A simple MRI-derived correction substantially reduces bias in caliper-based tumor volume estimation in subcutaneous tumor models

T2-Weighted MRI Images, Tumor Segmentations, and Caliper Measurement Data for Subcutaneous Breast Cancer Xenografts Overview This dataset contains T2-weighted magnetic resonance imaging (MRI) scans, manual tumor segmentations, and corresponding external caliper measurements from a longitudinal preclinical study of subcutaneous breast cancer xenografts. The dataset supports validation and refinement of caliper-based tumor volumetry methods used in oncology research. Dataset Contents The repository includes: T2-Weighted MRI Images: High-resolution anatomical scans acquired on a 9.4T preclinical scanner (Bruker BioSpin) with parameters optimized for tumor delineation (in-plane resolution 0.102 x 0.102 mm, slice thickness 1 mm) Manual Tumor Segmentations: Expert-annotated 3D tumor masks excluding overlying skin and fatty tissue, serving as the volumetric reference standard Caliper Measurements: Paired length and width measurements obtained with digital calipers, alongside MRI-derived corrections accounting for tissue offset artifacts Metadata: Complete animal identifiers, measurement timestamps, treatment status, tumor subtype, and study timepoints Relevant code: calc_pseudo_delta.py, find_ellipsoid_save_stats.py Study Design Total Measurements: 118 paired caliper-MRI measurements Tumor Subtypes: HER2-positive (SKBR-3) and triple-negative (MDA-MB-231) breast cancer xenografts Treatment Groups: Untreated controls and animals receiving neoadjuvant chemotherapy (Trastuzumab/Paclitaxel or Doxorubicin/Cyclophosphamide) Imaging Timepoints: Baseline (day 14), mid-study (day 16), and endpoint (day 28-30) Tumor Size Range: 5 to 1700 mm³ Key Applications This dataset supports research on: Validation of preclinical tumor measurement methodologies Development and optimization of caliper-based volume estimation equations Comparison of manual measurement techniques with imaging-based reference standards Impact of measurement accuracy on longitudinal tumor growth assessment and treatment response evaluation Refinement of preclinical imaging protocols aligned with the 3Rs principles Technical Specifications MRI Scanner: Bruker 9.4T BioSpin with PET-optimized 35mm volume coil Imaging Sequence: Rapid Acquisition with Relaxation Enhancement (RARE) Image Format: DICOM Segmentation Software: PMOD (version 4.4) Spatial Resolution: 0.102 x 0.102 x 1 mm³ per voxel Data Organization Files are organized by subject identifier with subdirectories containing: MRI *.nii files Segmentation masks (binary format, *.nii) Associated caliper measurement data (CSV format) Study metadata (Read_me.txt) Relevant Code (*.py) Ethical Compliance All animal experiments were approved by the Austrian Federal Ministry of Education, Science and Research and the Intramural Committee for Animal Experimentation at the Medical University of Vienna. Procedures adhered to EU Directive 2010/63/EU and ARRIVE guidelines. Citation If using this dataset, please cite: Prinz, D. et al. A simple MRI-derived correction substantially reduces bias in caliper-based tumor volume estimation in subcutaneous tumor models. Sci Rep (2026) doi:10.1038/s41598-026-70184-3. Contact & Support For data access requests, technical questions, or usage inquiries, please contact: [e-mail] DISCLAIMER:These data are freely available for non-commercial research purposes. Any publication, presentation, or redistribution of these data or derivatives thereof requires prior written permission from the corresponding author and proper citation of the original publication. Commercial use of any kind is strictly prohibited without a separate written agreement.