Abstract
BACKGROUND: While sarcopenia is typically defined using total psoas area (TPA), characterizing sarcopenia using only a single axial cross-sectional image may be inadequate. We sought to evaluate total psoas volume (TPV) as a new tool to define sarcopenia and compare patient outcomes relative to TPA and TPV. METHOD: Sarcopenia was assessed in 763 patients who underwent pancreatectomy for pancreatic adenocarcinoma between 1996 and 2014. It was defined as the TPA and TPV in the lowest sex-specific quartile. The impact of sarcopenia defined by TPA and TPV on overall morbidity and mortality was assessed using multivariable analysis. RESULT: Median TPA and TPV were both lower in women versus men (both P < 0.001). TPA identified 192 (25.1%) patients as sarcopenic, while TPV identified 152 patients (19.9%). Three hundred sixty-nine (48.4%) patients experienced a postoperative complication. While TPA-sarcopenia was not associated with higher risk of postoperative complications (OR 1.06; P = 0.72), sarcopenia defined by TPV was associated with morbidity (OR 1.79; P = 0.002). On multivariable analysis, TPV-sarcopenia remained independently associated with an increased risk of postoperative complications (OR 1.69; P = 0.006), as well as long-term survival (HR 1.46; P = 0.006). CONCLUSION: The use of TPV to define sarcopenia was associated with both short- and long-term outcomes following resection of pancreatic cancer. Assessment of the entire volume of the psoas muscle (TPV) may be a better means to define sarcopenia rather than a single axial image.