The clinical significance of indeterminate pulmonary nodules in melanoma patients at baseline and during follow-up chest CT

Magdy Soliman; Teresa Petrella; Pascal Tyrrell; Frances Wright; Nicole J Look Hong; Hua Lu; Petros Zezos; Laura Jimenez-Juan; Anastasia Oikonomou

doi:10.1016/j.ejro.2019.02.003

The clinical significance of indeterminate pulmonary nodules in melanoma patients at baseline and during follow-up chest CT

Eur J Radiol Open. 2019 Feb 11:6:85-90. doi: 10.1016/j.ejro.2019.02.003. eCollection 2019.

Authors

Magdy Soliman¹, Teresa Petrella², Pascal Tyrrell³, Frances Wright⁴, Nicole J Look Hong⁴, Hua Lu³, Petros Zezos⁵, Laura Jimenez-Juan¹, Anastasia Oikonomou¹

Affiliations

¹ Department of Medical Imaging, Sunnybrook Health Sciences Centre, University of Toronto, M4N 3M5, Toronto, ON, Canada.
² Department of Medicine, Sunnybrook Health Sciences Centre, University of Toronto, M4N 3M5, Toronto, ON, Canada.
³ Department of Medical Imaging, University of Toronto, M5T 1W7, Toronto, ON, Canada.
⁴ Department of Surgery, Sunnybrook Health Sciences Centre, University of Toronto, M4N 3M5, Toronto, ON, Canada.
⁵ Department of Medicine, North Ontario School of Medicine, ON P7B 5E1, Canada.

Abstract

Objective: This study aims to determine an appropriate timeline to monitor indeterminate pulmonary nodules (IPN) in melanoma patients to confirm metastatic origin.

Materials and methods: 588 clinically non-metastatic melanoma patients underwent curative intent surgery during 3 years. Patients with baseline chest CT and at least one follow-up (FU) CT were retrospectively analyzed to assess for IPN. Patients with definitely benign nodules, metastases and non-melanoma malignancies were excluded. Change in volume from first to FU CT, initial diameter (D1) and volume (V1), distance from pleura, peripheral and perifissural location, density and clinical stage were evaluated. Nodules were volumetrically measured on CTs and were considered metastases if they increased in size between two CTs or if increase was accompanied by multiple new nodules or extrapulmonary metastases.

Results: 148 patients were included. Two out of 243 baseline IPN detected in 70 patients, increased significantly in volume in 3 and 5 months and were proven metastases. During FU, 86% of 40 interval IPN detected in 28 patients, were proven metastases. Interval nodule (p < 0.0001, HR:243,CI:[57.32,1033.74]), 3-month volume change (OR:1.023,CI:[1.014,1.033]), V1 (OR:1.006,CI:[1.003,1.009]), D1 (OR:1.424,CI:[1.23,1.648]), distance from pleura (OR:1.03,CI:[1.003,1.059]), and combined stage IIC + III (OR:11.29,CI:[1.514,84.174]), were associated with increased risk for metastasis. 43%, 72% and 94% of patients with IPN were confirmed with metastases in the first FU CT at 3, 6 and 12 months respectively.

Conclusion: Baseline IPN are most likely benign, while interval IPN are high risk for metastasis. Absence of volume increase of IPN within 6 months excluded metastasis in most patients.

Keywords: FU, follow-up; GGO, ground glass opacity; IPN, indeterminate pulmonary nodules; Melanoma; Metastasis; Multiple pulmonary nodules; X-ray computed tomography.