About

Introduction to the Particle Therapy Cancer Research Institute

About one third of people will get cancer at some point during their lifetimes, affecting both those with the condition as well as their friends and relatives. While some cancers are associated with specific risks, many are not, and can strike anyone at any time. Since most forms of cancer (there are about 200 different types) increase with age, prevalence is expected to increase. Despite improvements, however, many current treatments for cancer have potentially harmful side effects, leading to short- and long-term reductions in quality of life.

Destroying cancer non-invasively using protons or charged light ions such as carbon (charged particle therapy or CPT) offers advantages over conventional radiotherapy using x-rays, since a far lower radiation dose is delivered to healthy tissues. Particle therapy can also be an alternative to radical cancer surgery.

Despite clear motivation for exploiting the benefits of charged particle therapy (CPT) over x-ray radiotherapy, there are few comprehensive reports of CPT efficacy and side effects and no formal clinical trials have been performed. Consequently, it is difficult to establish an economic case for CPT in the NHS when facilities cost £25M-£100M.

The Particle Therapy Cancer Research Institute (PTCRi) studies the clinical effectiveness of charged particle therapy to treat cancer, promoting its use in the UK and elsewhere on the basis of robust clinical evidence and analysis.

 

About Charged Particle Cancer Therapy

Radiotherapy successfully treats about 40% of cancers, but it can be an aggressive treatment limited in applications, for example if the cancer is near a vital organ (such as spinal cord or brain), and with a high risk of mild to severe side effects from tissue damage caused by x-ray irradiations.

In contrast, protons and charged particles, such as carbon ions, deposit energy far more selectively than x-rays due to the “Bragg peak” effect. It is illustrated in the diagram below that for a similar dose on the target area (highlighted in purple), the dose to a wide area of healthy tissue is much less with protons. In particular, there is no dose to tissues behind the cancer.

Dose profiles for x-rays and ions  

 

These peaks of radiation can be used to:

  • match the cancer position very precisely using modern imaging techniques, such as CT and MR scans;

  • produce a marked reduction in radiation dose to collateral normal tissues, much like the use of high precision bombing;

  • increase cancer doses even in clinically awkward situations, e.g. if a cancer is close to the brain, spinal cord, kidney, bowel etc;

  • produce good quality of life in cured cancer patients, continued vital organ function and a reduction in cancer formation due to radiation exposure.

Charged Particle Therapy is particularly appropriate for some rare but distressing forms of childhood cancer, where alternatives (surgery, chemotherapy and conventional radiotherapy) can lead to significant impairment in later life.

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Aims of the Institute

The key objectives of the Particle Therapy for Cancer Research Institute are to:

  • develop a worldwide database of CPT case histories in order to analyse and identify critical factors for success;

  • understand the critical factors determining the relative biological effectiveness (RBE) of radiation therapies;

  • assist scientists in Oxford and elsewhere in efforts to design more effective particle accelerators for clinical use;

  • develop a national education programme to disseminate information to doctors, administrators, research councils, charities and the NHS about the benefits of CPT .