The story of five-year-old Ashya King, who was taken by his parents from a Southampton hospital to seek specialised radiotherapy in Spain for a cancerous brain tumour is likely to have a particular significance for mesothelioma sufferers and their families.

The treatment being sought for Ashya, who had a 70 – 80 per cent chance of surviving five years, is known as Proton Beam Therapy (PBR), and despite not being widely available, has also been trialled with mesothelioma patients.

The use of body scanning technologies, such as X-rays, MRI, CT or CAT scans, and the more advanced PET/CT have been crucial to early mesothelioma cancer detection and delivering more effective asbestosis treatments. Increasingly seen as the way forward, targeted treatments have been used to treat spinal cord tumours, sarcomas near the spine or brain, prostate cancer, lung cancer, liver cancer, some children’s cancers and in malignant mesothelioma tumours.

Fewer side effects

PBR operates by targeting high energy protons directly at a tumour, which not only reduces the dose to surrounding tissues and organs but has also been observed to produce fewer side effects compared to highly intensive X-ray dosages. Protons can only travel through several centimetres of tissue and just 20 per cent of radiation is delivered beyond the treatment area, which is typically too weak to cause substantial side effects As a result, PBR has come to be seen as a potential “magic bullet” for patients with cancer tumours.

One of the key challenges in the treatment of mesothelioma has always been the exceptionally long gestation period of up to 50 years from the inhaling of fibre dust particles to the appearance of asbestosis symptoms. By the time a confirmed diagnosis can be made, the cancer will have often reached an advanced stage and spread to other organ tissues.

However, the decision over the treatment type and the different combinations to be administered in each individual case is unlikely to be straightforward.

Eligibility for therapy

PBR tends to be mostly approved for patients with cancer concentrated in only one location, known as Stage 1 when applied to the development and spread of mesothelioma. Unfortunately, in many cases mesothelioma patients are more likely to receive a confirmed diagnosed when the cancer has already spread to a later stage, and targeted PBR is no longer seen as an effective option. In the latter case of advanced stage cancer, patients are generally more responsive to other treatments.

Mesothelioma patients who are eligible to receive PBR will often also receive a combination of other treatments, known as ‘multimodal’ therapy, which involves chemotherapy and surgery. Consequently, the age and general health of a mesothelioma patient are also crucial for consideration before a course of treatment begins. Doctors generally stipulate that a candidate for PBR must weigh under 163.2 kgs (360 pounds) and be able to stay near or travel to the treatment facility for daily appointments.

Therapy dosage

Patients are prepared for the procedure by undergoing a ‘simulation’ session for around seven days before treatments are due to begin. PBR itself is delivered in cycles of up to seven or eight weeks, the length of treatment based on the dose of radiation required to treat the cancer. Typically, higher doses are administered in shorter cycles while lower doses are given over a longer period of time.

First developed in the 1950s, proton beam therapy has begun to be more widely available for specific clinical cancer treatments since the 1990s. Since 2009, there are now 38 facilities dedicated to providing PBR around the world. In December 2011, the UK’s Department of Health announced that PBR will be made available for patients in London and Manchester from 2018.

In the absence of a final cure for mesothelioma, the aim of extending life expectancy by faster and more targeted treatments, such as PBR, is a crucial treatment for all sufferers of the deadly disease.