TY - JOUR T1 - <strong>Al<sup>18</sup>F-PSMA-HBED-CC as a novel tracer for the evaluation of prostate cancer patients with biochemical relapse: Intraindividual comparison with <sup>68</sup>Ga-PSMA-HBED-CC</strong><strong/> JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1268 LP - 1268 VL - 61 IS - supplement 1 AU - Gerardo dos Santos AU - Monica Rodriguez Taroco AU - Javier Giglio AU - Eduardo Savio AU - Omar Alonso Y1 - 2020/05/01 UR - http://jnm.snmjournals.org/content/61/supplement_1/1268.abstract N2 - 1268Objectives: 68Ga-PSMA-HBED-CC (68Ga-PSMA-611) PET/CT represents a clinically relevant and commonly used technique for the evaluation of prostate cancer patients in the setting of secondary staging for biochemical recurrence after definitive therapy. A novel tracer developed in our Centre: [18F]AIF-PSMA-HBED-CC (18F-ALF-PSMA-11), can be produced on a large scale with suitable radiochemical purity for clinical purposes. The aim of this study was to prospectively compare the diagnostic values of 68Ga-PSMA-611 versus 18F-ALF-PSMA-11 in patients with prostate cancer and biochemical relapse after initial treatment. A sample of 37 patients (median age: 67, range: 53-85 years) with biochemical recurrence after primary treatment (median PSA level: 5.0 ng/mL; range: 0.7-10.0 ng/mL) were included between March 2018 and July 2019, of whom 28 (76%) had undergone radical prostatectomy and 9 treated with radiotherapy. Within 1-2 weeks a PET/CT scan was performed with 68Ga-PSMA followed by an Al18F-PSMA scan with an average dose of 2.0 and 4.0 MBq/kg, respectively, with a 64-slice PET/CT with TOF correction. We measured the SUVmax of all abnormal foci as well as the SUVmax ratio (SR) in all coincident lesions, selecting gluteal musculature as background. Histopathology (when available), correlative imaging, and/or clinical follow-up were considered as reference standard, with a follow-up of at least 6 months after PET/CT scanning. 68Ga-PMSA and Al18F-PSMA PET/CT demonstrated abnormal findings in 18 and 17 patients (positivity rate: 49% and 46%), respectively. Abnormal foci (n=76) were seen in the following sites: bone (n=35), lymph nodes (n=33) and prostate gland (n=8). Nine bone lesions were detected only with Al18F-PSMA (25%), while four abnormal lymph nodes (22%) were identified only with 68Ga-PSMA PET/CT. A significant correlation was found between the SUVmax of both radiopharmaceuticals (r=0.72, P=0.02). Furthermore, we found a significantly higher SUVm for 68Ga-PSMA compared to Al18F-PSMA in lymph node and prostate foci: 8.1 (2.77-25.49) versus 7.7 (2.55-24.78) and 17.3 (5.1-47.12) versus 14.5 (4.69-38.63), median (range), for each tracer, respectively (P &lt; 0.001). Al18F-PSMA SUVm was higher in bone foci compared with those from lymph node and prostate (8.6 vs 6.6 respectively, P &lt; 0.001). We found a significantly higher SR for Al18F-PSMA in concordant bone lesions (P=0.001) and for 68Ga-PSMA in lymph-node and prostate concordant lesions (P=0.015 and 0.041, respectively). On a per patient basis, sensitivity, specificity, positive and negative predictive values with their 95% C.I. were 0.63, 0.90, 0.94 and 0.47 for 68Ga-PSMA-11, and 0.50, 0.90, 0.94 and 0.45 for 18F-AlF-PSMA-11, respectively. We conclude that 68Ga-PSMA-11 and Al18F-PSMA have similar and clinically relevant diagnostic values for the detection of prostate cancer lesions in the biochemical recurrence scenario. ER -