CT Hounsfield Unit Is a Good Predictor of Growth in Meningiomas

Abstract

Predicting the growth rate of meningiomas is important in treatment planning. Although calcification may be an important sign of slow growth in meningiomas, the developmental process and its relation to the tumor growth pattern have not been elucidated. We retrospectively examined the location and degree of calcification in 150 meningiomas (131 asymptomatic tumors) using computed tomography (CT) scans and mean Hounsfield units (mHU). Tumor growth was evaluated using serial imaging studies wherein we calculated tumor doubling time (Td) and identified the growth curve pattern as exponential, intermediate, or decelerating. Tumors in women more frequently had calcification and showed higher mHU than those in men. The mHU was measured at least twice in 57 tumors. Tumors in women showed greater mHU increases than those in men. We found a significant correlation between Td and mHU (R = 0.49). Tumors in men and those in patients in the younger age group grew significantly faster. Multivariate analysis revealed that mHU was the only significant factor affecting Td (P <0.0001). The growth pattern was significantly related to calcification (n = 61, P = 0.0042). Tumors with decelerating growth more frequently showed calcification and had higher mHU than those with exponential growth. Receiver operating characteristic curve analysis revealed that mHU was a better predictor of growth pattern change compared with calcification on CT scan. Meningiomas with high mHU, even without calcification, were likely to show growth deceleration. Mean Hounsfield unit correlated with Td and may be a good quantitative indicator of the growth rate and pattern.

Natural History of Meningiomas: Review with Meta-analyses

“…After discarding duplicates, 344 articles remained. We read their abstracts and excluded case reports and reports of small series containing fewer than 10 cases (53), extracranial meningiomas (17), nonmeningiomas (57), treatment-related papers (83), radiological studies (37), those with descriptions of the pathology alone (13), and those on radiationinduced meningiomas (26). Among the remaining 58 papers, we selected those papers that had clinical data of untreated meningiomas with radiological examinations performed on at least two timepoints, but excluded neurofibromatosis case series.…”

“…We searched articles on "meningioma" published after December 2018 until April 2019 to find recent ones relevant to this study. Twenty-seven papers [3][4][5][6][7][8][9][10][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] were selected for data extraction. Among articles that included overlapping data previously reported from the same institute, [8][9][10]14,16,[22][23][24]30) we selected the papers that contained newer data or necessary data.…”

“…From the selected papers, seven studies included individual data about age, sex, initial and last tumor volumes (or diameters), follow-up interval, and radiological findings. 5,6,12,21,22,25,29) We were able to obtain individual data from two other series (31 28) and 104 tumors 26) of asymptomatic meningiomas). From another study 27) data were obtained from a growth curve graph using the software WebPlotDigitizer.…”

“…3,[14][15][16][17][18][19][20][21][22] Because these criteria in radioP lack a timescale, other research groups attempted to overcome this problem by performing analysis based on tumor growth speed. 6,7,13,[23][24][25][26][27] Growth speed was defined in various ways, such as annual volume change (AVC), tumor doubling time (Td), relative growth rate (RGR), and annual diameter change (ADC). These growth indices have different meanings in the natural growth of tumors, but their differences have not been properly interpreted.…”

“…Indeed, recent studies have revealed self-limiting growth in the majority of incidental meningiomas. 4,26,28) Therefore, factors predictive of sympP may not be concordant with those of radioP.…”