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International Journal of Bioprinting 3D bioprinting of boluses for radiotherapy

Table 2. Comparison of planning target volume’s parameters among different permutations of IMRT and VMAT plans

D min D mean D max V 95 D 95
(cGy) (cGy) (cGy) CI HI (%) (cGy)
Printed-IMRT 6128.6 6234.5 6537.6 0.30 1.04 99.49 6101.8
Printed-VMAT 6143.7 6237.5 6616.5 0.29 1.04 99.56 6120.8
Commercial-IMRT 6022.1 6136.1 6757.1 0.27 1.24 90.66 5194.9
Commercial-VMAT 6066.6 6154.7 6584.5 0.26 1.17 91.40 5458.7
Virtual-IMRT 6121.3 6234.8 6564.8 0.28 1.05 98.29 6080.0
Virtual-VMAT 6120.4 6219.4 6554.1 0.30 1.05 98.37 6081.4
Nobolus-IMRT 5701.1 6106.0 7113.8 0.31 1.21 80.01 5328.1
Nobolus-VMAT 5805.7 6175.9 6904.2 0.33 1.18 84.37 5519.8
Abbreviations: CI, conformity index; D , dose covering 95% of volume; HI, homogeneity index; V , volume covering 95% of dose.
95
95

Figure 7. Accurate positioning of the bolus on phantom. The top and middle rows show the computed tomography (CT) slice images and corresponding
prescription dose distribution of volume-modulated arc therapy (VMAT) plan with commercial and 3D-printed bolus, respectively. The bottom row shows
the cone beam computed tomography (CBCT) slice images with 3D-printed bolus, and the dose distribution of VMAT plan with virtual bolus.

application of traditional boluses. Additionally, the elastic compared to hydrogels, the gel exhibited superior stability,
modulus of printed gel was similar to that of human skin better control over water loss, and radiological properties
(ranging from 5 kPa to 140 MPa) , indicating that the that closely resemble to those of the skin. In addition, its
[41]
printed get is compatible with the patient’s body. The gel biocompatibility and potent anti-bacterial properties have
constructed in this study possessed a DN structure, which contributed significantly to the prevention of radiation-
endowed the gel with desirable mechanical properties induced dermatitis. In conclusion, this study demonstrated
and the ability to adhere to the skin surface. Moreover, the potential efficacy of 3D-printed gel-based boluses

Volume 10 Issue 2 (2024) 260 doi: 10.36922/ijb.1589