Impact of Cold Weather on Setup Errors in Radiotherapy

Area of Science:

• Radiotherapy
• Medical Physics
• Oncology

Background:

• Accurate patient positioning is crucial for effective radiotherapy.
• Environmental factors like temperature may influence patient setup accuracy.
• Previous research has not extensively explored the impact of cold weather on radiotherapy setup errors.

Purpose of the Study:

• To investigate the influence of cold weather on patient setup errors during radiotherapy.
• To compare setup errors in chest and pelvic cancer patients under different weather conditions.

Main Methods:

• Collected image-guided data (cone beam computed tomography) from 37 patients (18 chest, 19 pelvic) undergoing radiotherapy.
• Compared setup errors (translational and rotational) between cold weather days and usual weather days.
• Analyzed setup errors using the Mann-Whitney U test and calculated expansion boundary values.

Main Results:

• Chest cancer patients exhibited statistically significant increases in Z-axis translational setup errors during cold weather (p=0.005).
• No significant differences in rotational errors were observed for chest cancer patients between weather conditions.
• Pelvic cancer patients showed no significant differences in translational or rotational setup errors between cold and usual weather.

Conclusions:

• Cold weather can negatively impact radiotherapy setup accuracy, especially for chest cancer patients using thermoplastic molds, primarily affecting the ventrodorsal (Z-axis) direction.
• The findings suggest that patient immobilization methods may be more susceptible to temperature variations.
• Further research is warranted to optimize immobilization techniques in varying environmental conditions.