Author/Editor     Zobec Logar, Helena Barbara; Hudej, Robert; Šegedin, Barbara
Title     Development and assessment of 3D-printed individual applicators in gynecological MRI-guided brachytherapy
Type     članek
Vol. and No.     Letnik 11, št. 2
Publication year     2019
Volume     str. 128-136
ISSN     1689-832X - Journal of contemporary brachytherapy
Language     eng
Abstract     To evaluate the clinical use of 3D printing technology for the modelling of individual applicators for advanced gynecological tumors in magnetic resonance imaging (MRI)-based brachytherapy (BT). Material and methods: We tested individually designed 3D-printed applicators in nine patients with advanced gynecological cancer. Before BT was performed, all patients were treated with external beam radiotherapy (EBRT). The most common indication for individualized BT was advanced gynecological tumors where the use of standard BT applicators was not feasible. Other indications were suboptimal dose-volume histogram (DVH) parameters for high-risk clinical target volume (CTV-THR) at the first BT (V100 % 90% of CTV-THR volume and D98 % 80%, D90 % 100%, and D100 % 60% of dose aim). The EQD2 dose aim to the target volume D90 CTV-THR per one BT fraction was 20 Gy for cervical or recurrent endometrial cancer and 16 Gy for vaginal cancer patient. The first BT with the standard applicator in situ was used as the virtual plan for designing a 3D-printed applicator. The next BT was performed with a 3D-printed applicator in situ. The primary endpoint was to improve CTV-THR DVH parameters without exceeding the dose to the organs at risk (OARs). Results: All DVH parameters for CTV-THR were significantly higher with the use of an individually designed applicator. Mean D90 CTV-THR improved from 14.1 %5.4 Gy to 22.0 %2.5 Gy and from 7.1 Gy to 16.2 Gy for cervical/recurrent endometrial and vaginal cancer, respectively (p < 0.001). The mean D2cm3 bladder, rectum, sigmoid, and bowel dose was within institutional dose constraints, and increased from 13.0 %1.5 Gy to 13.6 %1.5 Gy (p = 0.045), 10.8 %1.2 Gy to 11.7 %1.3 Gy (p = 0.004), 8.9 %3.2 Gy to 10.3 %3.3 Gy (p = 0.008), and 8.7 %3.8 Gy to 9.2 %3.1 Gy (p = 0.2). Conclusions: With the use of individual 3D-printed applicators, all DVH parameters for CTV-THR significantly improved without compromising the dose constraints for the OARs.
Keywords     slikovno vodena brahiterapija
3D slikanje
ginekološki raki
image-guided brachytherapy
3D printing
gynecological cancer