to their clinical signs: low risk (TRL risk: 4.1%, ORP risk: 0%), moderate risk (TRL risk: 17.6%, ORP risk: 0%), high risk (TRL risk: 60.6%, ORP risk: 3%) and patients with atypical clinical signs (TRL risk: 28.6%, ORP risk: 28.6%). A specific investigation, based on data from CHRU of Lille, is carried out to determine direct cost of the tests. RESULTS: Optimal strategy regarding retrocochlear pathology risk and willingness-to-pay for the detection of a pathology (probability for the strategy to be optimal according to the sensitivity analysis): Willingness-to-pay for the detection of a pathology (a), Retrocochlear pathology risk of the patient: low risk, moderate risk, high risk, atypical clinical signs; Low value, ND (88.6%), LF (84.8%, HF (98.2%), HF (100%); Mean value: LF (57.6%), LF (72.6%), HF (99.5%), HF (100%); High value, LF (59.2%), HF (54.4%), HF (99.9%), HF (100%). (a) Based on the level of risk from which detection is considered as justified: low value (11.4%), mean value (4.1%), high value (0.8%). CONCLUSION: Low-field MRI is a useful screening test before high-field MRI for patients having a low or moderate risk of retrocochlear pathology. Systematic high-field MRI remains the best strategy for patients presenting a high risk or atypical clinical signs.

Publication Types:

• Meeting Abstracts

Keywords:

• Humans
• Magnetic Resonance Imaging
• Neuroma, Acoustic
• Sensitivity and Specificity
• diagnosis
• pathology
• hsrmtgs

Other ID:

• HTX/20602508

UI: 102194197

From Meeting Abstracts