What is LDR brachytherapy?
LDR brachytherapy is a targeted form of internal radiotherapy for prostate cancer and an effective, minimally invasive treatment. It has significant quality of life benefits over alternative treatments such as surgery and external radiotherapy. ,,
Patients with suspected prostate cancer are usually referred by their GP to a surgeon. Some will need surgery to remove the prostate and/or external radiotherapy, which may mean taking weeks out of ‘normal life’ and can permanently damage sexual and bladder function.
Many patients are suitable for LDR brachytherapy, a quick treatment with a much lower risk of sexual and bladder problems than other treatment options. However, LDR brachytherapy is frequently overlooked as a treatment, because they are unaware of the option.
About LDR brachytherapy
Low dose-rate brachytherapy (seed implantation) is a kind of internal radiotherapy for prostate cancer. It is targeted only at the site of the tumour so the radiation kills the cancer cells without causing major damage to surrounding healthy cells. Seeds which are tiny capsules, the size of a grain of rice, containing the radiation are passed through fine needles and positioned directly into the prostate gland. It is not major surgery and usually you will only spend 1 day in hospital. Generally LDR brachytherapy has a low complication rate, and most men return to their usual pre-treatment activities within a couple of days.
Prostate brachytherapy is a kind of radiotherapy. It is sometimes referred to as low dose-rate (LDR) brachytherapy, seed implantation.
It is different from External Beam Radiotherapy (EBRT), which uses x-rays beamed into the tumour site from outside the body. In EBRT the x-rays have to pass through other body tissues before reaching the tumour site, which means that the healthy parts of the body around the tumour may also be affected (see Figure 2, below).
LDR brachytherapy is different to external beam radiotherapy because it involves the insertion of tiny radioactive capsules or seeds into the prostate gland itself. Each seed is the size of a grain of rice, and between 80-120 seeds will be used, depending on the size of the prostate and the tumour location. Figure 3 (below) shows the size of the seeds and needles used. Figure 4 shows an illustration of how the needles are guided using a grid for precision and accuracy.
Radiation released from the brachytherapy seeds accurately targets the tumour, destroying the cancer cells. The seeds are positioned close to the tumour and because the radiation doesn't spread more than a few millimetres from each seed there is minimal or limited damage to any other non-cancerous or healthy tissue, such as the urethra (the tube through which urine passes), bladder and rectum. LDR brachytherapy is said to be more 'targeted' than conventional (external) beam radiotherapy, and it has a lower incidence of severe side effects. Figure 5 shows an illustration of the seeds in position.
Unlike other forms of radiotherapy, LDR brachytherapy is a much faster and more convenient procedure. It is often a same-day procedure carried out in the radiotherapy department of the hospital under general anaesthetic, but occasionally may involve an overnight stay. Patients can usually return to levels of pre-treatment activities within a couple of days of having LDR brachytherapy.
LDR brachytherapy procedure
A patient referred for LDR brachytherapy will first attend an appointment with the oncologist for treatment planning. The timing of this varies from hospital to hospital and could be as long as two weeks before the procedure or in some centres, immediately before treatment delivery.
During planning, ultrasound, computerised tomography (CT), computer Axial Tomography (CAT) or magnetic resonance maging (MRI) scanning of the prostate allows the clinicians to map the exact position of the tumour and to plan the appropriate radiation dose.
At the time of the procedure, the patient will have a general or epidural anaesthetic. Tiny radioactive ‘seeds’ about the size of a grain of rice are inserted into the prostate using hollow needles that allow accurate positioning according to the plan. Ultrasound is usually used to guide the needles to deliver the radioactive seeds through the perineum, the area of skin between the scrotum and the anus. After they have delivered the seeds, the needles are then removed.
The LDR brachytherapy procedure usually takes just one hour and after having time to recover from the anaesthetic, most patients return home the same day. The seeds remain in place, emitting very low doses of radiation over a period of months until none remains and they become inactive. This approach destroys the tumour with minimum damage to the surrounding healthy tissue and in a way which is least disruptive to ‘normal’ life.
After treatment, the patient will return periodically for monitoring of the treatment progress and prostate cancer tumour reduction.
Radiotherapy for cancer treatment
Brachytherapy is a type of radiotherapy which is used to treat many different cancers by destroying the cancer cells with radiation. In low dose rate (LDR) brachytherapy, the radioactive seeds remain in place. It is sometimes also called ‘internal radiotherapy’ or ‘permanent seed brachytherapy’. High dose rate (HDR) brachytherapy involves temporary placement of much stronger radioactive sources in the prostate over a series of procedures.
Another commonly used radiotherapy treatment is External Beam Radiotherapy (EBRT), which delivers the radiation from the outside and is therefore less targeted.
Treatments choices for cancer ultimately depend on the type and location of cancer as well as patient preferences. Options are usually discussed with the specialist to which a patient is referred to find the best solution for that individual.
Radiotherapy may be used in combination with other treatments such as hormone therapy and surgery.
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