Use of Whole Slide Imaging in GLP Nonclinical Toxicology Studies
This guidance addresses the use and management of whole slide imaging (WSI) in histopathology assessment and pathology peer review for GLP-compliant nonclinical toxicology studies using non-human specimens. It specifically focuses on documentation practices during generation, use, and retention of whole slide images.
What You Need to Know? 👇
What is whole slide imaging and how does it differ from traditional glass slide examination?
Whole slide imaging is a digital technology that creates two-dimensional images of glass histology slides using specialized software and hardware. The process involves scanning, processing, storing, and displaying images. Unlike glass slides, digital images are not exact copies but should include all elements needed for histopathological examination.
Are whole slide images required to be retained for GLP-compliant studies?
Yes, if whole slide images are used instead of glass slides to generate pathology raw data in GLP-compliant nonclinical toxicology studies, the image files must be retained as study records and archived. Additionally, the original glass slides must also be retained as study specimens per 21 CFR part 58.
What validation requirements apply to whole slide imaging systems in nonclinical studies?
When whole slide images generate raw data, the imaging system (software and hardware) must be validated specifically for its intended use. This validation ensures the system meets GLP requirements and produces reliable data for regulatory submissions and toxicology assessments.
How should whole slide image files be protected during transmission and storage?
Whole slide image files used to generate raw data must be protected following written procedures compliant with 21 CFR part 11. Protection measures include preventing data loss or alteration, maintaining chain of custody, controlling access, and securing data systems and transmission to maintain file integrity.
What documentation requirements exist for pathology reports using whole slide imaging?
The signed pathology report must clearly state whether glass slides or whole slide images were used for histopathological evaluation. Similarly, if pathology peer review is performed, the peer review statement must indicate whether glass slides or whole slide images were reviewed for the assessment.
What written procedures are needed for implementing whole slide imaging in GLP studies?
Written procedures for whole slide imaging processes are required when images may generate raw data. These procedures should cover training protocols, slide scanning processes, software management, file access controls, exchange procedures, and technical image processing modifications to ensure GLP compliance and data integrity.
What You Need to Do 👇
Recommended Actions
- Develop and implement written procedures for WSI processes
- Establish validation protocol for WSI system
- Implement data protection and security measures
- Create documentation system for technical image processing modifications
- Set up proper archival system for both glass slides and WSI files
- Update pathology report templates to include WSI usage documentation
- Establish training program for staff using WSI systems
- Implement version control system to ensure long-term accessibility of archived images
- Create procedures for file access and exchange control
- Establish compliance verification process with 21 CFR Part 11 requirements
Key Considerations
Non-clinical testing
- WSI should include all elements from glass slides needed for histopathological examination
- Glass slides must be retained as study specimens after study finalization
- Original WSI files must be retained if used to generate raw data
- Technical image processing modifications must be documented and retained
- Pathologists should not permanently alter original WSI files
Software
- WSI system (software and hardware) must be validated for intended use
- Written procedures for software management must be in place
- Compliance with 21 CFR part 11 for electronic records is required
Cybersecurity
- WSI files must be protected to prevent loss or alteration
- Chain of custody must be maintained
- Access control must be implemented
- Data systems and transmission must be secured
Labelling
- Pathology reports must state whether glass slides or WSI were used for evaluation
- Peer review statements must indicate whether glass slides or WSI were reviewed
Other considerations
- Written procedures for WSI processes must be in place
- Staff training procedures must be documented
- Archived digital images must remain viewable as software/hardware updates occur
Relevant Guidances 🔗
- Histopathology Peer Review in Nonclinical Toxicology Studies
- Electronic Records and Electronic Signatures - Scope and Application
Related references and norms 📂
- 21 CFR Part 58: Good Laboratory Practice for Nonclinical Laboratory Studies
- 21 CFR Part 11: Electronic Records; Electronic Signatures