The growth of acoustic neuromas in volumetric radiologic assessment

Objective: The volumetric assessments of neuroma were applied for radiologi c observation of tumor growth. The hypothesis that most of neuromas are sta ble or show only slight growth was tested. Study Design: This was an observational study. Setting: The study was performed in the university centers. Patients: The study group included 27 patients with 15 unilateral tumors an d 12 bilateral tumors. All patients had at least 2 magnetic resonance imagi ng (MRI) examinations, and the average interval between initial and control examinations was 11.4 months. Main Outcome Measure: Volume measurements were performed on T-1- weighted M RI spin echo sequences after injection of gadolinium using special software . Growth of the tumors was estimated by comparison of the results of three measurements from the initial and control MRI examinations. Results: The growth was confirmed in 17 of 27 tumors (63%). Growth was foun d in 10 of 12 neuromas of neurofibromatosis type 2 (83.7%). In 15 unilatera l neuromas, growth was found in 7 (43%). Unilateral neuromas were observed for a shorter period of time (6.3 months) than bilateral tumors (14.7 month s). The correlation between a neuroma volume gain and the follow-up period was statistically significant (p = 0.003, r = 0.544). Conclusions: The growth of tumors can be confirmed despite a short follow-u p period.