Brachytherapy Prostate Cancer Treatment

Probably the most used of these other treatments is brachytherapy. Brachytherapy has a long history, dating from 1909, when Parisian doctors Pasteau and Degrais reported their use of radium capsules, which they planted into the urethra of men with prostate cancer. The capsules were soon replaced by radium needles inserted into the cancers themselves, so that the source of the radiation was inside the tumor, rather than beside it. The technique of inserting sources of radioactivity into the prostate became known as brachytherapy, from the ancient Greek word hrachx, meaning short – that is, the source was a short distance from the tumor.

Throughout the twentieth century radium was replaced by radioactive iodine. (For the technically minded, the isotope used is I, the radiation from which has a very short held of activity. Needles containing the correct dose of I could be used to plant “seeds” of radioactive material at intervals of under 1 cm. and this would cover the whole prostate.) The aim was to give a higher dose of radiation to the tumor, but a much lower dose to the bladder and rectum nearby. The whole radiation dose is given with one insertion, so avoiding the repeated visits needed for external beam radiation, and saving the time of hospital staff and patients.

This process sounds ideal, but it had its problems. It was very difficult to “map” the prostate adequately and to get the distribution of the needles or seeds correct. Some parts of the prostate were overdosed and others underdosed, and long-term follow-up revealed unacceptably high failure rates. When external beam radiation became much more accurate, brachytherapy fell from favour.

However, it is now being revived. Its main enthusiasts are in the team in the Northwest Prostate Institute in Seattle, in the United States, led by Drs Haakon Ragde and Michael Brawer. They use ultrasound systems to guide the needles carrying the ‘seeds’ of radioactive material into exactly the correct sites. Some patients, mainly those with low-grade cancers, are given I. Others with cancers that appear more actively multiplying when examined under the microscope are given palladium, a radio-isotope that decays taster than I. It can be given in a much higher dose because the time of radiation is so much shorter, with the result of a greater “tumor-kill’ in men whose cancers are highly active and multiply­ing fast.
Brachytherapy

The Northwest team use this form of brachytherapy for men in stage T1 or T2 disease thought to be localized to the prostate. Not all men are suitable for it. The needles are inserted through the skin of the perineum. If the prostate is very large, the pelvic bones can make it difficult for the surgeon to place the needles in the ideal pattern. Such men may need anti-androgen treatment first, to shrink their prostates before they can be given their brachytherapy. Most men who have had a previous TURP for BPH are unsuitable for brachytherapy because there is not enough prostate tissue left into which the seeds can be planted correctly. In men at high risk of spread of their cancer, who have large tumors, a high Gleason score, and high PSA levels, the Northwest team first use external beam radiation and follow it up with brachytherapy two weeks later. The implants are inserted under general or spinal anaesthesia, so that the procedure is painless and even relatively comfortable.

Most men can go home within three hours of their brachytherapy. They may need standard everyday painkillers for a few hours afterwards, but it is remarkably free of after-effects, except for, perhaps, some blood in the urine. They may need drugs to ease the flow of urine from the bladder for about a month.
brachy seeds

In the past, people with inserted radium seeds were excluded from close company for a considerable time, because they were sources of radiation that might be dangerous to others. With modern brachy­therapy treatment, the radiation is almost completely confined to the prostate gland, so that such precautions are not needed. However, to be absolutely safe, men with seeds inserted should avoid close contact with pregnant women or with young children for two months. They may start having sex again after two weeks, providing they use a condom on the first few occasions to collect any seeds that may have migrated into the semen. Follow-up is the same as for radical prostatectomy and external beam radiation: after one month, then three-monthly, then annually after 19 months. PSAs are measured regularly and a prostate biopsy taken at 18 months.

How do the results of brachytherapy compare with those of radical prostatectomy and external beam radiation? Dr Ragde and his colleagues reported their results of 147 men given brachytherapy and followed for ten years. Given that they were elderly men to begin with (they ranged from 53 to 92 years old, most being around 70 when they were treated), their results are remarkable. Sixty-seven are still alive and well with no evidence of prostate disease. Fifty-three have died, but only three of them actually died from their prostate cancers. The rest died from the usual problems associated with old age and quite unrelated to their prostate disease. This means that there were three failures (deaths due to the disease) in 147 men, defined medically as 98 per cent disease-specific survival.

This is a huge success. Of course, some of the survivors still have their prostate cancers, but few of them appear to be life-threatening or to be advancing rapidly. Most of them, too, will reach old age without having to face death from their cancers. These results are similar to those produced by radical prostatectomy and external beam radiation. They are yet another reason for men with prostate cancer to be optimistic about the future.

Medical Health

Brachytherapy Prostate Cancer Treatment
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