Imaging for Metastatic Renal Cell Carcinoma

Abstract

Patients with renal cell carcinoma may develop metastases after radical nephrectomy, and therefore monitoring with imaging for recurrent or metastatic disease is critical. Imaging varies with specific suspected site of disease. Computed tomography/MRI of the abdomen and pelvis are mainstay modalities. Osseous and central nervous system imaging is reserved for symptomatic patients. Radiologic reporting is evolving to reflect effects of systemic therapy on lesion morphology. Nuclear medicine studies compliment routine imaging as newer agents are evaluated for more accurate tumor staging. Imaging research aims to fill gaps in treatment selection and monitoring of treatment response in metastatic renal cell carcinoma.

Keywords: CT; MRI; Metastatic disease; PET; Renal cell carcinoma.

Conflict of interest statement

Disclosure Dr S.K. Kang reports royalties from Wolters Kluwer for unrelated work. Dr E. Zan is involved in clinical trial support at AAA/Novartis and Perlmutter Cancer Center for unrelated work, and acting as a Co-PI in a study at the NIH for unrelated work. Dr S.V.L. Vig has no disclosures.

Copyright © 2020 Elsevier Inc. All rights reserved.

Figures

Figure 1.. Adrenal Collision Tumor with Clear Cell RCC:

A 69 y/o man with history of left clear cell RCC status post nephrectomy in 1987. He was found to have a right adrenal adenoma. T1-weighted in-phase (Image A) and out-of-phase (Image B) sequences demonstrate loss of signal on out-of-phase images, suggestive of microscopic fat as seen in adrenal adenomas. However, a central portion demonstrates India ink artifact, suggesting an interface of fat with non-fatty soft tissue. The center also avidly enhances on post contrast imaging (Image C), suggesting metastasis. Pathology confirmed adrenal adenoma containing metastatic RCC.

Figure 2.. Pancreatic Metastasis:

Patient with history of RCC was found to have a growing pancreatic tail mass on routine CT of the abdomen and pelvis. The mass enhances avidly on arterial phase images on CT (Image A) and arterial phase on MRI (Image B). On MRI, the lesion is T2 hyper-intense to surrounding tissue on T2-weighted fat-saturated images (Image C). Diffusion restriction entails high signal on high b value images (Image D) and low signal on the ADC map (Image E).

Figure 3.. Bone Scan of Diffuse Metastatic RCC:

A 68-year old man with history of metastatic RCC, clear cell type, had a right nephrectomy in 1986. A subsequent cancer was discovered in the contralateral kidney and treated with partial nephrectomy in 2012, later requiring a complete nephrectomy due to recurrence. The patient later developed metastasis to lymph nodes, liver, and bone. A bone scan was performed to assess the metastatic disease, and showed metastases of the axial skeleton, ribs and upper and lower extremities. Incidental note is made that patient is status post bilateral nephrectomy with no visualization of kidneys or bladder uptake.