NEW YORK (Reuters Health) –The theoretical advantages of stereotactic radiation therapy for treating tumors in the body have yet to be confirmed clinically — despite its widespread use — according to a report in the Annals of Internal Medicine online May 3.

At the request of the Agency for Healthcare Research and Quality for a technical brief on stereotactic body radiation therapy, a panel led by Dr. Karen Schoelles, with the Evidence-based Practice Center of the ECRI Institute in Plymouth Meeting, Pennsylvania, undertook a review the literature on the topic.

As the authors point out, their report “is not intended to assess comparative effectiveness, but to provide an overview of key issues.”

They note that stereotactic body radiation therapy, or SRBT, is based on the technique of stereotactic radiosurgery used to treat CNS lesions. 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 found that 384 of 700 facilities in the US listed their capacity to provide stereotactic body radiation therapy. Average charges were $52,471 for 4 fractions of SBRT – similar to the cost for 35 fractions of 3-dimensional conformal radiation therapy.

In their literature search, the panel identified 124 relevant studies. Tumor sites most commonly represented in the studies were in the lung or thorax, followed by the pancreas, liver, and colon. A few studies focused on tumors in the uterus, pelvis, kidney, thyroid, and prostate.

None of the included studies compared SBRT with another form of radiation treatment, the researchers found.

There have been seven systematic reviews assessing SBRT, according to the report, and the general consensus from these reviews “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 discussing their findings, the authors acknowledge that the option of stereotactic body radiation therapy is likely to appeal to patients because it entails fewer treatment sessions. However, they conclude 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.”

Still, they note that for the treatment of early-stage lung cancer, “two 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.”

Ann Intern Med 2011.