Pituitary tumors are one of the most common types of intracranial neoplasms, and can cause progressive visual loss. An ongoing challenge in the management of patients with pituitary tumors is the cost, availability, and reliability of current magnetic resonance imaging (MRI) techniques to capture clinically significant incremental tumor growth. The purpose of this study was to evaluate the various MRI-based structural analyses and to explore the relationship between measures of structure and function in the afferent visual pathway of patients with pituitary tumors.
We performed a critical review of literature on MRI-based structural analyses of pituitary adenomas using PubMed, Embase, Cochrane Library, and Google Scholar. In addition, preoperative structural characteristics of the optic apparatus, optic nerve compression, and optic chiasm elevation identified as important in the literature review, were examined in 18 of our patients from October 2010 to January 2014.
In our review of literature, a total of 443 citations were obtained from our search strategy and review of bibliographies. Eight of these studies met inclusion/exclusion criteria and were retrieved for critical review. Of the 8 included studies, only 2 studies examined the relationship between MRI-based structural measurements and postoperative visual recovery. In our small case-series, MRI analysis of chiasm elevation, severity of optic nerve compression, chiasm position, height of chiasm, tumor height, and tumor volume failed to differentiate patients with postoperative visual dysfunction vs those with visual recovery (P > 0.05).
Although MRI-based structural analysis is an important and useful tool for managing patients with pituitary tumors, there are limited objective measures shown to be predictive of postoperative visual recovery.
Department of Clinical Neurological Sciences (WHAR, YS), Division of Neurosurgery, University of Calgary, Alberta, Canada; Department of Clinical Neurological Sciences (JMB, FC), Division of Neurology, University of Calgary, Alberta, Canada; and Department of Surgery (JJ, FC), Division of Ophthalmology, University of Calgary, Alberta, Canada.
Address correspondence to Fiona Costello, MD, Foothills Medical Centre, Area 3, #1120H Health Sciences Centre, 3350 Hospital Drive, Calgary, AB T2N 4N1, Canada; E-mail: firstname.lastname@example.org
The authors report no conflicts of interest.