New Radiation Technique Benefits Patients With Nasal-Passage Cancer

"We found that cancer patients who were treated here with chemotherapy and IMRT were better off than the national standard," said K.S. Clifford Chao, M.D., assistant professor of radiology.

Chao and his colleagues present their results May 14 at the annual meeting of the American Society of Clinical Oncology in San Francisco.

The researchers studied 125 patients with tumors of the nasopharynx, or nasal passages. The patients were treated at Washington University’s Mallinckrodt Institute of Radiology between 1971 and 1999. One hundred and three received conventional radiation therapy alone. Twenty-two patients received radiation with chemotherapy. Of the latter, 13 received conventional radiation and nine were treated with the newer IMRT technique.

Chao and colleagues compared their results with findings from several medical centers nationwide that participated in research called the Intergroup Study. The larger study compared conventional radiation with radiation plus chemotherapy. It did not include any patients receiving IMRT. Three-year cancer-free survival for radiation therapy alone was 51 percent for MIR patients compared with 24 percent in the nationwide study. For those who received chemotherapy with radiation, the survival rate was 90 percent for MIR patients and 69 percent for patients nationally. For the 9 patients who received IMRT and chemotherapy, the rate was 100 percent.

As an emerging technique, IMRT precisely targets tumor cells while sparing surrounding normal tissue. This means nerves to the eyes and brain are less likely to receive unintended radiation during treatment of nasopharyngeal cancer.

"In general, the tumor gets a higher concentration of radiation with IMRT," said Chao, who also is a staff physician at Barnes-Jewish Hospital.

Chao previously showed that IMRT minimizes damage to salivary glands, sparing patients the long-term discomfort of dry mouth. Patients receiving conventional radiation for head and neck cancers often suffer from this side effect, which causes constant thirst and inability to speak or eat normally. The new study concurs with these findings. One year after radiation treatment, patients who had received IMRT had dryness of the mouth significantly less often than did patients who had received conventional radiation therapy.

Chao CK, Cegniz M, Perez CA, Arquette M. Superior functional outcome with IMRT in locally advanced nasopharyngeal carcinoma. Poster presentation at American Society for Clinical Oncology annual meeting, San Francisco, May 12-15, 2001.

Funding from the National Cancer Institute supported this research.

The full-time and volunteer faculty of Washington University School of Medicine are the physicians and surgeons of Barnes-Jewish and St. Louis Children's hospitals. The School of Medicine is one of the leading medical research, teaching and patient-care institutions in the nation. Through its affiliations with Barnes-Jewish and St. Louis Children's hospitals, the School of Medicine is linked to BJC HealthCare.