Primary Thoracic Cancers Incidentally Detected on CT Attenuation Correction Images During Myocardial Perfusion Scintigraphy

Abstract

Introduction: Incidental findings on CT attenuation correction images undertaken as part of myocardial perfusion scintigraphy may represent undiagnosed malignancy, but their routine review and reporting remains controversial. Methods: We present a series of 10 primary thoracic cancers incidentally detected in this way. They were identified as part of a retrospective review of incidental CT attenuation correction findings in 3122 consecutive myocardial perfusion studies over a forty-month period. Results: The nature and location within the thorax of the incidental findings which represented undiagnosed malignancy was varied. Early detection allowed curative surgical treatment to be undertaken in four cases, with no recurrence or metastasis at one year in these patients. The rate of new primary cancer detection was similar to previous studies. Conclusions: This series highlights the need for mandatory review and reporting with appropriate further investigation of incidental CT attenuation correction findings, and the potential of this to impact patient outcomes. The importance of clear communication between the nuclear medicine department and the treating medical team, to both avoid unnecessary delay in urgent cases clearly suspicious for malignancy and to ensure that appropriate follow-up of potentially important non-urgent findings is not missed, cannot be over-emphasised.

Incidental Non-cardiac Findings in Cardiovascular Imaging

“…In a meta-analysis of 5082 patients in 10 studies, the frequency of malignancy on CT was estimated as 0.7% [ 3 ••]. Similar rates of malignancy have been identified in the low-dose CT performed for attenuation correction in SPECT imaging [ 11 ].…”

Augmenting Follow-up of Incidental Imaging Findings

“…We found the work of Crable et al [1] very intriguing as it directly relates to a concept that we have promoted [2]. We very much favor referring doctors giving sufficient credence to incidental findings on imaging-of all modalities.…”

Follow-up of incidental findings on positron emission tomography

“…[4] This might be extrapolated to the standardized reporting of significant incidental imaging findings. Consensus guidelines might also be helpful, [5] endorsed by the appropriate Societies and specialist Colleges. We sincerely welcome further suggestions on any other possible helpful initiatives.…”