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What Is Psma In Prostate Cancer

What Is Prostate Cancer

PSMA-Targeted Therapy in Prostate Cancer

The disease occurs most commonly in African-American men. In addition to age and race, your risk may increase if your father or brother had the disease.

The incidence of prostate cancer increases with age: the older you are, the greater your chance of developing it. Rare in men younger than 40, the chance of having prostate cancer rises rapidly after age 50. About 6 in 10–or 60%–of cases of prostate cancer are found in men older than 65.

Targeting Psma: Not Just For Imaging

Like a number of other radiopharmaceuticals, 177Lu-PSMA-617 has two components: a drug that delivers the therapy to cancer cells and a radioactive particle. In the case of 177Lu-PSMA-617, the delivery vehicle is PSMA-617, a drug that latches onto a protein called PSMA that is often found at high levels on the surface of prostate cancer cells. The radioactive component is lutetium-177, which is being tested as a part of multiple radiopharmaceutical drugs.

As Dr. Morris explained, PSMA-617 is extremely adept at finding and locking on to the PSMA protein on cells. Once it binds to PSMA on a cancer cell, the whole molecule is internalized by the cell and the cell is exposed to a lethal dose of radiation from lutetium-177, he said.

The PSMA protein is also at the heart of a new type of imaging procedure called PSMA PET. This form of PET imaging is just starting to be used in men with prostate cancer to determine whether their cancer has spread, or metastasized, beyond the prostate. In the last several months, FDA has approved two such drugs, known as radiotracers, for PSMA PET imaging.

What About The Cancer Cells That Dont Make Psma

Pomper is developing new molecules and therapies to target PSMA-invisible forms of prostate cancer. We are working on agents that work through different mechanisms and can complement the PSMA-targeted agents, he says. I believe that combining theranostics with immunotherapy, PARP inhibitors and other emerging agents in addition to further optimization of dosage, dose rate and type of isotope of the PSMA-targeting agents will be able to stave off progression of the disease for years, and that eventually, these patients will not die of their prostate cancer.

There are even wider implications, too: It took a long time, but now were seeing many exciting offshoots of our work in other forms of cancer, as well. Some pretty amazing things are happening.

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What Are The Benefits Of Psma Pet Treatment At Ucsf

  • FDA approved imaging technique for prostate cancer.
  • The PSMA PET scan can identifiy cancer that is often missed by current standard-of-care imaging techniques.
  • The PSMA tracer can also be used in conjunction with CT or MRI scans.
  • UCSF is only one of two medical centers in the U.S. that offers the FDA approved PSMA PET.
  • PSMA PET is more effective and precise for localizing mestatic prostate cancer.
  • UCSF researchers, along with colleagues at UCLA, studied PSMA PET for several years to better precisely locate prostate cancer.
  • PSMA PET works using a radioactive tracer, called 68Ga-PSMA-11, which is manufactured on site at UCSF.

What Is Psma Pet Scan

SIU 2019: PSMA in Prostate Cancer â Diagnostic to Theranostics

The conventional imaging methods typically used for prostate cancer patents, including CT, MRI, and bone scan, have limitations when it comes to disease detection, according to Steve Huang, MD, Nuclear Medicine Department, Cleveland Clinic.

Compared with other imaging options, PSMA PET scan has greater sensitivity and can detect metastases sooner, allowing clinicians to better serve patients and make treatment decisions earlier, he says. PSMA PET scan makes it possible to see a smaller volume of cells, which allows oncologists to localize the disease and determine the best approach to treatment.

PSMA, or prostate-specific membrane antigen, is a protein on the surface of many prostate cells and it has been shown that radiotracers tagged to PSMA can identify early, low-volume sites of lymph node or distant metastases of prostate cancer, explains Dr. Tendulkar.

The first PSMA-targeted PET imaging drug for prostate cancerGallium 68 PSMA-11 was approved by the FDA in 2020 for patients with suspected prostate cancer recurrence and metastasis. This approval was based on phase III clinical trials that demonstrated a significant increase in accuracy for the detection of prostate cancer compared with standard imaging modalities. In 2021, a second FDA approval followed for Pylarify for the same indication.

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Two Agents Approved For Psma

On May 26, FDA approved piflufolastat F 18 for use in a type of imaging procedure called PSMA PET in people with prostate cancer. The approval covers the use of piflufolastat F 18 in patients suspected of having metastatic prostate cancer or recurrent prostate cancer . Last year, the agency approved another imaging agent for PSMA PET, Ga 68 PSMA-11, for the same uses, but its use is largely limited to the two institutions where it is made.

In a statement, Lantheus, which manufactures piflufolastat F 18, said the imaging agent will be immediately available in parts of the mid-Atlantic and southern regions with broad availability across the U.S. anticipated by year end.

PSMA is often overproduced by prostate cancer cells but is generally not produced by most normal cells, making it an excellent target for both PET imaging and targeted systemic radiation therapy like 177Lu-PSMA-617, Dr. Morris said.

Early Detection Is Key

When caught early and confined to the gland, prostate cancer is highly treatable. Yet, there are aggressive forms of the disease, which is why you and your doctor must carefully weigh the benefits of screening.

The Prostate Cancer Foundation urges men to begin annual screening for prostate cancer at age 50, providing they have no prostate-related symptoms or risk factors. If you are African American, then you should begin screening at age 45. If you have a family history of prostate cancer, then you should begin at age 40. If you are 55 to 69 but have no symptoms, then speak with your doctor.

Contact the Department of Molecular Imaging and Therapeutics to learn more about PSMA PET imaging. Quality of life for prostate cancer patients has definitely improved, Dr. Osborne says. Theres no question they live longer and better with this technology.

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Why Should I Choose Uchicago Medicine For Psma Pet Imaging

Our physicians are highly knowledgeable in PSMA PET technology and interpreting the scans.

  • UChicago Medicine was the only institution in Chicago to participate in both the CONDOR and OSPREY clinical trials required for the FDA approval of Pylarify. Our urologists, medical oncologists, radiologists, nuclear medicine physicians, and radiation oncologists collaborate closely to provide therapies based on the entirety of a patients diagnostic information.

Learn more from our prostate cancer experts about how PSMA PET improves prostate cancer care.

Has The Radiotracer Used In Psma Pet Scans Been Approved By The Fda

PSMA PET Scan Used For Prostate Cancer Memorial Cancer Institute

The radiotracer piflufolastat, also known as Pylarify, is safe and FDA-approved. Side effects are rare and temporary and may include headache and a change in taste. Piflufolastat is a radionuclide dye, so it contains a small amount of radiation. The amount is similar to the exposure you receive during a CT scan and the tracers radioactive element is entirely gone from your body within a few days.

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Treating Pca With A Psma

Targeted antibodies are a class of cancer immunotherapy treatment that send signals to the immune system to kill cancer cells. Antibodies are naturally produced proteins that target and bind to antigens on the cell surface.

There are now several types of targeted antibodies being researched for cancer treatment, including

  • Monocolonal antibodies , which target tumor cells rather than immune cells
  • Antibody-drug conjugates , which combines targeted antibodies with anti-cancer drugs
  • Bispecific antibodies, which can bind to two different targets

Researchers have developed several antibodies that are targeted at PSMA to eliminate prostate cancer cells. The first anti-PSMA antibody was the mAb 7E11, which recognized and bound a PSMA intracellular or cytoplasmic epitope. Newer antibodies have been developed to bind at different locations, such as the extracellular portion of PSMA. Additionally, recent PSMA antibodies are either fully immune or humanized, as opposed to murine antibodies.

Psma And Recurring Prostate Cancer

Reviewed by Michael Smith on March 29, 2021

American Cancer Society: Prostate Cancer Risk Factors.< br> CDC: What Is Screening for Prostate Cancer?< br> National Cancer Institute: PSMA PET-CT Accurately Detects Prostate Cancer Spread, Trial Shows.< br> Nuclear Medicine Communications: Normal distribution pattern and physiological variants of 68Ga-PSMA-11 PET/CT imaging.”< br> < i> RadioGraphics< /i> : Revisiting Prostate Cancer Recurrence with PSMA PET: Atlas of Typical and Atypical Patterns of Spread.< br> < i> The Lancet< /i> : Prostate-specific membrane antigen PET-CT in patients with high-risk prostate cancer before curative-intent surgery or radiotherapy : a prospective, randomised, multicentre study.< br> Memorial Sloan Kettering Cancer Center: PSMA: A New Target for Prostate Cancer Treatment.

If youve already been diagnosed with prostate cancer, your doctor may test for a prostate-specific membrane antigen, or PSMA. Heres how it works.

Next Up

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Is Psa The Same As Psma

The PSA test is different from the PSMA PET scan.

The PSA test is a blood test that measures the level of PSA in your blood. PSA is a protein produced by cells in your prostate gland. High levels of PSA are often a sign of prostate cancer.

The PSMA PET scan is used after PSA testing if your doctor isnt sure if or where prostate cancer has spread. It can more accurately pinpoint where prostate cancer cells are located throughout the body.

Your doctor may order a PSA blood test to:

  • screen for prostate cancer if you dont have symptoms of the disease
  • determine whether further tests are necessary to diagnose prostate cancer if you do have symptoms of the disease
  • check for signs that prostate cancer has come back if youve received successful treatment for the disease

PSA blood test results are not enough to diagnose prostate cancer or learn whether it has spread or returned. If you have high levels of PSA, your doctor will order other follow-up tests to develop an accurate diagnosis.

Your doctor will only order a PSMA PET scan if they think you may have prostate cancer that has spread beyond the prostate gland.

What Is A Psma Scan

Updated Trial for PSMA

PSMA stands for prostate specific membrane antigen, which is a complex protein found in the cell walls of many types of cell, but greatly increased in prostate cancer. Radio-tracers have been developed to attach to the antigen and thus show up abnormal cells, usually related to prostate cancer. A nuclear scan can detect the radiotracers and show their location on a CT scan done simultaneously. At Garran Medical Imaging we do a Technetium scan. We have developed a much higher resolution scan adapting the latest reconstruction techniques and utilising specialised windowing. Our results are comparable with Gallium PET scans.

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Greater Accuracy And Changing Treatment

Approximately 300 men were enrolled in the Australian trial, all with newly diagnosed localized prostate cancer , and all were considered to have high-risk disease. For all men in the trial, the planned treatment was either surgery or radiation therapy to the prostate only.

Half the men were randomly assigned to initially undergo a CT and bone scan, and the other half to PSMA PET-CT.

Based on the imaging, PSMA PET-CT was 27% more accurate than the standard approach at detecting any metastases . Accuracy was determined by combining the scans sensitivity and specificity, measures that show a tests ability to correctly identify when disease is present and not present.

PSMA PET-CT was more accurate for both metastases found in lymph nodes in the pelvis and in more distant parts of the body, including bone. Radiation exposure was also substantially lower with PSMA PET-CT than with the conventional approach.

The trial investigators also tracked how imaging results influenced clinicians treatment choices. Based on imaging findings, the initial treatment plan was changed for 15% of men who underwent conventional imaging compared with 28% of men who underwent PSMA PET-CT.

Another key finding, Dr. Hofman noted, was that PSMA PET-CT was much less likely to produce inconclusive, or equivocal, results .

Thats important, he continued, because if you have a scan with equivocal findings, it often leads to more scans or biopsies or other tests.

At What Age Does Medicare Stop Paying For Psa Test

Medicare coverage Medicare covers PSA blood test and a DRE once a year for all men with Medicare age 50 and over. There is no co-insurance and no Part B deductible for the PSA test. For other services , the beneficiary would pay 20% of the Medicare-approved amount after the yearly Part B deductible.

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What Happens During A Psma Pet Scan

Its simple, and you dont have to prepare beforehand for the procedure:

  • Once you arrive at the clinic, youll change into a hospital gown and receive an intravenous injection in your arm that contains the radiotracer. Youll wait roughly one hour so that its absorbed throughout your body.
  • Youll be brought to our PET imaging machine, where youll lie still for roughly 20 minutes as the machine scans your body. Once this is complete, you may leave.
  • The scans are sent to the nuclear medicine physician to evaluate. That report and the PET images are then reviewed by your cancer doctor.

Axumin Pet Scanning For Prostate Cancer Care

PSMA PET and Functional Imaging – 2021 Prostate Cancer Patient Conference

Axumin is an FDA-approved agent used for Axumin PET scans for prostate cancer. Axumin is often able to image and restage recurrent prostate cancer better than any other conventional imaging techniques. Biochemical recurrence, typically suspected with rising PSA levels, is the standard in monitoring patients for suspected recurrent prostate cancer. Traditional imaging techniques are often limited in that they may detect a small lymph node or suspicious finding, but cannot further functionally characterize the molecular activity to determine the level of suspicion. The introduction of Axumin PET scanning has been a breakthrough, allowing physicians the ability to accurately locate and restage prostate cancer with precision, especially in the setting of suspiciously rising PSA levels.

How Do Axumin PET Scans Work?

An Axumin PET uses a radioactive tracer, given as an injection, that is linked to an amino acid which is absorbed by prostate cancer at a much more rapid rate than normal cells. The rapid uptake of Axumin by prostate cancer cells is then imaged by the advanced technology within the PET scan equipment. The PET scan images are then reviewed in order to determine if there has been any spread to other areas in the body.

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Who Can Benefit From This New Diagnosis Method

Patients who are first diagnosed with high-risk prostate cancer can undergo a PSMA PET scan in order to have a clearer view of the tumor expansion. Also, patients who have had prostate cancer treatment and have rising PSA can benefit from the advantages of the new PSMA PET to localize the new tumor. In both cases, imaging techniques are extremely important. Why? First of all, doctors can know that a patient is having cancer that is growing by means of the PSA test. That is a blood test that checks for Prostate Specific Antigens in the blood. If, after treatment, the PSA is rising, doctors know that the patient is dealing with recurrent cancer. The problem is that they cannot clearly identify where it is located. Not knowing where the cancer is, doctors cannot treat it. Is surgery an option or external beam radiation? Exact localization by means of PSMA PET empowers doctors with the ability to design a specific care plan.

Studies are being done in order to determine how this new imaging technique will reshape the manner in which prostate cancer treatments are being prescribed and, furthermore, patients survival rates.

How Is Psma Pet Imaging Different From Current Prostate Cancer Imaging

  • Current standard technique called fluciclovine PET, involves physicians injecting patients with a synthetic radioactive amino acid.
  • PSMA PET imaging is a FDA approved scan with more precise detection of prostate cancer for better treatment planning and targeted care.
  • More effective in pinpointing and eliminating tumors not only in the prostate but also throughout the pelvis and the body in cases where the tumors have migrated.
  • Imaging with PSMA PET was able to detect significantly more prostate lesions than fluciclovine PET in men who had undergone a radical prostatectomy but had experienced a recurrence of their cancer.

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The Future Of Psma Pet

This is a solid study and reflects the real-world experience with PSMA PET-CT in other countries, Dr. Pomper said. Because there are several PSMA-targeted tracers, a next step will be to have them approved for use in the United States outside of clinical trials, he added.

He predicted that, eventually, the different PSMA tracers will be tested head to head.

The Australian trial adds to a growing body of research on improving the detection of metastatic tumors in men with prostate cancer. One imaging agent, fluciclovine F18 which targets prostate cancer cells in a different way than PSMA-targeted tracersis already approved in the United States for use in men with previously treated prostate cancer that appears to be progressing .

PSMA PET-CT is also being studied in this group of men, Dr. Shankar said. One small clinical trial that directly compared PSMA PET-CT with fluciclovine F18 PET-CT showed that the PSMA-targeted scan found more metastatic tumors, regardless of their location. NCI is funding a similar but larger clinical trial.

Dr. Pomper noted that PSMA also is found at relatively high levels in the vasculature of a number of other cancersincluding kidney, thyroid, and breastso hes hopeful that PSMA PET-CT might be useful beyond prostate cancer.

Urologists and radiation oncologists in many places are already ordering this scan as the standard of care, he said.


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