Prostate brachytherapy

rdf:langString Prostate brachytherapy

rdf:langString Prostate brachytherapy

rdf:langString Figure 1. Single and stranded brachytherapy seeds showing relative sizes of the seeds and needles used for insertion

rdf:langString Brachytherapy is a type of radiotherapy, or radiation treatment, offered to certain cancer patients. There are two types of brachytherapy – high dose-rate (HDR) and low dose-rate (LDR). LDR brachytherapy is the one most commonly used to treat prostate cancer. It may be referred to as 'seed implantation' or it may be called 'pinhole surgery'. In LDR brachytherapy, tiny radioactive particles the size of a grain of rice (Figure 1) are implanted directly into, or very close to, the tumour. These particles are known as 'seeds', and they can be inserted linked together as strands, or individually. The seeds deliver high doses of radiation to the tumour without affecting the normal healthy tissues around it. The procedure is less damaging than conventional radiation therapy, where the radioactive beam is delivered from outside the body and must pass through other tissues before reaching the tumour. In addition to seeds, a newer polymer-encapsulated LDR source is available. The source features 103Pd along the full length of the device which is contained using low-Z polymers. The polymer construction and linear radioactive distribution of this source creates a very homogenous dose distribution. LDR prostate brachytherapy (seed or line source implantation) is a proven treatment for low to high risk localized prostate cancer (when the cancer is contained within the prostate). Under a general anaesthetic, the radioactive seeds are injected through fine needles directly into the prostate, so that the radiotherapy can destroy the cancer cells. The seeds are permanently implanted. They remain in place but gradually become inactive as the radioactivity decays naturally and safely over time. Unlike traditional surgery, LDR brachytherapy requires no incisions and is normally carried out as an outpatient (day case) procedure. Sometimes a single overnight stay in hospital is required. Patients usually recover quickly from LDR brachytherapy. Most men can return to work or normal daily activities within a few days. LDR brachytherapy has fewer side-effects with less risk of incontinence or impotence than other treatment options. It is a popular alternative to major surgery (conventional radical prostatectomy or laparoscopic (keyhole surgery) radical prostatectomy). Isotopes used include iodine 125 (half-life 59.4 days) palladium 103 (half-life 17 days) and cesium-131 (half life 9.7 days).