NEW YORK (Reuters Health) - Whole-brain radiotherapy (WBRT) following surgery or radiosurgery of some brain metastases reduces intracranial relapses and neurologic deaths, but it doesn't improve overall survival or the duration of functional independence.
A team of European, Turkish, and Israeli researchers reported their findings, from a European Organization for Research and Treatment of Cancer phase III trial, online in the Journal of Clinical Oncology on November 1.
The 359 patients in the study were all in good condition, with stable systemic disease or asymptomatic solid tumors outside the brain and one to three brain metastases. Intracranial relapses occurred in only about 50% of patients who had received adjuvant WBRT, versus nearly 80% among those who had only undergone surgery or radiosurgery.
Patients whose brain metastases are treated locally by either surgery or radiosurgery run a substantial risk of developing new brain metastases, although this risk can be reduced by adjuvant whole brain irradiation, Dr. Martin Kocher of the University of Cologne, Germany, told Reuters Health by e-mail.
"If patients have close follow-up (MRI every three months)," he added, "it seems these new metastases can be detected early enough for effective salvage therapy. If the patient is willing to accept the risk of developing new metastases and late retreatment instead of early adjuvant treatment, adjuvant WBRT can be omitted."
This is especially true for patients treated with radiosurgery, Kocher explained, because patients who have primary (complete) surgery for brain metastases (mainly single large metastases) have an actuarial risk of 60% to develop recurrence in the surgical bed. This risk is cut to 30% by adjuvant WBRT.
Of the 359 patients, 199 received radiosurgery and 160 received complete surgery. Radiosurgeries were performed with either linear accelerators or gamma-knife devices.
Half of each group was randomized to undergo adjuvant WBRT, while the other half was assigned to observation.
Salvage therapy for intracranial relapses was more common in the observation arm (51%) than in the WBRT arm (16%). Salvage WBRT was used in 31% of patients in the observation arm.
Median overall survival didn't differ between the two arms; it was 10.9 months in the observation arm and 10.7 months in the WBRT arm. The time to loss of functional independence (WHO performance status greater than 2) was 10.0 months in the observation arm and 9.5 months in the WBRT arm.
The acute toxicity of WBRT was considered mild. And although severe acute toxicity was slightly more frequent in the WBRT arm, the authors wrote that "the long-term effects of WBRT are of more concern because it has been shown that WBRT may significantly impair learning and memory function."
"For the moment," Kocher concluded, "I would suggest using WBRT in most cases after surgery of brain metastases. It can be omitted after radiosurgery, if close follow-up and salvage treatment opportunities (radiosurgery, WBRT, surgery) are easily available."
By Scott Baltic
Source: http://link.reuters.com/sym94q
J Clin Oncol 2010;28.
Last Updated: 2010-11-11 11:47:11 -0400 (Reuters Health)
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