Letters to the Editor

In vivo analysis of fracture toughness of thyroid gland tumors

Nagesh Ragavendra¹ , JW Ju² , James W Sayre^1,6 , Sharon Hirschowitz³ , Inder Chopra⁴ and Michael W Yeh⁵

¹  Department of Radiology, The David Geffen School of Medicine at UCLA, Box 957437, 757 Westwood Plaza, Los Angeles, CA 90095, USA

²  Department of Civil & Environmental Engineering, UCLA, 10833 LeConte Avenue, Los Angeles, CA 90095, USA

³  Pathology, The David Geffen School of Medicine at UCLA, Box 957437, 757 Westwood Plaza, Los Angeles, CA 90095, USA

⁴  Medicine, The David Geffen School of Medicine at UCLA, Box 957437, 757 Westwood Plaza, Los Angeles, CA 90095, USA

⁵  Surgery, The David Geffen School of Medicine at UCLA, Box 957437, 757 Westwood Plaza, Los Angeles, CA 90095, USA

⁶  Biostatistics The David Geffen School of Medicine at UCLA, Box 957437, 757 Westwood Plaza, Los Angeles, CA 90095, USA

author email corresponding author email

Journal of Biological Engineering 2008, 2:12doi:10.1186/1754-1611-2-12

Published:	6 October 2008

Abstract

Background

Human solid tumors that are hard or firm on physical palpation are likely to be cancerous, a clinical maxim that has been successfully applied to cancer screening programs, such as breast self-examination. However, the biological relevance or prognostic significance of tumor hardness remains poorly understood. Here we present a fracture mechanics based in vivo approach for characterizing the fracture toughness of biological tissue of human thyroid gland tumors.

Methods

In a prospective study, 609 solid thyroid gland tumors were percutaneously probed using standard 25 gauge fine needles, their tissue toughness ranked on the basis of the nature and strength of the haptic force feedback cues, and subjected to standard fine needle biopsy. The tumors' toughness rankings and final cytological diagnoses were combined and analyzed. The interpreting cytopathologist was blinded to the tumors' toughness rankings.

Results

Our data showed that cancerous and noncancerous tumors displayed remarkable haptically distinguishable differences in their material toughness.

Conclusion

The qualitative method described here, though subject to some operator bias, identifies a previously unreported in vivo approach to classify fracture toughness of a solid tumor that can be correlated with malignancy, and paves the way for the development of a mechanical device that can accurately quantify the tissue toughness of a human tumor.