The correlation between apparent diffusion coefficient and tumor cellularity in patients: a meta-analysis.

Area of Science:

• Radiology and Medical Imaging
• Oncology
• Biostatistics

Background:

• Tumor cellularity is a key factor influencing tumor behavior and treatment response.
• Apparent diffusion coefficient (ADC) is a quantitative MRI biomarker reflecting water molecule diffusion within tissues.
• Understanding the relationship between ADC and cellularity can aid in non-invasive tumor characterization.

Purpose of the Study:

• To conduct a meta-analysis to determine the correlation between ADC and tumor cellularity.
• To synthesize existing research on this relationship across various patient populations.

Main Methods:

• Systematic literature search of medical and scientific databases for relevant studies published in English or Chinese before November 2012.
• Extraction of summary correlation coefficients (r) and calculation of 95% confidence intervals (CIs).
• Sensitivity and subgroup analyses to assess heterogeneity and explore variations by tumor type.

Main Results:

• Included 28 studies with 729 patients; initial pooled r was -0.57 (95% CI: -0.62, -0.52), indicating significant heterogeneity.
• After sensitivity analysis excluding two studies, the pooled r was -0.61 (95% CI: -0.66, -0.56) with no significant heterogeneity.
• A strong negative correlation was confirmed for brain tumors; no significant publication bias was detected.

Conclusions:

• A significant negative correlation exists between ADC and tumor cellularity in patients.
• This correlation is particularly pronounced in brain tumors, highlighting ADC's potential as a biomarker.
• Further large-scale, prospective studies are recommended to validate these findings across diverse cancer types.