A single treatment of 8 gray (Gy--a unit of measure of absorbed radiation dose) of radiation appears to be as effective in palliating painful bone metastases as the current U.S. standard treatment course of 30 Gy delivered in 10 daily treatments, according to a new study in the June 1 issue of the Journal of the National Cancer Institute.
Patients with a variety of solid tumor cancers, including lung, breast, and prostate, can develop painful metastases in the bones of the spine, pelvis, and extremities. Although the standard treatment, radiation therapy delivered in 10 daily sessions, is effective in providing relief--50% to 80% of patients experience improvement in their pain, and 20% to 50% have complete pain relief--a shorter course of treatment would be easier for patients and their families to arrange and would also have less impact on the timing of other treatments.
To determine whether a shorter course of radiation is equivalent to the standard treatment, William F. Hartsell, M.D., of Lutheran General Cancer Center in Park Ridge, Ill., and colleagues randomly assigned nearly 900 patients with breast or prostate cancer who had one to three sites of painful bone metastases to receive either 8 Gy of radiation in one treatment session or 30 Gy of radiation in 10 daily treatment sessions.
As assessed at three months after treatment, both regimens provided equivalent pain relief, and an equivalent proportion of patients no longer required narcotic medication. There was a higher rate of re-treatment but less acute toxicity in the group that received only one course of 8 Gy radiation compared with the 30-Gy group.
"Further analysis of data from [this] trial should yield important information on quality of life, health utilities (i.e., patient preferences for specific health states or treatments), and economic end points. These data will help determine whether a single dose of 8 Gy should become the standard treatment for palliation of localized painful bone metastases," they write.
In an editorial, Lisa Kachnic, M.D., of Boston University Medical Center, and Lawrence Berk, M.D., Ph.D., of Central Ohio Radiation Oncology in Columbus, discuss other trials that have addressed the use of short-course radiation for the palliation of bone metastases. "[T]hree very large randomized trials … have all demonstrated that single-fraction radiation therapy is sufficient to achieve palliation of painful bone metastases," they write. "It remains to be seen if this approach will become standard of care in the United States. The outcome may distinguish whether radiation oncologists in the United States practice evidence-based or remuneration-based medicine."