Percutaneous Image-Guided Cryoablation of Endophytic Renal Cell Carcinoma

Abstract

Purpose: Endophytic renal cancer treatment is a challenge. Due to difficulties in endophytic tumor visualization during surgical extirpation, image-guided percutaneous cryoablation (PCA) is an attractive alternative. The minimally invasive nature of PCA makes it favorable for comorbid patients as well as patients in which surgery is contraindicated. Oncological outcomes and complications after PCA of endophytic biopsy-proven renal cell carcinoma (RCC) were reviewed in this study.

Materials and methods: Patients were included after a multidisciplinary team conference from January 2015 to November 2021. Inclusion criteria were endophytic biopsy-proven T1 RCC treated with PCA with one year of follow-up. Complications were reported according to the Cardiovascular and Interventional Radiological Society of Europe (CIRSE) classification system and the Clavien-Dindo classification (CDC) system. Major complications were defined as a grade ≥ 3 according to the CDC.

Results: Fifty-six patients were included with a total of 56 endophytic tumors treated during 61 PCA sessions. The median RENAL nephrometry score was 9 (IQR 2), and the mean tumor size was 25.7 mm (SD ± 8.9 mm). Mean hospitalization time was 0.39 (SD ± 1.1) days. At a mean follow-up of 996 days (SD ± 559), 86% of tumors were recurrence free after one PCA. No patients progressed to metastatic disease. According to the CIRSE classification, 10.7% (n = 6) had grade 3 complications, and 5.4% (n = 3) had CDC major complications.

Conclusion: This study demonstrates that PCA of endophytic biopsy-proven T1 RCC is safe with few major complications and excellent local tumor control rates at almost three-year mean follow-up. LEVEL OF EVIDENCE 3: Retrospective cohort study.

Keywords: Ablation; Cryoablation; Endophytic tumor; PCA; Percutaneous; RCC; Renal cancer.

Fig. 1

Flowchart showing patient selection. ^aPercutaneous cryoablation (PCA). ^bRadius–endophytic–nearness–anterior–location (RENAL). ^cRenal cell carcinoma (RCC)

Fig. 2

Cumulative incidence estimates of local tumor progression

Fig. 3

CT images from a 62-year-old male patient with a 38-mm endophytic biopsy-proven clear cell RCC in the left kidney where PCA was performed. A Preprocedural CT images with intravenous contrast, venous phase. The tumor is marked with a white circle. B Intraprocedural CT images with the patient in an oblique position. The image demonstrates the iceball zone. C Venous contrast CT imaging one year after primary PCA shows no residual tumor mass. The ablation zone is marked with a white circle. ^aComputed tomography (CT). ^bRenal cell carcinoma (RCC).^cPercutaneous cryoablation (PCA)