@article {Jochumsen189, author = {Mads Jochumsen and Lars Tolbod and Bodil Pedersen and Jorgen Frokiaer and Michael Borre and Kirsten Bouchelouche and Jens Sorensen}, title = {Prostate 82Rb PET tumor blood flow measurement for detection of significant prostate cancer}, volume = {61}, number = {supplement 1}, pages = {189--189}, year = {2020}, publisher = {Society of Nuclear Medicine}, abstract = {189Objectives: Our previous studies suggest that tumor blood flow measured with 82Rb Positron Emission Tomography (PET) has potential as a biomarker of prostate cancer aggressiveness (1,2). The aim of the present study was to evaluate whether 82Rb PET can separate significant from insignificant prostate cancer. Methods: 102 patients suspected of having prostate cancer were included prior to MRI-guided prostate biopsies. 82Rb PET scan of the prostate gland was performed in all patients. Prostate cancer was biopsy-verified and given a Gleason Grade Group (GGG) in 98 lesions from 85 of the patients. Twenty-eight lesions were GGG1, 50 lesions were GGG2, six lesions were GGG3, nine lesions were GGG4 and five lesions were GGG5. Twenty-six lesions from 17 patients were biopsied with benign findings. Tumor delineation was performed at MR scans and subsequently fused with the 82Rb PET scans for measurement of tumor uptake of 82Rb. Results: Tumor 82Rb SUVmax was the best indicator of MRI-guided biopsy Gleason Grade Group with a moderate correlation (rho=0.57, p\<0.0001) compared to ADC-value and tumor volume on MRI. SUVmax was a significant predictor of Gleason Grade Group, even after correction for ADC value and tumor volume (p\<0.0001). Mean 82Rb SUVmax uptake in low-risk prostate cancer of 2.87 with 95\% CI [2.56; 3.17] was significantly lower than in both intermediate-risk 3.74 [3.53; 3.95], and high-risk prostate cancer 4.17 [3.63; 4.71] (p\<0.001). With an AUC of 0.81, 82Rb PET could separate GGG2-5 from GGG1 and benign biopsies with a sensitivity of 0.89 and a specificity of 0.69. And for separating GGG3-5 from GGG1-2 and benign biopsies the AUC was 0.83, with a sensitivity of 0.90 and a specificity of 0.68. Conclusions: Tumor 82Rb uptake is a significant predictor of Gleason Grade Group, independent of MRI-based ADC value and tumor volume. Hence, tumor blood flow may provide additional value in separating significant from insignificant prostate cancer. Financial support: This work was financially supported by The Danish Cancer Society, Health Research Fund of Central Denmark Region, P. Carl Petersens Mindefond, Aage og Johanne Louis-Hansens Fond, Harboefonden, Aase og Ejnar Danielsens Fond, Dagmar Marshalls Fond, Knud og Edith Eriksens Mindefond, Fabrikant Einar Willumsens Mindelegat, Agnes og Poul Friis Fond, T{\o}mmerhandler Vilhelm Bangs Fond.}, issn = {0161-5505}, URL = {https://jnm.snmjournals.org/content/61/supplement_1/189}, eprint = {https://jnm.snmjournals.org/content}, journal = {Journal of Nuclear Medicine} }