Lower Radiation Doses May Be Sufficient For Treating Certain Cancers, Report IAEA Experts

Five studies on radiation treatments for cancer and two investigative surveys of radiotherapy capacities in developing countries

The results of seven International Atomic Energy Agency (IAEA)-supported clinical trials, randomised studies and surveys related to cancer were presented at the 3rd European Society for Radiotherapy & Oncology (ESTRO) Forum in Barcelona (24-28 April 2015, Barcelona, Spain). Lower than standard doses of radiation could be sufficient for the treatment of certain cancer types, limiting radiation exposure for patients and decreasing health care costs, indicated results of clinical research trials presented at the special IAEA session.

“IAEA clinical studies focus on identifying radiotherapy treatment strategies that are effective while being resource-efficient and more convenient for patients,” said Eduardo Rosenblatt, Head of the Applied Radiation Biology and Radiotherapy Section at the IAEA. “This is particularly important for low-income countries where radiotherapy centres are often overloaded with patients, understaffed and rely on limited resources for treating patients with more advanced diseases,” he said. “By finding ways to provide effective treatments that require fewer resources and shorter treatment times, more patients can get the treatment they need.”

The session’s presentations featured five studies and trials on radiation treatments for cancer of the head and neck, breast, rectum, bone and lung, as well as two investigative surveys of radiotherapy capacities in developing countries. These were conducted with support from the IAEA and in collaboration with Member States and other organisations. The following results were presented:

Clinical trials and randomised studies on cancer treatment

  • Advanced head and neck cancer: A randomised study of 104 patients showed a treatment advantage when combining six radiotherapy treatments per week with a drug that sensitises cancer cells to radiation, known as a radiosensitiser nimorazole, compared to only administering the typical six radiotherapy treatments per week. The radiosensitiser nimorazole drug helped the radiation to be more effective.
  • Locally advanced lung cancer: A clinical study demonstrated that a shorter course of radiation showed similar results as the standard, longer course of radiotherapy used for survival and for mitigating symptoms of lung cancer.
  • Post-mastectomy breast cancer: A clinical trial involving 496 patients found that after removal of the breast, irradiation of the lymph nodes in the area around the collarbone may not be necessary in treating breast cancer patients.
  • Locally advanced rectal cancer: A preliminary analysis of a randomised clinical trial revealed that the results of a short course of radiotherapy (five treatments in one week) and surgery is equivalent to longer course radiotherapy (25 treatments in five weeks) and chemotherapy. Currently, the longer course radiotherapy and chemotherapy is the general treatment protocol for this type of cancer when it is in its advanced stages.
  • Bone metastases: A randomised clinical trial established that giving a single higher dose of radiation treatment is significantly more effective than a single lower dose for managing pain caused by cancer growths in bones.

Increased radiotherapy capacity in middle-income countries

In addition to the clinical trials, presenters also shared the results of research on cancer care capacities in various countries. One survey showed an increased use of radiotherapy machines in nine middle income countries, which was found to be comparable to the use levels in developed countries. Another presented data collected in 12 countries in Eastern Europe, the Caucasus region and central Asia, showing the number of radiotherapy centres, machines and staff available in the region — the first time such data had been compiled for these countries. This data will be combined with a second project phase assessing the quality of radiotherapy services. The data sets will form the first comprehensive overview of cancer care capabilities in these countries, which is expected to influence how they plan radiotherapy services.

“Planning radiotherapy services in a country or region requires a robust estimate of demand, as well as reliable data on existing resources. However, a description of the number of facilities and machines is not enough to assess patients’ access to services or the quality of treatments,” said Elena Fidarova, a radiation oncologist at the IAEA. “This project will paint a reliable picture of the status of radiotherapy services, which can help the IAEA and other organisations to focus their specific priorities when collaborating with these countries in developing their cancer care capacities.”
The session marked the first time that the IAEA received a dedicated presentation time during the ESTRO Forum. “The IAEA has a long-standing history of collaboration with ESTRO, mainly in the area of radiotherapy education,” said Rosenblatt. “In the last few years, this collaboration has strengthened, particularly through participation in IAEA coordinated research projects. In the future, we expect this collaboration to continue and to bring further developments to the field of radiation oncology.”