A 3D scanning system for measuring subcutaneous tumors in laboratory animals and expanded application to melanoma volume measurements.

In preclinical drug development, subcutaneous tumor volume is a critical parameter for evaluating disease progression and therapeutic efficacy. Although multiple techniques are now available for measuring tumor volume, manual calipers-despite their susceptibility to inaccuracy and observer bias-remain the conventional standard. This study systematically compares the accuracy, detection sensitivity, and observer variability of tumor volume measurements obtained via calipers versus 3D scanning. Both clay and tumor models were analyzed to assess measurement performance. Our results demonstrate that 3D scanning provides superior accuracy in tumor volume quantification compared to calipers. In clay models, 3D scanning exhibited stronger correlation with reference volumes. In vivo experiments further revealed that 3D scanning reduced measurement error, enabled earlier detection of radiotherapy responses, and improved observer reproducibility. Additionally, while the 3D scanner initially struggled with dark-colored melanoma and black clay models due to optical limitations, application of white food-grade spraying allowed accurate volumetric measurements, thereby expanding the technology's applicability across diverse tumor types. Collectively, these findings establish 3D scanning as a transformative approach for preclinical tumor volumetry, addressing the critical limitations of conventional caliper methods, and ultimately providing researchers with a more reliable and standardized tool for therapeutic assessment in cancer studies.