Validating A Currently Available Measuring Tool for Melanoma Gabor Hertz, M.D.

Validating A Currently Available Measuring Tool for Melanoma

Gabor Hertz, M.D.

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Telepathology System

Neuro

Other Surgicals

Ancillary uses could ease its adoption

• Skin cancers are common neoplasms in clinical practice (1/5)

• Melanoma • Treatment and

Prognosis depend on stage– <1 mm– 1-4 mm

Surgical Cases

Non-derm surgicals Skin

Validate the digital measuring tool available in microsuite 5

Design

• Retrospective validation study

• 18 cases 2006-2007

• Digitally imaged at varying optical mag.

• Measurements compared to clinically reported Breslow thickness

Validate Digital Measuring Tool

• Validated digital measurement against stage micrometer standard

ResultsCase # Mean mBreslow Clinically Reported Breslow Diff Stage

07-1825 0.53 0.3 75% I

07-04175 0.41 0.5 18% I

07-05848 3.79 1.45 175% IIA

07-06267 0.5 0.56 10% I

07-06998 0.3 0.31 3% I

07-10490 0.91 1 9% IIA

07-11673 1.8 >1.5 20% IIB

07-13229 3.14 3.48 10% IIB

07-14139 0.86 0.88 2% I

07-17863 3.79 4 5% IIB

07-17899 1.33 1.5 11% IIA

07-17942 1.04 >1.0 4% IIA

07-17972 0.32 0.4 20% I

07-22303 4.58 4.5 2% IIC

08-00367 0.3 0.4 25% I

08-001640 0.26 0.38 32% I

08-03681 0.35 0.35 0% I

08-07804 0.35 .35-.4 13% I

Results

• Validating against stage micrometer– Avg 0.3 mm

discrapency (30%/1mm)

• Validating against 18 clinical case– Avg 0.12 mm

discrepency (24%)

Discrepency against stage micrometer

• Technical problems with initial installation as it focused only on telepath system

• Optical input was not initially configured/calibrated

Slightly tighter correlation against clinical measurements

• Likely due to additional confounding variables– Pathologic diagnosis/measurement is really

semiquantitative and known to be subject to large intra and interobserver variation.

Lessons

• Even off the shelf products require anticipation of ancillary uses.

• New technology has a learning curve

• Applying highly accurate measuring tools will not by itself improve an inherently poorly reproducible measurement (sampling and interpretation variables need to be addressed)

Next Steps

• Develop the required technical understanding of digital medical imaging in microscopy

• Determine method and timing of input image calibration.

• Identify and rely on intra-image controls• Develop logistical support to manage

confounding variables (sampling & Dx variation)

Poster #482

• Available on Tues 10/21

System Requirements

• Pentium processor

• At least Windows 98

• 256 MB RAM

• 200 MB Free space

• VGA monitor with 1024 x 768 resolution and 256 colors

• Microsoft Internet Explorer 3.02

Case #Mean mBreslow

Clinically Reported Breslow Diff Stage

07-1825 0.56 0.3 87% I

07-04175 0.5 0.5 0% I

07-05848 1.66 1.45 15% IIA

07-06267 0.16 0.56 72% I

07-06998 0.31 0.31 0% I

07-10490 0..97 1 3% IIA

07-11673 1.5 >1.5 0% IIB

07-14139 1 0.88 14% I

07-17899 1.26 1.5 16% IIA

07-17942 2.48 >1.0 148% IIA

07-17972 0.26 0.4 35% I

07-22303 4.22 4.5 6% IIC

08-00367 0.32 0.4 20% I

08-001640 0.38 0.38 0% I

08-03681 0.36 0.35 3% I

08-07804 0.41 .35-.4 3% I