Radiation therapy controls tumors of the voicebox almost as well as surgery, according to a new study at Washington University School of Medicine in St. Louis. The treatment also restores the quality of the voice.
Clifford K.S. Chao, M.D., assistant professor of radiology at the school’s Mallinckrodt Institute of Radiology, will discuss these results Oct. 24 at the annual meeting of the American Society for Therapeutic Radiology and Oncology in Boston.
Cancer of the glottis—the voice-producing part of the larynx—usually is treated surgically with either hemilaryngectomy (removal of only half the larynx) or endoscopic resection (removal of the tumor by laser). But the researchers discovered that high-dose irradiation controlled tumors and preserved the voice almost as well as hemilaryngectomy. Endoscopic resection or low-dose radiation therapy were less effective the first time around, especially when patients had tumors on both sides of the head or neck.
Chao, Colin Painter, Ph.D., professor of otolaryngology, and colleagues studied patients with early stage tumors. Four hundred seventy-five underwent hemilaryngectomy, which controlled 92 percent of the very early stage tumors after two years follow-up.
One hundred twenty received high-dose radiation therapy, whose effectiveness was 89 percent. Sixty-one patients received endoscopic resection, which initially controlled only 77 percent of the tumors. The rate was 78 percent for the 137 people who received low-dose radiation.
Six months after treatment, the researchers assessed the voice quality of 25 patients who had received high-dose irradiation. They listened to the voice, made acoustic measurements and viewed the vocal cords with a video laryngoscope. They compared these patients with a control group of healthy individuals.
The patients sounded better and objective measurements of the quality of their voices were significantly higher than before irradiation, when their tumors greatly impaired their voices. "Radiation is almost equivalent to conservation surgery in cure rate, and quality of voice can be restored," Chao says.
Botero A, Chao KC, Duijndam I, Painter C, Fuller D, Spector JG, Sessions DG, Simpson JR, Perez CA, Haughey B.H. High dose radiation therapy yields satisfactory tumor control and the quality of voice as compared with those of hemilaryngectomy in early stage glottic carcinoma. Oral presentation at the annual meeting of the American Society for Therapeutic Radiology and Ocology. Oct. 22-26, 2000
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