RT Journal Article
SR Electronic
T1 Validation of <sup>18</sup>F-rhPSMA-7 and <sup>18</sup>F-rhPSMA-7.3 PET Imaging Results with Histopathology from Salvage Surgery in Patients with Biochemical Recurrence of Prostate Cancer
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 1809
OP 1814
DO 10.2967/jnumed.121.263707
VO 63
IS 12
A1 Kroenke, Markus
A1 Schweiger, Lilit
A1 Horn, Thomas
A1 Haller, Bernhard
A1 Schwamborn, Kristina
A1 Wurzer, Alexander
A1 Maurer, Tobias
A1 Wester, Hans-Jürgen
A1 Eiber, Matthias
A1 Rauscher, Isabel
YR 2022
UL http://jnm.snmjournals.org/content/63/12/1809.abstract
AB 18F-rhPSMA-7, and its single diastereoisomer form, 18F-rhPSMA-7.3, are prostate-specific membrane antigen (PSMA)–targeting radiopharmaceuticals. Here, we investigated their accuracy for the assessment of lymph node (LN) metastases validated by histopathology. Methods: Data from 58 patients with biochemical recurrence of prostate cancer after radical prostatectomy receiving salvage surgery after PET imaging with 18F-rhPSMA-7 or 18F-rhPSMA-7.3 were retrospectively reviewed. Two nuclear medicine physicians reviewed all PET scans and morphologic imaging in consensus. Readers were masked from the results of histopathology. PET and morphologic imaging were correlated with histopathology from resected LNs. Results: In 75 of 150 resected regions in 54 of 58 patients, tumor lesions were present in histopathology. The template-based specificity of PET (18F-rhPSMA-7 and 18F-rhPSMA-7.3 combined) and morphologic imaging was 93.3% and 100%, respectively. However, 18F-rhPSMA-7 and 18F-rhPSMA-7.3 PET detected metastases in 61 of 75 histopathologically proven metastatic LN fields (81.3%) whereas morphologic imaging was positive in only 9 of 75 (12.0%). The positive predictive value was 92.4% for 18F-rhPSMA-7 and 18F-rhPSMA-7.3 PET and 100% for morphologic imaging. 18F-rhPSMA-7 and 18F-rhPSMA-7.3 PET performance was significantly superior to morphologic imaging (difference in the areas under the receiver-operating-characteristic curves, 0.222; 95% CI, 0.147–0.298; P &lt; 0.001). The mean size of PET-positive and histologically confirmed LN metastases was 6.3 ± 3.1 mm (range, 2–15 mm) compared with a mean size of 9.8 ± 2.5 mm (range, 7–15 mm) on morphologic imaging. Conclusion: 18F-rhPSMA-7 and 18F-rhPSMA-7.3 PET offer a high positive predictive value comparable to that reported for 68Ga-PSMA-11 and represent a valuable tool for guiding salvage lymphadenectomy.