Localization errors in mantle-field irradiation for Hodgkin's disease

Area of Science:

• Radiation Oncology
• Medical Imaging
• Cancer Treatment

Background:

• Mantle-field irradiation is a common treatment for Hodgkin's disease.
• Accurate patient positioning is critical for effective radiation delivery and minimizing off-target exposure.

Purpose of the Study:

• To assess the frequency and magnitude of localization errors during mantle-field irradiation for Hodgkin's disease.
• To evaluate the effectiveness of verification films in detecting and correcting these errors.

Main Methods:

• Analysis of 216 treatment set-ups using verification films.
• Quantification of localization errors and assessment of margin adequacy.
• Evaluation of treatment set-up accuracy after corrections.

Main Results:

• 13% of initial verification films showed localization errors exceeding 1 cm.
• 9% of set-ups had critical margins between shielding blocks and tumor areas.
• Treatment adequacy improved from 60% after one correction to 84% after two corrections.

Conclusions:

• Verification films are highly effective in identifying significant localization errors.
• They aid in monitoring and verifying corrections, improving treatment accuracy.
• Initial verification films serve as a valuable check of the simulation plan.