Robert Downey Boutin MD, Presenter: Nothing to Disclose

Jeremy Richard Katz MD, Abstract Co-Author: Nothing to Disclose

Abhijit Jarawant Chaudhari PhD, Abstract Co-Author: Nothing to Disclose

Jonah Scott Hirschbein MD, Abstract Co-Author: Nothing to Disclose

Yves-Paul Nakache, Abstract Co-Author: Nothing to Disclose

Chin-Shang Li PhD, Abstract Co-Author: Nothing to Disclose

Ramit Lamba MD, Abstract Co-Author: Nothing to Disclose

Ghaneh Fananapazir MD, Abstract Co-Author: Nothing to Disclose

Robert Canter MD, Abstract Co-Author: Nothing to Disclose

To assess muscle and fat metrics as prognostic indicators of outcomes in sarcoma patients.

147 patients (81 M, 66F; mean age, 53 years; range, 1-85) diagnosed with a soft-tissue sarcoma between 2000 and 2013 with inclusion criteria (including availability of BMI, stage, grade, depth, abdominopelvic CT, follow-up) were retrospectively studied after IRB approval. Treatment included surgery (n=124), pre-op radiation (n=35), pre-op chemotherapy (n=13), or a combination. Using a routine CT exam, the L4 pedicle level was analyzed for 4 skeletal muscle metrics (total muscle area [TMA], average total muscle density [TMD], psoas area [PA], average psoas density [PD]) using manual segmentation by a musculoskeletal radiologist. Visceral and subcutaneous fat metrics (area, mean density, SD density) were quantitated at the same level using automated segmentation. Clinical outcome variables were evaluated, including overall survival and major post-surgical complications (within 30 days).

At presentation, stage distribution was as follows: stage 1 (n=51), 2 (n=27), 3 (n=55), 4 (n=14). Survival averaged 27.2 months (range, 0.2-156) from the date of diagnosis. Muscle and fat metrics varied widely among patients. TMA averaged 106 cm2 (range, 7-194), with a TMD of 32 HU (range, -24 to 75). Univariable Cox PH regression analysis demonstrated that PD was a significant prognostic indicator of overall survival (HR = 0.97 (0.94, 0.99), p = 0.002) in the entire cohort, as well as when stage 4 patients were excluded (HR = 0.95 (0.93, 0.98), p = 0.001). TMD also was a significant predictor of overall survival when stage 4 patients were excluded (HR = 0.97 (0.94, 0.99), p = 0.03). TMD (OR = 0.97 (0.95, 0.99), p = 0.04), PD (OR = 0.96 (0.92, 0.99), p = 0.03), visceral fat area (OR = 1.004 (1.0, 1.008), p < 0.05), and subcutaneous fat density SD (OR = 1.16 (1.01, 1.33), p = 0.04) were significant predictors of major surgical complications in univariable logistic regression analysis for the entire cohort, but not in the multivariable model.

Routine CT can be used to quantify muscle and fat metrics; some body composition measures appear to have prognostic significance in soft-tissue sarcoma patients.

Although muscle and fat metrics are not routinely analyzed on CT exams, both muscle and fat are routinely imaged, are easily measured, and are potential prognostic biomarkers for sarcoma patients.

Boutin, R, Katz, J, Chaudhari, A, Hirschbein, J, Nakache, Y, Li, C, Lamba, R, Fananapazir, G, Canter, R, Significance of Sarcopenia in Soft-tissue Sarcoma Patients:  Do Skeletal Muscle and Fat Measures of Body Composition on Routine CT Exams Help Predict Clinical Outcomes?.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14011743.html