Prostate cancer is a common type of cancer among men today.

Gallium 68 PSMA ( Prostate- Specific Membrane Antigen) is a smart molecule used in prostate cancer imaging and treatment. It is labeled with the radioactive element gallium 68 and administered intravenously to the patient, followed by imaging using a PET/CT device.

Ga-68-PSMA PET/CT is used in imaging high-risk prostate cancer, determining areas of spread throughout the body, detecting recurrent disease in patients who have had prostate surgery or have high PSA levels after radiotherapy (biochemical recurrence), planning Lu-177-PSMA (Lutetium) treatment, planning radiotherapy, and evaluating treatment responses.

More successful results are obtained in detecting recurrence and spread after treatment compared to other imaging methods such as ultrasonography, CT and MRI.

What are the distinguishing features/advantages of Gallium 68 PSMA?

Staging:

It is performed in the early stages of the disease, immediately after diagnosis, to assess the extent of the disease. It is not mandatory for all prostate cancer cases. It is generally preferred in cases with a moderate to high risk of metastasis, combined with pathological findings (tumor size and extent, Gleason score), laboratory data (PSA levels), and other clinical assessments. Proper patient selection can significantly impact the stage of the disease and, consequently, the treatment approach. It can guide the application of additional treatments by detecting the presence of disease in nearby tissues, such as lymph nodes and bone, where prostate cancer tends to spread. In some cases, it can guide the use of other treatments in combination instead of or in addition to surgery.

Recurrence detection:

It is used to identify recurrence in patients who have achieved a complete response after treatment, if PSA levels rise or if other imaging tests reveal suspicious findings. It can detect recurrence more accurately than other imaging methods. It can detect recurrence with greater sensitivity than a prostate-specific antigen (PSA) blood test and deliver results with over 90% accuracy.

Radiation and radioactive treatment plan:

It provides guidance in radiation therapy planning, identifying high-dose biological targets and sparing normal tissues. It helps predict treatment efficacy and appropriate patient selection by demonstrating disease activity prior to planning radioactive therapies, such as targeted Radium-223, Lutetium-177 PSMA, and Actinium PSMA.

Biopsy guidance:

It can indicate the targeted biopsy area in patients with negative biopsy results but still suspected of cancer.

Thanks to these properties, Gallium 68 PSMA plays an important role in prostate cancer management and provides guidance in treatment planning.

What is the Gallium 68 PSMA examination process?

• Fasting and planning: There is no need to be hungry for the test. The test should be planned the day before. An appointment must be made. It may be helpful to bring other test results, if available.
• Medication administration: The medication is administered intravenously. There is a 45-60 minute waiting period after the medication is administered.
• Imaging process: After medication administration, approximately 20 minutes are required for imaging on the PET/CT machine. It is important to remain still during this time.
• Time spent in the clinic: In total, it may take 2-3 hours for the examination in the Nuclear Medicine clinic.
• Water Consumption: It is recommended to drink plenty of water before and after the examination.
• Caution after radiation: After the examination, it is important to stay away from pregnant women and children, as there will still be radiation in the body for a while (6-12 hours).

This process includes steps such as preparation for the test, medication administration, imaging, and post-test considerations. It is important to follow the instructions of your healthcare professional throughout the test.

What are the applications of Gallium 68 PSMA?

Gallium 68 PSMA finds application in the following areas:

• For staging purposes: Used to assess the stage of disease in selected cancer patients.
• Evaluation of systemic treatment response in prostate cancer: It plays an important role in evaluating the response to systemic treatment, especially in prostate cancer.
• Recurrence detection: It is used to detect recurrence in patients after treatment and to determine how widespread the recurrence is.
• Radiation therapy planning: It helps to determine the spread and interaction areas of the disease during the planning phase of radiation therapy.
• Determining compliance with molecular radioactive therapies: Used to determine the feasibility of molecular radioactive therapies (such as Lutetium 177 PSMA) and the patient's potential to respond to these treatments.

These diverse applications of gallium 68 PSMA play a significant role in the management of prostate cancer and other select cancers. This method is used to provide more detailed and precise information about disease status.

Are there any side effects of Gallium 68 PSMA?

Side effects of gallium 68 PSMA are extremely rare or almost nonexistent. This substance is not a drug, and the radiation levels typically given off by radioactive gallium 68 are quite low. There are no known or proven radiation-related side effects at the doses used for the test.

However, due to the radiation involved, this test should only be performed on appropriate and necessary patients. As with any medical procedure, the recommendations and instructions of healthcare professionals should be followed before and after the test. Appropriate precautions should be taken, especially for pregnant or breastfeeding women and young children. In general, the side effects of Gallium 68 PSMA are minimal or nonexistent, but they should be carefully evaluated before use.