The suprasellar volume of nonfunctioning pituitary adenomas: a useful tool for predicting visual field deficits

Purpose: The aim of the present study is to assess the predictive value of the suprasellar volume (SSV) of nonfunctioning pituitary adenomas (NFPAs) for visual field (VF) impairment in order to guide clinical decision-making and improve neurosurgical management. Methods: Two independent samples of patients with NFPAs (exploratory population N = 50, testing population N = 98) were included in the present study. In the first phase, we determined the optimal cut-off value of the SSV correlating with VF deficits in the exploratory population. In the second phase, we then studied the accuracy of identified cut-off in predicting a VF deficit in the testing population. Results: In the exploratory population, the optimal cut-off value of the SSV to determine the presence of a VF deficit was 1.5 mL. Sensitivity and specificity of the cut-off were 81.3 and 100%, respectively. The positive predictive value (PPV) and the negative predictive value (NPV) were 100 and 75%, respectively. When we checked the identified cut-off score on the testing population, we found a sensitivity of 71% and a specificity of 100%. The PPV and NPV were 100 and 59.2%, respectively. In six cases with VF defects and SSV inferior to 1.5 mL, the displacement of optic chiasm was in superior position. Conclusion: The SSV may represent an accurate method in routinely clinical practice for predicting VF deficit in patients affected by NFPA.