Abstract 1373: Clinical and economic burden of incidental findings suspicious for cancer on non-contrast chest computed tomography performed during myocardial perfusion imaging.
Authors: Alirhayim Zaid , Khalid Fatima , Alarhayem Abdulqader , Hassan Syed , Qureshi Sophia , Qureshi Waqas 
Published: August 2014

Abstract
Background: Radionuclide myocardial imaging is often performed to rule out cardiac ischemia. One drawback is that tissue like breast or stomach can result in attenuation artifact. A common practice involves obtaining a non-contrast low resolution attenuation corrected chest CT (ACCT). No studies have evaluated the clinical & economic burden of findings suggestive for lung cancer on these ACCT images. Methods: Consecutive patients undergoing ACCT from Jan 2005 - Dec 2008 were enrolled. Clinically significant findings were defined as those requiring further follow-up or clearly having features suspicious for lung cancer. For non- calcified lung nodules, our size cutoff was &gt;4 mm in smokers & &gt;6 mm in non-smokers. Follow-up & economic data were obtained from review of hospital & claims records respectively. Mortality data were obtained by social security death index. Direct costs were calculated from procedure related costs & health care utilization costs. Results: Of 1139 patients that underwent ACCT (mean age 59.6 ± 11.3 years, women 47%), 1088 had a median follow up of 4 years. We found 62 patients with lung nodules, 1 with consolidation, 11 with pleural effusion, 5 with pleural plaques, 1 with esophageal mass, 2 with breast masses, & 5 with lymphadenopathy. Of these, a total of 15 patients were confirmed to have lung cancer, 1 with esophageal cancer, 1 breast cancer, & 1 lymphoma, 6 of whom suffered cancer related death. Of the 1001 patients without any clinically significant findings in whom follow up was available, 22 were later discovered to have a new cancer diagnosis localized to the chest within the field of vision of ACCT. Of the 22 patients with cancer, 6 died from their cancer related process, an overall proportion of 0.6%, markedly less than in those with clinically relevant findings (7%) on ACCT (chi2 = 28.3, p &lt;0.0001). In the 85 patients with clinically significant findings, a total of 166 diagnostic procedures (including bronchoscopy, CT guided biopsy, transbronchial biopsy) & additional imaging tests were performed to identify the suspicious lesions. Also, these patients logged a total of 49 ED/inpatient visits & 64 outpatient visits prior to confirmatory pathological diagnosis. The mean direct cost of investigating a suspicious lesion that was found to be malignant was $78,630 (rate current to June 2012). The mean direct cost incurred until death due to cancer in patients with clinically significant findings was $341,200 vs. $181,000 (p &lt;0.0001) in patients that died from cancer located in the chest area that did not initially have a clinically significant finding. Conclusion: This study is the first of its kind to characterize the clinical & economic burden of suspicious incidental findings on ACCT. Despite additional economic burden, patients with clinically significant incidental findings had a higher mortality rate.
Citation Format: Zaid Alirhayim, Fatima Khalid, Abdulqader Alarhayem, Syed Hassan, Sophia Qureshi, Waqas Qureshi. Clinical and economic burden of incidental findings suspicious for cancer on non-contrast chest computed tomography performed during myocardial perfusion imaging. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1373. doi:10.1158/1538-7445.AM2013-1373