Impact of sarcopenia in borderline resectable and locally advanced pancreatic cancer patients receiving stereotactic body radiation therapy.

backgroundTotal psoas area (TPA), a marker of sarcopenia, has been used as an independent predictor of clinical outcomes in gastrointestinal (GI) cancers as a proxy for frailty and nutritional status. Our study aimed to evaluate whether TPA, in contrast to traditional measurements of nutrition like body mass index (BMI) and body surface area (BSA), was predictive of outcomes in borderline resectable pancreatic cancer (BRPC) and locally advanced pancreatic cancer (LAPC) patients receiving stereotactic body radiation therapy (SBRT).

methodsRetrospective analysis of an institutional review board approved database of 222 BRPC and LAPC treated with SBRT from 2009-2016 yielded 183 patients that met our selection criteria of pre-SBRT computed tomography (CT) imaging with an identifiable L4 vertebra. Once the L4 vertebral level was identified, the bilateral psoas muscles were manually contoured. This area was normalized by patient height, with units described in mm

resultsLow TPA (OR =1.903, P=0.036) was predictive of acute toxicities, and only TPA was predictive of Grade 3 or higher acute toxicities (OR =10.24, P=0.007). Both findings were independent of tumor resectability. Pain (P=0.003), fatigue (P=0.040), and nausea (P=0.039) were significantly associated with low TPA. No association was identified between any measurement of nutritional status and the development of late toxicities, overall survival, local progression or local recurrence. However, BRPC patients survived longer (median =21.98 months) than their LAPC (median =16.2 months) counterparts (P=0.002), independent of nutritional status.

conclusionsTPA measurement is readily available and more specific than BMI or BSA as a predictor of acute radiotoxic complications following SBRT in BRPC/LAPC patients. A TPA of <500 mm