Chest CT findings among adult survivors of childhood and young adult cancer with a history of chest radiation.

Abstract

103 Background: While survivors of childhood and young adult cancer with a history of radiation therapy (RT) to the chest are known to be at increased risk for lung cancer, whether a CT-based lung cancer screening program is appropriate for this population is unknown. We sought to describe CT findings in a clinic-based population of childhood and young adult cancer survivors. Methods: We performed a detailed review of all diagnostic chest CT scans performed among patients seen in the Adult Long-Term Follow-Up Program at Memorial Sloan Kettering between August 2005 and May 2016. Included survivors were at least 5 years from diagnosis and had a history of RT to the mediastinum, mantle, axilla, lung, thoracic spine, or total body irradiation fields. Results were reviewed by at least two authors (ET, DB, or AK) and discrepancies were resolved by consultation with a pulmonologist (RK). Results: We identified 620 survivors with a history of chest field RT who were at least 5 years from diagnosis. The population was 48% male, with a median age at diagnosis of 17.2 years. Approximately half were survivors of Hodgkin Lymphoma (N=306; 49.5%) and almost one-third had undergone hematopoietic cell transplant (N=188; 31%); other diagnoses included non-Hodgkin Lymphoma and sarcoma. The most frequently cited RT field was mantle (N=219; 36%), followed by total body irradiation (N=142; 24%) and whole lung (N=110;18%). Among 351 survivors with at least one chest CT, 206 (59%) had at least one pulmonary nodule, 174 (50%) had fibrosis, and 132 (38%) had a ground glass opacity. Among those with a pulmonary nodule, the large majority (91% of those with a nodule) were followed expectantly or underwent repeat imaging; these patients were spared biopsy or resection. Among 18 patients who underwent biopsy, wedge resection, fine needle aspiration, or bronchoscopy, 4 were diagnosed with lung adenocarcinoma, 3 with metastatic sarcoma, and one with marginal zone lymphoma (MALT). Conclusions: Benign pulmonary nodules among adults with a history of RT for childhood or young adult cancer are common. Any strategy for lung cancer screening in this population will need to account for a high likelihood of benign findings on chest CT.