Despite the widespread use of stereotactic body radiation therapy (SBRT) for treating tumors in the body, its theoretical advantages have yet to be confirmed clinically, reveals a report that appeared yesterday in the online edition of Annals of Internal Medicine.
Responding to a request for a technical brief about SBRT, the report’s authors—led by Karen Schoelles, MD,SM, director of the ECRI Evidence-based Practice Center at the ECRI Institute, Plymouth Meeting, Pa.—initiated a review of the literature on the topic. The authors’ goal, they observe, was not to assess comparative effectiveness, but “to provide an overview of key issues." They note that SRBT is based on the technique of stereotactic radiosurgery used to treat CNS lesions, and that by combining multiple collimated radiation beams, it delivers a high dose of radiation to a target in the body in a single dose or a few fractions.
The team’s literature search identified 124 relevant studies, with the lung and thorax, followed by the pancreas, liver, and colon, the most commonly represented tumor sites therein. A few studies focused on tumors in the uterus, pelvis, kidney, thyroid, and prostate. Schoelles and her colleagues found that 384 of 700 facilities in the U.S. listed their capacity to provide stereotactic body radiation therapy. Average charges added up to $52,471 for four fractions of SBRT -- similar to the cost of 35 fractions of 3D conformal radiation therapy. None of the reviewed studies featured comparisons of SBRT with another form of radiation treatment, the researchers found.
Seven systematic reviews assessing SBRT have been conducted, the authors state. The general consensus from these reviews, they assert, "is that although single-group studies show potentially promising results for various cancer sites, prospective studies are necessary to determine the efficacy of SBRT compared with other available treatment options (for example, surgery or radiation therapy)."
In elaborating on their findings, the team acknowledges that the option of stereotactic body radiation therapy is likely to appeal to patients because it entails fewer treatment sessions, and that currently, "a full systematic review of the current literature cannot answer questions on the effectiveness and safety of SBRT compared with other radiotherapy interventions." However, they assert that for the treatment of early-stage lung cancer, "wo large ongoing trials scheduled for completion in 2013 have the potential to answer questions about the effectiveness and safety of SBRT compared with surgical resection.