Usefulness of cast-type bolus produced by 3D printing for photon beam treatment of primary cutaneous lymphoma: A phantom experiment

초록

Background: To examine the usefulness of photon beam radiation therapy for primary cutaneous lymphoma, a phantom experiment was conducted by fabricating and applying an M3 casting type customized bolus by three-dimensional (3D) printing. Materials and Methods: Several 3D printers were used to compare output times according to division to reduce the output time of cast-type bolus. The dose distribution and dose verification for each treatment plan of electron beam (6 MeV, 9 MeV) and photon beams (AP/PA, field-in-field 3D conformal radiation therapy [3D CRT], intensity modulated radiotherapy [IMRT]) were analyzed. During photon beam treatment, the inside of the molded bolus was filled with rice and M3 for the experiment. Results: Compared with the infill type, the split casting type output method improved the output speed of the 3D printer by up to 94.7% and could be applied to patients within 48 h. Moreover, the treatment plan of the photon beam, compared with that of the 9 MeV electron beam, improved the radical dose homogeneity index (rDHI) by 23.0% to 71.3% and the moderate homogeneity index (mDHI) by 7.5% to 18.6% in the planning tumor volume, indicating a more uniform dose distribution. Conclusion: The difference in treatment plan evaluations between M3 and rice was similar, but in dose delivery, the maximum errors were 3.1% and 6.5%, respectively, indicating that M3 was superior to rice.

키워드