Low yield of surveillance imaging after surgery for T1 kidney cancer

To examine the mode of relapse detection and subsequent treatment after partial or radical nephrectomy in patients with low-risk (pT1, N0, Nx) kidney cancer.

Retrospective study on 1404 patients treated with partial or radical nephrectomy for low-risk kidney cancer from the years 2000-2012. Scans for chest imaging (X-ray or CT) and abdominal imaging (CT, MRI, or ultrasound) are tabulated. For those patients with relapse, the site, mode of detection, and symptoms were recorded.

Twenty-one patients relapsed with a median follow-up of 4.1 years for patients who did not relapse. In 17 (81 %) patients, relapse was detected by imaging alone, while 4 (19 %) patients presented with symptoms. Of the patients who relapsed by imaging, 13 (76 %) were treated immediately, while 4 (24 %) continued observation. During the first 3 years of follow-up, 5762 imaging studies were performed to detect 8 relapses, with 6 patients receiving immediate treatment. The median number of imaging studies per patient per year for the first 3 years was 1.7 (interquartile range 1.0, 2.3) including 30 % CT, 3 % MRI, 36 % X-ray, and 31 % ultrasounds.

We found a low yield of surveillance imaging in the first 3 years for pT1 kidney cancer. Nearly 1000 imaging studies were performed to detect one relapse that required treatment. Further studies are needed to evaluate the clinical impact of imaging surveillance according to recent guidelines.