Beyond the Scalpel: the Role of Image-Guided Thermal Ablation in Management of Metastatic Renal Cell Carcinoma in the Era of Immunotherapy

Abstract

Renal cell carcinoma (RCC) is the most common type of kidney cancer and accounts for approximately 90% of all renal malignancies. About 30% of patients have metastatic disease at their initial presentation. Historically, these patients have very poor prognosis with a median survival of 12 months. The recent introduction of immune checkpoint inhibitors (ICI)-based immunotherapy, which disrupts cancer-induced immune tolerance and promotes immune-mediated cancer cell killing, has significantly improved patient outcome. While ICI-based therapy represents the standard of care for metastatic RCC, there are significant treatment-related adverse effects. This review article will examine how image-guided ablation, as an adjunct to immunotherapy, can improve survival and quality of life in patients with metastatic RCC.

Keywords: Cryoablation; Immunotherapy; Metastasis; Renal cell carcinoma; Thermal Ablation.

Fig. 1

A 67-year-old woman with asynchronous right paraaortic nodal RCC metastasis treated with cryoablation, allowing delay of initiation of immunotherapy. a Coronal reformatted contrast-enhanced CT abdomen showed primary right upper pole RCC (white arrow), which was resected by radial nephrectomy. Pathology showed clear cell RCC. b Axial contrast-enhanced CT abdomen performed 1 year after right nephrectomy showed right paraaortic nodal metastasis (white circle), c and d Under (c) CT and (d) fluoroscopic guidance, cryoablation of the right paraaortic nodal metastasis performed using two 17G cryoprobes (white arrow). A 22G spinal needle (dashed white arrow) was used for hydrodissection. Coil embolisation of a parasitic right diaphragmatic artery supplying the node also performed to reduce cold sink effect. e axial contrast-enhanced CT at 6 months post-cryoablation confirmed necrosis of nodal metastasis

Fig. 2

A 70-year-old man who received 18 months of immunotherapy with residual liver metastasis treated with microwave ablation. a Graphical illustration demonstrates that, after immunotherapy, the number of liver metastasis reduced from four to one but the patient was unable to reach complete response. b Axial T1-weighed post-contrast MR abdomen showed residual metastatic focus at subcapsular region of hepatic segment V (white circle). c Under US and CT guidance, the lesion was ablated using 16G microwave antenna (white arrow). A 22G spinal needle (dashed white arrow) was used for hydrodissection. d Contrast-enhanced CT performed four years after microwave ablation of liver metastasis confirmed complete disease remission.

Fig. 3

A 56-year-old man with advanced RCC and painful right ischial bone metastasis. a Unenhanced axial CT pelvis showed aggressive lytic bone metastasis at right ischium. b Under CT guidance, electrochemotherapy, i.e. reversible electroporation with intravenous bleomycin administration, was used to treat the right ischial bone metastasis. Electroporation needle was indicated by dashed white arrow. c Axial T1-weighed post-contrast MR pelvis showed necrosis of right ischial metastasis. The patient remained opioid-free for 6 months