Radiomics meets sarcopenia: Machine learning-based multimodal modeling for esophageal cancer outcomes

Table 2 Summary of the predictive models and collected features, including clinical data, body composition indices, and radiomics, used in the six reviewed studies

Ref.	Model	Clinical data	Body composition index	Radiomics features or index
Zhou et al[16]	Cox regression nomogram	Tumor stage, LVI, BMI, age, sex, number of PET-positive lymph nodes, treatment	SMI, VATI, SATI, and sarcopenia (SMI < 34.4 cm2/m2 in females, < 45.4 cm2/m2 in males)	Extracted 92 radiomic features, used LASSO for feature selection, calculated Rad-scores
Hinzpeter et al[17]	Metastatic disease: LGBM and RF, OS: Cox regression	Age, sex, race, BMI, ECOG score, histology (subtype and grade), disease stage (M0 vs M1), tumor stage, SUV/SUL parameters	Sarcopenia (SMI < 34.4 cm2/m2 in females, < 45.4 cm2/m2 in males)	Extracted 307 radiomic features, filtered features based on significant difference (P < 0.01) between groups
Vogele et al[18]	DT, KNN, RF	Sex, age, tumor type (gastric/esophageal), tumor stage, nodes stage, M stage, PD	TPA and TPI sarcopenia (the lowest gender-specific quartile of TPI values at each time point)	Extracted 85 radiomic features, used LASSO for feature selection
Iwashita et al[19]	Cox regression, nomogram	Age, sex, performance status, tumor location, chemotherapy, radiation dose, ENI, tumor, node, and metastasis stage, and various blood parameters (CRP, Albumin, NLR, PLR, PNI, mGPS)	SMI, PMI	Extracted 837 radiomic features, used LASSO-COX regression and VIF for feature selection
Hinzpeter et al[20]	Cox regression, clinical, clinical + SMI, clinical + SMI + CT, clinical + SMI + CT + PET	Age, sex, race, BMI, ECOG score, tumor stage, tumor histology, tumor grade, distance LN, pleura, metastasis organ, SUV/SUL parameters	Sarcopenia (SMI < 34.4 cm2/m2 in females, < 45.4 cm2/m2 in males)	No specificity description
Anconina et al[21]	Cox regression nomogram	Age, sex, race, BMI, ECOG score, tumor stage, nodes stage, LVI	Sarcopenia (SMI < 34.4 cm2/m2 in females, < 45.4 cm2/m2 in males)	Extracted 42 radiomic features, filtered features based on significant difference (P < 0.01) between groups

BMI: Body mass index; CRP: C-reactive protein; CT: Computed tomography; DT: Decision tree; ECOG: Eastern Cooperative Oncology Group; ENI: Elective lymph node irradiation; KNN: K-nearest neighbors; LASSO: Least absolute shrinkage and selection operator; LGBM: Light gradient boosting machine; LN: Lymph node; LVI: Lymphovascular invasion; M: Metastasis; mGPS: Modified Glasgow prognostic score; NLR: Neutrophil-lymphocyte ratio; OS: Overall survival; PD: Progressive disease; PET: Positron emission tomography; PLR: Platelet-lymphocyte ratio; PMI: Psoas muscle index; PNI: Prognostic nutritional index; RF: Random forest; SATI: Subcutaneous adipose tissue index; SMI: Skeletal muscle index; SUL: Standardized uptake value normalized by lean body mass; SUV: Standardized uptake value; TPA: Total psoas area; TPI: Total psoas index; VATI: Visceral adipose tissue index; VIF: Variance inflation factor.