We shared the common FFPE tissue dissection methods ranging from manual dissection to laser capture microdissection (LCM) in the previous post reviewing micro and macrodissection techniques for FFPE sample dissection. While those methods may be suitable for whole tumor analysis, molecular testing involving small and complex tumors require a solution that offers precision, automation and workflow value for routine clinical use. A digitally guided microdissection technology that employs automatic dissection with software guidance was introduced a few years back.1 The technique uses a milling tip to cut the tissue with guidance through a digital microscope. Providing a higher resolution than manual macrodissection, this system is more cost and time efficient compared to LCM.1
Making a (digital) mark
With this new methodology, reproducing the pathologist’s demarcation of areas of interest (AOI) digitally and optically circumvents inconsistencies that may arise with marker pens. Annotations from other digital pathology solutions can also be imported. Software advances also provides digital assistance to the workflow, enabling traceability and reporting of the dissection process.
Combining digital marking and automated dissection for enriched tumor content
Precise and automated mechanical milling of tissue further improves sample recovery from difficult to dissect slides with low tumor content.2 Targeted dissection also potentially reduces false negative results and increases actionable tumor information.2,3 Comparison between manual macrodissection and digitally guided microdissection has shown that the digitally guided approach identified additional KRAS mutations missed with manual macrodissection.2 Another study showed that digitally guided microdissection led to identification of additional clinically actionable variants compared to manual whole tumor dissection.3
With the phenomenal advances in targeted therapies, the requirement for enriched and specific tumor population for molecular analysis and diagnosis is immediate and real. Digitally guided microdissection seems to be the cost-effective and simple middle ground between manual and laser dissection methods with improved clinical utility. Perhaps this new approach will enrich not just tumor content, but the lives of pathologists and lab techs as well?