Impact of tissue-independent positron range correction on [ 68 Ga]Ga-DOTATOC and [ 68 Ga]Ga-PSMA PET image reconstructions: a patient data study.

Purpose: The positron range effect can impair PET image quality of Gallium-68 ( ⁶⁸ Ga). A positron range correction (PRC) can be applied to reduce this effect. In this study, the effect of a tissue-independent PRC for ⁶⁸ Ga was investigated on patient data.
Methods: PET/CT data (40 patients: [ ⁶⁸ Ga]Ga-DOTATOC or [ ⁶⁸ Ga]Ga-PSMA) were reconstructed using Q.Clear reconstruction algorithm. Two reconstructions were performed per patient, Q.Clear with and without PRC. SUV _max and contrast-to-noise ratio (CNR) values per lesion were compared between PRC and non-PRC images. Five experienced nuclear medicine physicians reviewed the images and chose the preferred reconstruction based on the image quality, lesion detectability, and diagnostic confidence.
Results: A total of 155 lesions were identified. The PRC resulted in statistically significant increase of the SUV _max and CNR for soft tissue lesions (6.4%, p < 0.001; 8.6%, p < 0.001), bone lesions (14.6%, p < 0.001; 12.5%, p < 0.001), and lung lesions (3.6%, p = 0.010; 6.3%, p = 0.001). This effect was most prominent in small lesions (SUV _max : 12.0%, p < 0.001, and CNR: 13.0%, p < 0.001). Similar or better image quality, lesion detectability, and diagnostic confidence was achieved in PRC images compared to the non-PRC images as those assessed by the expert readers.
Conclusions: A tissue-independent PRC increased the SUV _max and CNR in soft tissue, bone, and lung lesions with a larger effect for the small lesions. Visual assessment demonstrated similar or better image quality, lesion detectability, and diagnostic confidence in PRC images compared to the non-PRC images.
Competing Interests: Declarations. Ethics approval: This study was performed in line with the principles of the Declaration of Helsinki. Approval for this study was granted by the medical ethics committee METC azM/UM, Maastricht, The Netherlands (Date: 09-July-2021, No: 2021–2795). Consent to participate: Written informed consent was obtained from all individual participants included in the study. Consent to publish: Informed consent was obtained from all participants to publish their anonymized data. Competing interests: Felix M. Mottaghy is medical advisor for NanoMab Technology Ltd. and Advanced Accelerator Applications (AAA) GmbH/Novartis and has recently received institutional grants from NanoMab Technology Ltd., Siemens, and GE Precision HealthCare LLC. He is also 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). In addition, his research is funded by the German Federal Ministry of Research and Education (project 16GW0319K). Moreover, he is an editor in the European Journal of Nuclear Medicine and Molecular Imaging. Floris P. Jansen is employee of GE HealthCare. The other authors have no relevant financial or non-financial interests to disclose regarding this topic.
(© 2025. The Author(s).)