Diagnostic Impact of Dual-Time PET/CT with 68Gallium-PSMA in Prostate Cancer and 68Gallium-DOTATOC in Neuroendocrine Tumors

Damiano Librizzi; Friederike Eilsberger; Stefan Ottenthaler; Ali Ebrahimifard; Markus Luster; Behrooz H Yousefi

doi:10.3390/biomedicines11041052

Diagnostic Impact of Dual-Time PET/CT with ⁶⁸Gallium-PSMA in Prostate Cancer and ⁶⁸Gallium-DOTATOC in Neuroendocrine Tumors

Biomedicines. 2023 Mar 29;11(4):1052. doi: 10.3390/biomedicines11041052.

Authors

Damiano Librizzi¹, Friederike Eilsberger¹, Stefan Ottenthaler¹, Ali Ebrahimifard¹, Markus Luster¹, Behrooz H Yousefi¹

Affiliation

¹ Department of Nuclear Medicine, School of Medicine, Philipps University Marburg, 35043 Marburg, Germany.

Abstract

Background: The timing of imaging for ⁶⁸gallium (⁶⁸Ga)-PSMA and ⁶⁸Ga-DOTATOC are stated to be around 60 min post-injection (p.i.). In some lesions, late imaging (3-4 h p.i.) showed advantages. The aim of our evaluation was to demonstrate the relevance of an "early" late acquisition.

Methods: We retrospectively evaluated 112 patients who underwent ⁶⁸Ga-DOTATOC-PET/CT and 82 patients who underwent ⁶⁸Ga-PSMA-PET/CT. The first scan was acquired 60 min (±15 min) after application. In cases of diagnostic ambiguity, a second scan was performed 30-60 min later. Pathological lesions were analyzed.

Results: Almost half of all ⁶⁸Ga-DOTATOC cases and about one-third of all ⁶⁸Ga-PSMA examinations showed a change in findings due to the second acquisition. In total, 45.5% of neuroendocrine tumor (NET) patients and 66.7% of prostate cancer (PCa) patients showed relevant TNM classification changes. For ⁶⁸Ga-PSMA, there were significant increases in sensitivity and specificity from 81.8% to 95.7% and from 66.7% to 100%, respectively. Statistically significant improvements in sensitivity (from 53.3% to 93.3%) and specificity (from 54.6% to 86.4%) were demonstrated for NET patients.

Conclusion: Early second images can improve diagnostics with ⁶⁸Ga-DOTATOC and ⁶⁸Ga-PSMA PET/CT.

Keywords: 68gallium; DOTATOC; PET/CT; PSMA; dual-time; neuroendocrine tumor; prostate cancer.

Grants and funding

This research received no external funding. Open Access funding provided by the Open Access Publishing Fund of Philipps-Universität Marburg with support of the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation).