Prostate cancer is the most common cancer and second most common cause of cancer death in men in the UK. Based on 2011 UK statistics, 110 men are diagnosed with and 30 men die from prostate cancer every day (Cancer Research UK, 2014a).

Men with prostate cancer develop both general and specific disease symptoms including tiredness, weight loss, anorexia, difficulty and pain in passing urine, blood in the urine and bone pain (in cases of advanced metastatic disease).

A diagnosis of prostate cancer is established through a range of tests. These include: digital rectal examination; blood tests for the biomarker prostate‑specific antigen (PSA); imaging tests such as MRI, computed tomography (CT) or ultrasound; and prostate biopsy. Based on the results of these tests, men with prostate cancer are categorised into 1 of 3 risk groups as outlined in NICE's guideline on prostate cancer: diagnosis and treatment. These are:

  • Low risk: PSA score of less than 10 ng/ml, and small size tumour confined within the prostate (T1–T2a), and biopsy result showing a Gleason score of less than 6.

  • Intermediate risk: PSA score of 10–20 ng/ml, or tumour confined to the prostate involving more than 50% of 1 lobe (T2b), or biopsy results showing a Gleason score of 7.

  • High risk: PSA score of more than 20 ng/ml, or tumour confined to the prostate involving both lobes (T2c and above), or biopsy results showing a Gleason score of 8–10.

Depending on their risk group, men with prostate cancer have the following treatment options:

  • Active surveillance, which is where no treatment is had but men visit the hospital regularly for an examination and PSA test.

  • Radical prostatectomy with or without removal of lymph nodes.

  • External beam radiotherapy with or without brachytherapy.

  • Monotherapy using brachytherapy.

For more information regarding these treatment options, see NICE's guideline on prostate cancer: diagnosis and treatment.

NICE currently recommends 2 forms of radiotherapy as treatment options for prostate cancer. External beam radiotherapy (EBRT) involves using high‑energy x‑rays produced by an external radiation source (linear accelerator) to destroy the cancer cells. People having this treatment must attend hospital 5 days a week for several weeks. The second form is brachytherapy, whereby radioactive material is inserted directly into the prostate gland to kill the rapidly dividing cancer cells. The radioactive material can be inserted permanently using radioactive seed implants, or temporarily by attaching the radioactive source to the end of a wire that is inserted for a short time. Men having this treatment need to attend hospital for their treatment once or twice. Brachytherapy can be used on its own or in combination with EBRT (sometimes called a 'boost dose'). High‑dose‑rate (HDR) brachytherapy is where a high‑activity radioactive source (such as iridium‑192) is temporarily inserted into the prostate to deliver a high radiation dose.

The clinician performing brachytherapy uses imaging technology to guide the insertion of the radioactive source into the prostate and to develop the radiotherapy treatment plan. For prostate brachytherapy the clinical team can image this process using CT, MRI or ultrasound.

HDR brachytherapy is usually performed with the patient under general anaesthetic, or with local anaesthetic and sedation (see NICE's interventional procedure guidance on high dose rate brachytherapy in combination with external-beam radiotherapy for localised prostate cancer). On average 16 thin plastic or metallic needles, called applicators, are inserted through the perineal skin behind the scrotum into the prostate gland (the number of applicators varies according to the size and shape of the prostate). A radioactive source is then inserted from the afterloading platforms into each applicator. The radiation dose is controlled by varying the time that the radioactive source spends at different positions within each applicator in the prostate (this will usually last a few minutes depending on the prescribed radiation dose), and this limits the radiation dose to the surrounding healthy tissues and organs. After the appropriate dose has been administered, the applicators are removed, leaving no radioactive material in the prostate gland.

Conventional prostate brachytherapy is administered in a 2‑step approach, where the applicators are inserted while the patient is in the operating room, and the patient is then transferred from surgery to have a CT or MRI scan, or both. The clinician will use the images from the scan to define the radiation dose and to finalise the treatment plan, and then the radioactive sources are inserted into the applicators.

In contrast, the workflow for real‑time HDR prostate brachytherapy is a single‑step approach that allows the treatment to be provided in the operating theatre in a single session, without moving the patient. This is claimed to potentially reduce the procedural time and the risk that the applicators could become dislodged (Batchelar et al. 2011, Milickovic et al. 2001).