The growth of acoustic neuromas in volumetric radiologic assessment
The volumetric assessments of neuroma were applied for radiologic observation of tumor growth. The hypothesis that most of neuromas are stable or show only slight growth was tested. This was an observational study. The study was performed in the university centers. The study group included 27 patients with 15 unilateral tumors and 12 bilateral tumors. All patients had at least 2 magnetic resonance imaging (MRI) examinations, and the average interval between initial and control examinations was 11.4 months. Volume measurements were performed on T1- weighted MRI 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. The growth was confirmed in 17 of 27 tumors (63%). Growth was found in 10 of 12 neuromas of neurofibromatosis type 2 (83.7%). In 15 unilateral 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 months). The correlation between a neuroma volume gain and the follow-up period was statistically significant (p = 0.003, r = 0.544). The growth of tumors can be confirmed despite a short follow-up period.