Clinical application of 3D‐printed bolus in postmastectomy radiotherapy

For breast cancer radiotherapy patients immobilized using a vacuum bag, as evidenced by the CBCT images and phantom simulation, 3DPB provides a superior anatomical fit, reducing air gaps and associated dose loss in postmastectomy radiotherapy. When the air gap height ≤ 2 cm, dose attenuation with CB remains clinically acceptable, suggesting that 3D printing may not be necessary unless the skin in the gap area is at high risk for recurrence. However, for gaps > 2 cm, the dose reduction becomes significant, warranting the use of 3D-printed boluses to ensure adequate target coverage.