Brachytherapy – internal radiotherapy

Brachytherapy is an established, long-standing form of treatment. It is internally administered radiotherapy. We distinguish between two types of brachytherapy: high-dose rate (HDR) brachytherapy and low-dose rate (LDR) brachytherapy, also known as permanent seed implantation. The prostate is measured under anaesthetic using ultrasound and a computer program calculates the optimal distribution of seeds and distribution of radiation intensity through temporary implantation in the prostate. The needles are inserted into the organ in line with the radiation plan and deposited at precisely calculated locations, with the radiation directed at the calculated areas within the prostate.

Both treatments damage the tumour tissue, destroying the tumour cells in a way that offers excellent protection for the healthy prostate tissue. It is important to note that, following this type of contact therapy, subsequent surgical treatment of the prostate is possible but is more difficult.

What is the difference between LDR and HDR?

In LDR brachytherapy, the radiation sources called “seeds” are implanted in the prostate and left in place (permanent implantation). Ultrasound is used to measure the prostate under anaesthetic and calculate a programme for optimal distribution of the seeds. Hollow needles are used to place the seeds at precisely the calculated locations. These seeds are positioned so that they emit an equal amount of radiation into the surrounding tissue over the course of a year. However, these small seeds do not need to be removed and can be left in the prostate tissue. LDR brachytherapy is primarily suitable for combating less aggressive tumours identified at an early stage.

By contrast, HDR brachytherapy – i.e. the temporary implantation of a high-dose radiation source – can also be used against more aggressive tumours. In HDR therapy, the significantly higher-dosed radiation sources are removed after a few minutes (temporary implantation). The prostate is also measured under anaesthetic and a programme is calculated for optimal distribution of radiation intensity. The needles are inserted into the organ in line with the radiation plan, with the radiation directed at the calculated locations within the prostate. This procedure is then repeated one week later. A supplementary six-week course of daily percutaneous radiotherapy is then administered on an outpatient basis. Combining brachytherapy with additional external radiation offers a high level of patient safety during treatment.

The prostate is measured using ultrasound and a computer program calculates the optimal distribution of seeds and distribution of radiation intensity through temporary implantation in the prostate.