Pulmonary nodules are round opacities measuring up to 3 centimetres, with borders that are either well or poorly defined.1 They are typically monitored via computed tomography (CT),2,3 which carries an associated patient radiation exposure and healthcare cost. As reliance on CT surveillance has grown and imaging technology has improved, we are increasingly detecting subcentimetre pulmonary nodules, defined to be lesser than or equal to 8 millimetres in size.4 There is a paucity of information around surveillance of these nodules. As such, we aimed to audit...

Exemption from full ethics review was obtained. A chronological list of patients was generated through the radiology information system (RIS) used at our facility. Suitable patients were defined as those who had subcentimetre pulmonary nodule(s) incidentally identified after undergoing thoracic-related imaging in the last 4 years. After duplicates were filtered, the unit record number (URN) of the first 100 patients was recorded and their medical records perused. Data parameters of interest included type of imaging performed, Medicare benefit payable per study, dose length product (DLP)...

100 patients (50 male, 50 female, ranging from 33 years to 84 years of age) were included in this series. Patients had pulmonary nodules discovered on a variety of imaging modalities (77 via whole lung CT, 8 via partial lung CT and 15 via nuclear medicine studies). [Fig 1] Patients underwent an average of 4 imaging studies as part of identification and follow-up of their pulmonary nodules, with an average associated cost of AUD$1,699.69 and an average estimated effective dose of 5.7 millisieverts (mSV). 49/100...

Our series suggests follow-up of subcentimetre pulmonary nodules entails significant healthcare costs and radiation exposure to patients. Therefore, judicious use of cross-sectional imaging is important to ensure that risks such as radiation exposure are balanced against clinical need. Future efforts to streamline the referral, imaging and reporting process could be beneficial in this patient cohort.

Hansell DM, Bankier AA, MacMahon H, McLoud TC, Müller NL, Remy J. Fleischner Society: Glossary of Terms for Thoracic Imaging. Radiology. 2008 Mar;246(3):697-722. MacMahon H, Naidich DP, Goo JM, Lee KS, Leung ANC, Mayo JR, et al. Guidelines for Management of Incidental Pulmonary Nodules Detected on CT Images: From the Fleischner Society 2017. Radiology. 2017 Jul;284(1):228-43. Callister MEJ, Baldwin DR, Akram AR, Barnard S, Cane P, Draffan J, et al. British Thoracic Society guidelines for the investigation and management of pulmonary nodules: accredited by NICE....