Patients with painful bone metastases achieved similar relief of pain whether they were treated with a single fraction radiation therapy protocol or underwent a series of radiation treatment, according to a study presented here at the 56th Annual Meeting of the American Society for Radiation Oncology (ASTRO).
While previous clinical trials have suggested that a single treatment is equivalent to multiple fraction radiotherapy, Robert Olson, MD, British Columbia Cancer Agency Centre for the North, Prince George, British Columbia, said that the current study indicates that in a regular clinical setting, there is no difference in pain outcome between the strategies.
After controlling for gender, site of primary tumour, site of metastatic site, and re-treatment of complicated bone metastases, there was no difference in partial pain response by single fraction radiation therapy when compared with multiple fraction radiation therapy (P = .99).
“We also found no difference in complete pain response by single fraction radiation therapy versus multiple fraction radiation therapy,” said Dr. Olson.
All 6 centres of the British Columbia Cancer Agency participated in the study from May to December 2013. A total of 648 patients with bone metastases were evaluated, including 226 with metastases complicated by fracture or neurological compromise such as spinal cord compression. The mean patient age at diagnosis was 65 years and 54% were male.
Patients received either radiation strategy at the discretion of the treating oncologist, with 56% receiving single fraction radiation therapy and 44% receiving multiple fraction radiation therapy for treatment of the painful bone metastases.
Of the patients in the study, 31% had developed bone metastases due to spread of genitourinary cancers, 22% had lung cancer metastases, and 22% had breast cancer metastases. The most common site for the bone metastases was the spine (44%).
“There is a very low utilisation of single fraction radiation therapy for bone metastases worldwide, partially because oncologists are often reluctant to use the strategy for patients who do not meet the criteria of previous clinical trials,” said Dr. Olson. “We wanted to determine if single fraction radiation therapy is equally effective as multiple fraction radiation therapy in the broad clinical practice setting, capturing all types of patients who receive radiation therapy for bone metastases. This study is ongoing.”