Proton beam therapy

Contents

  1. Radiotherapy
  2. Proton Beam Therapy
  3. Issues and Concerns
  4. Private Health Care
  5. Conclusion
  6. References

Radiotherapy

The first type of cancer treatment using the electromagnetic spectrum was Radiotherapy.

Radiotherapy: The use of radiation to kill and/ or reduce the size of tumours.

Electromagnetic spectrum: A scale that plots electromagnetic radiation depending on their wavelength.

Proton: A proton is a subatomic packet of energy which at high energy states, can be ionising i.e able to damage cells (in this case, cancer).

Radiotherapy has been used in modern cancer-curing treatments since Wilhelm Röntgen first discovered X - Rays in 1895 [1] and was first used in America a year later in 1896 [2]. Radiotherapy has helped thousands of people in the UK and is one of the most popular forms of cancer treatment:

Stage as diagnosis Percentage of Patients
All stages combined 27.3%
Stage 1 28.4%
Stage 2 28.7%
Stage 3 38.1%
Stage 4 25.4%
Unknown Stage 15.6%

Table 1: All Cancers Combined (C00-97,excl C44), Percentage of Patients Receiving Radiotherapy as Part of Their Primary Treatment, Persons, All ages, England, 2013 - 2014

Stage 1 - The cancer is small and has not spread

Stage 2 - The cancer has increased in size, however, has not spread

Stage 3 - The cancer has increased in size and has potentially spread to the surrounding tissue

Stage 4 - The cancer has spread from its original position onto a minimum of one other organ

Recently, there has been a sort of revival and breakthrough for radiotherapy as in September 2012, there was a Radiotherapy innovation fund that generated £15 million but was then boosted to £23 million to help aid the NHS in England [3]. In addition to this, the Department of Health also announced a further £30 million investment in the latest radiotherapy machines [4].

Proton Beam Therapy

Proton Beam Therapy: Proton beam therapy (PBT) is an advanced form of radiotherapy, with radiation treatment delivered by accelerated proton beams rather than X-rays, generated via a large particle accelerator [5].

The reason why proton beam therapy is currently being funded by our government is that while it irradiates the tumors and consequently the surrounding healthy tissue, it does this at a much lower severity than radiotherapy, leading to less long term effects and consequences compared to radiotherapy although it will not eliminate them completely, it does minimise the damage to the important surrounding healthy tissues and vital organs such as the CNS (Central Nervous System). In this regard, it is much better than radiotherapy as it reduces the risk of a second spike of cancer cells multiplying and causing cancer in the patient a second time.

“Since it delivers a lower dose of radiation to surrounding tissues, proton beam therapy’s main advantage is in reducing side-effects, rather than improving survival or cure”

Issues and Concerns

One issue with radiotherapy is that once the dose has been administered, the X - Ray stays inside the body and keeps moving, inevitably leading to damage. This is especially harmful to children as their bodies are still developing and therefore may have a higher risk, than adults, to develop a second case of cancer later on in life. To reduce this risk, proton beam therapy was developed. There are other alternatives to radiotherapy other than PBT which will be briefly summarised later in this post.

Administering high energy protons at the tumour instead of X - Rays will reduce the risk substantially as once the cancer cells have been exposed to enough protons, they stop and do not go through the tumour and into the rest of the body.

This successfully reduces the chance of damaging the surrounding tissue which is especially important in vital areas of the body such as the bran. However, it still carries risks and is currently still being researched at hospitals all over the UK such as in UCLH in London and The Christie Hospital, Manchester [6]

Another main issue is that currently, Proton beam therapy is used to treat rare cancers, which means that it is quite difficult to gain solid scientific and reliable research [7] about PBT and any long - term effects it may or may not have. As a result of this, there have been little studies published compared to other treatments so it is hard to distinguish how effective this treatment is in battling cancer. Little research on a topic leads to little understanding which is dangerous in situations like these where it affects a person's life if gone wrong. Further research should be required before we head to a full-scale use of PBT.

“For most patients right now, there’s no strong evidence that proton beam radiotherapy is ‘better’ at curing cancer”

Private Health Care

Private sectors in healthcare are announcing their plans to build PBT centres in the UK [8], treating both NHS and private patients however, the NHS will have to cover the cost and since it is privately owned, the ones that will get access to this therapy will not be decided by the NHS and only special members of the private sector may get access. This is unfortunate, as the working class may have limited access to this technology simply due to funds.

Another issue is how much money this research is costing us, the UK. Currently, modern radiotherapy is increasing in its effectiveness day in and day out, with techniques such as intensity modulated radiotherapy [9] (which uses moving lead to reduce the exposed healthy tissue getting irradiated ) and stereotactic radiotherapy such as CyberKnife [10] ( where X-ray cameras that monitor the position of the tumour and enables the robot delivering the radiotherapy to reposition the radiotherapy beam during treatment to minimise the risk of radiation to healthy tissue ) or internal radiotherapy such as Brachytherapy [11] ( where radioactive material is placed inside your body and the tumor is irradiated and destroyed from the inside out ). This leads to debates on whether technologies such as this should be funded instead of radiotherapy. This is both good and bad as more research into these technologies means that there will be more treatments available for cancer however, if research is spread too thin between multiple sources, then it would take a longer time to get these ready which may cost lives.

In the past, there have been failures in the research of subatomic particles in cancer treatment such as the Neutron Beam Therapy back in the 20th century, which was invested into but the plans were discontinued in the UK. Cases like this show that while some new treatments may lead to a new way of battling cancer, it must be decided first whether the hard-working taxpayer's money should be spent on this new research or on ongoing research which is already in the works as there is not a full-proof way of knowing if the new idea will work.

CyberKnife

As explained previously, CyberKnife is a technique where X-ray cameras that monitor the position of the tumour and enables the robot delivering the radiotherapy to reposition the radiotherapy beam during treatment. This technique minimises the risk of radiation to healthy tissue and is an incredible design being used since July 2011 [10]. It has pinpoint accuracy due to its robotic precision which can be nothing but good.

This is one of the ways healthcare sectors are implementing AI technology into dangerous surgical procedures and reduce the risk of human errors that may lead to fatal mistakes.

Conclusion

While Proton Beam therapy is useful for rare cases of brain cancer such as ones in the CNS, availability for these PBT centres (which are currently being owned privately) will be primarily for patients that can afford it meaning there will be a competing demand and use of this treatment may just depend on the size of your income.

To know for sure how useful and effective Proton Beam Therapy is, data will be needed and this is only gathered through multiple trials and research. Their future in the medical field seems to be limited right now and we don't know what will happen to the treatment in the upcoming years. Until then, we cannot fully understand it and therefore I don't think a full scale use of this technology will be available in the near future.

By Owais M Siddiqi


References

[1] Riesz, P.B., 1995. The life of Wilhelm Conrad Roentgen. AJR. American journal of roentgenology, 165(6), pp.1533-1537.

[2] “News of Science”. Science. New Series. 125 (3236): 18–22. January 1957.

Table 1: National Cancer Registration & Analysis Service and Cancer Research UK: “Chemotherapy, Radiotherapy and Tumour Resections in England: 2013-2014” workbook. London: NCRAS; 2017.

[3] Cancer research UK, written by Dan Bridge, Sparking the radiotherapy revival, published July 11, 2013 [Accessed August 17, 2019]

[4] UK Goverment, Written by Department of Health and Social Care, Department of Health invests additional £30 million into cancer treatment, published August 26, 2013 [Accessed August 17, 2019]

[5] Royal College of Radiologists, University of Alabama at Birmingham Comprehensive Cancer Center, History of Radiation Oncology, What is proton beam therapy? [Accessed August 16, 2019]

[6] Crellin, A.M. and Burnet, N.G., 2014. Proton beam therapy: the context, future direction and challenges become clearer. Clinical Oncology, 26(12), pp.736-738.

[7] Cancer research UK, written by Kat Arney, Tackling rare cancers must be an international effort, published August 8, 2013 [Accessed August 18, 2019]

[8] The Guardian, written by Rebecca Ratcliffe,UK to get first three proton beam therapy centres in cancer care milestone, published April 4, 2015 [Accessed August 18, 2019]

[9] Intensity Modulated Radiation Therapy Collaborative Working Group, 2001. Intensity-modulated radiotherapy: current status and issues of interest. International Journal of Radiation Oncology, Biology, Physics, 51 (4), pp.880-914.

[10] The Royal Marsden, Supported by The Royal Marsden Cancer Charity, CyberKnife [Accessed August 18, 2019]

[11] The Christie, Supported by The NHS Foundation Trust, Brachytherapy [Accessed August 18, 2019]