Treatment with radioactive medicine has fewer side-effects

Every year more than 4,000 Danish men are treated for prostate cancer. Rigshospitalet is now ready with a new type of treatment using alpha rays in liquid form which has fewer side-effects and means better chances of survival. Despite its huge potential, the treatment itself is actually quite simple.

"You inject the substance into the arteries through a venflon catheter and then it flows around with the blood and becomes trapped in the bone metastases, where it accumulates. From here it emits alpha particles. The alpha particles have so much energy that they destroy the cells each time they hit one, although the impact also slows them down them a little. After 6-10 cells the particles stop completely, but they have completely destroyed the cancer cells they have hit," explained Jann Mortensen, who is a Consultant at the Department for Clinical Physiology, Nuclear Medicine and PET at Rigshospitalet.

The substance injected into patients is called Radium 223 and it is only administered in very small doses. It was not permitted to use Radium 223 in treatment until 2013.

"This is the first time we have been able to treat patients with alpha radiation. Previously, all other treatment has been with beta radiation. We treat more or less the same types of patients with alpha radiation as we did with beta; that is patients with prostate cancer with bone metastases, but beta radiation only helps pain relief; not survival. This is the first time a treatment has proven so effective that, in addition to pain relief, a patient also has a better chance of survival, and that's what makes this new treatment so exciting," said Jann Mortensen.

A mild but effective killer

Alpha radiation is an effective weapon against cancer cells. Yet alpha particles have fewer side effects because they are slowed down so rapidly that they do not reach healthy tissue, whereas the same treatment with beta radiation gets further out to healthy tissue and causes damage. Therefore, the new treatment avoids damaging a lot of normal tissue, and this leads to fewer side effects. Despite the fewer side effects, patients still have to meet some requirements before they can receive the treatment.

"You have to have sufficiently strong bone marrow function to tolerate the new treatment. It doesn't have to be completely normal, but it must be reasonably good. We assess from treatment to treatment. Before each treatment we check patients to ensure that we can go on with the next treatment," explained Jann Mortensen.

Extensive safety procedure

A course of treatment stretches over five months, during which the patient receives six treatments in total. Two laboratory technologists from the Department of Clinical Physiology Nuclear Medicine and PET will be conducting the treatment. The treatment involves extensive safety measures, which among other things mean that treatment personnel have to be checked for background radiation several times a day.

"We have to go through an extensive procedure every time we perform a treatment, but it's important that we protect our personnel and ensure that they do not become contaminated. Our permit to use alpha radiation is also conditional upon personnel being closely monitored," said Jann Mortensen, who expects to have his first patient undergoing treatment just after Easter.

First treatment site in Denmark

Rigshospitalet is the first place in Denmark to be granted authorisation to perform treatment with radioactive alpha particles, so until other hospitals in Denmark are also granted permits to perform the same treatment, Rigshospitalet will have to accept patients from throughout Denmark. In the long term the ambition is that Rigshospitalet will only receive patients from the Capital Region of Denmark.

Prostate physicians in Denmark have estimated that around 150 patients a year will need treatment, but it is really too early to say, as the treatment is so new and its potential has yet to be fully determined. In the long term, however, Jann Mortensen believes that alpha radiation treatment could become more widespread and include other types of cancer.

The treatment has so far only been approved for prostate cancer and bone metastases, but there are many other types of cancer which also spread to the bones, so in principle it will also be possible to treat all types of bone metastases. Trials with breast cancer have been initiated, and if these prove positive, this will probably be the next cancer type for treatment. Breast cancer patients are a large group and many also get bone metastases, so alpha radiation will be a valuable treatment for them.

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