Characterizing the tissue dielectric constant of skin basal cell cancer lesions

Background: Measuring tissue dielectric constant (TDC) of cancer tissues to distinguish them from normal or non-cancerous tissues has been an active area of research that has targeted several different cancer types usually using in vitro specimens. The goal of this study was to determine if and to what extent TDC values measured in vivo at 300 MHz using a simple hand-held measuring device might differentiate between skin cancer lesions and non-cancerous skin.

Materials and methods: Triplicate TDC measurements were made in 32 patients who were subsequently diagnosed with skin basal cell carcinoma (BCC) and in 14 patients subsequently diagnosed as having non-cancerous lesions. Lesion TDC values were compared to contralateral unaffected skin and between lesion types.

Results: A significantly lower TDC value (mean ± SD) of BCC lesions (TDC_L ) vs TDC values of contralateral non-affected skin (TDC_C ) was found (22.4 ± 16.2 vs 38.1 ± 15.2, P < .00001). A similar pattern was found for non-cancerous lesions with lesion TDC values less than non-affected skin (14.5 ± 9.0 vs 29.1 ± 9.0, P < .0001). However, TDC values were not statistically different between BCC lesions and non-cancerous lesions (22.4 ± 16.2 vs 14.5 ± 9.0, P = .096) and calculated TDC_L /TDC_C ratios between BCC lesions and non-cancerous lesions also were not significantly different (0.596 ± 0.345 vs 0.501 ± 0.261, P = .364).

Conclusions: (1) Main results do not support using TDC measurements to differentiate in vivo skin cancer lesions from non-cancerous lesions. (2) TDC values strongly suggest reduced water content of both cancerous and non-cancerous lesions. (3) Lesion TDC measurements provide reference values for future studies.