3-D Radiation Treatment Planning Reduces Feeding-tube Use

"Three-dimensional treatment planning appears to have a significant impact on improving quality of life by reducing feeding tube dependency," said medical intern Linna Li, M.D., who presented the results today at the 48th Annual Meeting of the American Society for Therapeutic Radiology and Oncology in Philadelphia.

The retrospective study analyzed treatment records since 1997 for patients receiving definitive radiation therapy--with or without surgery and chemotherapy--for squamous-cell carcinomas of the throat, including oropharynx, hypoharynx and larynx. Definitive radiotherapy is a curative course of radiation treatment designed to eradicate a known cancer.

Eligible patients--a total of 90--had either stage III or IV cancer with no prior surgery or radiation therapy in the head and neck region and remained cancer-free 18 months or more after completing radiation therapy. The majority of patients were men (82 percent) who had oropharyngeal cancer (63 percent) with a T stage (extent of primary tumor, including size, at diagnosis) of either T2 or T3 (71 percent).

Only 44 percent had neck surgery, but 58 percent had concurrent chemotherapy. Only 10 percent had radiation treatments using altered fractionation schemes. Sixty percent had two-dimensional treatment planning for radiation therapy while 40 percent had three-dimensional CT-based treatment planning.

A feeding tube was placed in 56 of these 90 patients (62 percent): 19 before radiation therapy; 26 during radiation therapy; and 11 after radiation therapy. Two-thirds of the men had the feeding tube removed during the follow-up period, with only 15 percent retaining the tube after 18 months.

"In analyzing the factors associated with feeding tube dependency at 18 months, only the higher T stage and 2-D treatment planning were independent predictors," Li said. "Of the 54 patients who had 2-D treatment planning, 20 were feeding-tube dependent at 18 months compared to just five of the 36 who had 3-D treatment planning. Of the three patients who had intensity-modulated radiation therapy instead of conventional radiation, none were feeding-tube dependent.

"Three-dimensional treatment planning can help patients avoid feeding tube dependency," Li concluded. "Possible explanations may be improved tumor targeting with smaller areas receiving high doses or more evenly distributed doses in large radiation fields."