|
KMID : 1164220080200010001
|
|
Journal of Korean Society for Radiotherapeutic Technology
2008 Volume.20 No. 1 p.1 ~ p.9
|
|
|
Implementation of Man-made Tongue Immobilization Devices in Treating Head and Neck Cancer Patients
|
|
Baek Jong-Geal
Kim Joo-Ho
Lee Sang-Kyu
Lee Won-Joo
Yoon Jong-Won
Cho Jeong-Hee
|
|
|
Abstract
|
|
|
Purpose: For head and neck cancer patients treated with radiation therapy, proper immobilization of intra-oral structures is crucial in reproducing treatment positions and optimizing dose distribution. We produced a man-made tongue immobilization device for each patient subjected to this study. Reproducibility of treatment positions and dose distributions at air-and-tissue interface were compared using man-made tongue immobilization devices and conventional tongue-bites.
Materials and Methods: Dental alginate and putty were used in producing man-made tongue immobilization devices. In order to evaluate reproducibility of treatment positions, all patients were CT-simulated, and linac-gram was repeated 5 times with each patient in the treatment position. An acrylic phantom was devised in order to evaluate safety of man-made tongue immobilization devices. Air, water, alginate and putty were placed in the phantom and dose distributions at air-and-tissue interface were calculated using Pinnacle (version 7.6c, Phillips, USA) and measured with EBT film. Two different field sizes (33 cm and 55 cm) were used for comparison.
Results: Evaluation of linac grams showed reproducibility of a treatment position was 4 times more accurate with man-made tongue immobilization devices compared with conventional tongue bites. Patients felt more comfortable using customized tongue immobilization devices during radiation treatment. Air-and-tissue interface dose distributions calculated using Pinnacle were 7.78% and 0.56% for 33 cm field and 55 cm field respectively. Dose distributions measured with EBT (international specialty products, USA) film were 36.5% and 11.8% for 33 cm field and 55 cm field respectively. Values from EBT film were higher.
Conclusion: Using man-made tongue immobilization devices made of dental alginate and putty in treatment of head and neck cancer patients showed higher reproducibility of treatment position compared with using conventional mouth pieces. Man-made immobilization devices can help optimizing air-and-tissue interface dose distributions and compensating limited accuracy of radiotherapy planning systems in calculating air-tissue interface dose distributions.
|
|
|
KEYWORD
|
|
|
reproducibility, man-made tongue immobilization device, interface dose
|
|
|
FullTexts / Linksout information
|
|
|
|
|
Listed journal information
|
|
|
|