Presentation Authors: Borna Kassiri*, Joseph Cheaib, Phillip Pierorazio, Baltimore, MD
Introduction: Active surveillance (AS) is recognized as a standard for the management of small renal masses (SRM). Renal cell carcinoma (RCC) can metastasize to the lungs, so yearly chest imaging has been indicated for the follow-up of patients with SRM on AS. However, given the low rates of metastasis from SRM and the potentially increased rates of incidental non-RCC related findings, the necessity of this yearly chest imaging comes into question.
Methods: We performed a retrospective analysis of 268 patients with SRM enrolled in the AS arm of the Delayed Intervention and Surveillance for Small Renal Masses (DISSRM) registry at our institution. Chest imaging reports were examined to identify patients with abnormal findings, which were then determined to be actionable or non-actionable based on receipt of further clinical investigations/interventions.
Results: Of the 268 patients, 51 (19%) were found to have abnormal baseline chest images; of these 51 images, 22 (43%) were actionable or eventually became actionable, and 29 (57%) were non-actionable. Of the 217 patients with normal baseline images, 23 (11%) developed abnormal findings in subsequent chest imaging. The findings were actionable in 10 (43%) of these 23 patients. Most of the 32 actionable findings were pulmonary nodules >5mm (N=20, 63%) and thyroid nodules (N=8, 25%), for which further chest CT (N=14, 44%), lung biopsies (N=6, 19%), and thyroid ultrasound (N=8, 25%) were performed. None of these patients were found to have metastatic RCC. Most of the 42 non-actionable findings included stable pulmonary nodules < 5mm (N=24, 58%) and scarring/post-inflammatory changes (N=8, 19%).
Conclusions: Routine chest imaging did not reveal metastatic disease in patients with SRM. The potential morbidity and cost of frequent chest imaging in these patients outweigh the chance of detecting metastasis. However, yearly chest imaging "for cause" could still be appropriate in: (1) patients with indeterminate pulmonary findings on baseline imaging, (2) patients with growing SRM, especially those that exceed 0.5cm/year or cross size thresholds of 3cm or 4cm, due to an increased risk of pulmonary metastases, and (3) patients electing crossover to surgical intervention for accurate re-staging prior to intervention.