2Department of Preventive Medicine, Dokuz Eylül University Faculty of Medicine, İzmir-Türkiye
3Department of Radiation Oncology, Dokuz Eylül University Faculty of Medicine, İzmir-Türkiye DOI : 10.5505/tjo.2022.3584 OBJECTIVE
The purpose of the study was to evaluate the treatment field deviations in lung cancer patients treated with thoracic radiotherapy (RT) performed using different immobilization devices into three different set-up positions and the influencing factors.
METHODS
Thirty lung cancer patients having palliative thoracic RT indication were randomized into three different
set-up positions using different immobilization devices (Group I: arm along the body, Group II:
lung board, and Group III: arm supported board). The treatment field center deviation was measured
on sternal (X and Y axis) and axillary (z and ? axis) cross. In addition, parameters such as age, pain,
pulmonary function test, set-up time, the temperature difference between the treatment room and the
outside environment, and patient education level that may cause set-up were evaluated.
RESULTS
Mean intra-fraction field center deviations of 5.66±4.15 mm were observed in the right (z) axis (p=0.049)
and 5.53±4.81 mm in the left (z) axis (p=0.015) in Group II which were statistically significantly larger
than the deviations in other groups. A statistically significant correlation was found between the indoor
and outdoor temperature difference and set-up time.
CONCLUSION
Both set-up positions of Groups I and III, gave better results than the position of Group II. According
to our results, if a lung board will be used, adding the arm supporting accessory will be necessary.
Random errors can be minimized and the set-up quality improved by using appropriate immobilization
devices, minimizing the total set-up time and balancing the in and outdoor temperature by air
conditioning system.