# The added value of preoperative thoracic CT imaging in the management of T1a renal cell carcinoma

## TL;DR

This study finds that routine preoperative chest CT scans for small kidney tumors in Sweden do not help detect lung metastases and may be unnecessary.

## Contribution

The study provides evidence against the routine use of preoperative thoracic CT for T1a renal cell carcinoma.

## Key findings

- Routine preoperative thoracic CT did not detect lung metastases in patients with T1a RCC.
- Six patients had local relapse, but none developed lung metastasis during follow-up.
- Omitting the CT scan could reduce costs and treatment delays for small renal tumors.

## Abstract

In Sweden, approximately 1300 patients are diagnosed with renal cell carcinoma (RCC) every year. The use of a computed tomography (CT) scan of the thoracic cavity in the preoperative work up of kidney cancer has increased in Sweden, and current national guidelines recommend that all patients, regardless of tumor size, should be evaluated this way

To investigate the need for the preoperative routine to include a CT scan of the thoracic cavity when investigating renal masses 4 cm or smaller.

Between 2017 and 2022, 496 patients at a university hospital and a regional hospital received treatment with curative intent for T1a tumors. Patient data and pathological findings were registered from patient records.

Median follow-up was 38 months. A total of 260 patients were examined with a preoperative CT scan of the thoracic cavity without pathology: 46 had not been scanned, 118 had indeterminate lesions, and metastasis was suspected in two cases. During follow-up, six patients had local relapse and none was diagnosed with lung metastasis. In no case did the preoperative CT of the thoracic cavity contribute to an early discovery of lung metastases.

Our conclusion is that a chest CT scan is superfluous in the preoperative work-up. The cost, and the time to treatment, could be reduced by precluding the chest CT in the preoperative work up for small renal tumors.