Improved dose homogeneity using electronic compensation technique for total body irradiation

Area of Science:

• Medical Physics
• Radiation Oncology
• Radiotherapy Technology

Background:

• Conventional total body irradiation (TBI) relies on manual lead compensators to manage dose variations due to patient anatomy.
• These manual methods can lead to suboptimal dose distributions and potential hotspots.
• Advancements in radiotherapy technology are needed to improve dose accuracy in TBI.

Purpose of the Study:

• To evaluate the efficacy of electronic compensation (E-comp) for delivering accurate and homogeneous doses in TBI.
• To compare the performance of E-comp against conventional compensation techniques.
• To assess the impact of E-comp on mean total body dose, maximum dose, and dose homogeneity.

Main Methods:

• Bilateral parallel-opposed TBI treatment plans were generated using E-comp for 15 patients.
• A desirable fluence pattern was manually optimized for uniform dose distribution.
• Conventional compensation was simulated using the field-in-field (FIF) method within the treatment planning system (TPS).
• Dose-volume histograms (DVH) were analyzed to compare treatment plans.

Main Results:

• E-comp resulted in a mean total body dose deviation of 2.4% from the prescribed dose, compared to 4.5% for conventional compensation.
• The average reduction in maximum dose with E-comp was 30.3% ± 6.6%.
• The s-index, indicating dose homogeneity, was significantly lower with E-comp (10.5% ± 0.7%) versus conventional methods (15.8% ± 4.4%).

Conclusions:

• Electronic compensation (E-comp) provides a more accurate and homogeneous dose delivery for total body irradiation (TBI) compared to conventional methods.
• E-comp significantly reduces the maximum dose and hotspots, improving patient safety.
• The study demonstrates the capability of E-comp to achieve precise dose compliance in TBI treatments.