New Targeted Therapies Changing the Role of Radiotherapy
Immunotherapy-related chemotherapeutics may work synergistically with high-dose radiotherapy and lead to significant changes in cancer care.
Immunotherapy-related chemotherapeutics may work synergistically with high-dose radiotherapy and lead to significant changes in how patients with cancer are managed in the next couple of years.
Dramatic improvements have occurred in radiotherapy and at the same time, new targeted therapies have changed the treatment landscape. Bruce D. Minsky, MD, who is the chair of the American Society for Radiation Oncology (ASTRO) and professor of radiation oncology at MD Anderson Cancer Center in Houston, TX, said targeted therapies probably won't replace radiotherapy, but will rather work together in a more tailored fashion throughout the next 5 years to improve clinical outcomes in patients with cancer.
There are several types of targeted therapies that are being used to treat cancer, and everyday more are being investigated.1 Targeted therapies come in 2 main forms: monoclonal antibodies and small molecule drugs, such as imatinib and dasatinib.
“I don't think they will ever replace radiation therapy. It is not an issue of replacement but a combination of them in the course of treatment,” Dr Minsky said in an interview with Cancer Therapy Advisor. “I think as cancer is transformed with all the new agents and it becomes a more chronic disease, the use of radiation will increase in the metastatic setting and that is a change that has occurred in the last 5 years.”
Dr Minsky said he envisions targeted therapies being used heavily as first-line therapy. Currently, targeted therapies are being used to treat a growing number of patients with cancer. However, he said cancer will still require a full armamentarium of different approaches.
Shelly Hayes, MD, director of Fox Chase Cancer Center Buckingham satellite, said the biggest changes in radiation over the past 5 years has been the delivery of very high doses of radiation in fewer fractions with precise targeting using stereotactic body radiotherapy (SBRT) and stereotactic radio surgery.
The use of SBRT in particular has escalated during the past 5 years primarily as a result of technologic advances in radiation equipment and the emergence of data showing that SBRT for some cancers is more effective and less toxic than conventional radiation techniques, according to Dr Hayes.
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“The biggest change that I anticipate over the next 5 years is how SBRT will be implemented in conjunction with systemic therapies, particularly targeted therapies and immunotherapies,” Dr Hayes told Cancer Therapy Advisor.
“The biggest impact that target cancer therapies have made is improving the therapeutic window, meaning better tumor control with less side effects. This applies to both targeted systemic therapies and targeted radiation. The field of oncology has seen dramatic improvements in survival for many types of cancer with systemic therapies that act on specific genes or mutations expressed by the tumor. This improvement in systemic control has enabled the local tumor control afforded by radiation to impact survival.”