Higher Does Not Mean Longer

Radiation oncologists believed that a higher dosage of radiation would extend the lives of patients with advanced lung cancer. It seemed logical, but the findings of a clinical trial don't support that logic.

Compared to the standard radiation dose (60 Gy), a higher dose (74 Gy) of radiation does not improve survival of patients with stage III non-small cell lung cancer that has spread to the lymph nodes. These are the findings of a phase III randomized trial designed to evaluate if radiation dosing and a chemotherapy drug - Erbitux (cetuximab) - could extend the lives of patients.

Standard dose radiation adequate for treating advanced lung cancer.

The study involved 423 patients who were randomly selected to receive different doses of radiotherapy along with standard chemotherapy agents (paclitaxel and carboplatin), with or without cetuximab.

Two types of radiation were used: three-dimensional conformal radiation therapy (3D-CRT), which uses advanced imaging technology to pinpoint radiation beams and limit damage to surrounding normal tissues; and intensity modulated radiation therapy, (IMRT), a newer, specialized form of 3D-CRT which minimizes radiation exposure to nearby tissue.

The trial found that patients receiving the higher dose radiation did not live longer than those receiving the standard dose.

Jeffrey Bradley, M.D., a radiation oncologist at the Washington University School of Medicine in St. Louis, says the findings were surprising. While the standard dose hasn't been tested in a phase III trial for more than 30 years, most specialists believed the higher doses would be more effective in curing more lung cancer, according to Dr. Bradley.

Findings from this trial were presented at the 53rd Annual Meeting of the American Society for Radiation Oncology (ASTRO).

It should be noted that research is considered preliminary until it has been published in a peer-reviewed journal.