Gallium-68 PSMA PET/CT
What is Gallium-68 PSMA PET/CT ?
Theranostic is an emerging field in the medical world. It is an approach in which tumor and metastases detected by imaging with a tumor-specific drug and they can be treated with a same specific drug, which is previously known, how far it will go, and how its power will affect the diseased tissue. This approach enables the transition from traditional medicine to contemporary personal medicine practices.
Cancer is caused by uncontrollably growing and proliferating cells. When cancer begins in the prostate gland tissue, it is called prostate cancer. The condition in which prostate cancer cells spread to other parts of the body forming multiple focuses is called metastatic prostate cancer.
Prostate specific membrane antigen or “PSMA” imaging is an innovative theranostic Nuclear Medicine imaging technique performed with a PET / CT device to detect prostate cancer. Ga-68 PSMA PET / CT has been shown to be far superior and sensitive in detecting prostate cancer than conventional imaging methods such as CT or whole body bone scan.
Your referring physician may recommend this test to evaluate the prostate tumor or metastasis more clearly. With this method, primary or recurrent prostate cancer can be accurately located and staged. Thus, it enables targeted therapy.
PSMA is a type of protein found in healthy prostate cell membranes with multiple cellular functions. Cancerous prostate tumors produce extremely high levels of PSMA (usually 1000 times higher than normal prostate cells). If prostate cancer has metastasized to other parts of the body, PSMA can also be seen in these areas. The Ga-68 atom is a radioactive element that we can label to the carrier molecule we call PSMA. When Ga-68 PSMA is administered intravenously, it travels to tumor tissues where PSMA is found and allows us to locate these cancer cells by attaching to the PSMA receptors in the cancerous tissue.
Tumoral tissues of prostate cancer that can be imaged with Ga-68 PSMA PET / CT can be targeted with 177Lu-PSMA. This is a very successful and new theranostic applications.
Is Gallium-68 PSMA PET/CT Safe ?
Ga-68 PSMA is not a contrast agent and no side effects (allergic reactions, skin rash, nausea, vomiting, etc.) are expected during administration. . However, it is necessary to be careful in terms of contrast allergy and other side effects in special cases if intravenous radiologic contrast agents is administering at the same time.
68Ga has a very short half-life such as 68 minutes, and the radiation in the body returns to its natural level at the latest 6 hours after the drug is administered, For this reason, contact with small children and pregnant women should be avoided for the first 6 hours after drug administration.
Radiation exposure due to Ga-68 PSMA PET / CT procedure is approximately 5 mSv. This dose is similar to the dose you would be exposed to with a conventional examination such as X-Ray computed tomography.
Who does Galyum-68 PSMA PET/BT Performed to ?
Scientific data currently support the use of Ga-68 PSMA PET / CT imaging, especially for the detection of cancer foci originating from the prostate. With this method; even small metastases that could not be detected by conventional imaging methods such as CT, MRI and bone scintigraphy, can be detected. Ga-68 PSMA PET / CT is mainly used for the following purposes:
● For the purpose of staging prostate cancer in newly diagnosed high-risk prostate cancer patients with positive prostate biopsy
● For restaging in patients with suspected biochemical recurrence, whose prostate has been surgically removed or has undergone radiotherapy, but increased PSA levels are detected during follow-up indicating that the cancer may recur.
● In order to evaluate the response to systemic therapy in metastatic prostate cancer
Preperation Before Gallium-68 PSMA PET/CT
While an appointment is scheduled, Nuclear Medicine staff will inform you in detail about the procedure and patient preparation. Before the procedure, you will be asked to bring test results and other documents regarding your disease in order to submit them to the Department of Nuclear Medicine, whatever is avalilable:
● Past imaging studies (CT, MRI, Ultrasound, Bone Scintigraphy, F18-FDG PET/CT, Ga68-PSMA PET/CT etc.), films, reports,and CDs,
● Pathology results regarding your disease,
● Details of treatment you have received (date of the last, surgery, chemotherapy, radiotherapy, any medication etc.)
● Up-to-date PSA test results
You do not need to be fasting for Ga-68 PSMA PET / CT. You can have a light breakfast up to about 2 hours before the examination. However, make sure that you do not eat or drink anything other than water for the 2 hours before administration. It will be useful to drink water before and during the procedure.
All metal items / jewelry / prostheses should be removed to avoid image deterioration.
How is Gallium-68 PSMA PET/CT performed ?
Due to the short half-life of Gallium-68, Ga-68 PSMA is prepared by our expert team in the imaging center and the whole process goes through strict quality control.
Small amount of Ga-68 PSMA; approximately 45-60 Min. before the imaging procedure, will be administered through the vascular access placed on your arm or back of the hand. Nothing is felt during this process. Meanwhile, diuretics (diuretics) can also be administered to improve image quality. The diuretic also provides rapid elimination of unbound Ga-68 PSMA from the body.
You should empty your bladder immediately before the PET/CT scan.
During PET / CT imaging (approximately 20-25 min.), You will be asked to lie on a special acquisition bed in a both ends open ring-shaped device, where body images are continuously recorded. The only troublesome part of the process; is that you stay stationary during this time. If you need, you can use the analgesics you brought with you before the imaging.
After the whole body imaging is completed, you can meet your toilet needs while your first images are examined by our specialist Nuclear Medicine Physician. If needed, our experts can take additional images. Additional imaging process takes approximately 10-15 minutes.
The vascular access in your arm will be removed after your imaging is complete and all your images are checked. With the approval of our healthcare staff, you can safely leave the Nuclear Medicine department.
Please note that you should avoid contact with young children and pregnant women for the first 6 hours after drug administration. Your images will be evaluated and reported by our Nuclear Medicine Experts within the specified time.