Respiratory gated PET/CT of the liver: A novel method and its impact on the detection of colorectal liver metastases

Anselm Schulz; Johannes Clemens Godt; Johann Baptist Dormagen; Jon Erik Holtedahl; Trond Velde Bogsrud; Knut Jørgen Labori; Nils-Einar Kløw; Tore Bach-Gansmo

doi:10.1016/j.ejrad.2015.05.011

Respiratory gated PET/CT of the liver: A novel method and its impact on the detection of colorectal liver metastases

Eur J Radiol. 2015 Aug;84(8):1424-1431. doi: 10.1016/j.ejrad.2015.05.011. Epub 2015 May 14.

Authors

Anselm Schulz¹, Johannes Clemens Godt², Johann Baptist Dormagen³, Jon Erik Holtedahl⁴, Trond Velde Bogsrud⁵, Knut Jørgen Labori⁶, Nils-Einar Kløw⁷, Tore Bach-Gansmo⁸

Affiliations

¹ Department of Radiology and Nuclear Medicine, Oslo University Hospital, Postboks Pb 4956 Nydalen, 0424 Oslo, Norway; Institute of Clinical Medicine, University of Oslo, P.O. Box 1171 Blindern, 0318 Oslo, Norway. Electronic address: anselm.schulz@gmail.com.
² Department of Radiology and Nuclear Medicine, Oslo University Hospital, Postboks Pb 4956 Nydalen, 0424 Oslo, Norway; Institute of Clinical Medicine, University of Oslo, P.O. Box 1171 Blindern, 0318 Oslo, Norway. Electronic address: UXGODJ@ous-hf.no.
³ Department of Radiology and Nuclear Medicine, Oslo University Hospital, Postboks Pb 4956 Nydalen, 0424 Oslo, Norway. Electronic address: UXJORM@ous-hf.no.
⁴ The Intervention Centre, Oslo University Hospital, Postboks 4950 Nydalen, 0424 Oslo, Norway. Electronic address: JONHOL@ous-hf.no.
⁵ Department of Radiology and Nuclear Medicine, Oslo University Hospital, Postboks Pb 4956 Nydalen, 0424 Oslo, Norway; Department of Nuclear Medicine and PET-Center, Aarhus University Hospital, Norrebrogade 44, DK-8000 Aarhus C, Denmark. Electronic address: tvbog@aol.com.
⁶ Department of Hepato-Pancreato-Biliary Surgery, Oslo University Hospital, Postboks 4950 Nydalen, 0424 Oslo, Norway. Electronic address: uxknab@ous-hf.no.
⁷ Department of Radiology and Nuclear Medicine, Oslo University Hospital, Postboks Pb 4956 Nydalen, 0424 Oslo, Norway; Institute of Clinical Medicine, University of Oslo, P.O. Box 1171 Blindern, 0318 Oslo, Norway. Electronic address: NILKLO@ous-hf.no.
⁸ Department of Radiology and Nuclear Medicine, Oslo University Hospital, Postboks Pb 4956 Nydalen, 0424 Oslo, Norway. Electronic address: bat@ous-hf.no.

PMID: 26044293
DOI: 10.1016/j.ejrad.2015.05.011

Abstract

Purpose: To evaluate the diagnostic performance of a new method for respiratory gated positron emission tomography (rgPET/CT) for colorectal liver metastases (CRLM), secondly, to assess its additional value to standard PET/CT (PET/CT).

Materials and methods: Forty-three patients scheduled for resection of suspected CRLM were prospectively included from September 2011 to January 2013. None of the patients had previously undergone treatment for their CRLM. All patients underwent PET/CT and rgPET/CT in the same session. For rgPET/CT an in-house developed electronic circuit was used which displayed a color-coded countdown for the patient. The patients held their breath according to the countdown and only the data from the inspiration breath-hold period was used for image reconstruction. Two independent and blinded readers evaluated both PET/CT and rgPET/CT separately. The reference standard was histopathological confirmation for 73 out of 131 CRLM and follow-up otherwise.

Results: Reference standard identified 131 CRLM in 39/43 patients. Nine patients accounted for 25 mucinous CRLM. The overall per-lesion sensitivity for detection of CRLM was for PET/CT 60.0%, for rgPET/CT 63.1%, and for standard+rgPET/CT 67.7%, respectively. Standard+rgPET/CT was overall significantly more sensitive for CRLM compared to PET/CT (p=0.002) and rgPET/CT (p=0.031). The overall positive predictive value (PPV) for detection of CRLM was for PET/CT 97.5%, for rgPET/CT 95.3%, and for standard+rgPET/CT 93.6%, respectively.

Conclusion: Combination of PET/CT and rgPET/CT improved the sensitivity significantly for CRLM. However, high patient compliance is mandatory to achieve optimal performance and further improvements are needed to overcome these limitations. The diagnostic performance of the evaluated new method for rgPET/CT was comparable to earlier reported technically more complex and expensive methods.

Keywords: Diagnostic performance; Liver; Metastases; PET/CT; Respiratory gated PET/CT.

MeSH terms

Aged
Colorectal Neoplasms / pathology*
Female
Humans
Liver / diagnostic imaging
Liver Neoplasms / diagnosis*
Liver Neoplasms / secondary
Male
Multimodal Imaging / methods*
Neoplasms, Second Primary / diagnosis*
Observer Variation
Positron-Emission Tomography / methods*
Prospective Studies
Reproducibility of Results
Sensitivity and Specificity
Tomography, X-Ray Computed / methods*