What Type of Patient Can Benefit From PRRT ?

For the past two decades, radiolabeled somatostatin analogs have been employed to treat well-differentiated neuroendocrine tumors (NETs) that express the somatostatin receptor (SSTR) type 2. The most often used peptides are 177Lutetium (177Lu)-DOTATATE and 90Yttrium (90Y)-DOTATOC, which release a beta or gamma-emitting radionuclides.

In 2018, the FDA approved 177Lu-DOTATATE to treat gastroenteropancreatic neuroendocrine tumors with PRRT Therapy. Other clinical trials are currently being tested in radiopharmaceuticals, isotopes, peptides, and combinations with other therapies.

What is PRRT?

The term PRRT stands for Peptide Receptor Radionuclide Therapy. It’s also known as radioisotope therapy or molecular therapy. PRRT has been discovered to be particularly effective in the treatment of neuroendocrine tumors, or NETs, as some of you may know them.

When a PRRT is performed, the following processes are carefully carried out and reviewed by certified Nuclear Medicine Physicians.

• A Radio Peptide is made by combining a cell-targeting protein or peptide with radioactive material. Somatostatin, a naturally occurring hormone in the human body, is identical to this cell targeting peptide.
• This radiopeptide, which is made up of a peptide plus radioactive material, is injected into the patient’s bloodstream.
• This radio peptide has the ability to connect to neuroendocrine tumor cells in a patient’s body. This is accomplished because of cell surface protein found in tumor cells called Somatostatin Receptors, which have the ability to bind to Somatostatin.
• This radio peptide has the ability to deliver a high dose of radiation directly to cancer cells, causing structural alterations in the cancer cells and eventually killing them.

Who may benefit from PRRT?

Patients with somatostatin receptor-positive gastroenteropancreatic NETs (common neuroendocrine tumors of the stomach, rectum, pancreas, and small and large intestine) should receive PRRT therapy in India. Because NETs are usually not discovered until they have progressed, surgery may not be indicated because it may not remove all of the tumors. Hormone therapy is used to decrease symptoms and tumor growth in gastroenteropancreatic NETs that cannot be removed surgically.

However, if tumors persist after treatment, the PRRT medicine 177-Lu-Dotatate, which mixes the produced form of somatostatin with radioactive material, may be used as a second-line treatment. In clinical trials, patients who were administered 177-Lu-Dotatate for cancers that were progressing despite first-line treatments lived nearly three years longer without cancer progression than those who were given hormone therapy.

Because somatostatin receptors are not present in all gastroenteropancreatic NETs, PRRT is not an option for all NET patients.

How is PRRT performed?

A set of four PRRT treatments in India with 177Lu-DOTATATE spaced about 8 weeks apart is the most common procedure. Protocols may differ depending on the location. This treatment may be performed as an outpatient procedure or may require a few days in the hospital. In the United States, this treatment is usually done as a half-or full-day outpatient operation, with only a few patients staying overnight at the hospital. 

Pre-medications for nausea are given before each PRRT session, followed by an amino acid solution. The amino acid solution is given intravenously to protect the kidneys of the patient from the treatment’s side effects. The radioactive substance is then put into the patient, which takes around 30 minutes, and an additional amino acid solution is administered. The treatment session lasts about four to five hours in total.

Post-treatment 177Lu scans are used before and after therapy to see where the injected radioactive medication has moved in the body, although they are not required by the FDA.

What conditions are treated with PRRT?

PRRT is used to treat NETs, particularly gastro-entero-pancreatic NETs, which are NETs that arise from the stomach, intestine, or pancreas, and are also known as carcinoids and islet cell carcinomas of the pancreas, and are the current FDA-approved indication. For the following patients, PRRT Therapy in India is an option:

• Who have somatostatin receptor imaging (e.g. 68Ga-DOTATATE/NETSPOT or 64Cu Dotatate/Detecnet) positive neuroendocrine tumors that are progressed (metastatic) and/or progressing (e.g. to SSA).
• Who are not surgical candidates?
• Whose symptoms are resistant to other medicinal treatments

Symptom relief, tumor progression slowing, and overall survival are all advantages of PRRT.

More personalized cancer treatment with PRRT Therapy in India and other molecular medicines is possible. Because these radioactive medications are very selective in their capacity to preferentially reach and kill neuroendocrine tumor cells while reducing radiation exposure to healthy tissue, PRRT is referred to as targeted therapy. PRRT is therefore often well accepted.

PRRT is a highly effective therapeutic option for advanced, metastatic, or incurable progressive neuroendocrine tumors. Although PRRT Therapy in India is rarely curative, it has been demonstrated to improve symptoms, decrease tumors, and halt disease progression.

What are the side effects of PRRT?

The PRRT itself is well-tolerated, but the amino acid solution administered for kidney protection might cause nausea and vomiting in certain patients, especially with certain types of amino acid solutions. Anti-nausea medicine or slowing down the amino acid infusion can help with this. Long-term adverse effects include a modest to moderate suppression of blood cell counts in the majority of instances. The emergence of subsequent blood diseases (called myelodysplastic syndrome) or permanent kidney injury are rare delayed adverse effects. The majority of patients tolerate the treatment well.