RESUMO
Context: Bioelectrical impedance analysis (BIA) detects changes in tissue electrical properties and has been seen as a prognostic tool in several chronic conditions, including cancer. AIMS: The study was conducted to investigate whether there are any tissue electrical differences in patients with head and neck cancer (H and NC) before and after surgery treatment. Settings and Design: The observational study was performed at the Otolaryngology Department, Head and Neck Oncology. Materials and Methods : Tissue electrical properties were assessed in 31 patients with H and NC before and 2 weeks after surgery treatment. Direct bioimpedance measures [resistance, reactance, phase angle (PA)] were determined by BIA. Statistical Analysis Used: The Shapiro-Wilk test was used to assess the distribution conformity of examined parameters with a normal distribution; the Fisher (F) test was used to assess variance homogeneity. For group comparisons of metric data we used the Mann-Whitney U test. P value < 0.05 was considered as statistically significant. The statistical analysis for this study was performed using the computer software STATISTICA v. 8.0 (StatSoft). Results: PA at 50 kHz was found to be significantly (P = 0.000009) lower after surgery in patients with H and NC than before treatment (4.69° ±0.71 vs. 4.22 ± 0.83, respectively). Resistance was significantly (P = 0.0005) greater after surgery in patients with H and NC than before (596.24 ± 96.31 ohm vs 647.64 ± 276.11 ohm, respectively). Conclusions: There are tissue electrical differences before and after surgery in patients diagnosed with H and NC. Further observations would be useful to feedback in support therapy planning of individual patients.