Simplifying Tumor Volume Estimation from Linear Dimensions for Intra-Cranial Lesions Treated with Stereotactic...

Area of Science:

• Neurosurgery
• Medical Imaging
• Biostatistics

Background:

• Accurate cranial tumor volume calculation is crucial for treatment planning.
• Traditional methods may lack precision in volume estimation.
• Standardized measurement techniques are needed for reproducible results.

Purpose of the Study:

• To derive simple, robust formulas for cranial tumor volume calculation using linear dimensions (AP, ML, CC).
• To propose a reproducible methodology for measuring tumor dimensions from MRI.
• To compare the accuracy of derived formulas against traditional ellipsoid methods.

Main Methods:

• Analysis of 337 brain tumor MRIs using Leksell Gamma Plan (LGP) software.
• Measurement of maximum tumor diameters in three orthogonal directions (AP, ML, CC).
• Derivation of volume formulas using linear regression and validation with Bland-Altman plots.

Main Results:

• Two distinct formulas were developed for "small" (0-2.5cc) and "large" (2.5-36cc) tumors.
• The formula for small tumors showed an average bias of 0.0005cc.
• The formula for large tumors demonstrated an average bias of 0.007cc.

Conclusions:

• The proposed formulas offer improved accuracy for cranial tumor volume estimation compared to the ellipsoid method.
• The developed methodology for linear dimension measurement is both simple and reproducible.
• These findings can enhance the precision of radiosurgery planning for brain tumors.