In the UK treatment goes through strict regulating bodies. Treatments have to be weighed up against issues such as side effects and costs. For example, with expensive treatments, reducing a risk of serious side effects by a small amount and reducing access to the number of patients treated by a large amount is a difficult desicion and is made using equations for the most ethical and efficient desicion for the whole country.
Proton therapy sounds great, it is a focused beam of radiation. with reduced spread to nearby tissue. Sounds great? The problem is it is expensive. This has several drawbacks. One, getting acces to it. Two, with few people using it, the research into long term negative effects and benefits will be reduced. However, even a brief glance highlights issues with secondary cancers due to the treatment when used in children.
So what does the research say. I literally took a quick look at JUST the latest research and the top few results included research that was relevant. Hopefully this will give an appreciation of the specialists potential point of view.
Intensity-modulated radiation therapy, protons, and the risk of second cancers
- Eric J. Hall D.Phil., D.Sc.
International Journal of Radiation Oncology*Biology*Physics
1 May 2006, Vol.65(1):1–7, doi:10.1016/j.ijrobp.2006.01.027
"Intensity-modulated radiation therapy (IMRT) allows dose to be concentrated in the tumor volume while sparing normal tissues. However, the downside to IMRT is the potential to increase the number of radiation-induced second cancers. The reasons for this potential are more monitor units and, therefore, a larger total-body dose because of leakage radiation and, because IMRT involves more fields, a bigger volume of normal tissue is exposed to lower radiation doses. Intensity-modulated radiation therapy may double the incidence of solid cancers in long-term survivors. This outcome may be acceptable in older patients if balanced by an improvement in local tumor control and reduced acute toxicity. On the other hand, the incidence of second cancers is much higher in children, so that doubling it may not be acceptable. IMRT represents a special case for children for three reasons. First, children are more sensitive to radiation-induced cancer than are adults. Second, radiation scattered from the treatment volume is more important in the small body of the child. Third, the question of genetic susceptibility arises because many childhood cancers involve a germline mutation. The levels of leakage radiation in current Linacs are not inevitable. Leakage can be reduced but at substantial cost. An alternative strategy is to replace X-rays with protons. However, this change is only an advantage if the proton machine employs a pencil scanning beam. Many proton facilities use passive modulation to produce a field of sufficient size, but the use of a scattering foil produces neutrons, which results in an effective dose to the patient higher than that characteristic of IMRT. The benefit of protons is only achieved if a scanning beam is used in which the doses are 10 times lower than with IMRT."
and a second paper....
Risk of Developing Second Cancer From Neutron Dose in Proton Therapy as Function of Field Characteristics, Organ, and Patient Age
- Christina Zacharatou Jarlskog Ph.D.
- Harald Paganetti Ph.D.
International Journal of Radiation Oncology*Biology*Physics
1 September 2008, Vol.72(1):228–235, doi:10.1016/j.ijrobp.2008.04.069
"Purpose
To estimate the risk of a second malignancy after treatment of a primary brain cancer using passive scattered proton beam therapy. The focus was on the cancer risk caused by neutrons outside the treatment volume and the dependency on the patient's age.
Methods and Materials
Organ-specific neutron-equivalent doses previously calculated for eight different proton therapy brain fields were considered. Organ-specific models were applied to assess the risk of developing solid cancers and leukemia.
Results
The main contributors (>80%) to the neutron-induced risk are neutrons generated in the treatment head. Treatment volume can influence the risk by up to a factor of ∼2. Young patients are subject to significantly greater risks than are adult patients because of the geometric differences and age dependency of the risk models. Breast cancer should be the main concern for females. For males, the risks of lung cancer, leukemia, and thyroid cancer were significant for pediatric patients. In contrast, leukemia was the leading risk for an adult. Most lifetime risks were <1% (70-Gy treatment). The only exceptions were breast, thyroid, and lung cancer for females. For female thyroid cancer, the treatment risk can exceed the baseline risk.
Conclusion
The risk of developing a second malignancy from neutrons from proton beam therapy of a brain lesion is small (i.e., presumably outweighed by the therapeutic benefit) but not negligible (i.e., potentially greater than the baseline risk). The patient's age at treatment plays a major role."
I hope this helps people appercaite that the treatments used and suggested have to be evidence based and specialists with over 20yrs training, usually really have a good appreciation of the best therapy and treatments. When doctors kids get sick in the uk, they end up in the same hospitals, with the same treatments. It isn't like the USA where you can go to another insurance company and get a better treatment. We offer the same for everyone and we make those choices based on evidence. Our protocols and guidelines come from NICE.
https://www.nice.org.uk
Very sad situation for the family. Difficult situation for all involved, but I must admit I was very concerned for the young boy when they decided to take him out of significant hospital care and even out of the country. Hopefully it will end well for all involved.
Hope you are all well here x
