Head- to Head Comparison of [68Ga]Ga-PSMA-11 With [18F]PSMA-1007 PET/CT in Staging Prostate Cancer Using Histopathology and Immunohistochemical Analysis as Reference-Standard

PSMA (Prostate Specific Membrane Antigen) is overexpressed in prostate cancer cells.

The 68Ga-PSMA PET / CT test, using small molecules that bind to the PSMA protein and undergo intercellularization, is a test that has been shown to be more sensitive and specific than other conventional and molecular imaging modalities (CT, MRI, bone mapping, Disease in prostate cancer patients and its consequences often change therapeutic decisions in patients. In light of this, the examination of the health basket of the State of Israel was introduced to the staging of patients at moderate or high risk, as well as to the extent of the disease in patients with biochemical failure.

However, testing with 68Ga-PSMA has several limitations, resulting from the use of 68 Ga, which can be overcome by switching to fluorine-18 (18F) -based materials:

A. The generation capacity of the generator is low and therefore limits the number of tests that can be performed at a given time. In contrast, 18F is produced in cyclotron.

B. 68 Ga has a short half-life of 68 minutes, which is a logical consequence of its availability to remote medical centers from the place of production, the time of the test and the patient's comfort, and the possibility of subsequent mappings. The half-life of 18F is 110 minutes.

third. 18F has less energy than 68Ga (0.65 MEV vs. 1.9) and, as a result, a better maximum resolution that would potentially enable the demonstration of smaller lymph nodes involved in the disease.

Among the fluorine-18 (18F) materials selected for clinical application is 18F-PSMA-1007, both because the uptake is higher in the tumor than in the background, and because its removal is mainly the pathobiliary and only a small fraction of the material is released in the urine. This is another advantage of 18F-PSMA-1007 over 68Ga-PSMA, potentially enabling a better demonstration of disease sites in the pelvis, without significant absorption of the bladder material.

To date, accumulated promising experience, in Germany, in imaging with 18F-PSMA-1007. In one published case, 17 degenerative disease sites were detected in one patient with biochemical failure 9 years after undergoing radical prostatectomy, which was not demonstrated by other imaging modalities, including CT, MRI and bone mapping