Chad Burk, MD Radiology, PGY-4 Loma Linda University Cross-sectional Psoas Area as a Predictor of Postoperative Morbidity and Mortality in Surgical Oncology Patients Chad Burk, MD Radiology, PGY-4 Loma Linda University

Rationale Pancreatectomy Hepatic resection Postoperative complications 5 year survival 20-25% Morbidity still up to 40% Hepatic resection Morbidity up to 50% Postoperative complications Prolong hospital stays Increase utilization & cost Delay subsequent therapy Adversely impact long-term survival Preoperatively risk stratify patients Pancreatectomy survival Improved over the last few decades Hepatic resection for CRC metasteses Desire to preoperatively risk stratify patients for post-operative complications Coined in the 1980s

Rationale Albumin is imperfect laboratory indicator Sarcopenia: loss of lean skeletal muscle Sarcopenia Independent risk factor all-cause mortality in elderly Predictor of postoperative infection & inpatient rehabilitation in colon cancer resection Tripled 3 year mortality following liver transplantation Desire to preoperatively risk stratify patients for post-operative complications Sarcopenia coined in the 1980s Sarcopenia: loss of lean skeletal muscle, is a component of frailty and may indicate loss of physiologic reserve Sarcopenia is a common issue in the normal patient populations and is likely more common in oncologic patients

Sarcopenia Background CT and MRI are more specific measures of sarcopenia DEXA Bioelectrical impedance Single cross-sectional image of the psoas muscles at the level of L3 Preoperatively identify patients with sarcopenia c

General Research Question Can sarcopenia, as estimated by psoas muscle area on CT, be used as an prognostic marker for post-operative morbidity and mortality following major cancer surgery at Loma Linda University Medical Center?

Hypothesis Sarcopenia as defined by low total psoas muscle area on preoperative CT is a predictor of: increased mortality following major cancer surgery at 3 years increased post operative complications following major cancer surgery, including: Prolonged hospital length of stay Wound infection Need for inpatient rehabilitation Hospital readmission within 30 days

Cohort Inclusion Criteria Retrospective study Loma Linda Surgical Oncology Database, CNExT Major oncological surgical resection: Hepatectomy Pancreatectomy 01/2000 - 12/2015 Preoperative CT within 90 days of surgery Routine preoperative assessment

Radiographic Methods Radiologist blinded to clinical factors Total Psoas cross-sectional Area (TPA) Caudal-most image with both L3 transverse processes visible Manual outlining of psoas muscle borders Calculated using TeraRecon Normalized thresholds: < 362 mm2/m2 for females < 492 mm2/m2 for males

Total Psoas Area as a Function of Age

Normalized Total Psoas Area by Gender *** P-value < 0.0001 On cursory analysis of the data, there was no statistically significant difference in post operative complications correlated with sarcopenia. We were therefore unable to reject the null hypothesis.

Normalized Total Psoas Cross Sectional Area by Primary Tumor * P-value = 0.0269 On cursory analysis of the data, there was no statistically significant difference in post operative complications correlated with sarcopenia. We were therefore unable to reject the null hypothesis.

Preoperative Albumin (3 g/dL) as a Predictor of Hospital Length of Stay Following Pancreatectomy

Sarcopenia ± Albumin as Prognostic Markers of Hospital LOS Following Pancreatectomy

Conclusion Psoas muscle measurements can be easily and objectively obtained Lean muscle mass varies: inversely proportional to age proportional to BMI with gender Sarcopenia distribution varies depending on disease process Improved prognosticator of postoperative hospital length of stay compared to albumin Combined preoperative albumin and TPA offers best assessment of patients at risk for prolonged hospital length of stay Monitored preoperative exercise and nutrition (“prehabilitation”) may help decrease sarcopenia and improve surgical outcomes and long term mortality Subjectivity in clinical frailty measures TPV-based sarcopenia was associated with poor short-term outcomes following pancreatectomy, while TPA- sarcopenia is not Average length of hospital stay 2 days longer 69% increase in postoperative complications TPV-based sarcopenia was strongly coorelated with long-term prognosis following pancreatectomy 46% increased risk of mortality even after correcting for tumor specific variables compared to patients without sarcopenia

Next Directions Refine sarcopenia definition Sarcopenic Obesity Further subgroup analysis Post operative morbitidy and mortality Psoas Volume Sarcopenia may be a generalizable robust indicator of short term morbidity and long term mortality following surgical procedures, including orthopedic and spinal surgeries Total psoas volume, a more representative sample of lean muscle mass, may be a better means to define sarcopenia rather than cross-sectional area obtained on a single axial image

Thank you Contributors: E. Bianchi, MD; M. Senthil, MD; D. DeBow, MD Special thanks: U. Oyoyo, MPH, PACS Administrators, ISP faculty Questions? References: Amini, et al. “Impact Total Psoas Volume on Short- and Long-Term Outcomes in Patients Undergoing Curative Resection for Pancreatic Adenocarcinoma: a New Tool to Assess Sarcopenia”. J Gastrointest Surg (2015) 19:1593–1602. Peng, et al. “Impact of Sarcopenia on Outcomes Following Resection of Pancreatic Adenocarcinoma”. J Gastrointest Surg. August 2012; 16(8): 1478–1486. doi:10.1007/s11605-012-1923-5. Lieffers, et al. “Sarcopenia is associated with postoperative infection and delayed recovery from colorectal cancer resection surgery”. British Journal of Cancer (2012) 107, 931–936 Taguchi, et al. “Sarcopenia Evaluated Using the Skeletal Muscle Index Is a Significant Prognostic Factor for Metastatic Urothelial Carcinoma”. Clinical Genitourinary Cancer. March 2015. FightSarcopenia.com