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Information on the treatment of metastatic prostate cancer with 177LU – PSMA
PSMA Therapy - Answers to the most important questions:
- General information about PSMA Therapy
- Concept
- Side Effects and Complications
PSMA Therapy General
In Austria, the PSMA RLT (Radio - Ligand - Therapy) has been used individually for about 9 years.
Only prostate cancer patients in whom the tumor disease progresses despite the use of all conventional therapies will be treated.
However, PSMA therapy – even when used in late stages – can be life-prolonging and also significantly improve the quality of life.
Numerous patients have shown excellent results due to good to very good tolerability and a clear response to therapy.
Various clinical studies have also shown that tumor growth can be limited or even significantly reduced in size. In addition, therapy can reduce pain and significantly improve quality of life.
The effectiveness of Lutetium PSMA therapies in earlier stages of the disease – e.g. as first line therapy – is currently the subject of clinical research.
In case of exclusively skeletal metastases, nuclear medicine therapy with 223RA (radium) dichloride (XOFIGO) is also possible.
Fluoride PETCT with generalised bone metastasis in prostate carcinoma
(PSA tumor marker 1523 ng/ml).
PSMA Concept
Therapy requirements: Tumors with sufficient PSMA expression on the cell surface!
Prostate cancer cells usually have - in high density - the so - called Prostate – Specific –Membrane – Antigen (PSMA) on the cell surface. Thus, PSMA is so to say a magnetic docking site for certain peptides, which are radioactively labelled with a therapeutically effective beta emitter (177LU).
With the help of 177LU PSMA therapy, the surface feature of the cancer cells is detected and the radioactively labelled molecule (177 Lutetium PSMA) is bound to it.
The cells are thus visualised, specifically irradiated and destroyed. Compared to radiotherapy (which works from the outside), 177LU PSMA RLT generally delivers a higher and therefore more effective dose of radiation directly to the tumor cells.
The way it works
After injection, 177LU PSMA moves with the blood directly to the tumor tissue (e.g. metastases), binds to specific receptors on these tumor cells and leads to targeted irradiation of the malignant cells.
The tumor cells are prevented from growing by the radioactive radiation, damaged and finally destroyed. Healthy tissue, on the other hand, is largely spared.
The range of the radioactive radiation into the surrounding tissue is only approx. 1 - 2 millimetres.
Minor side effects and complications are more common, but serious, acute complications are generally rare (for details, see Side Effects and Complications).
Tests before Beginning
The most important finding is PET – CT imaging
The main requirement for an efficient therapy is a current PSMA PETCT, which shows the relevant PSMA characteristics of the tumor tissue.
Current preliminary results (CD, DVD, USB and written report) must not be than 6 weeks.
PSMA PETCT with generalized lymph node and bone metastases in prostate cancer (PSA tumor marker massively increased at 2546 ng/ml).
Further tests required
After an interdisciplinary tumor board decision has been made, the essential issues are the availability of current laboratory tests (blood count and PSA tumor marker) and sufficient kidney and bone marrow function.
In some cases, additional imaging (kidney scintigraphy and /or salivary gland scintigraphy) may also be needed.
Therapy Procedure
The OUTPATIENT 177LU PSMA therapy at the Theranosticum Vienna at the Döbling Private Clinic is administered intravenously in the arm and lasts approximately 15 – 20 minutes .
Approximately 30 minutes before PSMA therapy, an additional anti - emetic infusion is administered for better tolerability.
During and after therapy, vital functions (blood pressure, pulse) are optionally checked.
In order to keep the kidney load and the radiation exposure to healthy tissue as low as possible, sufficient fluid intake (approx. 2.0 - 2.5 liters per day) should be ensured both on the day of therapy and in the following days.
Due to legal radiation protection requirements, a standardized measurement of the radiation emitted by the patient is carried out before discharge.
AFTER THERAPY
Immediately after the therapy, the patient receives an information sheet containing the relevant behavioral recommendations and the most important radiation protection instructions.
Due to radioactivity, contact with other people – especially pregnant women and small children – must be reduced during the first days.
For more precise calculation of the individual tumor dose as well as the exposure on healthy tissue (so-called dosimetry), nuclear medicine whole - body and/or SPECT – CT images may be necessary in the following days (i.e. up to the 4th post - treatment day) .
Follow - up Settings
After therapy, laboratory tests (including blood count, kidney and liver parameters) are necessary, initially every 2 weeks and then every 4 weeks. These can be carried out by urologists, oncologists or family doctors.
Just in time communication and feedback of these results is essential for planning further therapy cycles !
Please inform us immediately if any relevant complaints or symptoms occur after therapy.
Once again, the most important finding is PETCT imaging
To monitor our therapy success, 68GA PSMA PETCT imaging should be performed approximately 4 weeks after the 3rd therapy cycle. Depending on this, further therapy cycles can be planned and carried out if the the blood count and kidney function as well as any side effects reports allow this.
PSMA PETCT (LEFT)
After just 3 treatment cycles with 177 Lutetium PSMA, almost complete remission of metastases (PSA drop to 6.0 ng/ml).
PSMA PETCT (RIGHT)
Patient with numerous lymph nodes and bone metastases before starting 177 Lutetium PSMA therapy (PSA baseline 38 ng/ml).
Side Effects and Complications
The therapy is generally very well tolerated. You are welcome to arrange an additional outpatient appointment for detailed information and consultation.
General Information
Despite extraordinary diligence, side effects and complications may occur with 117LU PSMA RLT, as with any therapy, but these must be assessed on an individual basis.
Serious and/or acute complications are not to be expected.
Since LONG - TERM EXPERIENCE IS LACKING, previously unknown side effects may also occur.
An effective protection of the salivary glands with medication is not yet available.
The following side effects and complications are currently known
THERAPY - RELATED SIDE EFFECTS - General
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tiredness or fatigue (more common);
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discomfort and nausea (rare);
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increased hair loss or changes in taste (rare);
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electrolyte (blood salt) shifts (rare) | e.g. high potassium concentration (hyperkalemia);
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allergic reactions (rare);
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long - term effects or harmful long - term effects have not yet occurred/are not known.
THERAPY - RELATED SIDE EFFECTS - after multiple therapies
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changes in blood count: decrease in erythrocytes (red blood cells), leukocytes (white blood cells), thrombocytes (platelets);
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restrictions in kidney function (rare) | permanent restrictions in single cases;
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reduction in tear and saliva production (rare) | dry mouth due to radiogenic sialadenitis;
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in single cases, life - threatening impairment of bone marrow function with the need for a blood transfusion may occur after repeated therapies.
Therapy NOT RECOMMENDED for the following diseases
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severe renal insufficiency;
-
severe bone marrow failure;
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rapidly progressing secondary malignancies;
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myocardial infarction within the last 6 weeks;
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acute febrile infections;
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compression (entrapment) of the spinal cord and/or nerves (tumor - related);
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lack of patient compliance (need for care, stoma care, dementia etc).