ABSTRACT
BACKGROUND: The purpose is to investigate the clinical significance of body morphomics changes in stage III-IV oropharyngeal cancer patients during concurrent chemoradiotherapy (CRT). METHODS: Fifty patients who underwent CRT were selected for body composition analyses by either availability of pre/post treatment DEXA scans or a novel CT-based approach of body morphomics analysis (BMA). BMA changes (lean psoas and total psoas area) were compared to total lean body mass changes by DEXA scans using two-sample t tests. Pearson correlation was used to compare the BMA measures to head and neck specific quality of life outcomes. Cox hazards model was used to predict mortality and tumor recurrence. RESULTS: Clinically significant declines in total psoas area and lean body mass of similar magnitude were observed in both BMA and DEXA cohorts after CRT. Loss of psoas area (P < 0.05) was associated with greater frailty and mobility issues (3 out of 15 UWQOL domains). Total psoas area is more sensitive for local recurrence than weight changes and T-stage on multivariate analyses. CONCLUSIONS: BMA specifically evaluating psoas area appears to correlate with head and neck cancer quality of life physical domains. Pre- and post-treatment total psoas area at L4 appears prognostic for tumor recurrence.
ABSTRACT
Radio frequency energy (RFE) thermal chondroplasty has been a widely-utilized method of cartilage debridement in the past. Little is known regarding its effect on tissue mechanics. This study investigated the acute biomechanical effects of bipolar RFE treatment on human chondromalacic cartilage. Articular cartilage specimens were extracted (n = 50) from femoral condyle samples of patients undergoing total knee arthroplasty. Chondromalacia was graded with the Outerbridge classification system. Tissue thicknesses were measured using a needle punch test. Specimens underwent pretreatment load-relaxation testing using a spherical indenter. Bipolar RFE treatment was applied for 45 s and the indentation protocol was repeated. Structural properties were derived from the force-time data. Mechanical properties were derived using a fibril-reinforced biphasic cartilage model. Statistics were performed using repeated measures ANOVA. Cartilage thickness decreased after RFE treatment from a mean of 2.61 mm to 2.20 mm in Grade II, II-III, and III specimens (P < 0.001 each). Peak force increased after RFE treatment from a mean of 3.91 N to 4.91 N in Grade II and III specimens (P = 0.002 and P = 0.003, respectively). Equilibrium force increased after RFE treatment from a mean of 0.236 N to 0.457 N (P < 0.001 each grade). Time constant decreased after RFE treatment from a mean of 0.392 to 0.234 (P < 0.001 for each grade). Matrix modulus increased in all specimens following RFE treatment from a mean 259.12 kPa to 523.36 kPa (P < 0.001 each grade). Collagen fibril modulus decreased in Grade II and II-III specimens from 60.50 MPa to 42.04 MPa (P < 0.001 and P = 0.005, respectively). Tissue permeability decreased in Grade II and III specimens from 2.04 ∗10(-15) m(4)/Ns to 0.91 ∗10(-15) m(4)/Ns (P < 0.001 and P = 0.009, respectively). RFE treatment decreased thickness, time constant, fibril modulus, permeability, but increased peak force, equilibrium force, and matrix modulus. While resistance to shear and tension could be compromised due to removal of the superficial layer and decreased fibril modulus, RFE treatment increases matrix modulus and decreases tissue permeability which may restore the load- bearing capacity of the cartilage.
