Staging CT chest for cT1a renal masses: Does it change management?

Baseline staging investigations for renal masses invariably include a CT of the chest. However, EAU guidelines have given a weak recommendation that CT chest can be omitted in incidental T1a tumours (≤4 cm) without systemic symptoms, due to the low incidence of pulmonary metastases. This study aimed to assess if a baseline staging CT chest has been clinically useful in a cohort with T1a renal tumours.

Consecutive patients with solid and cystic cT1a renal tumours were prospectively screened for eligibility to the NEST study (ISRCTN 18156881) at a single tertiary referral centre multidisciplinary team meeting (MDT). Four hundred consecutive eligible patients between 28/05/2019 and 13/01/2021 were included in this study. Electronic records were reviewed retrospectively for follow-up data. Seventeen patients with incomplete follow-up data were excluded.

Of 383 included patients (63% male, median age 65 years, median tumour diameter 2.4 cm), 264 (69%) had a baseline CT chest as part of their clinical staging investigations. No thoracic renal metastases were diagnosed. Abnormalities were reported in 37/264 cases (14%), including indeterminate lung lesions in 32 patients that were deemed benign on further investigations, three synchronous primary lung tumours, one pre-existing mesothelioma and one pleural effusion related to known renal failure.

CT chest is of limited value in clinical staging investigations for cT1a renal tumours and has a negligible impact on subsequent renal tumour management. Rather, it triggered further investigations and follow-up for 14% of incidentalomas and ultimately detected concurrent incidental primary lung tumours in 1% of patients.