Limited Additional Value of a Chest CT in Whole-Body Staging with PET-MRI: A Retrospective Cohort Study

Tineke van de Weijer; Wilhelmina L van der Meer; Rik P M Moonen; Thiemo J A van Nijnatten; Hester A Gietema; Cristina Mitea; Jochem A J van der Pol; Joachim E Wildberger; Felix M Mottaghy

doi:10.3390/cancers16122265

Limited Additional Value of a Chest CT in Whole-Body Staging with PET-MRI: A Retrospective Cohort Study

Cancers (Basel). 2024 Jun 19;16(12):2265. doi: 10.3390/cancers16122265.

Authors

Tineke van de Weijer^{1

2}, Wilhelmina L van der Meer¹, Rik P M Moonen¹, Thiemo J A van Nijnatten^{1

3}, Hester A Gietema^{1

3}, Cristina Mitea^{1

3}, Jochem A J van der Pol^{1

4}, Joachim E Wildberger^{1

3}, Felix M Mottaghy^{1

5}

Affiliations

¹ Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, P. Debeylaan 25, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands.
² School of Nutrition and Translational Research in Metabolism (NUTRIM), 6200 MD Maastricht, The Netherlands.
³ School for Oncology and Reproduction (GROW), 6200 MD Maastricht, The Netherlands.
⁴ School for Cardiovascular Diseases (CARIM), 6202 AZ Maastricht, The Netherlands.
⁵ Department of Nuclear Medicine, University Hospital, RWTH Aachen University, 52074 Aachen, Germany.

Abstract

Hybrid PET-MRI systems are being used more frequently. One of the drawbacks of PET-MRI imaging is its inferiority in detecting lung nodules, so it is often combined with a computed tomography (CT) of the chest. However, chest CT often detects additional, indeterminate lung nodules. The objective of this study was to assess the sensitivity of detecting metastatic versus indeterminate nodules with PET-MRI compared to chest CT. A total of 328 patients were included. All patients had a PET/MRI whole-body scan for (re)staging of cancer combined with an unenhanced chest CT performed at our center between 2014 and 2020. Patients had at least a two-year follow-up. Six percent of the patients had lung metastases at initial staging. The sensitivity and specificity of PET-MRI for detecting lung metastases were 85% and 100%, respectively. The incidence of indeterminate lung nodules on chest CT was 30%. The sensitivity of PET-MRI to detect indeterminate lung nodules was poor (23.0%). The average size of the indeterminate lung nodules detected on PET-MRI was 7 ± 4 mm, and the missed indeterminate nodules on PET-MRI were 4 ± 1 mm (p < 0.001). The detection of metastatic lung nodules is fairly good with PET-MRI, whereas the sensitivity of PET-MRI for detecting indeterminate lung nodules is size-dependent. This may be an advantage, limiting unnecessary follow-up of small, indeterminate lung nodules while adequately detecting metastases.

Keywords: CT; Oncology; PET/MRI.

Grants and funding

The research presented in this paper received no dedicated external funding. FMM is supported by the German Research Foundation (DFG) within the framework of the Research Training Group 2375 “Tumor-targeted Drug Delivery” (grant 331065168), the Clinical Research Unit CRU 5011 “Integrating emerging methods to advance translational kidney research (InteraKD)” (project 445703531), and the Research Unit 2591 “Severity assessment in animal-based research” (project 321137804). In addition, his research is funded by German Cancer Aid (projects 70113779 and 70113780) and the German Federal Ministry of Research and Education (project 16GW0319K).