Single-fraction radiation therapy (SFRT) as effective as multiple-fraction (MFRT) for palliating bone metastases
Standardizing prescribing practices for single-fraction radiation therapy (SFRT) for palliation of bone metastases could lead to cost savings and improvement in patients' quality of life, according to a new study.
Bone metastases are a common manifestation of distant spread of disease, occurring most frequently with prostate, breast, and lung cancers. Of these patients, two-thirds develop bone metastases to the spine, pelvis, or extremities. Radiation therapy is an effective form of palliative treatment for bone metastases. More than 25 randomized controlled trials demonstrate that SFRT provides the same amount of pain control as multiple-fraction radiation therapy (MFRT); however, use of SFRT for bone metastases is low internationally.
This study, published in the International Journal of Radiation Oncology • Biology • Physics (2014; doi:10.1016/j.ijrobp.2014.04.048), is one of the largest, current studies on the use of SFRT. The study was designed to determine the use of SFRT in British Columbia, Canada, which is a publicly funded health care system where there is no financial incentive for extended fractionation and all radiation therapy is provided by the BC Cancer Agency with no direct cost to patients.
Patients who received palliative radiation therapy for bone metastases, regardless of the primary cancer site at diagnosis, from 2007 to 2011 were identified using the BC Cancer Agency's Cancer Agency Information System (CAIS). During the study period, 8,601 patients received 16,898 courses of radiation therapy. Patients who received re-irradiation for bone metastases were included, and patients who received more than one course of radiation therapy were considered independently for each course (patients could be counted more than once). Radiation therapy fractionation was divided into two categories: SFRT or MFRT. The most common primary disease site was breast (23%), and the most frequently treated bony metastatic site was the spine (42%).
SFRT was used to treat bone metastases in 49% (7,097) of the radiation therapy courses. SFRT was most commonly used to treat bone metastases that originated from hematologic (57%) and prostate (56%) cancers; the most common bony metastatic sites treated with SFRT were the ribs (83%) and extremity (66%).
There was a significant variation in the use of SFRT by each of the five cancer centers operated by the BC Cancer Agency during the time of the study, with a range of 25.5% to 73.4% (P<.001), with an overall utilization rate of 49.2% in British Columbia. SFRT use is much higher, however, than in the United States, where SFRT use ranges from 3% to 13%.
“Previous research has shown that single-fraction radiation therapy is equally as effective as longer multiple-fraction courses. Single-fraction radiation therapy offers greater convenience for patients, is associated with fewer side effects, and incurs a lower cost. Even a modest change in the frequency of single-fraction radiation therapy use, in Canada and America, could lead to meaningful cost savings, improved patient convenience, and reduced patient side effects, thereby increasing patients' quality of life,” said lead author Robert A. Olson, MD, MSc, the research and clinical trials lead and a radiation oncologist at the BC Cancer Agency Centre for the North.