Three-dimensional treatment planning for maxillary cancer using a CT simulator.
OBJECTIVE
The results of three-dimensional treatment planning using a computed tomography simulator were evaluated in patients with maxillary cancer.


METHODS
Treatment planning was done in 25 patients using an x-ray simulator and plain x-ray films (1979-1982, group 1) in 34 patients using an x-ray simulator and computed tomography films (1983-1987, group 2), in 24 patients using a computed tomography simulator (1988-1992, group 3). The number of patients with Stage IV disease increased in the order of group 1 to group 3.


RESULTS
The average radiation field was smallest in group 3 (66.5 cm2) followed by group 2 (67.4 cm2) and group 1 (72.9 cm2). A radiation dose of more than 30 Gy to the lens of the effected side was delivered to 13% of group 3, 44% of group 2, and 44% of group 1. The dose to the lens on the uneffected side was zero in 56% of group 1, 74% of group 2, and 96% of group 3. A long-term decrease in visual activity on the effected side occurred in 11% of group 3, 32% of group 2, and 44% of group 1. However, a significant increase in survival was only noted between groups 1 and 2, because the three population of patients were different.


CONCLUSIONS
The three-dimensional treatment planning results in a better treatment than two-dimensional treatment planning as measured by complication rates and field sizes.
Nagata
Y
Y
Department of Radiology, Kyoto University Hospital, Japan.
Okajima
K
K
Murata
R
R
Mitsumori
M
M
Mizowaki
T
T
Tsutsui
K
K
Ono
K
K
Nishimura
Y
Y
Hiraoka
M
M
Nishidai
T
T
D000368:Aged; D003198:Computer Simulation; D005260:Female; D006801:Humans; D008297:Male; D008441:Maxillary Neoplasms / Q000532:radiotherapy*; D008875:Middle Aged; D011879:Radiotherapy Dosage; D011881:Radiotherapy, Computer-Assisted / Q000379:methods*; D016019:Survival Analysis; D014057:Tomography, X-Ray Computed / Q000379:methods*