Sterke correlatie tussen de intensiteit van prostaatkankerrecidieven op de PSMA PET/CT-scan en het intra-operatieve gammasonde signaal.

Prostate-specific membrane antigen (PSMA) positron emission tomography (PET) is used to select patients with biochemical recurrence for metastasis-directed radio-guided surgery (RGS). During RGS cancerous tissue can be identified after intravenous injection of the PSMA-targeted tracer [99mTc]Tc-PSMA-I&S. The aim was to study the correlation between the maximum standardized uptake value (SUVmax) on the preoperative PSMA PET/CT and the intraoperative numerical signal (counts/second) of the lesion measured by Drop-In gamma probe. Twenty-nine patients were included in this prospective TRACE-study (NCT03857113). Thirty-three lesions (29 nodal, 4 local recurrence) were preoperatively identified with a median SUVmax of 6.2 (interquartile range [IQR] 4.2–9.7). Median intraoperative signal was 134 counts/s (IQR 81–220) in vivo and 109 (IQR 72–219) ex vivo, showing strong correlation with SUVmax-values (ρs 0.728 and 0.763; p < 0.001, respectively). Our findings show a direct relation between SUVmax-values on PSMA PET/CT and numerical signal from the gamma probe, indicating SUVmax can be used to select patients for PSMA-RGS. [ABSTRACT FROM AUTHOR]