Predicting Model Based on Evidence-based Pathological Diagnose Criteria for RCC Tumor Thrombus With IVC Wall Invasion

Preoperative Imaging Diagnostic Evaluation Model Based on Evidence-based Pathological Diagnose Criteria for Renal Cell Carcinoma Tumor Thrombus With Inferior Vena Cava Wall Invasion

The goal of this observational study is to establish a preoperative imaging diagnostic model which highly consistent with the histopathological examinations, as well as a accurate and systematic pathological grading standard of inferior vena cava (IVC) vascular wall invasion in renal cell carcinoma (RCC) with tumor thrombus invading vascular wall.The main questions it aims to answer are:

• To establish a preoperative imaging diagnostic model which highly consistent with the histopathological examinations.
• To determine what impact does different vascular wall layer invasion make on the long-term prognosis in RCC with IVC tumor thrombus;
• To determine which layer invasion according to pathological examination make sense to clinical treatment (can significantly affect prognosis); Participants with IVC vascular wall invasion/ non-invasion are divided into experimental group (invaded group) or control group (non-invaded group) respectively according to pathological examinations, in order to establish a prospective cohort with three-year follow-up. The pathological characteristics of local recurrence and poor prognosis are summarized, and postoperative pathological diagnostic criteria of IVC vascular wall invasion and established. The local recurrence and distant recurrence outcomes are compared between experiment group and control group, in order to analyze the long-term influence of vascular wall invasion. Then the preoperative imaging diagnostic evaluation model will be established.

Radical nephrectomy and thrombectomy are essential surgical treatments for renal cell carcinoma (RCC) with inferior vena cava (IVC) tumor thrombus. IVC vascular wall invasion leads to higher recurrence risk and worse long-term prognosis. The diagnosis and treatment of RCC tumor thrombus with IVC vascular wall invaded are affected by prominent difficulties: First, there is a lack of the preoperative diagnostic evaluation system consisting to the postoperative histopathological examinations, which is regarded as the gold standard of vascular wall invasion, therefore hinders the development of the neoadjuvant therapy strategy and surgery plan; Besides, the pathological diagnostic criteria of IVC vascular wall adhesion or invasion is inconsistent among different centers, an accurate and systematic criteria is needed.

This study consecutively includes patients admitted in Peking University Third Hospital between January 2023 to January 2026, who were diagnosed with primary renal cell carcinoma with IVC tumor thrombus with/without vascular wall invasion, and accepted radical nephrectomy and at least one IVC thrombectomy (including IVC incision only, IVC partial resection, IVC diagonal resection, and IVC segmental resection). The patients with IVC vascular wall invasion/ non-invasion are divided into experimental group (invaded group) or control group (non-invaded group) respectively according to pathological examinations, in order to establish a prospective cohort with three-year follow-up. For the invaded group, micro invasion subgroup and tumor thrombus capsule subgroup analysis are conducted. The pathological characteristics of local recurrence and poor prognosis are summarized, and postoperative pathological diagnostic criteria of IVC vascular wall invasion and established. The local recurrence and distant recurrences outcomes are compared between experiment group and control group, in order to analyze the long-term influence of vascular wall invasion. Then the preoperative imaging diagnostic evaluation model were established: re-diagnose patients in two groups according to the established pathological diagnostic criteria, and divide them into truly-invaded group and truly-non-invaded group. Analyzing the preoperative abdominal ultrasound scan, contrast-enhanced ultrasonography, computed tomography (CT) and magnetic resonance imaging (MRI), thus explore the imaging characteristics of vascular wall invasion and establish the preoperative diagnostic model. This study aims at establish a preoperative imaging diagnostic model which highly consistent with the histopathological examinations, as well as a accurate and systematic pathological grading standard of IVC vascular wall invasion, therefore contribute to the development of a more accurate and effective preoperative treatment strategy and surgery plan.

Inclusion Criteria:

• Adults ≥18 years of age;
• Accepted abdominal ultrasonography, contrast-induced ultrasonography, enhanced CT and MRI before the surgery;
• Diagnosis of primary renal cell carcinoma with tumor thrombus before and during the surgery;
• Received radical nephrectomy and at least one kind of thrombectomy (including IVC incision only, IVC partial resection, IVC diagonal resection, and IVC segmental resection)
• Can tolerate the surgery;
• Eastern Cooperative Oncology Group Performance Status Scale (ECOG-PS) 0~2;
• No previous history of malignant tumor;
• Willing to return for required follow-up visits

Exclusion Criteria:

• Failed to receive standard nephrectomy for any reason;
• Attached other addition operations in the surgery;
• Received neoadjuvant treatment before the surgery;
• Experience any other conditions that may affect the curative effect (e.g. active tuberculosis, autoimmune disease, or oral glucocorticoids treatment);
• Experience serious consequences or death due to anesthesia accident during operation;