Association of AI-derived abdominal organ volumetry with postoperative outcomes in clear cell renal cell carcinoma: a multicentre study.

BACKGROUND: CT-derived body composition parameters are associated with clinical outcomes in clear cell renal cell carcinoma (ccRCC), but the prognostic value of abdominal solid organ volumes remains unclear. METHODS: In this multicentre study, 1,720 patients with ccRCC who underwent nephrectomy across four centres and 3,052 healthy controls were included. A deep learning algorithm was used to automatically quantify abdominal organ volumes. Organ volume indices were calculated by normalizing volumes to body surface area. Associations between abdominal organ volumes and recurrence-free survival (RFS) and overall survival (OS) were evaluated using centre-stratified Cox regression models. Multivariable models were adjusted for age, gender, tumour size, laterality, surgical approach, pT stage, pN stage, International Society of Urological Pathology grade and tumor necrosis. RESULTS: During a median follow-up of 51.6 (49.2-52.8) months, 165 patients experienced recurrence and 95 died. Organ volume distributions were similar across centres. Compared with healthy controls, ccRCC patients showed higher spleen and adrenal gland volume indices and lower pancreatic volume index. In multivariable Cox analyses, higher liver volume (HR = 1.42, P adj = 0.035), liver volume index (HR = 1.31, P adj = 0.035), right adrenal gland volume (HR = 1.34, P adj = 0.035) and right adrenal gland volume index (HR = 1.29, P adj = 0.035) were independently associated with worse OS. No parameter was associated with RFS after multiple-testing correction. CONCLUSIONS: Higher liver and right adrenal gland volumes were associated with worse OS in ccRCC. These findings warrant external validation and further mechanistic investigation.