Details

Autor(en) / Beteiligte

• Mihatsch, Patrick W
• Beissert, Matthias
• Pomper, Martin G
• Bley, Thorsten A
• Seitz, Anna K
• Kübler, Hubert
• Buck, Andreas K
• Rowe, Steven P
• Serfling, Sebastian E
• Hartrampf, Philipp E
• Werner, Rudolf A

Titel

Changing Threshold-Based Segmentation Has No Relevant Impact on Semi-Quantification in the Context of Structured Reporting for PSMA-PET/CT

Ist Teil von

• Cancers, 2022-01, Vol.14 (2), p.270

Ort / Verlag

Switzerland: MDPI AG

Erscheinungsjahr

2022

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• Prostate-specific membrane antigen (PSMA)-directed positron emission tomography/computed tomography (PET/CT) is increasingly utilized for staging of men with prostate cancer (PC). To increase interpretive certainty, the standardized PSMA reporting and data system (RADS) has been proposed. Using PSMA-RADS, we characterized lesions in 18 patients imaged with F-PSMA-1007 PET/CT for primary staging and determined the stability of semi-quantitative parameters. Six hundred twenty-three lesions were categorized according to PSMA-RADS and manually segmented. In this context, PSMA-RADS-3A (soft-tissue) or -3B (bone) lesions are defined as being indeterminate for the presence of PC. For PMSA-RADS-4 and -5 lesions; however, PC is highly likely or almost certainly present [with further distinction based on absence (PSMA-RADS-4) or presence (PSMA-RADS-5) of correlative findings on CT]. Standardized uptake values (SUV , SUV , SUV ) were recorded, and volumetric parameters [PSMA-derived tumor volume (PSMA-TV); total lesion PSMA (TL-PSMA)] were determined using different maximum intensity thresholds (MIT) (40 vs. 45 vs. 50%). SUV was significantly higher in PSMA-RADS-5 lesions compared to all other PSMA-RADS categories ( ≤ 0.0322). In particular, the clinically challenging PSMA-RADS-3A lesions showed significantly lower SUV and SUV compared to the entire PSMA-RADS-4 or -5 cohort ( < 0.0001), while for PSMA-RADS-3B this only applies when compared to the entire PSMA-RADS-5 cohort ( < 0.0001), but not to the PSMA-RADS-4 cohort (SUV , = 0.07; SUV , = 0.08). SUV ( = 0.30) and TL-PSMA ( = 0.16) in PSMA-RADS-5 lesions were not influenced by changing the MIT, while PSMA-TV showed significant differences when comparing 40 vs. 50% MIT ( = 0.0066), which was driven by lymph nodes ( = 0.0239), but not bone lesions ( = 0.15). SUV was significantly higher in PSMA-RADS-5 lesions compared to all other PSMA-RADS categories in F-PSMA-1007 PET/CT. As such, the latter parameter may assist the interpreting molecular imaging specialist in assigning the correct PSMA-RADS score to sites of disease, thereby increasing diagnostic certainty. In addition, changes of the MIT in PSMA-RADS-5 lesions had no significant impact on SUV and TL-PSMA in contrast to PSMA-TV.