Conservative management of vestibular schwannomas - second review of a prospective longitudinal study

Abstract

Vestibular schwannomas have been traditionally managed with microsurgical removal and in recent years, stereotactic radiotherapy. However, there is a group of patients in whom a conservative management approach might represent a desirable alternative. The aim of this study was to determine the natural history and outcome following the conservative management of 72 patients with unilateral vestibular schwannomas. This is a prospective cohort review of a previously published group of patients [Clin. Otolaryngol. (2000) 25, 28-39] with unilateral vestibular schwannoma that were initially analysed at our institution in 1998 [Walsh R.M., Bath A.P., Bance M.L. et al., Clin. Otolaryngol. (2000) 25, 28]. The mean duration of follow-up was 80 months (range 52-242 months). All the patients in the study underwent serial magnetic resonance imaging (MRI) for assessment of tumour growth. Patients were deemed to have failed conservative management if there was evidence of rapid radiological tumour growth and/or increasing signs and symptoms, which necessitated active intervention. The mean tumour growth rate for the entire group at the second review was 1 mm/year (range -0.84-9.65 mm/year). The mean growth rate for cerebellopontine angle tumours (1.3 mm/year) was significantly greater than that of internal auditory canal (IAC) tumours (0 mm/year) (P = 0.005). The majority of tumours (87.14%) grew <2 mm/year. There was significant tumour growth seen in 38.9%, no or insignificant growth in 41.7%, and negative growth in 19.4%. Twenty-three patients (32%) failed conservative management at the second review. There was no difference in the outcome of these failed patients in comparison with patients who underwent primary treatment without a period of conservative management. The mean growth rate of tumours in patients that failed conservative management (3.1 mm/year) was significantly greater than that in patients who did not fail (0.2 mm/year) (P < 0.001). No factors predictive of tumour growth or failure of conservative management were identified. Hearing deterioration with pure tone averages (0.5, 1, 2, 3 kHz) and speech discrimination scores occurred irrespective of tumour growth. This prospective study further emphasizes the role of conservative management in selected cases of vestibular schwannomas. Tumours in this study confined to the IAC typically demonstrated minimal or no growth on serial MRI scanning. Regular follow-up with interval scanning is mandatory in all patients.

Evaluation of the necessity of contrast for the follow up MR imaging of schwannomas

“…Studies have shown that the majority of vestibular schwannomas tend to grow slowly (38-43%) (9, 10). Conservative management of these tumors is appropriate in select cases, such as in patients with advanced age, poor general health or small tumors (3,11).…”

“…MRI is the imaging technique used in the conservative management of vestibular schwannomas (2,3). T1W sequences with a gadolinium-based contrast agent are the gold standard for the initial detection and follow-up examinations of these tumors (5, 7).…”

“…A total tumor growth of >1 mm/year was considered significant radiologic growth and was referred to as tumor progression (3,8). Contrast-enhanced T1W images were considered the gold standard to assess progression.…”

Calidad de vida tras la cirugía del schwannoma vestibular

“…Mientras que la observación con RNM seriadas se recomienda frecuentemente para los pacientes mayores con tumores pequeños 9,26 , en los pacientes jóvenes con buen estado de salud y tumores grandes se recomienda normalmente la resección quirúrgica.…”

An update on unilateral sporadic small vestibular schwannoma

“…57,81 The data, however, do not always show a linear correlation between the rate of tumor growth and deterioration of hearing. 38,39,82,96,104 …”