Imaging with Ga-68 PSMA – Treatment of Prostate Cancer

Ga-68 PSMA and Prostate Cancer

There have been new developments in the diagnosis and treatment of Prostate Cancer, in recent years. The name of this important development is the PET/CT procedure which is performed with Ga-68 PSMA.

Prostate cancer is the most common and fatal cancer type in men older than 50 years of age, after lung cancer.

PSMA, meaning Prostate Specific Membrane Antigen, is a molecule which has the trait of attaching to the receptors, on the surface of 95% of the prostate tumor cells. When we connect this molecule to a radioactive material, named Ga-68, it becomes a radiopharmaceutical, extremely suitable for imaging. PSMA, marked with Ga-68, allows the detection of recurrences, even at very low levels of PSA. We successfully use Ga-68 PSA in diagnosis, staging, treatment planning and evaluation of response to therapy for prostate cancer.

Ga-68-Dotatate and Neuroendocrine Tumors

Neuroendocrine tumors is a disease group, which is rarely seen and can be originated from many organs and whose signs can be confused with other diseases; for this reason, it is a disease group which is very difficult to diagnose.

The sensitivity of the classical imaging methods like ultrasound, tomography and MRI is low especially in the diagnosis of small-sized neuroendocrine tumors. Neuroendocrine tumors are one of the ideal tumor types for molecular imaging. The existence of peptides which can attach to the somatostatin receptors, known to be on the surfaces of neuroendocrine tumors, provides an opportunity for imaging these tumors.

On PET/CT imaging, made with Ga-68 DOTA-TATE, it was determined that 29% of patients’ stages changed and changes were made in 75% patients’ treatment plans. The combination of the peptides, known to attach to the somatostatin receptors, located on the neuroendocrine tumor cells, with a radioactive component allows them to be visualized. DOTA-TATE, marked with Ga-68, is one of the ideal agents, developed for this purpose. Especially in the treatment methods, performed with theranostic agents, the imaging of somatostatin receptors’ existence with Ga-68 shows that this tumor type is also convenient for Rutesium-177 therapy, and this means the beginning of a new treatment method.