E425: Sarcopenia After Neoadjuvant Radiation Negatively Impacts Length of Stay Following Resection of Retroperitoneal Sarcoma

ePoster Abstract Author(s)

Leah E. Hendrick, MD, MS

Surgical Oncology Fellow
Moffitt Cancer Center, United States

Submitter(s)

Leah E. Hendrick, MD, MS

Surgical Oncology Fellow
Moffitt Cancer Center, United States

Author(s)

Leah E. Hendrick, MD, MS

Surgical Oncology Fellow
Moffitt Cancer Center, United States
RM

Rikesh Makanji, MD

Diagnostic Radiologist
Division of Gastrointestinal Oncology, Moffitt Cancer Center, United States
RV

Rachel Voss, MD, MPH

Assistant Member
Sarcoma Department, Moffitt Cancer Center, United States
RG

Ricardo J. Gonzalez, MD

Chair, Sarcoma Department
Moffitt Cancer Center
Tampa, Florida, United States
John E. Mullinax, MD

Associate Member
Sarcoma Department, Moffitt Cancer Center
Tampa, Florida, United States

Introduction: Sarcopenia, defined as the loss of muscle mass and function, has been identified as a negative prognostic factor in outcomes of major abdominal cancer operations. Using the psoas muscle index (PMI) as a surrogate, we sought to understand the impact of sarcopenia during neoadjuvant radiation (NR) on perioperative outcomes in patients with retroperitoneal sarcoma (RPS).

Methods: We performed a single institution retrospective review of patients with RPS undergoing resection between 2017-2023. Data were extracted for patient demographics, details of NR, surgical resection, length of stay (LOS), and 30-day postoperative complications (Clavien-Dindo Scale). PMI was defined as total psoas muscle area at the 3rd lumbar vertebra divided by height squared, measured on preoperative imaging. PMI was stratified by quartile and patients were evaluated for any PMI loss during NR. Data were analyzed using chi-square/Fisher’s exact test for categorical variables and Student's t-test/one-way ANOVA for continuous variables.

Results: We identified 133 patients with retroperitoneal sarcoma, 47 of whom had pre- and post-NR images available for review. Patients were 53% male, and 39.9% had at least one comorbidity (HTN, DM, COPD, or coronary artery disease). Subtype diagnoses included dedifferentiated liposarcoma (43%), well differentiated liposarcoma (29%), leiomyosarcoma (18%), and other (10%). PMI was lower in females than males (7.49 vs 10.19 cm2/m2, p< 0.001). There were no differences in baseline characteristics between lowest and highest quartile PMI patients. Patients with PMI loss during NR did not have more (p=0.101) or worse (p=0.157) 30-day complications; however lowest quartile PMI patients had significantly longer hospital LOS (8.3±5.9 vs 5.7±2.4; p=0.022) compared to those in the highest quartile.

Conclusions: In patients with RPS, sarcopenia is associated with longer hospital LOS. Loss of PMI during NR is an objective measure of poor radiation tolerance, and can stratify those at risk for a prolonged postoperative course. Prospective calculation of preoperative PMI can inform targeted prehabilitation programs or stratified ERAS pathways. Validation of these findings with larger, multi-institutional studies may significantly impact the perioperative cost of care.

Learning Objectives:

Upon completion, participants will be able to define sarcopenia and discuss its implications in the perioperative period.
Upon completion, participants will be able to identify unique challenges associated with perioperative care of patients with retroperitoneal sarcoma and marginal or poor tolerance of neoadjuvant radiation.
Upon completion, participants will be able to demonstrate understanding of accepted indications for neoadjuvant radiation therapy in the management of retroperitoneal sarcoma, and discuss potential risks and benefits of therapy.