High-radiodensity skeletal muscle index is the best predictor of major postoperative complication in gynecologic cancer: muscle quality and postoperative complication

Abstract

Purpose: This study aimed to evaluate the influence of sarcopenia and the indicators of skeletal muscle (SM) quality on surgical outcomes in women with ovarian and endometrial cancer who underwent oncologic surgery. Methods: Endometrial and ovarian cancer patients admitted between 2008-2015 and who had computerized tomography (CT) images available within 45 days before surgery were enrolled in a retrospective cohort (n=250). CT images at the third lumbar vertebra were used to assess SM. Skeletal muscle index (SMI) was calculated in the range -29+150 Hounsfield Units (HU); reduced muscle attenuation (range -29 + 29HU) was classified as low-radiodensity skeletal muscle index (LRSMI). By subtracting the LRSMI area from total SMI, High Radiodensity Skeletal Muscle Index (HRSMI) was created. Sarcopenia was defined when SMI was ≤38,9cm 2 /m 2 . Multiple logistic regression evaluated predictors of surgical complications. Results: Patients in lower HRSMI quartiles and in the highest quartiles of LRSMI had more surgical postoperative complication and remained more time hospitalized. Both sarcopenia and the quality indicators of SM were predictors of increased risk of surgical complication, being the HRSMI the strongest predictor.However, in a combined adjustment for HRSMI and sarcopenia, only HRSMI remained in the model as an independent predictor for surgical complication. Additionally, HRSMI was the only indicator associated with early mortality ( ≤30 days). Conclusion: The indicators of SM quality were the most significant predictors of surgical complications. Classifying muscle quality in terms of low- or high-radiodensity area is a promissing strategy to understand the impact of muscle mass quality on unfavourable outcomes in oncology.