Imaging skeletal muscle volume, density, and FDG uptake before and after induction therapy for non-small cell lung cancer.

AIM: To assess whether changes in body composition could be assessed serially using conventional thoracic computed tomography (CT) and positron-emission tomography (PET)/CT imaging in patients receiving induction chemotherapy for non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: CT-based skeletal muscle volume and density were measured retrospectively from thoracic and lumbar segment CT images from 88 patients with newly diagnosed and untreated NSCLC before and after induction chemotherapy. Skeletal muscle 2-[18F]-fluoro-2-deoxy-d-glucose (FDG) uptake was measured from PET/CT images from a subset of patients (n=42). Comparisons of each metric before and after induction chemotherapy were conducted using the non-parametric Wilcoxon signed-rank test for paired data. The association between clinical factors and percentage change in muscle volume was examined using univariate linear regression models, with adjustment for baseline muscle volume. RESULTS: Following induction chemotherapy, thoracic (-3.3%, p=0.0005) and lumbar (-2.6%, p=0.0101) skeletal muscle volume were reduced (adiposity remained unchanged). The proportion of skeletal muscle with a density <0 HU increased (7.9%, p<0.0001), reflecting a decrease in skeletal muscle density and skeletal muscle FDG uptake increased (10.4-31%, p<0.05). No imaging biomarkers were correlated with overall survival. CONCLUSION: Changes in body composition can be measured from routine thoracic imaging. During chemotherapy skeletal muscle volume and metabolism are altered; however, there was no impact on survival in this retrospective series, and further validation in prospective, well-controlled studies are required.

Cardiopulmonary exercise testing prior to myeloablative allo-SCT: a feasibility study.

The feasibility of symptom-limited cardiopulmonary exercise testing (CPET) prior to allo-SCT was assessed in addition to the prognostic value of CPET-derived measures. CPET was performed prospectively on 21 patients with hematologic malignancies, with assessments of peak (for example, peak oxygen consumption, VO2peak) and submaximal (for example, ventilatory threshold (VT)) measures of cardiopulmonary function. No serious adverse events were observed during CPET procedures, with 95% of patients achieving criteria for a peak test. Mean VO2peak was 24.7±6.4 mL kg(-1 )min(-1) (range: 10.9-35.5), equivalent to 29%±17% below that of age-matched healthy controls. All patients proceeded with the conditioning regimen followed by allo-SCT. Median follow-up was 25 months. During this period, 11 (52.4%) patients died (n=6, relapsed disease; n=5, non-relapse mortality (NRM)); 9 patients (43%) developed pulmonary toxicity. In univariate analyses, both peak and submaximal markers of cardiopulmonary function were predictors of OS, pulmonary toxicity and NRM. For OS, the HR for VO2peak and VT were 0.89 (95% CI, 0.8-0.99, P=0.04) and 0.84 (95% CI, 0.71-0.98, P=0.03), respectively. In conclusion, CPET is safe and feasible prior to allo-SCT. Patients have marked impairments in cardiopulmonary function prior to allo-SCT. CPET-derived metrics may complement conventional measures to improve risk stratification.